The base class for all widgets.
Gtk::Widget is the base class all widgets in GTK derive from. It manages the
widget lifecycle, layout, 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 widget implementations.
If you implement a direct Gtk::Widget subclass that supports
height-for-width or width-for-height geometry management for itself
or its child widgets, the Gtk::Widget#request_mode virtual
function must be implemented as well and return the widget's preferred
request mode. The default implementation of this virtual function
returns %GTK_SIZE_REQUEST_CONSTANT_SIZE, which means that the widget will
only ever get -1 passed as the for_size value to its
Gtk::Widget#measure implementation.
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 Gtk::SizeRequestMode 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 of %GTK_ORIENTATION_HORIZONTAL and a for_size of -1.
Because the preferred widths for each widget 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.
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#default_size=). During the
recursive allocation process it’s important to note that request cycles
will be recursively executed while widgets allocate their children.
Each 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 Gtk::Widget 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, Gtk::Widget caches a small number of results
to avoid re-querying for the same sizes in one allocation cycle.
If a widget does move content around to intelligently use up the
allocated size then it must support the request in both
Gtk::SizeRequestModes even if the widget in question only
trades sizes in a single orientation.
For instance, a Gtk::Label that does height-for-width word wrapping
will not expect to have Gtk::Widget#measure with an orientation of
%GTK_ORIENTATION_VERTICAL 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:
WARNING ⚠️ The following code is in c ⚠️
static void
foo_widget_measure (Gtk::Widget *widget,
Gtk::Orientation orientation,
int for_size,
int *minimum_size,
int *natural_size,
int *minimum_baseline,
int *natural_baseline)
{
if (orientation == GTK_ORIENTATION_HORIZONTAL)
{
// Calculate minimum and natural width
}
else // VERTICAL
{
if (i_am_in_height_for_width_mode)
{
int min_width, dummy;
// First, get the minimum width of our widget
GTK_WIDGET_GET_CLASS (widget)->measure (widget, GTK_ORIENTATION_HORIZONTAL, -1,
&min_width, &dummy, &dummy, &dummy);
// Now use the minimum width to retrieve the minimum and natural height to display
// that width.
GTK_WIDGET_GET_CLASS (widget)->measure (widget, GTK_ORIENTATION_VERTICAL, min_width,
minimum_size, natural_size, &dummy, &dummy);
}
else
{
// ... some widgets do both.
}
}
}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 in the code example above.
It will not work to use the wrapper function Gtk::Widget#measure
inside your own Gtk::Widget#size_allocate implementation.
These return a request adjusted by Gtk::SizeGroup, the widget's
align and expand flags, as well as its CSS style.
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 widget, you must use #gtk_widget_measure; otherwise, you
would not properly consider widget margins, Gtk::SizeGroup, and
so forth.
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 widget 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 also done by the
Gtk::Widget#measure virtual function. It allows you to report
both a minimum and natural size.
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 the baseline has a
value other than -1 you need to align the widget such that the baseline
appears at the position.
The Gtk::Widget implementation of the Gtk::Buildable interface
supports various custom elements to specify additional aspects of widgets
that are not directly expressed as properties.
If the widget uses a Gtk::LayoutManager, Gtk::Widget supports
a custom <layout> element, used to define layout properties:
WARNING ⚠️ The following code is in xml ⚠️
<object class="Gtk::Grid" id="my_grid">
<child>
<object class="Gtk::Label" id="label1">
<property name="label">Description</property>
<layout>
<property name="column">0</property>
<property name="row">0</property>
<property name="row-span">1</property>
<property name="column-span">1</property>
</layout>
</object>
</child>
<child>
<object class="Gtk::Entry" id="description_entry">
<layout>
<property name="column">1</property>
<property name="row">0</property>
<property name="row-span">1</property>
<property name="column-span">1</property>
</layout>
</object>
</child>
</object>Gtk::Widget allows style information such as style classes to
be associated with widgets, using the custom <style> element:
WARNING ⚠️ The following code is in xml ⚠️
<object class="Gtk::Button" id="button1">
<style>
<class name="my-special-button-class"/>
<class name="dark-button"/>
</style>
</object>Gtk::Widget allows defining accessibility information, such as properties,
relations, and states, using the custom <accessibility> element:
WARNING ⚠️ The following code is in xml ⚠️
<object class="Gtk::Button" id="button1">
<accessibility>
<property name="label">Download</property>
<relation name="labelled-by">label1</relation>
</accessibility>
</object>Gtk::Widget exposes some facilities to automate the procedure
of creating composite widgets using "templates".
