614 lines
17 KiB
C
614 lines
17 KiB
C
/*
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* gtkoverlay.c
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* This file is part of gtk
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*
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* Copyright (C) 2011 - Ignacio Casal Quinteiro, Mike Krüger
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "config.h"
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#include "gtkoverlay.h"
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#include "gtkoverlaylayout.h"
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#include "gtkbuildable.h"
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#include "gtkmarshalers.h"
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#include "gtkprivate.h"
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#include "gtkscrolledwindow.h"
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#include "gtksnapshot.h"
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#include "gtkwidgetprivate.h"
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/**
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* GtkOverlay
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*
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* `GtkOverlay` is a container which contains a single main child, on top
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* of which it can place “overlay” widgets.
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*
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* 
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*
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* The position of each overlay widget is determined by its
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* [property@Gtk.Widget:halign] and [property@Gtk.Widget:valign]
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* properties. E.g. a widget with both alignments set to %GTK_ALIGN_START
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* will be placed at the top left corner of the `GtkOverlay` container,
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* whereas an overlay with halign set to %GTK_ALIGN_CENTER and valign set
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* to %GTK_ALIGN_END will be placed a the bottom edge of the `GtkOverlay`,
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* horizontally centered. The position can be adjusted by setting the margin
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* properties of the child to non-zero values.
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*
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* More complicated placement of overlays is possible by connecting
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* to the [signal@Gtk.Overlay::get-child-position] signal.
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*
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* An overlay’s minimum and natural sizes are those of its main child.
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* The sizes of overlay children are not considered when measuring these
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* preferred sizes.
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*
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* # GtkOverlay as GtkBuildable
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*
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* The `GtkOverlay` implementation of the `GtkBuildable` interface
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* supports placing a child as an overlay by specifying “overlay” as
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* the “type” attribute of a `<child>` element.
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*
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* # CSS nodes
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*
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* `GtkOverlay` has a single CSS node with the name “overlay”. Overlay children
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* whose alignments cause them to be positioned at an edge get the style classes
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* “.left”, “.right”, “.top”, and/or “.bottom” according to their position.
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*/
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enum {
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GET_CHILD_POSITION,
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LAST_SIGNAL
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};
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static guint signals[LAST_SIGNAL] = { 0 };
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enum {
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PROP_CHILD = 1
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};
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static void gtk_overlay_buildable_init (GtkBuildableIface *iface);
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typedef struct _GtkOverlayClass GtkOverlayClass;
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struct _GtkOverlay
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{
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GtkWidget parent_instance;
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GtkWidget *child;
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};
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struct _GtkOverlayClass
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{
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GtkWidgetClass parent_class;
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gboolean (*get_child_position) (GtkOverlay *overlay,
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GtkWidget *widget,
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GtkAllocation *allocation);
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};
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G_DEFINE_TYPE_WITH_CODE (GtkOverlay, gtk_overlay, GTK_TYPE_WIDGET,
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G_IMPLEMENT_INTERFACE (GTK_TYPE_BUILDABLE,
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gtk_overlay_buildable_init))
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static GtkAlign
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effective_align (GtkAlign align,
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GtkTextDirection direction)
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{
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switch (align)
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{
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case GTK_ALIGN_START:
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return direction == GTK_TEXT_DIR_RTL ? GTK_ALIGN_END : GTK_ALIGN_START;
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case GTK_ALIGN_END:
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return direction == GTK_TEXT_DIR_RTL ? GTK_ALIGN_START : GTK_ALIGN_END;
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case GTK_ALIGN_FILL:
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case GTK_ALIGN_CENTER:
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case GTK_ALIGN_BASELINE_FILL:
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case GTK_ALIGN_BASELINE_CENTER:
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default:
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return align;
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}
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}
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static gboolean
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gtk_overlay_get_child_position (GtkOverlay *overlay,
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GtkWidget *widget,
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GtkAllocation *alloc)
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{
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GtkRequisition min, req;
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GtkAlign halign;
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GtkTextDirection direction;
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int width, height;
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gtk_widget_get_preferred_size (widget, &min, &req);
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width = gtk_widget_get_width (GTK_WIDGET (overlay));
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height = gtk_widget_get_height (GTK_WIDGET (overlay));
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alloc->x = 0;
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alloc->width = MAX (min.width, MIN (width, req.width));
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direction = _gtk_widget_get_direction (widget);
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halign = gtk_widget_get_halign (widget);
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switch (effective_align (halign, direction))
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{
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case GTK_ALIGN_START:
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/* nothing to do */
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break;
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case GTK_ALIGN_FILL:
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alloc->width = MAX (alloc->width, width);
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break;
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case GTK_ALIGN_CENTER:
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alloc->x += width / 2 - alloc->width / 2;
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break;
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case GTK_ALIGN_END:
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alloc->x += width - alloc->width;
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break;
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case GTK_ALIGN_BASELINE_FILL:
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case GTK_ALIGN_BASELINE_CENTER:
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default:
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g_assert_not_reached ();
