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GtkWidget | |
struct | GtkWidgetClass |
GtkRequisition | |
typedef | GtkAllocation |
enum | GtkTextDirection |
enum | GtkSizeRequestMode |
struct | GtkRequestedSize |
enum | GtkAlign |
GtkWidget is the base class all widgets in GTK+ derive from. It manages the widget lifecycle, states and style.
GTK+ uses a height-for-width (and width-for-height) geometry management system. Height-for-width means that a widget can change how much vertical space it needs, depending on the amount of horizontal space that it is given (and similar for width-for-height). The most common example is a label that reflows to fill up the available width, wraps to fewer lines, and therefore needs less height.
Height-for-width geometry management is implemented in GTK+ by way of two virtual methods:
There are some important things to keep in mind when implementing height-for-width and when using it in container implementations.
The geometry management system will query a widget hierarchy in only one orientation at a time. When widgets are initially queried for their minimum sizes it is generally done in two initial passes in the GtkSizeRequestMode chosen by the toplevel.
For example, when queried in the normal
GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH
mode:
First, the default minimum and natural width for each widget
in the interface will be computed using gtk_widget_measure()
with an orientation
or GTK_ORIENTATION_HORIZONTAL
and a for_size of -1.
Because the preferred widths for each container depend on the preferred
widths of their children, this information propagates up the hierarchy,
and finally a minimum and natural width is determined for the entire
toplevel. Next, the toplevel will use the minimum width to query for the
minimum height contextual to that width using gtk_widget_measure()
with an
orientation of GTK_ORIENTATION_VERTICAL
and a for_size of the just computed
width. This will also be a highly recursive operation.
The minimum height for the minimum width is normally
used to set the minimum size constraint on the toplevel
(unless gtk_window_set_geometry_hints()
is explicitly used instead).
After the toplevel window has initially requested its size in both
dimensions it can go on to allocate itself a reasonable size (or a size
previously specified with gtk_window_set_default_size()
). During the
recursive allocation process it’s important to note that request cycles
will be recursively executed while container widgets allocate their children.
Each container widget, once allocated a size, will go on to first share the
space in one orientation among its children and then request each child's
height for its target allocated width or its width for allocated height,
depending. In this way a GtkWidget will typically be requested its size
a number of times before actually being allocated a size. The size a
widget is finally allocated can of course differ from the size it has
requested. For this reason, GtkWidget caches a small number of results
to avoid re-querying for the same sizes in one allocation cycle.
See GtkContainer’s geometry management section to learn more about how height-for-width allocations are performed by container widgets.
If a widget does move content around to intelligently use up the allocated size then it must support the request in both GtkSizeRequestModes even if the widget in question only trades sizes in a single orientation.
For instance, a GtkLabel that does height-for-width word wrapping
will not expect to have GtkWidgetClass.get_preferred_height()
called
because that call is specific to a width-for-height request. In this
case the label must return the height required for its own minimum
possible width. By following this rule any widget that handles
height-for-width or width-for-height requests will always be allocated
at least enough space to fit its own content.
Here are some examples of how a GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH
widget
generally deals with width-for-height requests, for GtkWidgetClass.get_preferred_height()
it will do:
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static void foo_widget_get_preferred_height (GtkWidget *widget, gint *min_height, gint *nat_height) { if (i_am_in_height_for_width_mode) { gint min_width, nat_width; GTK_WIDGET_GET_CLASS (widget)->get_preferred_width (widget, &min_width, &nat_width); GTK_WIDGET_GET_CLASS (widget)->get_preferred_height_for_width (widget, min_width, min_height, nat_height); } else { ... some widgets do both. For instance, if a GtkLabel is rotated to 90 degrees it will return the minimum and natural height for the rotated label here. } } |
And in GtkWidgetClass.get_preferred_width_for_height()
it will simply return
the minimum and natural width:
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static void foo_widget_get_preferred_width_for_height (GtkWidget *widget, gint for_height, gint *min_width, gint *nat_width) { if (i_am_in_height_for_width_mode) { GTK_WIDGET_GET_CLASS (widget)->get_preferred_width (widget, min_width, nat_width); } else { ... again if a widget is sometimes operating in width-for-height mode (like a rotated GtkLabel) it can go ahead and do its real width for height calculation here. } } |
Often a widget needs to get its own request during size request or allocation. For example, when computing height it may need to also compute width. Or when deciding how to use an allocation, the widget may need to know its natural size. In these cases, the widget should be careful to call its virtual methods directly, like this:
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GTK_WIDGET_GET_CLASS(widget)->get_preferred_width (widget, &min, &natural); |
It will not work to use the wrapper functions, such as
gtk_widget_get_preferred_width()
inside your own size request
implementation. These return a request adjusted by GtkSizeGroup
and by the GtkWidgetClass.adjust_size_request()
virtual method. If a
widget used the wrappers inside its virtual method implementations,
then the adjustments (such as widget margins) would be applied
twice. GTK+ therefore does not allow this and will warn if you try
to do it.
Of course if you are getting the size request for another widget, such as a child of a container, you must use the wrapper APIs. Otherwise, you would not properly consider widget margins, GtkSizeGroup, and so forth.
Since 3.10 GTK+ also supports baseline vertical alignment of widgets. This
means that widgets are positioned such that the typographical baseline of
widgets in the same row are aligned. This happens if a widget supports baselines,
has a vertical alignment of GTK_ALIGN_BASELINE
, and is inside a container
that supports baselines and has a natural “row” that it aligns to the baseline,
or a baseline assigned to it by the grandparent.
Baseline alignment support for a widget is done by the GtkWidgetClass.get_preferred_height_and_baseline_for_width()
virtual function. It allows you to report a baseline in combination with the
minimum and natural height. If there is no baseline you can return -1 to indicate
this. The default implementation of this virtual function calls into the
GtkWidgetClass.get_preferred_height()
and GtkWidgetClass.get_preferred_height_for_width()
,
so if baselines are not supported it doesn’t need to be implemented.
If a widget ends up baseline aligned it will be allocated all the space in the parent
as if it was GTK_ALIGN_FILL
, but the selected baseline can be found via gtk_widget_get_allocated_baseline()
.
If this has a value other than -1 you need to align the widget such that the baseline
appears at the position.
The GtkWidget implementation of the GtkBuildable interface supports a custom <accelerator> element, which has attributes named ”key”, ”modifiers” and ”signal” and allows to specify accelerators.
An example of a UI definition fragment specifying an accelerator:
1 2 3 |
<object class="GtkButton"> <accelerator key="q" modifiers="GDK_CONTROL_MASK" signal="clicked"/> </object> |
In addition to accelerators, GtkWidget also support a custom <accessible> element, which supports actions and relations. Properties on the accessible implementation of an object can be set by accessing the internal child “accessible” of a GtkWidget.
An example of a UI definition fragment specifying an accessible:
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<object class="GtkButton" id="label1"/> <property name="label">I am a Label for a Button</property> </object> <object class="GtkButton" id="button1"> <accessibility> <action action_name="click" translatable="yes">Click the button.</action> <relation target="label1" type="labelled-by"/> </accessibility> <child internal-child="accessible"> <object class="AtkObject" id="a11y-button1"> <property name="accessible-name">Clickable Button</property> </object> </child> </object> |
Finally, GtkWidget allows style information such as style classes to be associated with widgets, using the custom <style> element:
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<object class="GtkButton" id="button1"> <style> <class name="my-special-button-class"/> <class name="dark-button"/> </style> </object> |
GtkWidget exposes some facilities to automate the procedure of creating composite widgets using GtkBuilder interface description language.
To create composite widgets with GtkBuilder XML, one must associate
the interface description with the widget class at class initialization
time using gtk_widget_class_set_template()
.
The interface description semantics expected in composite template descriptions is slightly different from regular GtkBuilder XML.
Unlike regular interface descriptions, gtk_widget_class_set_template()
will
expect a <template> tag as a direct child of the toplevel <interface>
tag. The <template> tag must specify the “class” attribute which must be
the type name of the widget. Optionally, the “parent” attribute may be
specified to specify the direct parent type of the widget type, this is
ignored by the GtkBuilder but required for Glade to introspect what kind
of properties and internal children exist for a given type when the actual
type does not exist.
The XML which is contained inside the <template> tag behaves as if it were
added to the <object> tag defining widget
itself. You may set properties
on widget
by inserting <property> tags into the <template> tag, and also
add <child> tags to add children and extend widget
in the normal way you
would with <object> tags.
Additionally, <object> tags can also be added before and after the initial <template> tag in the normal way, allowing one to define auxiliary objects which might be referenced by other widgets declared as children of the <template> tag.
An example of a GtkBuilder Template Definition:
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<interface> <template class="FooWidget" parent="GtkBox"> <property name="orientation">GTK_ORIENTATION_HORIZONTAL</property> <property name="spacing">4</property> <child> <object class="GtkButton" id="hello_button"> <property name="label">Hello World</property> <signal name="clicked" handler="hello_button_clicked" object="FooWidget" swapped="yes"/> </object> </child> <child> <object class="GtkButton" id="goodbye_button"> <property name="label">Goodbye World</property> </object> </child> </template> </interface> |
Typically, you'll place the template fragment into a file that is
bundled with your project, using GResource. In order to load the
template, you need to call gtk_widget_class_set_template_from_resource()
from the class initialization of your GtkWidget type:
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static void foo_widget_class_init (FooWidgetClass *klass) { // ... gtk_widget_class_set_template_from_resource (GTK_WIDGET_CLASS (klass), "/com/example/ui/foowidget.ui"); } |
You will also need to call gtk_widget_init_template()
from the instance
initialization function:
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static void foo_widget_init (FooWidget *self) { // ... gtk_widget_init_template (GTK_WIDGET (self)); } |
You can access widgets defined in the template using the
gtk_widget_get_template_child()
function, but you will typically declare
a pointer in the instance private data structure of your type using the same
name as the widget in the template definition, and call
gtk_widget_class_bind_template_child_private()
with that name, e.g.
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typedef struct { GtkWidget *hello_button; GtkWidget *goodbye_button; } FooWidgetPrivate; G_DEFINE_TYPE_WITH_PRIVATE (FooWidget, foo_widget, GTK_TYPE_BOX) static void foo_widget_class_init (FooWidgetClass *klass) { // ... gtk_widget_class_set_template_from_resource (GTK_WIDGET_CLASS (klass), "/com/example/ui/foowidget.ui"); gtk_widget_class_bind_template_child_private (GTK_WIDGET_CLASS (klass), FooWidget, hello_button); gtk_widget_class_bind_template_child_private (GTK_WIDGET_CLASS (klass), FooWidget, goodbye_button); } |
You can also use gtk_widget_class_bind_template_callback()
to connect a signal
callback defined in the template with a function visible in the scope of the
class, e.g.
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// the signal handler has the instance and user data swapped // because of the swapped="yes" attribute in the template XML static void hello_button_clicked (FooWidget *self, GtkButton *button) { g_print ("Hello, world!\n"); } static void foo_widget_class_init (FooWidgetClass *klass) { // ... gtk_widget_class_set_template_from_resource (GTK_WIDGET_CLASS (klass), "/com/example/ui/foowidget.ui"); gtk_widget_class_bind_template_callback (GTK_WIDGET_CLASS (klass), hello_button_clicked); } |
void (*GtkCallback) (GtkWidget *widget
,gpointer data
);
The type of the callback functions used for e.g. iterating over
the children of a container, see gtk_container_foreach()
.
GtkWidget * gtk_widget_new (GType type
,const gchar *first_property_name
,...
);
This is a convenience function for creating a widget and setting
its properties in one go. For example you might write:
gtk_widget_new (GTK_TYPE_LABEL, "label", "Hello World", "xalign",
0.0, NULL)
to create a left-aligned label. Equivalent to
g_object_new()
, but returns a widget so you don’t have to
cast the object yourself.
type |
type ID of the widget to create |
|
first_property_name |
name of first property to set |
|
... |
value of first property, followed by more properties,
|
void
gtk_widget_destroy (GtkWidget *widget
);
Destroys a widget.