To create composite widgets with Gtk::Builder XML, one must associate
the interface description with the widget class at class initialization
time using Gtk::WidgetClass#template=.
The interface description semantics expected in composite template descriptions
is slightly different from regular Gtk::Builder XML.
Unlike regular interface descriptions, Gtk::WidgetClass#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 Gtk::Builder but required for UI design tools like
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 the widget itself. You may set properties
on a widget by inserting <property> tags into the <template> tag, and also
add <child> tags to add children and extend a 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 template definition:
WARNING ⚠️ The following code is in xml ⚠️
<interface>
<template class="FooWidget" parent="Gtk::Box">
<property name="orientation">horizontal</property>
<property name="spacing">4</property>
<child>
<object class="Gtk::Button" 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="Gtk::Button" 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::WidgetClass#template_from_resource=
from the class initialization of your Gtk::Widget type:
WARNING ⚠️ The following code is in c ⚠️
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:
WARNING ⚠️ The following code is in c ⚠️
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::WidgetClass#bind_template_child_full (or one of its wrapper macros
Gtk::widget_class_bind_template_child and Gtk::widget_class_bind_template_child_private)
with that name, e.g.
WARNING ⚠️ The following code is in c ⚠️
typedef struct {
Gtk::Widget *hello_button;
Gtk::Widget *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);
}
static void
foo_widget_init (FooWidget *widget)
{
}You can also use Gtk::WidgetClass#bind_template_callback_full (or
is wrapper macro 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.
WARNING ⚠️ The following code is in c ⚠️
// 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,
Gtk::Button *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);
}Initialize a new Widget.
Obtains the current default reading direction.
Sets the default reading direction for widgets.
Returns the type id (GType) registered in GLib type system.
Returns true if this reference is the same as other.
Enable or disable an action installed with gtk_widget_class_install_action().
For widgets that can be “activated” (buttons, menu items, etc.), this function activates them.
Looks up the action in the action groups associated with widget and its ancestors, and activates it.
Activates the default.activate action from widget.
Adds controller to widget so that it will receive events.
Adds a style class to widget.
Adds a widget to the list of mnemonic labels for this widget.
Queues an animation frame update and adds a callback to be called before each frame.
This function is only used by Gtk::Widget subclasses, to assign a size, position and (optionally) baseline to their child widgets.
Returns the baseline that has currently been allocated to widget.
Returns the height that has currently been allocated to widget.
Returns the width that has currently been allocated to widget.
Retrieves the widget’s allocation.
Gets the first ancestor of widget with type widget_type.
Determines whether the input focus can enter widget or any of its children.
Specifies whether the input focus can enter the widget or any of its children.
Queries whether widget can be the target of pointer events.
Sets whether widget can be the target of pointer events.
Called by widgets as the user moves around the window using keyboard shortcuts.
Gets the value set with gtk_widget_set_child_visible().
Sets whether widget should be mapped along with its parent.
Returns an Iterator over widget children.
Gets the clipboard object for widget.
Computes the bounds for widget in the coordinate space of target.
Computes whether a container should give this widget extra space when possible.
Translates the given point in widget's coordinates to coordinates relative to target’s coordinate system.
Computes a matrix suitable to describe a transformation from widget's coordinate system into target's coordinate system.
Tests if the point at (@x, y) is contained in widget.
Creates a new Pango::Context with the appropriate font map, font options, font description, and base direction for drawing text for this widget.
Creates a new Pango::Layout with the appropriate font map, font description, and base direction for drawing text for this widget.
Returns the list of style classes applied to widget.
Clear all style classes applied to widget and replace them with classes.
Returns the CSS name that is used for self.
Set #css_name property to nil.
Same as #css_name, but can return nil.
Queries the cursor set on widget.
Sets the cursor to be shown when pointer devices point towards widget.
Sets a named cursor to be shown when pointer devices point towards widget.
Gets the reading direction for a particular widget.
Sets the reading direction on a particular widget.
Get the Gdk::Display for the toplevel window associated with this widget.
Checks to see if a drag movement has passed the GTK drag threshold.
Notifies the user about an input-related error on this widget.
Returns the widgets first child.
Returns the current focus child of widget.
Set child as the current focus child of widget.
Returns whether the widget should grab focus when it is clicked with the mouse.
Sets whether the widget should grab focus when it is clicked with the mouse.
Determines whether widget can own the input focus.
Specifies whether widget can own the input focus.
Gets the font map of widget.