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break;
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}
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alloc->y = 0;
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alloc->height = MAX (min.height, MIN (height, req.height));
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switch (gtk_widget_get_valign (widget))
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{
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case GTK_ALIGN_START:
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/* nothing to do */
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break;
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case GTK_ALIGN_FILL:
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alloc->height = MAX (alloc->height, height);
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break;
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case GTK_ALIGN_CENTER:
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alloc->y += height / 2 - alloc->height / 2;
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break;
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case GTK_ALIGN_END:
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alloc->y += height - alloc->height;
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break;
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case GTK_ALIGN_BASELINE_FILL:
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case GTK_ALIGN_BASELINE_CENTER:
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default:
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g_assert_not_reached ();
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break;
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}
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return TRUE;
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}
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static void
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gtk_overlay_snapshot_child (GtkWidget *overlay,
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GtkWidget *child,
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GtkSnapshot *snapshot)
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{
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graphene_rect_t bounds;
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gboolean clip_set;
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clip_set = gtk_overlay_get_clip_overlay (GTK_OVERLAY (overlay), child);
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if (!clip_set)
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{
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gtk_widget_snapshot_child (overlay, child, snapshot);
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return;
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}
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graphene_rect_init (&bounds, 0, 0,
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gtk_widget_get_width (overlay),
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gtk_widget_get_height (overlay));
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gtk_snapshot_push_clip (snapshot, &bounds);
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gtk_widget_snapshot_child (overlay, child, snapshot);
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gtk_snapshot_pop (snapshot);
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}
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static void
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gtk_overlay_snapshot (GtkWidget *widget,
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GtkSnapshot *snapshot)
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{
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GtkWidget *child;
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for (child = _gtk_widget_get_first_child (widget);
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child != NULL;
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child = _gtk_widget_get_next_sibling (child))
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{
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gtk_overlay_snapshot_child (widget, child, snapshot);
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}
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}
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static void
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gtk_overlay_get_property (GObject *object,
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guint prop_id,
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GValue *value,
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GParamSpec *pspec)
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{
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GtkOverlay *overlay = GTK_OVERLAY (object);
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switch (prop_id)
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{
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case PROP_CHILD:
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g_value_set_object (value, gtk_overlay_get_child (overlay));
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break;
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default:
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G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
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break;
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}
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}
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static void
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gtk_overlay_set_property (GObject *object,
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guint prop_id,
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const GValue *value,
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GParamSpec *pspec)
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{
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GtkOverlay *overlay = GTK_OVERLAY (object);
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switch (prop_id)
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{
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case PROP_CHILD:
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gtk_overlay_set_child (overlay, g_value_get_object (value));
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break;
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default:
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G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
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break;
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}
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}
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static void
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gtk_overlay_dispose (GObject *object)
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{
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GtkOverlay *overlay = GTK_OVERLAY (object);
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GtkWidget *child;
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g_clear_pointer (&overlay->child, gtk_widget_unparent);
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while ((child = gtk_widget_get_first_child (GTK_WIDGET (overlay))))
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gtk_widget_unparent (child);
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G_OBJECT_CLASS (gtk_overlay_parent_class)->dispose (object);
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}
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static void
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gtk_overlay_compute_expand (GtkWidget *widget,
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gboolean *hexpand,
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gboolean *vexpand)
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{
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GtkOverlay *overlay = GTK_OVERLAY (widget);
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if (overlay->child)
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{
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*hexpand = gtk_widget_compute_expand (overlay->child, GTK_ORIENTATION_HORIZONTAL);
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*vexpand = gtk_widget_compute_expand (overlay->child, GTK_ORIENTATION_VERTICAL);
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}
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else
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{
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*hexpand = FALSE;
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*vexpand = FALSE;
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}
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}
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static void
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gtk_overlay_class_init (GtkOverlayClass *klass)
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{
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GObjectClass *object_class = G_OBJECT_CLASS (klass);
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GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
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object_class->dispose = gtk_overlay_dispose;
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object_class->get_property = gtk_overlay_get_property;
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object_class->set_property = gtk_overlay_set_property;
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widget_class->snapshot = gtk_overlay_snapshot;
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widget_class->compute_expand = gtk_overlay_compute_expand;
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klass->get_child_position = gtk_overlay_get_child_position;
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/**
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* GtkOverlay:child: (attributes org.gtk.Property.get=gtk_overlay_get_child org.gtk.Property.set=gtk_overlay_set_child)
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*
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* The main child widget.