When a widget is destroyed all references it holds on other objects will be released:
if the widget is inside a container, it will be removed from its parent
if the widget is a container, all its children will be destroyed, recursively
if the widget is a top level, it will be removed from the list of top level widgets that GTK+ maintains internally
It's expected that all references held on the widget will also
be released; you should connect to the “destroy” signal
if you hold a reference to widget
and you wish to remove it when
this function is called. It is not necessary to do so if you are
implementing a GtkContainer, as you'll be able to use the
GtkContainerClass.remove()
virtual function for that.
It's important to notice that gtk_widget_destroy()
will only cause
the widget
to be finalized if no additional references, acquired
using g_object_ref()
, are held on it. In case additional references
are in place, the widget
will be in an "inert" state after calling
this function; widget
will still point to valid memory, allowing you
to release the references you hold, but you may not query the widget's
own state.
You should typically call this function on top level widgets, and rarely on child widgets.
See also: gtk_container_remove()
gboolean
gtk_widget_in_destruction (GtkWidget *widget
);
Returns whether the widget is currently being destroyed. This information can sometimes be used to avoid doing unnecessary work.
void gtk_widget_destroyed (GtkWidget *widget
,GtkWidget **widget_pointer
);
This function sets *widget_pointer
to NULL
if widget_pointer
!=
NULL
. It’s intended to be used as a callback connected to the
“destroy” signal of a widget. You connect gtk_widget_destroyed()
as a signal handler, and pass the address of your widget variable
as user data. Then when the widget is destroyed, the variable will
be set to NULL
. Useful for example to avoid multiple copies
of the same dialog.
void
gtk_widget_unparent (GtkWidget *widget
);
This function is only for use in widget implementations.
Should be called by parent widgets to dissociate widget
from the parent.
void
gtk_widget_show (GtkWidget *widget
);
Flags a widget to be displayed. Any widget that isn’t shown will not appear on the screen.
Remember that you have to show the containers containing a widget, in addition to the widget itself, before it will appear onscreen.
When a toplevel container is shown, it is immediately realized and mapped; other shown widgets are realized and mapped when their toplevel container is realized and mapped.
void
gtk_widget_show_now (GtkWidget *widget
);
Shows a widget. If the widget is an unmapped toplevel widget (i.e. a GtkWindow that has not yet been shown), enter the main loop and wait for the window to actually be mapped. Be careful; because the main loop is running, anything can happen during this function.
void
gtk_widget_hide (GtkWidget *widget
);
Reverses the effects of gtk_widget_show()
, causing the widget to be
hidden (invisible to the user).
void
gtk_widget_map (GtkWidget *widget
);
This function is only for use in widget implementations. Causes a widget to be mapped if it isn’t already.
void
gtk_widget_unmap (GtkWidget *widget
);
This function is only for use in widget implementations. Causes a widget to be unmapped if it’s currently mapped.
void
gtk_widget_realize (GtkWidget *widget
);
Creates the GDK (windowing system) resources associated with a
widget. For example, widget->window
will be created when a widget
is realized. Normally realization happens implicitly; if you show
a widget and all its parent containers, then the widget will be
realized and mapped automatically.
Realizing a widget requires all
the widget’s parent widgets to be realized; calling
gtk_widget_realize()
realizes the widget’s parents in addition to
widget
itself. If a widget is not yet inside a toplevel window
when you realize it, bad things will happen.
This function is primarily used in widget implementations, and
isn’t very useful otherwise. Many times when you think you might
need it, a better approach is to connect to a signal that will be
called after the widget is realized automatically, such as
“draw”. Or simply g_signal_connect()
to the
“realize” signal.
void
gtk_widget_unrealize (GtkWidget *widget
);
This function is only useful in widget implementations.
Causes a widget to be unrealized (frees all GDK resources
associated with the widget, such as widget->window
).
void gtk_widget_draw (GtkWidget *widget
,cairo_t *cr
);
Draws widget
to cr
. The top left corner of the widget will be
drawn to the currently set origin point of cr
.
You should pass a cairo context as cr
argument that is in an
original state. Otherwise the resulting drawing is undefined. For
example changing the operator using cairo_set_operator()
or the
line width using cairo_set_line_width()
might have unwanted side
effects.
You may however change the context’s transform matrix - like with
cairo_scale()
, cairo_translate()
or cairo_set_matrix()
and clip
region with cairo_clip()
prior to calling this function. Also, it
is fine to modify the context with cairo_save()
and
cairo_push_group()
prior to calling this function.
Note that special-purpose widgets may contain special code for
rendering to the screen and might appear differently on screen
and when rendered using gtk_widget_draw()
.
widget |
the widget to draw. It must be drawable (see
|
|
cr |
a cairo context to draw to |
Since: 3.0
void
gtk_widget_queue_draw (GtkWidget *widget
);
Equivalent to calling gtk_widget_queue_draw_area()
for the
entire area of a widget.
void
gtk_widget_queue_resize (GtkWidget *widget
);
This function is only for use in widget implementations. Flags a widget to have its size renegotiated; should be called when a widget for some reason has a new size request. For example, when you change the text in a GtkLabel, GtkLabel queues a resize to ensure there’s enough space for the new text.
Note that you cannot call gtk_widget_queue_resize()
on a widget
from inside its implementation of the GtkWidgetClass::size_allocate
virtual method. Calls to gtk_widget_queue_resize()
from inside
GtkWidgetClass::size_allocate will be silently ignored.
void
gtk_widget_queue_resize_no_redraw (GtkWidget *widget
);
This function works like gtk_widget_queue_resize()
,
except that the widget is not invalidated.
Since: 2.4
void
gtk_widget_queue_allocate (GtkWidget *widget
);
This function is only for use in widget implementations.
Flags the widget for a rerun of the GtkWidgetClass::size_allocate
function. Use this function instead of gtk_widget_queue_resize()
when the widget
's size request didn't change but it wants to
reposition its contents.
An example user of this function is gtk_widget_set_halign()
.
Since: 3.20
GdkFrameClock *
gtk_widget_get_frame_clock (GtkWidget *widget
);
Obtains the frame clock for a widget. The frame clock is a global
“ticker” that can be used to drive animations and repaints. The
most common reason to get the frame clock is to call
gdk_frame_clock_get_frame_time()
, in order to get a time to use for
animating. For example you might record the start of the animation
with an initial value from gdk_frame_clock_get_frame_time()
, and
then update the animation by calling
gdk_frame_clock_get_frame_time()
again during each repaint.
gdk_frame_clock_request_phase() will result in a new frame on the
clock, but won’t necessarily repaint any widgets. To repaint a
widget, you have to use gtk_widget_queue_draw()
which invalidates
the widget (thus scheduling it to receive a draw on the next
frame). gtk_widget_queue_draw()
will also end up requesting a frame
on the appropriate frame clock.
A widget’s frame clock will not change while the widget is mapped. Reparenting a widget (which implies a temporary unmap) can change the widget’s frame clock.
Unrealized widgets do not have a frame clock.
Since: 3.8
gint
gtk_widget_get_scale_factor (GtkWidget *widget
);
Retrieves the internal scale factor that maps from window coordinates to the actual device pixels. On traditional systems this is 1, on high density outputs, it can be a higher value (typically 2).
See gdk_window_get_scale_factor()
.
Since: 3.10
gboolean (*GtkTickCallback) (GtkWidget *widget
,GdkFrameClock *frame_clock
,gpointer user_data
);
Callback type for adding a function to update animations. See gtk_widget_add_tick_callback()
.
widget |
the widget |
|
frame_clock |
the frame clock for the widget (same as calling |
|
user_data |
user data passed to |
G_SOURCE_CONTINUE
if the tick callback should continue to be called,
G_SOURCE_REMOVE
if the tick callback should be removed.
Since: 3.8
guint gtk_widget_add_tick_callback (GtkWidget *widget
,GtkTickCallback callback
,gpointer user_data
,GDestroyNotify notify
);
Queues an animation frame update and adds a callback to be called
before each frame. Until the tick callback is removed, it will be
called frequently (usually at the frame rate of the output device
or as quickly as the application can be repainted, whichever is
slower). For this reason, is most suitable for handling graphics
that change every frame or every few frames. The tick callback does
not automatically imply a relayout or repaint. If you want a
repaint or relayout, and aren’t changing widget properties that
would trigger that (for example, changing the text of a GtkLabel),
then you will have to call gtk_widget_queue_resize()
or
gtk_widget_queue_draw_area()
yourself.
gdk_frame_clock_get_frame_time() should generally be used for timing
continuous animations and
gdk_frame_timings_get_predicted_presentation_time()
if you are
trying to display isolated frames at particular times.
This is a more convenient alternative to connecting directly to the “update” signal of GdkFrameClock, since you don't have to worry about when a GdkFrameClock is assigned to a widget.
widget |
||
callback |
function to call for updating animations |
|
user_data |
data to pass to |
|
notify |
function to call to free |
an id for the connection of this callback. Remove the callback
by passing it to gtk_widget_remove_tick_callback()
Since: 3.8
void gtk_widget_remove_tick_callback (GtkWidget *widget
,guint id
);
Removes a tick callback previously registered with
gtk_widget_add_tick_callback()
.
Since: 3.8
void gtk_widget_size_allocate (GtkWidget *widget
,const GtkAllocation *allocation
,int baseline
,GtkAllocation *out_clip
);
This function is only used by GtkWidget subclasses, to assign a size, position and (optionally) baseline to their child widgets.
In this function, the allocation and baseline may be adjusted. The given allocation will be forced to be bigger than the widget's minimum size, as well as at least 1×1 in size.
widget |
||
allocation |
position and size to be allocated to |
|
baseline |
The baseline of the child, or -1 |
|
out_clip |
Return location for |
[out] |
Since: 3.10
void gtk_widget_add_accelerator (GtkWidget *widget
,const gchar *accel_signal
,GtkAccelGroup *accel_group
,guint accel_key
,GdkModifierType accel_mods
,GtkAccelFlags accel_flags
);
Installs an accelerator for this widget
in accel_group
that causes
accel_signal
to be emitted if the accelerator is activated.
The accel_group
needs to be added to the widget’s toplevel via
gtk_window_add_accel_group()
, and the signal must be of type G_SIGNAL_ACTION
.
Accelerators added through this function are not user changeable during
runtime. If you want to support accelerators that can be changed by the
user, use gtk_accel_map_add_entry()
and gtk_widget_set_accel_path()
or
gtk_menu_item_set_accel_path()
instead.
widget |
widget to install an accelerator on |
|
accel_signal |
widget signal to emit on accelerator activation |
|
accel_group |
accel group for this widget, added to its toplevel |
|
accel_key |
GDK keyval of the accelerator |
|
accel_mods |
modifier key combination of the accelerator |
|
accel_flags |
flag accelerators, e.g. |
gboolean gtk_widget_remove_accelerator (GtkWidget *widget
,GtkAccelGroup *accel_group
,guint accel_key
,GdkModifierType accel_mods
);
Removes an accelerator from widget
, previously installed with
gtk_widget_add_accelerator()
.
void gtk_widget_set_accel_path (GtkWidget *widget
,const gchar *accel_path
,GtkAccelGroup *accel_group
);
Given an accelerator group, accel_group
, and an accelerator path,
accel_path
, sets up an accelerator in accel_group
so whenever the
key binding that is defined for accel_path
is pressed, widget
will be activated. This removes any accelerators (for any
accelerator group) installed by previous calls to
gtk_widget_set_accel_path()
. Associating accelerators with
paths allows them to be modified by the user and the modifications
to be saved for future use. (See gtk_accel_map_save()
.)
This function is a low level function that would most likely be used by a menu creation system.
If you only want to
set up accelerators on menu items gtk_menu_item_set_accel_path()
provides a somewhat more convenient interface.
Note that accel_path
string will be stored in a GQuark. Therefore, if you
pass a static string, you can save some memory by interning it first with
g_intern_static_string()
.
GList *
gtk_widget_list_accel_closures (GtkWidget *widget
);
Lists the closures used by widget
for accelerator group connections
with gtk_accel_group_connect_by_path()
or gtk_accel_group_connect()
.