Sets the font map to use for Pango rendering.
Returns the cairo_::font_options_t of widget.
Sets the cairo_::font_options_t used for Pango rendering in this widget.
Obtains the frame clock for a widget.
Causes widget to have the keyboard focus for the Gtk::Window it's inside.
Gets the horizontal alignment of widget.
Sets the horizontal alignment of widget.
Returns whether css_class is currently applied to widget.
Determines whether widget is the current default widget within its toplevel.
Determines if the widget has the global input focus.
Returns the current value of the has-tooltip property.
Sets the has-tooltip property on widget to has_tooltip.
Determines if the widget should show a visible indication that it has the global input focus.
See Object#hash(hasher)
Returns the content height of the widget.
Gets whether the widget would like any available extra horizontal space.
Sets whether the widget would like any available extra horizontal space.
Gets whether gtk_widget_set_hexpand() has been used to explicitly set the expand flag on this widget.
Sets whether the hexpand flag will be used.
Reverses the effects of gtk_widget_show().
Returns whether the widget is currently being destroyed.
Creates and initializes child widgets defined in templates.
Inserts group into widget.
Inserts widget into the child widget list of parent.
Inserts widget into the child widget list of parent.
Determines whether widget is somewhere inside ancestor, possibly with intermediate containers.
Determines whether widget can be drawn to.
Determines if the widget is the focus widget within its toplevel.
Returns the widget’s effective sensitivity.
Determines whether the widget and all its parents are marked as visible.
Emits the ::keynav-failed signal on the widget.
Returns the widgets last child.
Retrieves the layout manager used by widget.
Sets the layout manager delegate instance that provides an implementation for measuring and allocating the children of widget.
Returns the widgets for which this widget is the target of a mnemonic.
Causes a widget to be mapped if it isn’t already.
Whether the widget is mapped.
Gets the bottom margin of widget.
Sets the bottom margin of widget.
Gets the end margin of widget.
Sets the end margin of widget.
Gets the start margin of widget.
Sets the start margin of widget.
Gets the top margin of widget.
Sets the top margin of widget.
Measures widget in the orientation orientation and for the given for_size.
Emits the ::mnemonic-activate signal.
Retrieves the name of a widget.
Sets a widgets name.
Set #name property to nil.
Same as #name, but can return nil.
Returns the nearest Gtk::Native ancestor of widget.
Returns the widgets next sibling.
Returns a GListModel to track the children of widget.
Returns a GListModel to track the Gtk::EventControllers of widget.
#Fetches the requested opacity for this widget.
Request the widget to be rendered partially transparent.
Returns the widgets overflow value.
Sets how widget treats content that is drawn outside the widget's content area.
Gets a Pango::Context with the appropriate font map, font description, and base direction for this widget.
Returns the parent widget of widget.
Sets parent as the parent widget of widget.
Finds the descendant of widget closest to the point (@x, y).
Retrieves the minimum and natural size of a widget, taking into account the widget’s preference for height-for-width management.
Returns the widgets previous sibling.
Gets the primary clipboard of widget.
Flags the widget for a rerun of the Gtk::Widget#size_allocate function.
Schedules this widget to be redrawn in the paint phase of the current or the next frame.
Flags a widget to have its size renegotiated.
Creates the GDK resources associated with a widget.
Determines whether widget is realized.
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.
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.
Removes controller from widget, so that it doesn't process events anymore.
Removes a style from widget.
Removes a widget from the list of mnemonic labels for this widget.
Removes a tick callback previously registered with gtk_widget_add_tick_callback().
Gets whether the widget prefers a height-for-width layout or a width-for-height layout.
Returns the Gtk::Root widget of widget.
Retrieves the internal scale factor that maps from window coordinates to the actual device pixels.
Returns the widget’s sensitivity.
Sets the sensitivity of a widget.
Sets the minimum size of a widget.
Turns on flag values in the current widget state.
Gets the settings object holding the settings used for this widget.
Returns whether widget should contribute to the measuring and allocation of its parent.
Flags a widget to be displayed.
Returns the content width or height of the widget.
Allocates widget with a transformation that translates the origin to the position in allocation.
Gets the size request that was explicitly set for the widget using gtk_widget_set_size_request().
Snapshot the a child of widget.
Returns the widget state as a flag set.
Returns the style context associated to widget.
Fetch an object build from the template XML for widget_type in this widget instance.
Convenient function, same as #template_child(self.class.g_type, name).
Gets the contents of the tooltip for widget.