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*/
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g_object_class_install_property (object_class,
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PROP_CHILD,
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g_param_spec_object ("child", NULL, NULL,
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GTK_TYPE_WIDGET,
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GTK_PARAM_READWRITE|G_PARAM_EXPLICIT_NOTIFY));
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/**
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* GtkOverlay::get-child-position:
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* @overlay: the `GtkOverlay`
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* @widget: the child widget to position
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* @allocation: (type Gdk.Rectangle) (out caller-allocates): return
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* location for the allocation
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*
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* Emitted to determine the position and size of any overlay
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* child widgets.
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*
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* A handler for this signal should fill @allocation with
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* the desired position and size for @widget, relative to
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* the 'main' child of @overlay.
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*
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* The default handler for this signal uses the @widget's
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* halign and valign properties to determine the position
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* and gives the widget its natural size (except that an
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* alignment of %GTK_ALIGN_FILL will cause the overlay to
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* be full-width/height). If the main child is a
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* `GtkScrolledWindow`, the overlays are placed relative
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* to its contents.
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*
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* Returns: %TRUE if the @allocation has been filled
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*/
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signals[GET_CHILD_POSITION] =
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g_signal_new (I_("get-child-position"),
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G_TYPE_FROM_CLASS (object_class),
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G_SIGNAL_RUN_LAST,
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G_STRUCT_OFFSET (GtkOverlayClass, get_child_position),
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_gtk_boolean_handled_accumulator, NULL,
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_gtk_marshal_BOOLEAN__OBJECT_BOXED,
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G_TYPE_BOOLEAN, 2,
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GTK_TYPE_WIDGET,
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GDK_TYPE_RECTANGLE | G_SIGNAL_TYPE_STATIC_SCOPE);
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g_signal_set_va_marshaller (signals[GET_CHILD_POSITION],
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G_TYPE_FROM_CLASS (object_class),
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_gtk_marshal_BOOLEAN__OBJECT_BOXEDv);
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gtk_widget_class_set_css_name (widget_class, I_("overlay"));
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gtk_widget_class_set_layout_manager_type (widget_class, GTK_TYPE_OVERLAY_LAYOUT);
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}
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static void
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gtk_overlay_init (GtkOverlay *overlay)
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{
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}
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static GtkBuildableIface *parent_buildable_iface;
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static void
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gtk_overlay_buildable_add_child (GtkBuildable *buildable,
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GtkBuilder *builder,
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GObject *child,
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const char *type)
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{
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if (GTK_IS_WIDGET (child))
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{
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if (type && strcmp (type, "overlay") == 0)
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gtk_overlay_add_overlay (GTK_OVERLAY (buildable), GTK_WIDGET (child));
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else if (!type)
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gtk_overlay_set_child (GTK_OVERLAY (buildable), GTK_WIDGET (child));
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else
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GTK_BUILDER_WARN_INVALID_CHILD_TYPE (buildable, type);
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}
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else
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{
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parent_buildable_iface->add_child (buildable, builder, child, type);
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}
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}
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static void
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gtk_overlay_buildable_init (GtkBuildableIface *iface)
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{
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parent_buildable_iface = g_type_interface_peek_parent (iface);
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iface->add_child = gtk_overlay_buildable_add_child;
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}
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/**
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* gtk_overlay_new:
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*
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* Creates a new `GtkOverlay`.