The closures can be used to monitor accelerator changes on widget
,
by connecting to the GtkAccelGroup
::accel-changed signal of the
GtkAccelGroup of a closure which can be found out with
gtk_accel_group_from_accel_closure()
.
gboolean gtk_widget_can_activate_accel (GtkWidget *widget
,guint signal_id
);
Determines whether an accelerator that activates the signal
identified by signal_id
can currently be activated.
This is done by emitting the “can-activate-accel”
signal on widget
; if the signal isn’t overridden by a
handler or in a derived widget, then the default check is
that the widget must be sensitive, and the widget and all
its ancestors mapped.
Since: 2.4
gboolean gtk_widget_event (GtkWidget *widget
,const GdkEvent *event
);
Rarely-used function. This function is used to emit
the event signals on a widget (those signals should never
be emitted without using this function to do so).
If you want to synthesize an event though, don’t use this function;
instead, use gtk_main_do_event()
so the event will behave as if
it were in the event queue. Don’t synthesize expose events; instead,
use gtk_widget_queue_draw_region()
to invalidate a region of the
window.
gboolean
gtk_widget_activate (GtkWidget *widget
);
For widgets that can be “activated” (buttons, menu items, etc.)
this function activates them. Activation is what happens when you
press Enter on a widget during key navigation. If widget
isn't
activatable, the function returns FALSE
.
gboolean gtk_widget_intersect (GtkWidget *widget
,const GdkRectangle *area
,GdkRectangle *intersection
);
Computes the intersection of a widget
’s area and area
, storing
the intersection in intersection
, and returns TRUE
if there was
an intersection. intersection
may be NULL
if you’re only
interested in whether there was an intersection.
gboolean
gtk_widget_is_focus (GtkWidget *widget
);
Determines if the widget is the focus widget within its toplevel. (This does not mean that the “has-focus” property is necessarily set; “has-focus” will only be set if the toplevel widget additionally has the global input focus.)
void
gtk_widget_grab_focus (GtkWidget *widget
);
Causes widget
to have the keyboard focus for the GtkWindow it's
inside. widget
must be a focusable widget, such as a GtkEntry;
something like GtkFrame won’t work.
More precisely, it must have the GTK_CAN_FOCUS
flag set. Use
gtk_widget_set_can_focus()
to modify that flag.
The widget also needs to be realized and mapped. This is indicated by the related signals. Grabbing the focus immediately after creating the widget will likely fail and cause critical warnings.
void
gtk_widget_grab_default (GtkWidget *widget
);
Causes widget
to become the default widget. widget
must be able to be
a default widget; typically you would ensure this yourself
by calling gtk_widget_set_can_default()
with a TRUE
value.
The default widget is activated when
the user presses Enter in a window. Default widgets must be
activatable, that is, gtk_widget_activate()
should affect them. Note
that GtkEntry widgets require the “activates-default” property
set to TRUE
before they activate the default widget when Enter
is pressed and the GtkEntry is focused.
void gtk_widget_set_name (GtkWidget *widget
,const gchar *name
);
Widgets can be named, which allows you to refer to them from a CSS file. You can apply a style to widgets with a particular name in the CSS file. See the documentation for the CSS syntax (on the same page as the docs for GtkStyleContext).
Note that the CSS syntax has certain special characters to delimit and represent elements in a selector (period, #, >, *...), so using these will make your widget impossible to match by name. Any combination of alphanumeric symbols, dashes and underscores will suffice.
const gchar *
gtk_widget_get_name (GtkWidget *widget
);
Retrieves the name of a widget. See gtk_widget_set_name()
for the
significance of widget names.
void gtk_widget_set_sensitive (GtkWidget *widget
,gboolean sensitive
);
Sets the sensitivity of a widget. A widget is sensitive if the user can interact with it. Insensitive widgets are “grayed out” and the user can’t interact with them. Insensitive widgets are known as “inactive”, “disabled”, or “ghosted” in some other toolkits.
void gtk_widget_set_parent (GtkWidget *widget
,GtkWidget *parent
);
This function is useful only when implementing subclasses of
GtkWidget.
Sets parent
as the parent widget of widget
, and takes care of
some details such as updating the state and style of the child
to reflect its new location and resizing the parent. The opposite
function is gtk_widget_unparent()
.
void gtk_widget_set_parent_window (GtkWidget *widget
,GdkWindow *parent_window
);
Sets a non default parent window for widget
.
For GtkWindow classes, setting a parent_window
effects whether
the window is a toplevel window or can be embedded into other
widgets.
For GtkWindow classes, this needs to be called before the window is realized.
GdkWindow *
gtk_widget_get_parent_window (GtkWidget *widget
);
Gets widget
’s parent window, or NULL
if it does not have one.
the parent window of widget
, or NULL
if it does not have a parent window.
[transfer none][nullable]
void gtk_widget_set_device_enabled (GtkWidget *widget
,GdkDevice *device
,gboolean enabled
);
Enables or disables a GdkDevice to interact with widget
and all its children.
It does so by descending through the GdkWindow hierarchy
and enabling the same mask that is has for core events
(i.e. the one that gdk_window_get_events()
returns).
Since: 3.0
gboolean gtk_widget_get_device_enabled (GtkWidget *widget
,GdkDevice *device
);
Returns whether device
can interact with widget
and its
children. See gtk_widget_set_device_enabled()
.
Since: 3.0
GtkWidget *
gtk_widget_get_toplevel (GtkWidget *widget
);
This function returns the topmost widget in the container hierarchy
widget
is a part of. If widget
has no parent widgets, it will be
returned as the topmost widget. No reference will be added to the
returned widget; it should not be unreferenced.
Note the difference in behavior vs. gtk_widget_get_ancestor()
;
gtk_widget_get_ancestor (widget, GTK_TYPE_WINDOW)
would return
NULL
if widget
wasn’t inside a toplevel window, and if the
window was inside a GtkWindow-derived widget which was in turn
inside the toplevel GtkWindow.
To reliably find the toplevel GtkWindow, use
gtk_widget_get_toplevel()
and call gtk_widget_is_toplevel()
on the result.
1 2 3 4 5 |
GtkWidget *toplevel = gtk_widget_get_toplevel (widget); if (gtk_widget_is_toplevel (toplevel)) { // Perform action on toplevel. } |
GtkWidget * gtk_widget_get_ancestor (GtkWidget *widget
,GType widget_type
);
Gets the first ancestor of widget
with type widget_type
. For example,
gtk_widget_get_ancestor (widget, GTK_TYPE_BOX)
gets
the first GtkBox that’s an ancestor of widget
. No reference will be
added to the returned widget; it should not be unreferenced. See note
about checking for a toplevel GtkWindow in the docs for
gtk_widget_get_toplevel()
.
Note that unlike gtk_widget_is_ancestor()
, gtk_widget_get_ancestor()
considers widget
to be an ancestor of itself.
gboolean gtk_widget_is_ancestor (GtkWidget *widget
,GtkWidget *ancestor
);
Determines whether widget
is somewhere inside ancestor
, possibly with
intermediate containers.
gboolean gtk_widget_translate_coordinates (GtkWidget *src_widget
,GtkWidget *dest_widget
,gint src_x
,gint src_y
,gint *dest_x
,gint *dest_y
);
Translate coordinates relative to src_widget
’s allocation to coordinates
relative to dest_widget
’s allocations. In order to perform this
operation, both widgets must be realized, and must share a common
toplevel.
gboolean
gtk_widget_hide_on_delete (GtkWidget *widget
);
Utility function; intended to be connected to the “delete-event”
signal on a GtkWindow. The function calls gtk_widget_hide()
on its
argument, then returns TRUE
. If connected to ::delete-event, the
result is that clicking the close button for a window (on the
window frame, top right corner usually) will hide but not destroy
the window. By default, GTK+ destroys windows when ::delete-event
is received.
void gtk_widget_set_direction (GtkWidget *widget
,GtkTextDirection dir
);
Sets the reading direction on a particular widget. This direction controls the primary direction for widgets containing text, and also the direction in which the children of a container are packed. The ability to set the direction is present in order so that correct localization into languages with right-to-left reading directions can be done. Generally, applications will let the default reading direction present, except for containers where the containers are arranged in an order that is explicitly visual rather than logical (such as buttons for text justification).
If the direction is set to GTK_TEXT_DIR_NONE
, then the value
set by gtk_widget_set_default_direction()
will be used.
GtkTextDirection
gtk_widget_get_direction (GtkWidget *widget
);
Gets the reading direction for a particular widget. See
gtk_widget_set_direction()
.
void
gtk_widget_set_default_direction (GtkTextDirection dir
);
Sets the default reading direction for widgets where the
direction has not been explicitly set by gtk_widget_set_direction()
.
GtkTextDirection
gtk_widget_get_default_direction (void
);
Obtains the current default reading direction. See
gtk_widget_set_default_direction()
.
void gtk_widget_shape_combine_region (GtkWidget *widget
,cairo_region_t *region
);
Sets a shape for this widget’s GDK window. This allows for
transparent windows etc., see gdk_window_shape_combine_region()
for more information.
Since: 3.0
void gtk_widget_input_shape_combine_region (GtkWidget *widget
,cairo_region_t *region
);
Sets an input shape for this widget’s GDK window. This allows for
windows which react to mouse click in a nonrectangular region, see
gdk_window_input_shape_combine_region()
for more information.
Since: 3.0
PangoContext *
gtk_widget_create_pango_context (GtkWidget *widget
);
Creates a new PangoContext with the appropriate font map,
font options, font description, and base direction for drawing
text for this widget. See also gtk_widget_get_pango_context()
.
PangoContext *
gtk_widget_get_pango_context (GtkWidget *widget
);
Gets a PangoContext with the appropriate font map, font description,
and base direction for this widget. Unlike the context returned
by gtk_widget_create_pango_context()
, this context is owned by
the widget (it can be used until the screen for the widget changes
or the widget is removed from its toplevel), and will be updated to
match any changes to the widget’s attributes. This can be tracked
by using the “screen-changed” signal on the widget.
void gtk_widget_set_font_options (GtkWidget *widget
,const cairo_font_options_t *options
);
Sets the cairo_font_options_t used for Pango rendering in this widget. When not set, the default font options for the GdkScreen will be used.
Since: 3.18
const cairo_font_options_t *
gtk_widget_get_font_options (GtkWidget *widget
);
Returns the cairo_font_options_t used for Pango rendering. When not set, the defaults font options for the GdkScreen will be used.
Since: 3.18
void gtk_widget_set_font_map (GtkWidget *widget
,PangoFontMap *font_map
);
Sets the font map to use for Pango rendering. When not set, the widget will inherit the font map from its parent.
widget |
||
font_map |
a PangoFontMap, or |
[allow-none] |
Since: 3.18
PangoFontMap *
gtk_widget_get_font_map (GtkWidget *widget
);
Gets the font map that has been set with gtk_widget_set_font_map()
.
Since: 3.18
PangoLayout * gtk_widget_create_pango_layout (GtkWidget *widget
,const gchar *text
);
Creates a new PangoLayout with the appropriate font map, font description, and base direction for drawing text for this widget.
If you keep a PangoLayout created in this way around, you need to re-create it when the widget PangoContext is replaced. This can be tracked by using the “screen-changed” signal on the widget.
void gtk_widget_queue_draw_area (GtkWidget *widget
,gint x
,gint y
,gint width
,gint height
);
Convenience function that calls gtk_widget_queue_draw_region()
on
the region created from the given coordinates.
The region here is specified in widget coordinates.
Widget coordinates are a bit odd; for historical reasons, they are
defined as widget->window
coordinates for widgets that return TRUE
for
gtk_widget_get_has_window()
, and are relative to widget->allocation.x
,
widget->allocation.y
otherwise.
width
or height
may be 0, in this case this function does
nothing. Negative values for width
and height
are not allowed.
void gtk_widget_queue_draw_region (GtkWidget *widget
,const cairo_region_t *region
);
Invalidates the area of widget
defined by region
by notifying
the parent via its GtkWidgetClass::queue_draw_child()
function.