Set #tooltip_markup property to nil.
Sets markup as the contents of the tooltip, which is marked up with Pango markup.
Same as #tooltip_markup, but can return nil.
Gets the contents of the tooltip for widget.
Set #tooltip_text property to nil.
Sets text as the contents of the tooltip.
Same as #tooltip_text, but can return nil.
Translate coordinates relative to src_widget’s allocation to coordinates relative to dest_widget’s allocations.
Triggers a tooltip query on the display where the toplevel of widget is located.
Causes a widget to be unmapped if it’s currently mapped.
Dissociate widget from its parent.
Causes a widget to be unrealized (frees all GDK resources associated with the widget).
Turns off flag values for the current widget state.
Gets the vertical alignment of widget.
Sets the vertical alignment of widget.
Gets whether the widget would like any available extra vertical space.
Sets whether the widget would like any available extra vertical space.
Gets whether gtk_widget_set_vexpand() has been used to explicitly set the expand flag on this widget.
Sets whether the vexpand flag will be used.
Determines whether the widget is visible.
Sets the visibility state of widget.
Returns the content width of the widget.
Gtk::ConstraintTargetGtk::ConstraintTargetGtk::ConstraintTargetGtk::BuildableGtk::BuildableGtk::BuildableGtk::AccessibleGtk::AccessibleGtk::AccessibleGObject::InitiallyUnownedGObject::InitiallyUnownedGObject::InitiallyUnownedGObject::ObjectGObject::ObjectGObject::ObjectGObject::ObjectSets the default reading direction for widgets.
Returns the type id (GType) registered in GLib type system.
Returns true if this reference is the same as other. Invokes same?.
Enable or disable an action installed with gtk_widget_class_install_action().
For widgets that can be “activated” (buttons, menu items, etc.), this function activates them.
The activation will emit the signal set using
Gtk::WidgetClass#activate_signal= during class initialization.
Activation is what happens when you press Enter on a widget during key navigation.
If you wish to handle the activation keybinding yourself, it is
recommended to use Gtk::WidgetClass#add_shortcut with an action
created with Gtk::SignalAction.new.
If widget isn't activatable, the function returns false.
Looks up the action in the action groups associated with widget and its ancestors, and activates it.
This is a wrapper around Gtk::Widget#activate_action_variant
that constructs the args variant according to format_string.
Adds controller to widget so that it will receive events.
You will usually want to call this function right after
creating any kind of Gtk::EventController.
Adds a style class to widget.
After calling this function, the widgets style will match for css_class, according to CSS matching rules.
Use Gtk::Widget#remove_css_class to remove the
style again.
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.
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 Gtk::Label), then you will have to call
Gtk::Widget#queue_resize or Gtk::Widget#queue_draw
yourself.
Gdk::FrameClock#frame_time should generally be used
for timing continuous animations and
Gdk::FrameTimings#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
Gdk::FrameClock::#update signal of Gdk::FrameClock, since you
don't have to worry about when a Gdk::FrameClock is assigned to a widget.
This function is only used by Gtk::Widget 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 0×0 in size.
For a version that does not take a transform, see
Gtk::Widget#size_allocate.
Returns the baseline that has currently been allocated to widget.
This function is intended to be used when implementing handlers
for the Gtk::WidgetClass.snapshot() function, and when allocating
child widgets in Gtk::WidgetClass.size_allocate().
Returns the height that has currently been allocated to widget.
Returns the width that has currently been allocated to widget.
Retrieves the widget’s allocation.
Note, when implementing a layout container: a widget’s allocation
will be its “adjusted” allocation, that is, the widget’s parent
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#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 layout container is guaranteed that its children stay inside the assigned bounds, but not that they have exactly the bounds the container assigned.
Gets the first ancestor of widget with type widget_type.
For example, gtk_widget_get_ancestor (widget, GTK_TYPE_BOX)
gets the first Gtk::Box that’s an ancestor of widget. No
reference will be added to the returned widget; it should
not be unreferenced.
Note that unlike Gtk::Widget#is_ancestor?, this function
considers widget to be an ancestor of itself.
Determines whether the input focus can enter widget or any of its children.
Specifies whether the input focus can enter the widget or any of its children.
Applications should set can_focus to false to mark a
widget as for pointer/touch use only.
Note that having can_focus be true is only one of the
necessary conditions for being focusable. A widget must
also be sensitive and focusable and not have an ancestor
that is marked as not can-focus in order to receive input
focus.
See Gtk::Widget#grab_focus for actually setting
the input focus on a widget.