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*
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* Returns: a new `GtkOverlay` object.
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*/
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GtkWidget *
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gtk_overlay_new (void)
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{
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return g_object_new (GTK_TYPE_OVERLAY, NULL);
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}
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/**
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* gtk_overlay_add_overlay:
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* @overlay: a `GtkOverlay`
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* @widget: a `GtkWidget` to be added to the container
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*
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* Adds @widget to @overlay.
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*
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* The widget will be stacked on top of the main widget
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* added with [method@Gtk.Overlay.set_child].
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*
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* The position at which @widget is placed is determined
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* from its [property@Gtk.Widget:halign] and
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* [property@Gtk.Widget:valign] properties.
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*/
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void
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gtk_overlay_add_overlay (GtkOverlay *overlay,
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GtkWidget *widget)
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{
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g_return_if_fail (GTK_IS_OVERLAY (overlay));
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g_return_if_fail (GTK_IS_WIDGET (widget));
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g_return_if_fail (widget != overlay->child);
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gtk_widget_insert_before (widget, GTK_WIDGET (overlay), NULL);
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}
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/**
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* gtk_overlay_remove_overlay:
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* @overlay: a `GtkOverlay`
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* @widget: a `GtkWidget` to be removed
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*
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* Removes an overlay that was added with gtk_overlay_add_overlay().
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*/
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void
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gtk_overlay_remove_overlay (GtkOverlay *overlay,
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GtkWidget *widget)
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{
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g_return_if_fail (GTK_IS_OVERLAY (overlay));
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g_return_if_fail (GTK_IS_WIDGET (widget));
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g_return_if_fail (gtk_widget_get_parent (widget) == GTK_WIDGET (overlay));
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g_return_if_fail (widget != overlay->child);
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gtk_widget_unparent (widget);
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}
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/**
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* gtk_overlay_set_measure_overlay:
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* @overlay: a `GtkOverlay`
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* @widget: an overlay child of `GtkOverlay`
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* @measure: whether the child should be measured
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*
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* Sets whether @widget is included in the measured size of @overlay.
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*
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* The overlay will request the size of the largest child that has
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* this property set to %TRUE. Children who are not included may
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* be drawn outside of @overlay's allocation if they are too large.
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*/
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void
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gtk_overlay_set_measure_overlay (GtkOverlay *overlay,
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GtkWidget *widget,
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gboolean measure)
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{
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GtkLayoutManager *layout;
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GtkOverlayLayoutChild *child;
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g_return_if_fail (GTK_IS_OVERLAY (overlay));
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g_return_if_fail (GTK_IS_WIDGET (widget));
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layout = gtk_widget_get_layout_manager (GTK_WIDGET (overlay));
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child = GTK_OVERLAY_LAYOUT_CHILD (gtk_layout_manager_get_layout_child (layout, widget));
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gtk_overlay_layout_child_set_measure (child, measure);
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}
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/**
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* gtk_overlay_get_measure_overlay:
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* @overlay: a `GtkOverlay`
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* @widget: an overlay child of `GtkOverlay`
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*
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* Gets whether @widget's size is included in the measurement of
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* @overlay.