Once the main loop becomes idle (after the current batch of
events has been processed, roughly), the window will receive
expose events for the union of all regions that have been
invalidated.
Normally you would only use this function in widget implementations. You might also use it to schedule a redraw of a GtkDrawingArea or some portion thereof.
Since: 3.0
void gtk_widget_set_redraw_on_allocate (GtkWidget *widget
,gboolean redraw_on_allocate
);
Sets whether the entire widget is queued for drawing when its size
allocation changes. By default, this setting is TRUE
and
the entire widget is redrawn on every size change. If your widget
leaves the upper left unchanged when made bigger, turning this
setting off will improve performance.
Note that for widgets where gtk_widget_get_has_window()
is FALSE
setting this flag to FALSE
turns off all allocation on resizing:
the widget will not even redraw if its position changes; this is to
allow containers that don’t draw anything to avoid excess
invalidations. If you set this flag on a widget with no window that
does draw on widget->window
, you are
responsible for invalidating both the old and new allocation of the
widget when the widget is moved and responsible for invalidating
regions newly when the widget increases size.
gboolean gtk_widget_mnemonic_activate (GtkWidget *widget
,gboolean group_cycling
);
Emits the “mnemonic-activate” signal.
gboolean gtk_widget_send_focus_change (GtkWidget *widget
,GdkEvent *event
);
Sends the focus change event
to widget
This function is not meant to be used by applications. The only time it should be used is when it is necessary for a GtkWidget to assign focus to a widget that is semantically owned by the first widget even though it’s not a direct child - for instance, a search entry in a floating window similar to the quick search in GtkTreeView.
An example of its usage is:
1 2 3 4 5 6 7 8 9 10 11 |
GdkEvent *fevent = gdk_event_new (GDK_FOCUS_CHANGE); fevent->focus_change.type = GDK_FOCUS_CHANGE; fevent->focus_change.in = TRUE; fevent->focus_change.window = _gtk_widget_get_window (widget); if (fevent->focus_change.window != NULL) g_object_ref (fevent->focus_change.window); gtk_widget_send_focus_change (widget, fevent); gdk_event_free (event); |
the return value from the event signal emission: TRUE
if the event was handled, and FALSE
otherwise
Since: 2.20
void gtk_widget_class_set_accessible_type (GtkWidgetClass *widget_class
,GType type
);
Sets the type to be used for creating accessibles for widgets of
widget_class
. The given type
must be a subtype of the type used for
accessibles of the parent class.
This function should only be called from class init functions of widgets.
widget_class |
class to set the accessible type for |
|
type |
The object type that implements the accessible for |
Since: 3.2
void gtk_widget_class_set_accessible_role (GtkWidgetClass *widget_class
,AtkRole role
);
Sets the default AtkRole to be set on accessibles created for
widgets of widget_class
. Accessibles may decide to not honor this
setting if their role reporting is more refined. Calls to
gtk_widget_class_set_accessible_type()
will reset this value.
In cases where you want more fine-grained control over the role of
accessibles created for widget_class
, you should provide your own
accessible type and use gtk_widget_class_set_accessible_type()
instead.
If role
is ATK_ROLE_INVALID, the default role will not be changed
and the accessible’s default role will be used instead.
This function should only be called from class init functions of widgets.
widget_class |
class to set the accessible role for |
|
role |
The role to use for accessibles created for |
Since: 3.2
AtkObject *
gtk_widget_get_accessible (GtkWidget *widget
);
Returns the accessible object that describes the widget to an assistive technology.
If accessibility support is not available, this AtkObject instance may be a no-op. Likewise, if no class-specific AtkObject implementation is available for the widget instance in question, it will inherit an AtkObject implementation from the first ancestor class for which such an implementation is defined.
The documentation of the ATK library contains more information about accessible objects and their uses.
gboolean gtk_widget_child_focus (GtkWidget *widget
,GtkDirectionType direction
);
This function is used by custom widget implementations; if you're
writing an app, you’d use gtk_widget_grab_focus()
to move the focus
to a particular widget, and gtk_container_set_focus_chain()
to
change the focus tab order. So you may want to investigate those
functions instead.
gtk_widget_child_focus() is called by containers as the user moves
around the window using keyboard shortcuts. direction
indicates
what kind of motion is taking place (up, down, left, right, tab
forward, tab backward). gtk_widget_child_focus()
emits the
“focus” signal; widgets override the default handler
for this signal in order to implement appropriate focus behavior.
The default ::focus handler for a widget should return TRUE
if
moving in direction
left the focus on a focusable location inside
that widget, and FALSE
if moving in direction
moved the focus
outside the widget. If returning TRUE
, widgets normally
call gtk_widget_grab_focus()
to place the focus accordingly;
if returning FALSE
, they don’t modify the current focus location.
void gtk_widget_child_notify (GtkWidget *widget
,const gchar *child_property
);
Emits a “child-notify” signal for the
child property child_property
on widget
.
This is the analogue of g_object_notify()
for child properties.
Also see gtk_container_child_notify()
.
void
gtk_widget_freeze_child_notify (GtkWidget *widget
);
Stops emission of “child-notify” signals on widget
. The
signals are queued until gtk_widget_thaw_child_notify()
is called
on widget
.
This is the analogue of g_object_freeze_notify()
for child properties.
gboolean
gtk_widget_get_child_visible (GtkWidget *widget
);
Gets the value set with gtk_widget_set_child_visible()
.
If you feel a need to use this function, your code probably
needs reorganization.
This function is only useful for container implementations and never should be called by an application.
GtkWidget *
gtk_widget_get_parent (GtkWidget *widget
);
Returns the parent widget of widget
.
GtkSettings *
gtk_widget_get_settings (GtkWidget *widget
);
Gets the settings object holding the settings used for this widget.
Note that this function can only be called when the GtkWidget is attached to a toplevel, since the settings object is specific to a particular GdkScreen.
GtkClipboard * gtk_widget_get_clipboard (GtkWidget *widget
,GdkAtom selection
);
Returns the clipboard object for the given selection to
be used with widget
. widget
must have a GdkDisplay
associated with it, so must be attached to a toplevel
window.
widget |
||
selection |
a GdkAtom which identifies the clipboard
to use. |
the appropriate clipboard object. If no clipboard already exists, a new one will be created. Once a clipboard object has been created, it is persistent for all time.
[transfer none]
Since: 2.2
GdkDisplay *
gtk_widget_get_display (GtkWidget *widget
);
Get the GdkDisplay for the toplevel window associated with this widget. This function can only be called after the widget has been added to a widget hierarchy with a GtkWindow at the top.
In general, you should only create display specific resources when a widget has been realized, and you should free those resources when the widget is unrealized.
Since: 2.2
GdkScreen *
gtk_widget_get_screen (GtkWidget *widget
);
Get the GdkScreen from the toplevel window associated with this widget. This function can only be called after the widget has been added to a widget hierarchy with a GtkWindow at the top.
In general, you should only create screen specific resources when a widget has been realized, and you should free those resources when the widget is unrealized.
Since: 2.2
gboolean
gtk_widget_has_screen (GtkWidget *widget
);
Checks whether there is a GdkScreen is associated with this widget. All toplevel widgets have an associated screen, and all widgets added into a hierarchy with a toplevel window at the top.
Since: 2.2
void gtk_widget_get_size_request (GtkWidget *widget
,gint *width
,gint *height
);
Gets the size request that was explicitly set for the widget using
gtk_widget_set_size_request()
. A value of -1 stored in width
or
height
indicates that that dimension has not been set explicitly
and the natural requisition of the widget will be used instead. See
gtk_widget_set_size_request()
. To get the size a widget will
actually request, call gtk_widget_measure()
instead of
this function.
void gtk_widget_set_child_visible (GtkWidget *widget
,gboolean is_visible
);
Sets whether widget
should be mapped along with its when its parent
is mapped and widget
has been shown with gtk_widget_show()
.
The child visibility can be set for widget before it is added to
a container with gtk_widget_set_parent()
, to avoid mapping
children unnecessary before immediately unmapping them. However
it will be reset to its default state of TRUE
when the widget
is removed from a container.
Note that changing the child visibility of a widget does not queue a resize on the widget. Most of the time, the size of a widget is computed from all visible children, whether or not they are mapped. If this is not the case, the container can queue a resize itself.
This function is only useful for container implementations and never should be called by an application.
void gtk_widget_set_size_request (GtkWidget *widget
,gint width
,gint height
);
Sets the minimum size of a widget; that is, the widget’s size
request will be at least width
by height
. You can use this
function to force a widget to be larger than it normally would be.
In most cases, gtk_window_set_default_size()
is a better choice for
toplevel windows than this function; setting the default size will
still allow users to shrink the window. Setting the size request
will force them to leave the window at least as large as the size
request. When dealing with window sizes,
gtk_window_set_geometry_hints()
can be a useful function as well.
Note the inherent danger of setting any fixed size - themes, translations into other languages, different fonts, and user action can all change the appropriate size for a given widget. So, it's basically impossible to hardcode a size that will always be correct.
The size request of a widget is the smallest size a widget can accept while still functioning well and drawing itself correctly. However in some strange cases a widget may be allocated less than its requested size, and in many cases a widget may be allocated more space than it requested.
If the size request in a given direction is -1 (unset), then the “natural” size request of the widget will be used instead.
The size request set here does not include any margin from the GtkWidget properties margin-left, margin-right, margin-top, and margin-bottom, but it does include pretty much all other padding or border properties set by any subclass of GtkWidget.
void
gtk_widget_thaw_child_notify (GtkWidget *widget
);
Reverts the effect of a previous call to gtk_widget_freeze_child_notify()
.
This causes all queued “child-notify” signals on widget
to be
emitted.
GList *
gtk_widget_list_mnemonic_labels (GtkWidget *widget
);
Returns a newly allocated list of the widgets, normally labels, for
which this widget is the target of a mnemonic (see for example,
gtk_label_set_mnemonic_widget()
).
The widgets in the list are not individually referenced. If you
want to iterate through the list and perform actions involving
callbacks that might destroy the widgets, you
must call g_list_foreach (result,
(GFunc)g_object_ref, NULL)
first, and then unref all the
widgets afterwards.
the list of
mnemonic labels; free this list
with g_list_free()
when you are done with it.
[element-type GtkWidget][transfer container]
Since: 2.4
void gtk_widget_add_mnemonic_label (GtkWidget *widget
,GtkWidget *label
);
Adds a widget to the list of mnemonic labels for
this widget. (See gtk_widget_list_mnemonic_labels()
). Note the
list of mnemonic labels for the widget is cleared when the
widget is destroyed, so the caller must make sure to update
its internal state at this point as well, by using a connection
to the “destroy” signal or a weak notifier.
Since: 2.4
void gtk_widget_remove_mnemonic_label (GtkWidget *widget
,GtkWidget *label
);
Removes a widget from the list of mnemonic labels for
this widget. (See gtk_widget_list_mnemonic_labels()
). The widget
must have previously been added to the list with
gtk_widget_add_mnemonic_label()
.
widget |
||
label |
a GtkWidget that was previously set as a mnemonic label for
|
Since: 2.4
void
gtk_widget_error_bell (GtkWidget *widget
);
Notifies the user about an input-related error on this widget.
If the “gtk-error-bell” setting is TRUE
, it calls
gdk_window_beep()
, otherwise it does nothing.
Note that the effect of gdk_window_beep()
can be configured in many
ways, depending on the windowing backend and the desktop environment
or window manager that is used.
Since: 2.12
gboolean gtk_widget_keynav_failed (GtkWidget *widget
,GtkDirectionType direction
);
This function should be called whenever keyboard navigation within
a single widget hits a boundary. The function emits the
“keynav-failed” signal on the widget and its return
value should be interpreted in a way similar to the return value of
gtk_widget_child_focus()
:
When TRUE
is returned, stay in the widget, the failed keyboard
navigation is OK and/or there is nowhere we can/should move the
focus to.
When FALSE
is returned, the caller should continue with keyboard
navigation outside the widget, e.g. by calling
gtk_widget_child_focus()
on the widget’s toplevel.