Sets whether widget can be the target of pointer events.
Called by widgets as the user moves around the window using keyboard shortcuts.
The direction argument indicates what kind of motion is taking place (up, down, left, right, tab forward, tab backward).
This function calls the Gtk::Widget#focus virtual function; widgets
can override the virtual function in order to implement appropriate focus
behavior.
The default focus() virtual function 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. When returning TRUE, widgets normallycall Gtk::Widget#grab_focus
to place the focus accordingly; when returning FALSE, they don’t modify
the current focus location.
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.
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 should never be called by an application.
Sets whether widget should be mapped along with its parent.
The child visibility can be set for widget before it is added
to a container with Gtk::Widget#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 should never be called by an application.
Returns an Iterator over widget children. Call .to_a on it if you need to allocate an
array with all children.
widget.children.with_index do |child, i|
puts "Hi, I'm child #{i}, #{child}"
endGets the clipboard object for widget.
This is a utility function to get the clipboard object for the
Gdk::Display that widget is using.
Note that this function always works, even when widget is not realized yet.
Computes the bounds for widget in the coordinate space of target.
FIXME Explain what "bounds" are.
If the operation is successful, true is returned. If widget has no
bounds or the bounds cannot be expressed in target's coordinate space
(for example if both widgets are in different windows), false is
returned and bounds is set to the zero rectangle.
It is valid for widget and target to be the same widget.
Computes whether a container should give this widget extra space when possible.
Containers should check this, rather than looking at
Gtk::Widget#hexpand or Gtk::Widget#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.
Translates the given point in widget's coordinates to coordinates relative to target’s coordinate system.
In order to perform this operation, both widgets must share a common ancestor.
Computes a matrix suitable to describe a transformation from widget's coordinate system into target's coordinate system.
The transform can not be computed in certain cases, for example when widget and target do not share a common ancestor. In that case out_transform gets set to the identity matrix.
Tests if the point at (@x, y) is contained in widget.
The coordinates for (@x, y) must be in widget coordinates, so (0, 0) is assumed to be the top left of widget's content area.
Creates a new Pango::Context with the appropriate font map,
font options, font description, and base direction for drawing
text for this widget.
See also Gtk::Widget#pango_context.
Creates a new Pango::Layout with the appropriate font map,
font description, and base direction for drawing text for
this widget.
If you keep a Pango::Layout created in this way around,
you need to re-create it when the widget Pango::Context
is replaced. This can be tracked by listening to changes
of the Gtk::Widget#root property on the widget.
Returns the list of style classes applied to widget.
Clear all style classes applied to widget and replace them with classes.
Queries the cursor set on widget.
See Gtk::Widget#cursor= for details.
Sets the cursor to be shown when pointer devices point towards widget.
If the cursor is NULL, widget will use the cursor inherited from the parent widget.
Sets a named cursor to be shown when pointer devices point towards widget.
This is a utility function that creates a cursor via
Gdk::Cursor#new_from_name and then sets it on widget
with Gtk::Widget#cursor=. See those functions for
details.
On top of that, this function allows name to be nil, which
will do the same as calling Gtk::Widget#cursor=
with a nil cursor.
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#default_direction= will be used.
Get the Gdk::Display 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 Gtk::Window 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.
Checks to see if a drag movement has passed the GTK drag threshold.
Notifies the user about an input-related error on this widget.
If the [property@Gtk.Settings:gtk-error-bell] setting is true,
it calls Gdk::Surface#beep, otherwise it does nothing.
Note that the effect of Gdk::Surface#beep can be configured
in many ways, depending on the windowing backend and the desktop
environment or window manager that is used.
Returns the widgets first child.
This API is primarily meant for widget implementations.
Set child as the current focus child of widget.
This function is only suitable for widget implementations.
If you want a certain widget to get the input focus, call
Gtk::Widget#grab_focus on it.
Returns whether the widget should grab focus when it is clicked with the mouse.
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.
Determines whether widget can own the input focus.
Specifies whether widget can own the input focus.
Widget implementations should set focusable to true in
their init() function if they want to receive keyboard input.
Note that having focusable be true is only one of the
necessary conditions for being focusable. A widget must
also be sensitive and can-focus and not have an ancestor
that is marked as not can-focus in order to receive input
focus.
See Gtk::Widget#grab_focus for actually setting
the input focus on a widget.
Sets the font map to use for Pango rendering.
The font map is the object that is used to look up fonts. Setting a custom font map can be useful in special situations, e.g. when you need to add application-specific fonts to the set of available fonts.