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*
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* Returns: whether the widget is measured
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*/
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gboolean
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gtk_overlay_get_measure_overlay (GtkOverlay *overlay,
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GtkWidget *widget)
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{
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GtkLayoutManager *layout;
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GtkOverlayLayoutChild *child;
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g_return_val_if_fail (GTK_IS_OVERLAY (overlay), FALSE);
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g_return_val_if_fail (GTK_IS_WIDGET (widget), FALSE);
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layout = gtk_widget_get_layout_manager (GTK_WIDGET (overlay));
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child = GTK_OVERLAY_LAYOUT_CHILD (gtk_layout_manager_get_layout_child (layout, widget));
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return gtk_overlay_layout_child_get_measure (child);
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}
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/**
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* gtk_overlay_set_clip_overlay:
|
||
* @overlay: a `GtkOverlay`
|
||
* @widget: an overlay child of `GtkOverlay`
|
||
* @clip_overlay: whether the child should be clipped
|
||
*
|
||
* Sets whether @widget should be clipped within the parent.
|
||
*/
|
||
void
|
||
gtk_overlay_set_clip_overlay (GtkOverlay *overlay,
|
||
GtkWidget *widget,
|
||
gboolean clip_overlay)
|
||
{
|
||
GtkLayoutManager *layout;
|
||
GtkOverlayLayoutChild *child;
|
||
|
||
g_return_if_fail (GTK_IS_OVERLAY (overlay));
|
||
g_return_if_fail (GTK_IS_WIDGET (widget));
|
||
|
||
layout = gtk_widget_get_layout_manager (GTK_WIDGET (overlay));
|
||
child = GTK_OVERLAY_LAYOUT_CHILD (gtk_layout_manager_get_layout_child (layout, widget));
|
||
gtk_overlay_layout_child_set_clip_overlay (child, clip_overlay);
|
||
}
|
||
|
||
/**
|
||
* gtk_overlay_get_clip_overlay:
|
||
* @overlay: a `GtkOverlay`
|
||
* @widget: an overlay child of `GtkOverlay`
|
||
*
|
||
* Gets whether @widget should be clipped within the parent.
|
||
*
|
||
* Returns: whether the widget is clipped within the parent.
|
||
*/
|
||
gboolean
|
||
gtk_overlay_get_clip_overlay (GtkOverlay *overlay,
|
||
GtkWidget *widget)
|
||
{
|
||
GtkLayoutManager *layout;
|
||
GtkOverlayLayoutChild *child;
|
||
|
||
g_return_val_if_fail (GTK_IS_OVERLAY (overlay), FALSE);
|
||
g_return_val_if_fail (GTK_IS_WIDGET (widget), FALSE);
|
||
|
||
layout = gtk_widget_get_layout_manager (GTK_WIDGET (overlay));
|
||
child = GTK_OVERLAY_LAYOUT_CHILD (gtk_layout_manager_get_layout_child (layout, widget));
|
||
|
||
return gtk_overlay_layout_child_get_clip_overlay (child);
|
||
}
|
||
|
||
/**
|
||
* gtk_overlay_set_child:
|
||
* @overlay: a `GtkOverlay`
|
||
* @child: (nullable): the child widget
|
||
*
|
||
* Sets the child widget of @overlay.
|
||
*/
|
||
void
|
||
gtk_overlay_set_child (GtkOverlay *overlay,
|
||
GtkWidget *child)
|
||
{
|
||
g_return_if_fail (GTK_IS_OVERLAY (overlay));
|
||
g_return_if_fail (child == NULL || overlay->child == child || gtk_widget_get_parent (child) == NULL);
|
||
|
||
if (overlay->child == child)
|
||
return;
|
||
|
||
g_clear_pointer (&overlay->child, gtk_widget_unparent);
|
||
|
||
overlay->child = child;
|
||
|
||
if (child)
|
||
{
|
||
/* Make sure the main-child node is the first one */
|
||
gtk_widget_insert_after (child, GTK_WIDGET (overlay), NULL);
|
||
}
|
||
|
||
g_object_notify (G_OBJECT (overlay), "child");
|
||
}
|
||
|
||
/**
|
||
* gtk_overlay_get_child:
|
||
* @overlay: a `GtkOverlay`
|
||
*
|
||
* Gets the child widget of @overlay.
|
||
*
|
||
* Returns: (nullable) (transfer none): the child widget of @overlay
|
||
*/
|
||
GtkWidget *
|
||
gtk_overlay_get_child (GtkOverlay *overlay)
|
||
{
|
||
g_return_val_if_fail (GTK_IS_OVERLAY (overlay), NULL);
|
||
|
||
return overlay->child;
|
||
}
|