The default ::keynav-failed handler returns TRUE
for
GTK_DIR_TAB_FORWARD
and GTK_DIR_TAB_BACKWARD
. For the other
values of GtkDirectionType it returns FALSE
.
Whenever the default handler returns TRUE
, it also calls
gtk_widget_error_bell()
to notify the user of the failed keyboard
navigation.
A use case for providing an own implementation of ::keynav-failed (either by connecting to it or by overriding it) would be a row of GtkEntry widgets where the user should be able to navigate the entire row with the cursor keys, as e.g. known from user interfaces that require entering license keys.
TRUE
if stopping keyboard navigation is fine, FALSE
if the emitting widget should try to handle the keyboard
navigation attempt in its parent container(s).
Since: 2.12
gchar *
gtk_widget_get_tooltip_markup (GtkWidget *widget
);
Gets the contents of the tooltip for widget
.
the tooltip text, or NULL
. You should free the
returned string with g_free()
when done.
[nullable]
Since: 2.12
void gtk_widget_set_tooltip_markup (GtkWidget *widget
,const gchar *markup
);
Sets markup
as the contents of the tooltip, which is marked up with
the Pango text markup language.
This function will take care of setting “has-tooltip” to TRUE
and of the default handler for the “query-tooltip” signal.
See also the “tooltip-markup” property and
gtk_tooltip_set_markup()
.
Since: 2.12
gchar *
gtk_widget_get_tooltip_text (GtkWidget *widget
);
Gets the contents of the tooltip for widget
.
the tooltip text, or NULL
. You should free the
returned string with g_free()
when done.
[nullable]
Since: 2.12
void gtk_widget_set_tooltip_text (GtkWidget *widget
,const gchar *text
);
Sets text
as the contents of the tooltip. This function will take
care of setting “has-tooltip” to TRUE
and of the default
handler for the “query-tooltip” signal.
See also the “tooltip-text” property and gtk_tooltip_set_text()
.
Since: 2.12
GtkWindow *
gtk_widget_get_tooltip_window (GtkWidget *widget
);
Returns the GtkWindow of the current tooltip. This can be the
GtkWindow created by default, or the custom tooltip window set
using gtk_widget_set_tooltip_window()
.
Since: 2.12
void gtk_widget_set_tooltip_window (GtkWidget *widget
,GtkWindow *custom_window
);
Replaces the default, usually yellow, window used for displaying
tooltips with custom_window
. GTK+ will take care of showing and
hiding custom_window
at the right moment, to behave likewise as
the default tooltip window. If custom_window
is NULL
, the default
tooltip window will be used.
If the custom window should have the default theming it needs to
have the name “gtk-tooltip”, see gtk_widget_set_name()
.
Since: 2.12
gboolean
gtk_widget_get_has_tooltip (GtkWidget *widget
);
Returns the current value of the has-tooltip property. See “has-tooltip” for more information.
Since: 2.12
void gtk_widget_set_has_tooltip (GtkWidget *widget
,gboolean has_tooltip
);
Sets the has-tooltip property on widget
to has_tooltip
. See
“has-tooltip” for more information.
Since: 2.12
void
gtk_widget_trigger_tooltip_query (GtkWidget *widget
);
Triggers a tooltip query on the display where the toplevel of widget
is located. See gtk_tooltip_trigger_tooltip_query()
for more
information.
Since: 2.12
GdkWindow *
gtk_widget_get_window (GtkWidget *widget
);
Returns the widget’s window if it is realized, NULL
otherwise
Since: 2.14
void gtk_widget_register_window (GtkWidget *widget
,GdkWindow *window
);
Registers a GdkWindow with the widget and sets it up so that
the widget receives events for it. Call gtk_widget_unregister_window()
when destroying the window.
Before 3.8 you needed to call gdk_window_set_user_data()
directly to set
this up. This is now deprecated and you should use gtk_widget_register_window()
instead. Old code will keep working as is, although some new features like
transparency might not work perfectly.
Since: 3.8
void gtk_widget_unregister_window (GtkWidget *widget
,GdkWindow *window
);
Unregisters a GdkWindow from the widget that was previously set up with
gtk_widget_register_window()
. You need to call this when the window is
no longer used by the widget, such as when you destroy it.
Since: 3.8
int
gtk_widget_get_allocated_width (GtkWidget *widget
);
Returns the width that has currently been allocated to widget
.
This function is intended to be used when implementing handlers
for the “draw” function.
int
gtk_widget_get_allocated_height (GtkWidget *widget
);
Returns the height that has currently been allocated to widget
.
This function is intended to be used when implementing handlers
for the “draw” function.
void gtk_widget_get_allocation (GtkWidget *widget
,GtkAllocation *allocation
);
Retrieves the widget’s allocation.
Note, when implementing a GtkContainer: a widget’s allocation will
be its “adjusted” allocation, that is, the widget’s parent
container typically calls gtk_widget_size_allocate()
with an
allocation, and that allocation is then adjusted (to handle margin
and alignment for example) before assignment to the widget.
gtk_widget_get_allocation()
returns the adjusted allocation that
was actually assigned to the widget. The adjusted allocation is
guaranteed to be completely contained within the
gtk_widget_size_allocate()
allocation, however. So a GtkContainer
is guaranteed that its children stay inside the assigned bounds,
but not that they have exactly the bounds the container assigned.
There is no way to get the original allocation assigned by
gtk_widget_size_allocate()
, since it isn’t stored; if a container
implementation needs that information it will have to track it itself.
Since: 2.18
int
gtk_widget_get_allocated_baseline (GtkWidget *widget
);
Returns the baseline that has currently been allocated to widget
.
This function is intended to be used when implementing handlers
for the “draw” function, and when allocating child
widgets in “size_allocate”.
Since: 3.10
void gtk_widget_get_allocated_size (GtkWidget *widget
,GtkAllocation *allocation
,int *baseline
);
Retrieves the widget’s allocated size.
This function returns the last values passed to
gtk_widget_size_allocate()
. The value differs from
the size returned in gtk_widget_get_allocation()
in that functions
like gtk_widget_set_halign()
can adjust the allocation, but not
the value returned by this function.
If a widget is not visible, its allocated size is 0.
widget |
||
allocation |
a pointer to a GtkAllocation to copy to. |
[out] |
baseline |
a pointer to an integer to copy to. |
[out][allow-none] |
Since: 3.20
void gtk_widget_get_clip (GtkWidget *widget
,GtkAllocation *clip
);
Retrieves the widget’s clip area.
The clip area is the area in which all of widget
's drawing will
happen. Other toolkits call it the bounding box.
Historically, in GTK+ the clip area has been equal to the allocation
retrieved via gtk_widget_get_allocation()
.
Since: 3.14
gboolean
gtk_widget_get_can_default (GtkWidget *widget
);
Determines whether widget
can be a default widget. See
gtk_widget_set_can_default()
.
Since: 2.18
void gtk_widget_set_can_default (GtkWidget *widget
,gboolean can_default
);
Specifies whether widget
can be a default widget. See
gtk_widget_grab_default()
for details about the meaning of
“default”.
Since: 2.18
gboolean
gtk_widget_get_can_focus (GtkWidget *widget
);
Determines whether widget
can own the input focus. See
gtk_widget_set_can_focus()
.
Since: 2.18
void gtk_widget_set_can_focus (GtkWidget *widget
,gboolean can_focus
);
Specifies whether widget
can own the input focus. See
gtk_widget_grab_focus()
for actually setting the input focus on a
widget.
Since: 2.18
gboolean
gtk_widget_get_focus_on_click (GtkWidget *widget
);
Returns whether the widget should grab focus when it is clicked with the mouse.
See gtk_widget_set_focus_on_click()
.
Since: 3.20
void gtk_widget_set_focus_on_click (GtkWidget *widget
,gboolean focus_on_click
);
Sets whether the widget should grab focus when it is clicked with the mouse. Making mouse clicks not grab focus is useful in places like toolbars where you don’t want the keyboard focus removed from the main area of the application.
Since: 3.20
gboolean
gtk_widget_get_has_window (GtkWidget *widget
);
Determines whether widget
has a GdkWindow of its own. See
gtk_widget_set_has_window()
.
Since: 2.18
void gtk_widget_set_has_window (GtkWidget *widget
,gboolean has_window
);
Specifies whether widget
has a GdkWindow of its own. Note that
all realized widgets have a non-NULL
“window” pointer
(gtk_widget_get_window()
never returns a NULL
window when a widget
is realized), but for many of them it’s actually the GdkWindow of
one of its parent widgets. Widgets that do not create a window
for
themselves in “realize” must announce this by
calling this function with has_window
= FALSE
.
This function should only be called by widget implementations,
and they should call it in their init()
function.
Since: 2.18
gboolean
gtk_widget_get_sensitive (GtkWidget *widget
);
Returns the widget’s sensitivity (in the sense of returning
the value that has been set using gtk_widget_set_sensitive()
).
The effective sensitivity of a widget is however determined by both its
own and its parent widget’s sensitivity. See gtk_widget_is_sensitive()
.
Since: 2.18
gboolean
gtk_widget_is_sensitive (GtkWidget *widget
);
Returns the widget’s effective sensitivity, which means it is sensitive itself and also its parent widget is sensitive
Since: 2.18
gboolean
gtk_widget_get_visible (GtkWidget *widget
);
Determines whether the widget is visible. If you want to
take into account whether the widget’s parent is also marked as
visible, use gtk_widget_is_visible()
instead.
This function does not check if the widget is obscured in any way.
Since: 2.18
gboolean
gtk_widget_is_visible (GtkWidget *widget
);
Determines whether the widget and all its parents are marked as visible.
This function does not check if the widget is obscured in any way.
See also gtk_widget_get_visible()
and gtk_widget_set_visible()
Since: 3.8
void gtk_widget_set_visible (GtkWidget *widget
,gboolean visible
);
Sets the visibility state of widget
. Note that setting this to
TRUE
doesn’t mean the widget is actually viewable, see
gtk_widget_get_visible()
.
This function simply calls gtk_widget_show()
or gtk_widget_hide()
but is nicer to use when the visibility of the widget depends on
some condition.
Since: 2.18
void gtk_widget_set_state_flags (GtkWidget *widget
,GtkStateFlags flags
,gboolean clear
);
This function is for use in widget implementations. Turns on flag values in the current widget state (insensitive, prelighted, etc.).
This function accepts the values GTK_STATE_FLAG_DIR_LTR
and
GTK_STATE_FLAG_DIR_RTL
but ignores them. If you want to set the widget's
direction, use gtk_widget_set_direction()
.
It is worth mentioning that any other state than GTK_STATE_FLAG_INSENSITIVE
,
will be propagated down to all non-internal children if widget
is a
GtkContainer, while GTK_STATE_FLAG_INSENSITIVE
itself will be propagated
down to all GtkContainer children by different means than turning on the
state flag down the hierarchy, both gtk_widget_get_state_flags()
and
gtk_widget_is_sensitive()
will make use of these.
Since: 3.0
void gtk_widget_unset_state_flags (GtkWidget *widget
,GtkStateFlags flags
);
This function is for use in widget implementations. Turns off flag
values for the current widget state (insensitive, prelighted, etc.).
See gtk_widget_set_state_flags()
.
Since: 3.0
GtkStateFlags
gtk_widget_get_state_flags (GtkWidget *widget
);
Returns the widget state as a flag set. It is worth mentioning
that the effective GTK_STATE_FLAG_INSENSITIVE
state will be
returned, that is, also based on parent insensitivity, even if
widget
itself is sensitive.
Also note that if you are looking for a way to obtain the
GtkStateFlags to pass to a GtkStyleContext method, you
should look at gtk_style_context_get_state()
.
Since: 3.0
gboolean
gtk_widget_has_default (GtkWidget *widget
);
Determines whether widget
is the current default widget within its
toplevel. See gtk_widget_set_can_default()
.
Since: 2.18
gboolean
gtk_widget_has_focus (GtkWidget *widget
);
Determines if the widget has the global input focus. See
gtk_widget_is_focus()
for the difference between having the global
input focus, and only having the focus within a toplevel.
