gtk2/gtk/gtkoverlay.c

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/*
* gtkoverlay.c
* This file is part of gtk
*
* Copyright (C) 2011 - Ignacio Casal Quinteiro, Mike Krüger
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* 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/>.
*/
#include "config.h"
#include "gtkoverlay.h"
#include "gtkbuildable.h"
#include "gtkscrolledwindow.h"
#include "gtkwidgetprivate.h"
#include "gtkmarshalers.h"
#include "gtkprivate.h"
#include "gtkintl.h"
/**
* SECTION:gtkoverlay
* @short_description: A container which overlays widgets on top of each other
* @title: GtkOverlay
*
* GtkOverlay is a container which contains a single main child, on top
* of which it can place overlay widgets. The position of each overlay
* widget is determined by its #GtkWidget:halign and #GtkWidget:valign
* properties. E.g. a widget with both alignments set to %GTK_ALIGN_START
* will be placed at the top left corner of the GtkOverlay container,
* whereas an overlay with halign set to %GTK_ALIGN_CENTER and valign set
* to %GTK_ALIGN_END will be placed a the bottom edge of the GtkOverlay,
* horizontally centered. The position can be adjusted by setting the margin
* properties of the child to non-zero values.
*
* More complicated placement of overlays is possible by connecting
* to the #GtkOverlay::get-child-position signal.
*
* # GtkOverlay as GtkBuildable
*
* The GtkOverlay implementation of the GtkBuildable interface
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* supports placing a child as an overlay by specifying overlay as
* the type attribute of a `<child>` element.
*/
struct _GtkOverlayPrivate
{
GSList *children;
};
typedef struct _GtkOverlayChild GtkOverlayChild;
struct _GtkOverlayChild
{
GtkWidget *widget;
gboolean pass_through;
};
enum {
GET_CHILD_POSITION,
LAST_SIGNAL
};
enum
{
CHILD_PROP_0,
CHILD_PROP_PASS_THROUGH,
CHILD_PROP_INDEX
};
static guint signals[LAST_SIGNAL] = { 0 };
static void gtk_overlay_buildable_init (GtkBuildableIface *iface);
G_DEFINE_TYPE_WITH_CODE (GtkOverlay, gtk_overlay, GTK_TYPE_BIN,
G_ADD_PRIVATE (GtkOverlay)
G_IMPLEMENT_INTERFACE (GTK_TYPE_BUILDABLE,
gtk_overlay_buildable_init))
static void
gtk_overlay_compute_child_allocation (GtkOverlay *overlay,
GtkOverlayChild *child,
GtkAllocation *widget_allocation)
{
GtkAllocation allocation;
gboolean result;
g_signal_emit (overlay, signals[GET_CHILD_POSITION],
0, child->widget, &allocation, &result);
widget_allocation->x = allocation.x;
widget_allocation->y = allocation.y;
widget_allocation->width = allocation.width;
widget_allocation->height = allocation.height;
}
static GtkAlign
effective_align (GtkAlign align,
GtkTextDirection direction)
{
switch (align)
{
case GTK_ALIGN_START:
return direction == GTK_TEXT_DIR_RTL ? GTK_ALIGN_END : GTK_ALIGN_START;
case GTK_ALIGN_END:
return direction == GTK_TEXT_DIR_RTL ? GTK_ALIGN_START : GTK_ALIGN_END;
default:
return align;
}
}
static void
gtk_overlay_get_main_widget_allocation (GtkOverlay *overlay,
GtkAllocation *main_alloc_out)
{
GtkWidget *main_widget;
GtkAllocation main_alloc;
main_widget = gtk_bin_get_child (GTK_BIN (overlay));
/* special-case scrolled windows */
if (GTK_IS_SCROLLED_WINDOW (main_widget))
{
GtkWidget *grandchild;
gint x, y;
gboolean res;
grandchild = gtk_bin_get_child (GTK_BIN (main_widget));
res = gtk_widget_translate_coordinates (grandchild, main_widget, 0, 0, &x, &y);
if (res)
{
main_alloc.x = x;
main_alloc.y = y;
}
else
{
main_alloc.x = 0;
main_alloc.y = 0;
}
main_alloc.width = gtk_widget_get_allocated_width (grandchild);
main_alloc.height = gtk_widget_get_allocated_height (grandchild);
}
else
{
main_alloc.x = 0;
main_alloc.y = 0;
main_alloc.width = gtk_widget_get_allocated_width (GTK_WIDGET (overlay));
main_alloc.height = gtk_widget_get_allocated_height (GTK_WIDGET (overlay));
}
if (main_alloc_out)
*main_alloc_out = main_alloc;
}
static void
gtk_overlay_child_update_style_classes (GtkOverlay *overlay,
GtkWidget *child,
GtkAllocation *child_allocation)
{
GtkAllocation overlay_allocation, main_allocation;
GtkAlign valign, halign;
gboolean is_left, is_right, is_top, is_bottom;
gboolean has_left, has_right, has_top, has_bottom;
GtkStyleContext *context;
context = gtk_widget_get_style_context (child);
has_left = gtk_style_context_has_class (context, GTK_STYLE_CLASS_LEFT);
has_right = gtk_style_context_has_class (context, GTK_STYLE_CLASS_RIGHT);
has_top = gtk_style_context_has_class (context, GTK_STYLE_CLASS_TOP);
has_bottom = gtk_style_context_has_class (context, GTK_STYLE_CLASS_BOTTOM);
is_left = is_right = is_top = is_bottom = FALSE;
gtk_overlay_get_main_widget_allocation (overlay, &main_allocation);
gtk_widget_get_allocation (GTK_WIDGET (overlay), &overlay_allocation);
main_allocation.x += overlay_allocation.x;