When not set, the widget will inherit the font map from its parent.
Sets the cairo_::font_options_t used for Pango rendering
in this widget.
When not set, the default font options for the Gdk::Display
will be used.
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::FrameClock#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::FrameClock#frame_time, and then update the animation
by calling Gdk::FrameClock#frame_time again during each repaint.
Gdk::FrameClock#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.
Causes widget to have the keyboard focus for the Gtk::Window it's inside.
If widget is not focusable, or its Gtk::Widget#grab_focus
implementation cannot transfer the focus to a descendant of widget
that is focusable, it will not take focus and false will be returned.
Calling Gtk::Widget#grab_focus on an already focused widget
is allowed, should not have an effect, and return true.
Gets the horizontal alignment of widget.
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.
Returns whether css_class is currently applied to widget.
Determines whether widget is the current default widget within its toplevel.
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.
Sets the has-tooltip property on widget to has_tooltip.
Determines if the widget should show a visible indication that it has the global input focus.
This is a convenience function that takes into account whether
focus indication should currently be shown in the toplevel window
of widget. See Gtk::Window#focus_visible for more
information about focus indication.
To find out if the widget has the global input focus, use
Gtk::Widget#has_focus.
Returns the content height of the widget.
This function returns the height passed to its
size-allocate implementation, which is the height you
should be using in Gtk::Widget#snapshot.
For pointer events, see Gtk::Widget#contains.
Gets whether the widget would like any available extra horizontal space.
When a user resizes a Gtk::Window, 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.
Sets whether the widget would like any available extra horizontal space.
When a user resizes a Gtk::Window, 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 Gtk::Widget.).
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#hexpand= sets the hexpand-set property (see
Gtk::Widget#hexpand_set=) which causes the widget’s hexpand
value to be used, rather than looking at children and widget state.
Gets whether gtk_widget_set_hexpand() has been used to explicitly set the expand flag on this widget.
If Gtk::Widget#hexpand property 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.
Sets whether the hexpand flag will be used.
The [property@Gtk.Widget:hexpand-set] property will be set
automatically when you call Gtk::Widget#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.
Reverses the effects of gtk_widget_show().
This is causing the widget to be hidden (invisible to the user).
Returns whether the widget is currently being destroyed.
This information can sometimes be used to avoid doing unnecessary work.
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::WidgetClass#template=.
It is important to call this function in the instance initializer
of a Gtk::Widget subclass and not in GObject.constructed() or
GObject.constructor() for two reasons:
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 XMLA good rule of thumb is to call this function as the first thing in an instance initialization function.
Inserts group into widget.
Children of widget that implement Gtk::Actionable can
then be associated with actions in group by setting their
“action-name” to prefix.action-name.
Note that inheritance is defined for individual actions. I.e. even if you insert a group with prefix prefix, actions with the same prefix will still be inherited from the parent, unless the group contains an action with the same name.
If group is nil, a previously inserted group for name is
removed from widget.
Inserts widget into the child widget list of parent.
It will be placed after previous_sibling, or at the beginning if previous_sibling is nil.
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.
This API is primarily meant for widget implementations; if you are just using a widget, you must use its own API for adding children.
Inserts widget into the child widget list of parent.
It will be placed before next_sibling, or at the end if next_sibling is nil.
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.
This API is primarily meant for widget implementations; if you are just using a widget, you must use its own API for adding children.
Determines whether widget is somewhere inside ancestor, possibly with intermediate containers.
Determines whether widget can be drawn to.
A widget can be drawn if it is mapped and visible.
Determines if the widget is the focus widget within its toplevel.
This does not mean that the [property@Gtk.Widget:has-focus] property is necessarily set; [property@Gtk.Widget:has-focus] will only be set if the toplevel widget additionally has the global input focus.
Returns the widget’s effective sensitivity.
This means it is sensitive itself and also its parent widget is sensitive.
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#visible and
Gtk::Widget#visible=.
Returns the widgets last child.
This API is primarily meant for widget implementations.
Sets the layout manager delegate instance that provides an implementation for measuring and allocating the children of widget.
Returns the widgets for which this widget is the target of a mnemonic.
Typically, these widgets will be labels. See, for example,
Gtk::Label#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.
Causes a widget to be mapped if it isn’t already.
This function is only for use in widget implementations.
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.
See Gtk::Widget’s geometry management section for
a more details on implementing Gtk::WidgetClass.measure().
Emits the ::mnemonic-activate signal.