Since: 2.18
gboolean
gtk_widget_has_visible_focus (GtkWidget *widget
);
Determines if the widget should show a visible indication that
it has the global input focus. This is a convenience function for
use in ::draw handlers that takes into account whether focus
indication should currently be shown in the toplevel window of
widget
. See gtk_window_get_focus_visible()
for more information
about focus indication.
To find out if the widget has the global input focus, use
gtk_widget_has_focus()
.
Since: 3.2
gboolean
gtk_widget_has_grab (GtkWidget *widget
);
Determines whether the widget is currently grabbing events, so it is the only widget receiving input events (keyboard and mouse).
See also gtk_grab_add()
.
Since: 2.18
gboolean
gtk_widget_is_drawable (GtkWidget *widget
);
Determines whether widget
can be drawn to. A widget can be drawn
to if it is mapped and visible.
Since: 2.18
gboolean
gtk_widget_is_toplevel (GtkWidget *widget
);
Determines whether widget
is a toplevel widget.
Currently only GtkWindow and GtkInvisible are toplevel widgets. Toplevel widgets have no parent widget.
Since: 2.18
void gtk_widget_set_window (GtkWidget *widget
,GdkWindow *window
);
Sets a widget’s window. This function should only be used in a
widget’s “realize” implementation. The window
passed is
usually either new window created with gdk_window_new()
, or the
window of its parent widget as returned by
gtk_widget_get_parent_window()
.
Widgets must indicate whether they will create their own GdkWindow
by calling gtk_widget_set_has_window()
. This is usually done in the
widget’s init()
function.
Note that this function does not add any reference to window
.
Since: 2.18
void gtk_widget_set_receives_default (GtkWidget *widget
,gboolean receives_default
);
Specifies whether widget
will be treated as the default widget
within its toplevel when it has the focus, even if another widget
is the default.
See gtk_widget_grab_default()
for details about the meaning of
“default”.
Since: 2.18
gboolean
gtk_widget_get_receives_default (GtkWidget *widget
);
Determines whether widget
is always treated as the default widget
within its toplevel when it has the focus, even if another widget
is the default.
See gtk_widget_set_receives_default()
.
Since: 2.18
void gtk_widget_set_support_multidevice (GtkWidget *widget
,gboolean support_multidevice
);
Enables or disables multiple pointer awareness. If this setting is TRUE
,
widget
will start receiving multiple, per device enter/leave events. Note
that if custom GdkWindows are created in “realize”,
gdk_window_set_support_multidevice()
will have to be called manually on them.
Since: 3.0
gboolean
gtk_widget_get_support_multidevice (GtkWidget *widget
);
Returns TRUE
if widget
is multiple pointer aware. See
gtk_widget_set_support_multidevice()
for more information.
void gtk_widget_set_realized (GtkWidget *widget
,gboolean realized
);
Marks the widget as being realized. This function must only be
called after all GdkWindows for the widget
have been created
and registered.
This function should only ever be called in a derived widget's “realize” or “unrealize” implementation.
Since: 2.20
gboolean
gtk_widget_get_realized (GtkWidget *widget
);
Determines whether widget
is realized.
Since: 2.20
gboolean
gtk_widget_get_mapped (GtkWidget *widget
);
Whether the widget is mapped.
Since: 2.20
gboolean gtk_widget_device_is_shadowed (GtkWidget *widget
,GdkDevice *device
);
Returns TRUE
if device
has been shadowed by a GTK+
device grab on another widget, so it would stop sending
events to widget
. This may be used in the
“grab-notify” signal to check for specific
devices. See gtk_device_grab_add()
.
Since: 3.0
GdkModifierType gtk_widget_get_modifier_mask (GtkWidget *widget
,GdkModifierIntent intent
);
Returns the modifier mask the widget
’s windowing system backend
uses for a particular purpose.
See gdk_keymap_get_modifier_mask()
.
Since: 3.4
void gtk_widget_insert_action_group (GtkWidget *widget
,const gchar *name
,GActionGroup *group
);
Inserts group
into widget
. Children of widget
that implement
GtkActionable can then be associated with actions in group
by
setting their “action-name” to
prefix
.action-name
.
If group
is NULL
, a previously inserted group for name
is removed
from widget
.
Since: 3.6
double
gtk_widget_get_opacity (GtkWidget *widget
);
Fetches the requested opacity for this widget.
See gtk_widget_set_opacity()
.
Since: 3.8
void gtk_widget_set_opacity (GtkWidget *widget
,double opacity
);
Request the widget
to be rendered partially transparent,
with opacity 0 being fully transparent and 1 fully opaque. (Opacity values
are clamped to the [0,1] range.).
This works on both toplevel widget, and child widgets, although there
are some limitations:
For toplevel widgets this depends on the capabilities of the windowing
system. On X11 this has any effect only on X displays with a compositing manager
running. See gdk_display_is_composited()
. On Windows it should work
always, although setting a window’s opacity after the window has been
shown causes it to flicker once on Windows.
For child widgets it doesn’t work if any affected widget has a native window.
Since: 3.8
const gchar **
gtk_widget_list_action_prefixes (GtkWidget *widget
);
Retrieves a NULL
-terminated array of strings containing the prefixes of
GActionGroup's available to widget
.
Since: 3.16
GActionGroup * gtk_widget_get_action_group (GtkWidget *widget
,const gchar *prefix
);
Retrieves the GActionGroup that was registered using prefix
. The resulting
GActionGroup may have been registered to widget
or any GtkWidget in its
ancestry.
If no action group was found matching prefix
, then NULL
is returned.
Since: 3.16
void gtk_widget_measure (GtkWidget *widget
,GtkOrientation orientation
,int for_size
,int *minimum
,int *natural
,int *minimum_baseline
,int *natural_baseline
);
Measures widget
in the orientation orientation
and for the given for_size
.
As an example, if orientation
is GTK_ORIENTATION_HORIZONTAL and for_size
is 300,
this functions will compute the minimum and natural width of widget
if
it is allocated at a height of 300 pixels.
widget |
A GtkWidget instance |
|
orientation |
the orientation to measure |
|
for_size |
Size for the opposite of |
|
minimum |
location to store the minimum size, or |
[out][optional] |
natural |
location to store the natural size, or |
[out][optional] |
minimum_baseline |
location to store the baseline
position for the minimum size, or |
[out][optional] |
natural_baseline |
location to store the baseline
position for the natural size, or |
[out][optional] |
Since: 3.90
void gtk_widget_snapshot_child (GtkWidget *widget
,GtkWidget *child
,GtkSnapshot *snapshot
);
When a widget receives a call to the snapshot function, it must send
synthetic “snapshot” calls to all children. This function
provides a convenient way of doing this. A widget, when it receives
a call to its “snapshot” function, calls
gtk_widget_snapshot_child()
once for each child, passing in
the snapshot
the widget received.
gtk_widget_snapshot_child() takes care of translating the origin of
snapshot
, and deciding whether the child needs to be snapshot. It is a
convenient and optimized way of getting the same effect as calling
gtk_widget_snapshot()
on the child directly.
widget |
||
child |
a child of |
|
snapshot |
GtkSnapshot as passed to the widget. In particular, no
calls to |
GtkWidget *
gtk_widget_get_next_sibling (GtkWidget *widget
);
Since: 3.90
GtkWidget *
gtk_widget_get_prev_sibling (GtkWidget *widget
);
Since: 3.90
GtkWidget *
gtk_widget_get_first_child (GtkWidget *widget
);
Since: 3.90
void gtk_widget_insert_before (GtkWidget *widget
,GtkWidget *parent
,GtkWidget *next_sibling
);
Inserts widget
into the child widget list of parent
.
It will be placed before next_sibling
, or at the end if next_sibling
is NULL
.
After calling this function, gtk_widget_get_next_sibling(widget) will return next_sibling
.
If parent
is already set as the parent widget of widget
, this function can also be used
to reorder widget
in the child widget list of parent
.
Since: 3.92
void gtk_widget_insert_after (GtkWidget *widget
,GtkWidget *parent
,GtkWidget *previous_sibling
);
Inserts widget
into the child widget list of parent
.
It will be placed after previous_sibling
, or at the beginning if previous_sibling
is NULL
.
After calling this function, gtk_widget_get_prev_sibling(widget) will return previous_sibling
.
If parent
is already set as the parent widget of widget
, this function can also be used
to reorder widget
in the child widget list of parent
.
Since: 3.92
GtkWidgetPath *
gtk_widget_get_path (GtkWidget *widget
);
Returns the GtkWidgetPath representing widget
, if the widget
is not connected to a toplevel widget, a partial path will be
created.
GtkStyleContext *
gtk_widget_get_style_context (GtkWidget *widget
);
Returns the style context associated to widget
. The returned object is
guaranteed to be the same for the lifetime of widget
.
void
gtk_widget_reset_style (GtkWidget *widget
);
Updates the style context of widget
and all descendants
by updating its widget path. GtkContainers may want
to use this on a child when reordering it in a way that a different
style might apply to it. See also gtk_container_get_path_for_child()
.
Since: 3.0
const char *
gtk_widget_class_get_css_name (GtkWidgetClass *widget_class
);
Gets the name used by this class for matching in CSS code. See
gtk_widget_class_set_css_name()
for details.
Since: 3.20
void gtk_widget_class_set_css_name (GtkWidgetClass *widget_class
,const char *name
);
Sets the name to be used for CSS matching of widgets.
If this function is not called for a given class, the name of the parent class is used.
Since: 3.20
GtkRequisition *
gtk_requisition_new (void
);
Allocates a new GtkRequisition and initializes its elements to zero.
a new empty GtkRequisition. The newly allocated GtkRequisition should
be freed with gtk_requisition_free()
.
Since: 3.0
GtkRequisition *
gtk_requisition_copy (const GtkRequisition *requisition
);
Copies a GtkRequisition.
void
gtk_requisition_free (GtkRequisition *requisition
);
Frees a GtkRequisition.
GtkSizeRequestMode
gtk_widget_get_request_mode (GtkWidget *widget
);
Gets whether the widget prefers a height-for-width layout or a width-for-height layout.
GtkBin widgets generally propagate the preference of their child, container widgets need to request something either in context of their children or in context of their allocation capabilities.
Since: 3.0
void gtk_widget_get_preferred_size (GtkWidget *widget
,GtkRequisition *minimum_size
,GtkRequisition *natural_size
);
Retrieves the minimum and natural size of a widget, taking into account the widget’s preference for height-for-width management.
This is used to retrieve a suitable size by container widgets which do not impose any restrictions on the child placement. It can be used to deduce toplevel window and menu sizes as well as child widgets in free-form containers such as GtkLayout.
Handle with care. Note that the natural height of a height-for-width widget will generally be a smaller size than the minimum height, since the required height for the natural width is generally smaller than the required height for the minimum width.
Use gtk_widget_measure()
if you want to support
baseline alignment.
Since: 3.0
gint gtk_distribute_natural_allocation (gint extra_space
,guint n_requested_sizes
,GtkRequestedSize *sizes
);
Distributes extra_space
to child sizes
by bringing smaller
children up to natural size first.
The remaining space will be added to the minimum_size
member of the
GtkRequestedSize struct. If all sizes reach their natural size then
the remaining space is returned.
extra_space |
Extra space to redistribute among children after subtracting minimum sizes and any child padding from the overall allocation |
|
n_requested_sizes |
Number of requests to fit into the allocation |
|
sizes |
An array of structs with a client pointer and a minimum/natural size in the orientation of the allocation. |
GtkAlign
gtk_widget_get_halign (GtkWidget *widget
);
Gets the value of the “halign” property.
For backwards compatibility reasons this method will never return
GTK_ALIGN_BASELINE
, but instead it will convert it to
GTK_ALIGN_FILL
. Baselines are not supported for horizontal
alignment.
void gtk_widget_set_halign (GtkWidget *widget
,GtkAlign align
);
Sets the horizontal alignment of widget
.
See the “halign” property.
GtkAlign
gtk_widget_get_valign (GtkWidget *widget
);
Gets the value of the “valign” property.
void gtk_widget_set_valign (GtkWidget *widget
,GtkAlign align
);
Sets the vertical alignment of widget
.
See the “valign” property.
gint
gtk_widget_get_margin_start (GtkWidget *widget
);
Gets the value of the “margin-start” property.
Since: 3.12
void gtk_widget_set_margin_start (GtkWidget *widget
,gint margin
);
Sets the start margin of widget
.
See the “margin-start” property.
Since: 3.12
gint
gtk_widget_get_margin_end (GtkWidget *widget
);
Gets the value of the “margin-end” property.
Since: 3.12
void gtk_widget_set_margin_end (GtkWidget *widget
,gint margin
);
Sets the end margin of widget
.
See the “margin-end” property.
Since: 3.12
gint
gtk_widget_get_margin_top (GtkWidget *widget
);
Gets the value of the “margin-top” property.
Since: 3.0
void gtk_widget_set_margin_top (GtkWidget *widget
,gint margin
);
Sets the top margin of widget
.
See the “margin-top” property.
Since: 3.0
gint
gtk_widget_get_margin_bottom (GtkWidget *widget
);
Gets the value of the “margin-bottom” property.
Since: 3.0
void gtk_widget_set_margin_bottom (GtkWidget *widget
,gint margin
);
Sets the bottom margin of widget
.
See the “margin-bottom” property.
Since: 3.0
gboolean
gtk_widget_get_hexpand (GtkWidget *widget
);
Gets whether the widget would like any available extra horizontal space. When a user resizes a GtkWindow, widgets with expand=TRUE generally receive the extra space. For example, a list or scrollable area or document in your window would often be set to expand.
Containers should use gtk_widget_compute_expand()
rather than
this function, to see whether a widget, or any of its children,
has the expand flag set. If any child of a widget wants to
expand, the parent may ask to expand also.
This function only looks at the widget’s own hexpand flag, rather than computing whether the entire widget tree rooted at this widget wants to expand.
void gtk_widget_set_hexpand (GtkWidget *widget
,gboolean expand
);
Sets whether the widget would like any available extra horizontal space. When a user resizes a GtkWindow, widgets with expand=TRUE generally receive the extra space. For example, a list or scrollable area or document in your window would often be set to expand.
Call this function to set the expand flag if you would like your widget to become larger horizontally when the window has extra room.
By default, widgets automatically expand if any of their children
want to expand. (To see if a widget will automatically expand given
its current children and state, call gtk_widget_compute_expand()
. A
container can decide how the expandability of children affects the
expansion of the container by overriding the compute_expand virtual
method on GtkWidget.).
Setting hexpand explicitly with this function will override the automatic expand behavior.
This function forces the widget to expand or not to expand,
regardless of children. The override occurs because
gtk_widget_set_hexpand()
sets the hexpand-set property (see
gtk_widget_set_hexpand_set()
) which causes the widget’s hexpand
value to be used, rather than looking at children and widget state.
gboolean
gtk_widget_get_hexpand_set (GtkWidget *widget
);
Gets whether gtk_widget_set_hexpand()
has been used to
explicitly set the expand flag on this widget.
If hexpand is set, then it overrides any computed expand value based on child widgets. If hexpand is not set, then the expand value depends on whether any children of the widget would like to expand.
There are few reasons to use this function, but it’s here for completeness and consistency.
void gtk_widget_set_hexpand_set (GtkWidget *widget
,gboolean set
);
Sets whether the hexpand flag (see gtk_widget_get_hexpand()
) will
be used.
The hexpand-set property will be set automatically when you call
gtk_widget_set_hexpand()
to set hexpand, so the most likely
reason to use this function would be to unset an explicit expand
flag.
If hexpand is set, then it overrides any computed expand value based on child widgets. If hexpand is not set, then the expand value depends on whether any children of the widget would like to expand.
There are few reasons to use this function, but it’s here for completeness and consistency.
gboolean
gtk_widget_get_vexpand (GtkWidget *widget
);
Gets whether the widget would like any available extra vertical space.
See gtk_widget_get_hexpand()
for more detail.
void gtk_widget_set_vexpand (GtkWidget *widget
,gboolean expand
);
Sets whether the widget would like any available extra vertical space.
See gtk_widget_set_hexpand()
for more detail.
gboolean
gtk_widget_get_vexpand_set (GtkWidget *widget
);
Gets whether gtk_widget_set_vexpand()
has been used to
explicitly set the expand flag on this widget.
See gtk_widget_get_hexpand_set()
for more detail.
void gtk_widget_set_vexpand_set (GtkWidget *widget
,gboolean set
);
Sets whether the vexpand flag (see gtk_widget_get_vexpand()
) will
be used.
See gtk_widget_set_hexpand_set()
for more detail.
void
gtk_widget_queue_compute_expand (GtkWidget *widget
);
Mark widget
as needing to recompute its expand flags. Call
this function when setting legacy expand child properties
on the child of a container.
gboolean gtk_widget_compute_expand (GtkWidget *widget
,GtkOrientation orientation
);
Computes whether a container should give this widget extra space
when possible. Containers should check this, rather than
looking at gtk_widget_get_hexpand()
or gtk_widget_get_vexpand()
.
This function already checks whether the widget is visible, so visibility does not need to be checked separately. Non-visible widgets are not expanded.
The computed expand value uses either the expand setting explicitly set on the widget itself, or, if none has been explicitly set, the widget may expand if some of its children do.
void
gtk_widget_init_template (GtkWidget *widget
);
Creates and initializes child widgets defined in templates. This
function must be called in the instance initializer for any
class which assigned itself a template using gtk_widget_class_set_template()
It is important to call this function in the instance initializer
of a GtkWidget subclass and not in GObject.constructed()
or
GObject.constructor()
for two reasons.
One reason is that generally derived widgets will assume that parent class composite widgets have been created in their instance initializers.
Another reason is that when calling g_object_new()
on a widget with
composite templates, it’s important to build the composite widgets
before the construct properties are set. Properties passed to g_object_new()
should take precedence over properties set in the private template XML.
Since: 3.10
void gtk_widget_class_set_template (GtkWidgetClass *widget_class
,GBytes *template_bytes
);
This should be called at class initialization time to specify the GtkBuilder XML to be used to extend a widget.
For convenience, gtk_widget_class_set_template_from_resource()
is also provided.
Note that any class that installs templates must call gtk_widget_init_template()
in the widget’s instance initializer.
Since: 3.10
void gtk_widget_class_set_template_from_resource (GtkWidgetClass *widget_class
,const gchar *resource_name
);
A convenience function to call gtk_widget_class_set_template()
.
Note that any class that installs templates must call gtk_widget_init_template()
in the widget’s instance initializer.
Since: 3.10
GObject * gtk_widget_get_template_child (GtkWidget *widget
,GType widget_type
,const gchar *name
);
Fetch an object build from the template XML for widget_type
in this widget
instance.
This will only report children which were previously declared with
gtk_widget_class_bind_template_child_full()
or one of its
variants.
This function is only meant to be called for code which is private to the widget_type
which
declared the child and is meant for language bindings which cannot easily make use
of the GObject structure offsets.
#define gtk_widget_class_bind_template_child(widget_class, TypeName, member_name)
Binds a child widget defined in a template to the widget_class
.
This macro is a convenience wrapper around the
gtk_widget_class_bind_template_child_full()
function.
This macro will use the offset of the member_name
inside the TypeName
instance structure.
widget_class |
||
TypeName |
the type name of this widget |
|
member_name |
name of the instance member in the instance struct for |
Since: 3.10
#define gtk_widget_class_bind_template_child_internal(widget_class, TypeName, member_name)
Binds a child widget defined in a template to the widget_class
, and
also makes it available as an internal child in GtkBuilder, under the
name member_name
.
This macro is a convenience wrapper around the
gtk_widget_class_bind_template_child_full()
function.
This macro will use the offset of the member_name
inside the TypeName
instance structure.
widget_class |
||
TypeName |
the type name, in CamelCase |
|
member_name |
name of the instance member in the instance struct for |
Since: 3.10
#define gtk_widget_class_bind_template_child_private(widget_class, TypeName, member_name)
Binds a child widget defined in a template to the widget_class
.
This macro is a convenience wrapper around the
gtk_widget_class_bind_template_child_full()
function.
This macro will use the offset of the member_name
inside the TypeName
private data structure (it uses G_PRIVATE_OFFSET()
, so the private struct
must be added with G_ADD_PRIVATE()
).
widget_class |
||
TypeName |
the type name of this widget |
|
member_name |
name of the instance private member in the private struct for |
Since: 3.10
#define gtk_widget_class_bind_template_child_internal_private(widget_class, TypeName, member_name)
Binds a child widget defined in a template to the widget_class
, and
also makes it available as an internal child in GtkBuilder, under the
name member_name
.
This macro is a convenience wrapper around the
gtk_widget_class_bind_template_child_full()
function.
This macro will use the offset of the member_name
inside the TypeName
private data structure.
widget_class |
||
TypeName |
the type name, in CamelCase |
|
member_name |
name of the instance private member on the private struct for |
Since: 3.10
void gtk_widget_class_bind_template_child_full (GtkWidgetClass *widget_class
,const gchar *name
,gboolean internal_child
,gssize struct_offset
);
Automatically assign an object declared in the class template XML to be set to a location
on a freshly built instance’s private data, or alternatively accessible via gtk_widget_get_template_child()
.
The struct can point either into the public instance, then you should use G_STRUCT_OFFSET(WidgetType, member)
for struct_offset
, or in the private struct, then you should use G_PRIVATE_OFFSET(WidgetType, member).
An explicit strong reference will be held automatically for the duration of your
instance’s life cycle, it will be released automatically when GObjectClass.dispose()
runs
on your instance and if a struct_offset
that is != 0 is specified, then the automatic location
in your instance public or private data will be set to NULL
. You can however access an automated child
pointer the first time your classes GObjectClass.dispose()
runs, or alternatively in
GtkWidgetClass.destroy()
.
If internal_child
is specified, GtkBuildableIface.get_internal_child()
will be automatically
implemented by the GtkWidget class so there is no need to implement it manually.
The wrapper macros gtk_widget_class_bind_template_child()
, gtk_widget_class_bind_template_child_internal()
,
gtk_widget_class_bind_template_child_private()
and gtk_widget_class_bind_template_child_internal_private()
might be more convenient to use.
Note that this must be called from a composite widget classes class
initializer after calling gtk_widget_class_set_template()
.
widget_class |
||
name |
The “id” of the child defined in the template XML |
|
internal_child |
Whether the child should be accessible as an “internal-child” when this class is used in GtkBuilder XML |
|
struct_offset |
The structure offset into the composite widget’s instance public or private structure where the automated child pointer should be set, or 0 to not assign the pointer. |
Since: 3.10
#define gtk_widget_class_bind_template_callback(widget_class, callback)
Binds a callback function defined in a template to the widget_class
.
This macro is a convenience wrapper around the
gtk_widget_class_bind_template_callback_full()
function.
Since: 3.10
void gtk_widget_class_bind_template_callback_full (GtkWidgetClass *widget_class
,const gchar *callback_name
,GCallback callback_symbol
);
Declares a callback_symbol
to handle callback_name
from the template XML
defined for widget_type
. See gtk_builder_add_callback_symbol()
.
Note that this must be called from a composite widget classes class
initializer after calling gtk_widget_class_set_template()
.
widget_class |
||
callback_name |
The name of the callback as expected in the template XML |
|
callback_symbol |
The callback symbol. |
[scope async] |
Since: 3.10
void gtk_widget_class_set_connect_func (GtkWidgetClass *widget_class
,GtkBuilderConnectFunc connect_func
,gpointer connect_data
,GDestroyNotify connect_data_destroy
);
For use in language bindings, this will override the default GtkBuilderConnectFunc to be used when parsing GtkBuilder XML from this class’s template data.