See [signal@Gtk.Widget::mnemonic-activate].
Retrieves the name of a widget.
See Gtk::Widget#name= for the significance of widget names.
Sets a widgets name.
Setting a name allows you to refer to the widget 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 Gtk::StyleContext.
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.
Returns the nearest Gtk::Native ancestor of widget.
This function will return nil if the widget is not
contained inside a widget tree with a native ancestor.
Gtk::Native widgets will return themselves here.
Returns the widgets next sibling.
This API is primarily meant for widget implementations.
Returns a GListModel to track the children of widget.
Calling this function will enable extra internal bookkeeping to track children and emit signals on the returned listmodel. It may slow down operations a lot.
Applications should try hard to avoid calling this function because of the slowdowns.
Returns a GListModel to track the Gtk::EventControllers
of widget.
Calling this function will enable extra internal bookkeeping to track controllers and emit signals on the returned listmodel. It may slow down operations a lot.
Applications should try hard to avoid calling this function because of the slowdowns.
#Fetches the requested opacity for this widget.
See Gtk::Widget#opacity=.
Request the widget to be rendered partially transparent.
An opacity of 0 is fully transparent and an opacity of 1 is fully opaque.
Opacity works on both toplevel widgets and child widgets, although there are some limitations: For toplevel widgets, applying opacity depends on the capabilities of the windowing system. On X11, this has any effect only on X displays with a compositing manager, see gdk_display_is_composited(). On Windows and Wayland it should always work, although setting a window’s opacity after the window has been shown may cause some flicker.
Note that the opacity is inherited through inclusion — if you set
a toplevel to be partially translucent, all of its content will
appear translucent, since it is ultimatively rendered on that
toplevel. The opacity value itself is not inherited by child
widgets (since that would make widgets deeper in the hierarchy
progressively more translucent). As a consequence, Gtk::Popovers
and other Gtk::Native widgets with their own surface will use their
own opacity value, and thus by default appear non-translucent,
even if they are attached to a toplevel that is translucent.
Sets how widget treats content that is drawn outside the widget's content area.
See the definition of Gtk::Overflow for details.
This setting is provided for widget implementations and should not be used by application code.
The default value is %GTK_OVERFLOW_VISIBLE.
Gets a Pango::Context 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 listening to changes of the
Gtk::Widget#root property on the widget.
Sets parent as the parent widget of widget.
This takes care of 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.
This function is useful only when implementing subclasses of
Gtk::Widget.
Finds the descendant of widget closest to the point (@x, y).
The point must be given in widget coordinates, so (0, 0) is assumed to be the top left of widget's content area.
Usually widgets will return nil if the given coordinate is not
contained in widget checked via Gtk::Widget#contains.
Otherwise they will recursively try to find a child that does
not return nil. Widgets are however free to customize their
picking algorithm.
This function is used on the toplevel to determine the widget below the mouse cursor for purposes of hover highlighting and delivering events.
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 Gtk::Fixed.
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.
Returns the widgets previous sibling.
This API is primarily meant for widget implementations.
Gets the primary clipboard of widget.
This is a utility function to get the primary clipboard object
for the Gdk::Display that widget is using.
Note that this function always works, even when widget is not realized yet.
Flags the widget for a rerun of the Gtk::Widget#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#halign=.
This function is only for use in widget implementations.
Schedules this widget to be redrawn in the paint phase of the current or the next frame.
This means widget's Gtk::Widget#snapshot
implementation will be called.
Flags a widget to have its size renegotiated.
This should be called when a widget for some reason has a new
size request. For example, when you change the text in a
Gtk::Label, the label 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 Gtk::Widget#size_allocate
virtual method. Calls to gtk_widget_queue_resize() from inside
Gtk::Widget#size_allocate will be silently ignored.
This function is only for use in widget implementations.
Creates the GDK resources associated with a widget.
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 this function 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
Gtk::Widget::#realize.
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.
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.
Removes controller from widget, so that it doesn't process events anymore.
It should not be used again.
Widgets will remove all event controllers automatically when they are destroyed, there is normally no need to call this function.
Removes a style from widget.
After this, the style of widget will stop matching for css_class.
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.
Removes a tick callback previously registered with gtk_widget_add_tick_callback().
Gets whether the widget prefers a height-for-width layout or a width-for-height layout.
Single-child widgets generally propagate the preference of their child, more complex widgets need to request something either in context of their children or in context of their allocation capabilities.
Returns the Gtk::Root widget of widget.