Note that this must be called from a composite widget classes class
initializer after calling gtk_widget_class_set_template()
.
widget_class |
||
connect_func |
The GtkBuilderConnectFunc to use when connecting signals in the class template |
|
connect_data |
The data to pass to |
|
connect_data_destroy |
The GDestroyNotify to free |
Since: 3.10
struct GtkWidgetClass { GInitiallyUnownedClass parent_class; guint activate_signal; /* seldomly overidden */ void (*dispatch_child_properties_changed) (GtkWidget *widget, guint n_pspecs, GParamSpec **pspecs); /* basics */ void (* destroy) (GtkWidget *widget); void (* show) (GtkWidget *widget); void (* hide) (GtkWidget *widget); void (* map) (GtkWidget *widget); void (* unmap) (GtkWidget *widget); void (* realize) (GtkWidget *widget); void (* unrealize) (GtkWidget *widget); void (* size_allocate) (GtkWidget *widget, const GtkAllocation *allocation, int baseline, GtkAllocation *out_clip); void (* state_flags_changed) (GtkWidget *widget, GtkStateFlags previous_state_flags); void (* parent_set) (GtkWidget *widget, GtkWidget *previous_parent); void (* hierarchy_changed) (GtkWidget *widget, GtkWidget *previous_toplevel); void (* direction_changed) (GtkWidget *widget, GtkTextDirection previous_direction); void (* grab_notify) (GtkWidget *widget, gboolean was_grabbed); void (* child_notify) (GtkWidget *widget, GParamSpec *child_property); gboolean (* draw) (GtkWidget *widget, cairo_t *cr); /* size requests */ GtkSizeRequestMode (* get_request_mode) (GtkWidget *widget); void (* measure) (GtkWidget *widget, GtkOrientation orientation, int for_size, int *minimum, int *natural, int *minimum_baseline, int *natural_baseline); /* Mnemonics */ gboolean (* mnemonic_activate) (GtkWidget *widget, gboolean group_cycling); /* explicit focus */ void (* grab_focus) (GtkWidget *widget); gboolean (* focus) (GtkWidget *widget, GtkDirectionType direction); /* keyboard navigation */ void (* move_focus) (GtkWidget *widget, GtkDirectionType direction); gboolean (* keynav_failed) (GtkWidget *widget, GtkDirectionType direction); /* events */ gboolean (* event) (GtkWidget *widget, GdkEvent *event); gboolean (* button_press_event) (GtkWidget *widget, GdkEventButton *event); gboolean (* button_release_event) (GtkWidget *widget, GdkEventButton *event); gboolean (* scroll_event) (GtkWidget *widget, GdkEventScroll *event); gboolean (* motion_notify_event) (GtkWidget *widget, GdkEventMotion *event); gboolean (* delete_event) (GtkWidget *widget, GdkEventAny *event); gboolean (* destroy_event) (GtkWidget *widget, GdkEventAny *event); gboolean (* key_press_event) (GtkWidget *widget, GdkEventKey *event); gboolean (* key_release_event) (GtkWidget *widget, GdkEventKey *event); gboolean (* enter_notify_event) (GtkWidget *widget, GdkEventCrossing *event); gboolean (* leave_notify_event) (GtkWidget *widget, GdkEventCrossing *event); gboolean (* configure_event) (GtkWidget *widget, GdkEventConfigure *event); gboolean (* focus_in_event) (GtkWidget *widget, GdkEventFocus *event); gboolean (* focus_out_event) (GtkWidget *widget, GdkEventFocus *event); gboolean (* map_event) (GtkWidget *widget, GdkEventAny *event); gboolean (* unmap_event) (GtkWidget *widget, GdkEventAny *event); gboolean (* property_notify_event) (GtkWidget *widget, GdkEventProperty *event); gboolean (* selection_clear_event) (GtkWidget *widget, GdkEventSelection *event); gboolean (* selection_request_event) (GtkWidget *widget, GdkEventSelection *event); gboolean (* selection_notify_event) (GtkWidget *widget, GdkEventSelection *event); gboolean (* proximity_in_event) (GtkWidget *widget, GdkEventProximity *event); gboolean (* proximity_out_event) (GtkWidget *widget, GdkEventProximity *event); gboolean (* window_state_event) (GtkWidget *widget, GdkEventWindowState *event); gboolean (* grab_broken_event) (GtkWidget *widget, GdkEventGrabBroken *event); /* selection */ void (* selection_get) (GtkWidget *widget, GtkSelectionData *selection_data, guint info, guint time_); void (* selection_received) (GtkWidget *widget, GtkSelectionData *selection_data, guint time_); /* Source side drag signals */ void (* drag_begin) (GtkWidget *widget, GdkDragContext *context); void (* drag_end) (GtkWidget *widget, GdkDragContext *context); void (* drag_data_get) (GtkWidget *widget, GdkDragContext *context, GtkSelectionData *selection_data, guint info, guint time_); void (* drag_data_delete) (GtkWidget *widget, GdkDragContext *context); /* Target side drag signals */ void (* drag_leave) (GtkWidget *widget, GdkDragContext *context, guint time_); gboolean (* drag_motion) (GtkWidget *widget, GdkDragContext *context, gint x, gint y, guint time_); gboolean (* drag_drop) (GtkWidget *widget, GdkDragContext *context, gint x, gint y, guint time_); void (* drag_data_received) (GtkWidget *widget, GdkDragContext *context, gint x, gint y, GtkSelectionData *selection_data, guint info, guint time_); gboolean (* drag_failed) (GtkWidget *widget, GdkDragContext *context, GtkDragResult result); /* Signals used only for keybindings */ gboolean (* popup_menu) (GtkWidget *widget); /* accessibility support */ AtkObject * (* get_accessible) (GtkWidget *widget); void (* screen_changed) (GtkWidget *widget, GdkScreen *previous_screen); gboolean (* can_activate_accel) (GtkWidget *widget, guint signal_id); gboolean (* query_tooltip) (GtkWidget *widget, gint x, gint y, gboolean keyboard_tooltip, GtkTooltip *tooltip); void (* compute_expand) (GtkWidget *widget, gboolean *hexpand_p, gboolean *vexpand_p); void (* style_updated) (GtkWidget *widget); gboolean (* touch_event) (GtkWidget *widget, GdkEventTouch *event); void (* snapshot) (GtkWidget *widget, GtkSnapshot *snapshot); GtkWidget * (* pick) (GtkWidget *widget, gdouble x, gdouble y, gdouble *x_out, gdouble *y_out); };
guint |
The signal to emit when a widget of this class is
activated, |
|
Seldomly overidden. |
||
Signals that all holders of a reference to the widget should release the reference that they hold. |
||
Signal emitted when widget is shown |
||
Signal emitted when widget is hidden. |
||
Signal emitted when widget is going to be mapped, that is
when the widget is visible (which is controlled with
|
||
Signal emitted when widget is going to be unmapped, which means that either it or any of its parents up to the toplevel widget have been set as hidden. |
||
Signal emitted when widget is associated with a
GdkWindow, which means that |
||
Signal emitted when the GdkWindow associated with
widget is destroyed, which means that |
||
Signal emitted to get the widget allocation. |
||
Signal emitted when the widget state changes,
see |
||
Signal emitted when a new parent has been set on a widget. |
||
Signal emitted when the anchored state of a widget changes. |
||
Signal emitted when the text direction of a widget changes. |
||
Signal emitted when a widget becomes shadowed by a GTK+ grab (not a pointer or keyboard grab) on another widget, or when it becomes unshadowed due to a grab being removed. |
||
Signal emitted for each child property that has changed on an object. |
||
Signal emitted when a widget is supposed to render itself. |
||
This allows a widget to tell its parent container whether
it prefers to be allocated in |
||
This is called by containers to obtain the minimum and natural size of the widget. Depending on the orientation parameter, the passed for_size can be interpreted as width or height. A widget will never be allocated less than its minimum size. |
||
Activates the |
||
Causes |
||
Signal emitted when a change of focus is requested |
||
Signal emitted if keyboard navigation fails. |
||
The GTK+ main loop will emit three signals for each GDK event delivered to a widget: one generic ::event signal, another, more specific, signal that matches the type of event delivered (e.g. "key-press-event") and finally a generic "event-after" signal. |
||
Signal will be emitted when a button (typically from a mouse) is pressed. |
||
Signal will be emitted when a button (typically from a mouse) is released. |
||
Signal emitted when a button in the 4 to 7 range is pressed. |
||
Signal emitted when the pointer moves over the widget’s GdkWindow. |
||
Signal emitted if a user requests that a toplevel window is closed. |
||
Signal is emitted when a GdkWindow is destroyed. |
||
Signal emitted when a key is pressed. |
||
Signal is emitted when a key is released. |
||
Signal event will be emitted when the pointer enters the widget’s window. |
||
Will be emitted when the pointer leaves the widget’s window. |
||
Signal will be emitted when the size, position or stacking of the widget’s window has changed. |
||
Signal emitted when the keyboard focus enters the widget’s window. |
||
Signal emitted when the keyboard focus leaves the widget’s window. |
||
Signal emitted when the widget’s window is mapped. |
||
Signal will be emitted when the widget’s window is unmapped. |
||
Signal will be emitted when a property on the widget’s window has been changed or deleted. |
||
Signal will be emitted when the the widget’s window has lost ownership of a selection. |
||
Signal will be emitted when another client requests ownership of the selection owned by the widget's window. |
||
Signal emitted when the state of the toplevel window associated to the widget changes. |
||
Signal emitted when a pointer or keyboard grab on a window belonging to widget gets broken. |
||
Signal emitted on the drag source when a drag is started. |
||
Signal emitted on the drag source when a drag is finished. |
||
Signal emitted on the drag source when the drop site requests the data which is dragged. |
||
Signal emitted on the drag source when a drag
with the action |
||
Signal emitted on the drop site when the cursor leaves the widget. |
||
signal emitted on the drop site when the user moves the cursor over the widget during a drag. |
||
Signal emitted on the drop site when the user drops the data onto the widget. |
||
Signal emitted on the drop site when the dragged data has been received. |
||
Signal emitted on the drag source when a drag has failed. |
||
Signal emitted whenever a widget should pop up a context menu. |
||
Returns the accessible object that describes the widget to an assistive technology. |
||
Signal emitted when the screen of a widget has changed. |
||
Signal allows applications and derived widgets to override the default GtkWidget handling for determining whether an accelerator can be activated. |
||
Signal emitted when “has-tooltip” is |
||
Computes whether a container should give this widget extra space when possible. |
||
Signal emitted when the GtkStyleContext of a widget is changed. |
||
Signal emitted when a widget is supposed to create a snapshot of itself. |
||
typedef struct { gint width; gint height; } GtkRequisition;
A GtkRequisition represents the desired size of a widget. See GtkWidget’s geometry management section for more information.
typedef GdkRectangle GtkAllocation;
A GtkAllocation of a widget represents region which has been allocated to the widget by its parent. It is a subregion of its parents allocation. See GtkWidget’s geometry management section for more information.
Specifies a preference for height-for-width or width-for-height geometry management.
struct GtkRequestedSize { gpointer data; gint minimum_size; gint natural_size; };
Represents a request of a screen object in a given orientation. These
are primarily used in container implementations when allocating a natural
size for children calling. See gtk_distribute_natural_allocation()
.
Controls how a widget deals with extra space in a single (x or y) dimension.
Alignment only matters if the widget receives a “too large” allocation, for example if you packed the widget with the “expand” flag inside a GtkBox, then the widget might get extra space. If you have for example a 16x16 icon inside a 32x32 space, the icon could be scaled and stretched, it could be centered, or it could be positioned to one side of the space.
Note that in horizontal context GTK_ALIGN_START
and GTK_ALIGN_END
are interpreted relative to text direction.
GTK_ALIGN_BASELINE support for it is optional for containers and widgets, and
it is only supported for vertical alignment. When its not supported by
a child or a container it is treated as GTK_ALIGN_FILL
.
stretch to fill all space if possible, center if no meaningful way to stretch |
||
snap to left or top side, leaving space on right or bottom |
||
snap to right or bottom side, leaving space on left or top |
||
center natural width of widget inside the allocation |
||
align the widget according to the baseline. Since 3.10. |