This function will return nil if the widget is not contained
inside a widget tree with a root widget.
Gtk::Root widgets will return themselves here.
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).
Returns the widget’s sensitivity.
This function returns the value that has been set using
Gtk::Widget#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?.
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.
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#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.
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
properties
[property@Gtk.Widget:margin-start],
[property@Gtk.Widget:margin-end],
[property@Gtk.Widget:margin-top], and
[property@Gtk.Widget:margin-bottom], but it does include pretty
much all other padding or border properties set by any subclass
of Gtk::Widget.
Turns on flag values in the current widget state.
Typical widget states are 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#direction=.
This function is for use in widget implementations.
Gets the settings object holding the settings used for this widget.
Note that this function can only be called when the Gtk::Widget
is attached to a toplevel, since the settings object is specific
to a particular Gdk::Display. If you want to monitor the widget for
changes in its settings, connect to the notify::display signal.
Returns whether widget should contribute to the measuring and allocation of its parent.
This is false for invisible children, but also
for children that have their own surface.
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.
Returns the content width or height of the widget.
Which dimension is returned depends on orientation.
This is equivalent to calling Gtk::Widget#width
for %GTK_ORIENTATION_HORIZONTAL or Gtk::Widget#height
for %GTK_ORIENTATION_VERTICAL, but can be used when
writing orientation-independent code, such as when
implementing Gtk::Orientable widgets.
Allocates widget with a transformation that translates the origin to the position in allocation.
This is a simple form of Gtk::Widget#allocate.
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#size_request=. To get the size a widget will
actually request, call Gtk::Widget#measure instead of
this function.
Snapshot the a child of widget.
When a widget receives a call to the snapshot function,
it must send synthetic Gtk::Widget#snapshot calls
to all children. This function provides a convenient way
of doing this. A widget, when it receives a call to its
Gtk::Widget#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.
This function does nothing for children that implement Gtk::Native.
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
Gtk::StateFlags to pass to a Gtk::StyleContext
method, you should look at Gtk::StyleContext#state.
Returns the style context associated to widget.
The returned object is guaranteed to be the same for the lifetime of widget.
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::WidgetClass#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.
Convenient function, same as #template_child(self.class.g_type, name).
Gets the contents of the tooltip for widget.
If the tooltip has not been set using
Gtk::Widget#tooltip_markup=, this
function returns nil.
Sets markup as the contents of the tooltip, which is marked up with Pango markup.
This function will take care of setting the [property@Gtk.Widget:has-tooltip] as a side effect, and of the default handler for the [signal@Gtk.Widget::query-tooltip] signal.
See also Gtk::Tooltip#markup=.
Gets the contents of the tooltip for widget.
If the widget's tooltip was set using
Gtk::Widget#tooltip_markup=,
this function will return the escaped text.
Sets text as the contents of the tooltip.
If text contains any markup, it will be escaped.
This function will take care of setting [property@Gtk.Widget:has-tooltip] as a side effect, and of the default handler for the [signal@Gtk.Widget::query-tooltip] signal.
See also Gtk::Tooltip#text=.
Translate coordinates relative to src_widget’s allocation to coordinates relative to dest_widget’s allocations.
In order to perform this operation, both widget must share a common ancestor.
Triggers a tooltip query on the display where the toplevel of widget is located.
Causes a widget to be unmapped if it’s currently mapped.
This function is only for use in widget implementations.
Dissociate widget from its parent.
This function is only for use in widget implementations, typically in dispose.
Causes a widget to be unrealized (frees all GDK resources associated with the widget).
This function is only useful in widget implementations.
Turns off flag values for the current widget state.
See Gtk::Widget#state_flags=.
This function is for use in widget implementations.
Gets whether the widget would like any available extra vertical space.
See Gtk::Widget#hexpand for more detail.
Sets whether the widget would like any available extra vertical space.
See Gtk::Widget#hexpand= for more detail.
Gets whether gtk_widget_set_vexpand() has been used to explicitly set the expand flag on this widget.
See Gtk::Widget#hexpand_set for more detail.
Sets whether the vexpand flag will be used.
See Gtk::Widget#hexpand_set= for more detail.
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.
See Gtk::Widget#visible=.
Sets the visibility state of widget.
Note that setting this to true doesn’t mean the widget is
actually viewable, see Gtk::Widget#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.
Returns the content width of the widget.
This function returns the width passed to its
size-allocate implementation, which is the width you
should be using in Gtk::Widget#snapshot.
For pointer events, see Gtk::Widget#contains.