main_allocation.y += overlay_allocation.y;
halign = effective_align (gtk_widget_get_halign (child),
gtk_widget_get_direction (child));
if (halign == GTK_ALIGN_START)
is_left = (child_allocation->x == main_allocation.x);
else if (halign == GTK_ALIGN_END)
is_right = (child_allocation->x + child_allocation->width ==
main_allocation.x + main_allocation.width);
valign = gtk_widget_get_valign (child);
if (valign == GTK_ALIGN_START)
is_top = (child_allocation->y == main_allocation.y);
else if (valign == GTK_ALIGN_END)
is_bottom = (child_allocation->y + child_allocation->height ==
main_allocation.y + main_allocation.height);
if (has_left && !is_left)
gtk_style_context_remove_class (context, GTK_STYLE_CLASS_LEFT);
else if (!has_left && is_left)
gtk_style_context_add_class (context, GTK_STYLE_CLASS_LEFT);
if (has_right && !is_right)
gtk_style_context_remove_class (context, GTK_STYLE_CLASS_RIGHT);
else if (!has_right && is_right)
gtk_style_context_add_class (context, GTK_STYLE_CLASS_RIGHT);
if (has_top && !is_top)
gtk_style_context_remove_class (context, GTK_STYLE_CLASS_TOP);
else if (!has_top && is_top)
gtk_style_context_add_class (context, GTK_STYLE_CLASS_TOP);
if (has_bottom && !is_bottom)
gtk_style_context_remove_class (context, GTK_STYLE_CLASS_BOTTOM);
else if (!has_bottom && is_bottom)
gtk_style_context_add_class (context, GTK_STYLE_CLASS_BOTTOM);
}
static void
gtk_overlay_child_allocate (GtkOverlay *overlay,
GtkOverlayChild *child)
{
GtkAllocation child_allocation;
GtkAllocation child_clip;
if (!gtk_widget_get_visible (child->widget))
return;
gtk_overlay_compute_child_allocation (overlay, child, &child_allocation);
gtk_overlay_child_update_style_classes (overlay, child->widget, &child_allocation);
gtk_widget_size_allocate (child->widget, &child_allocation, -1, &child_clip);
}
static void
gtk_overlay_size_allocate (GtkWidget *widget,
const GtkAllocation *allocation,
int baseline,
GtkAllocation *out_clip)
{
GtkOverlay *overlay = GTK_OVERLAY (widget);
GtkOverlayPrivate *priv = overlay->priv;
GSList *children;
GtkWidget *main_widget;
GTK_WIDGET_CLASS (gtk_overlay_parent_class)->size_allocate (widget, allocation, baseline, out_clip);
main_widget = gtk_bin_get_child (GTK_BIN (overlay));
if (main_widget && gtk_widget_get_visible (main_widget))
gtk_widget_size_allocate (main_widget, allocation, -1, out_clip);
for (children = priv->children; children; children = children->next)
gtk_overlay_child_allocate (overlay, children->data);
}
static gboolean
gtk_overlay_get_child_position (GtkOverlay *overlay,
GtkWidget *widget,
GtkAllocation *alloc)
{
GtkAllocation main_alloc;
GtkRequisition min, req;
GtkAlign halign;
GtkTextDirection direction;
gtk_overlay_get_main_widget_allocation (overlay, &main_alloc);
gtk_widget_get_preferred_size (widget, &min, &req);
alloc->x = main_alloc.x;
alloc->width = MAX (min.width, MIN (main_alloc.width, req.width));
direction = _gtk_widget_get_direction (widget);
halign = gtk_widget_get_halign (widget);
switch (effective_align (halign, direction))
{
case GTK_ALIGN_START:
/* nothing to do */
break;
case GTK_ALIGN_FILL:
alloc->width = MAX (alloc->width, main_alloc.width);
break;
case GTK_ALIGN_CENTER:
alloc->x += main_alloc.width / 2 - alloc->width / 2;
break;
case GTK_ALIGN_END:
alloc->x += main_alloc.width - alloc->width;
break;
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case GTK_ALIGN_BASELINE:
default:
g_assert_not_reached ();
break;
}
alloc->y = main_alloc.y;
alloc->height = MAX (min.height, MIN (main_alloc.height, req.height));
switch (gtk_widget_get_valign (widget))
{
case GTK_ALIGN_START:
/* nothing to do */
break;
case GTK_ALIGN_FILL:
alloc->height = MAX (alloc->height, main_alloc.height);
break;
case GTK_ALIGN_CENTER:
alloc->y += main_alloc.height / 2 - alloc->height / 2;
break;
case GTK_ALIGN_END:
alloc->y += main_alloc.height - alloc->height;
break;
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case GTK_ALIGN_BASELINE:
default:
g_assert_not_reached ();
break;
}
return TRUE;
}
static void
gtk_overlay_add (GtkContainer *container,
GtkWidget *widget)
{
/* We only get into this path if we have no child
* (since GtkOverlay is a GtkBin) and the only child
* we can add through gtk_container_add is the main child,
* which we want to keep the lowest in the hierarchy. */
gtk_widget_insert_after (widget, GTK_WIDGET (container), NULL);
_gtk_bin_set_child (GTK_BIN (container), widget);
}
static void
gtk_overlay_remove (GtkContainer *container,
GtkWidget *widget)
{
GtkOverlayPrivate *priv = GTK_OVERLAY (container)->priv;
GtkOverlayChild *child;
GSList *children, *next;
gboolean removed;
removed = FALSE;
for (children = priv->children; children; children = next)
{
child = children->data;
next = children->next;
if (child->widget == widget)
{
gtk_widget_unparent (widget);
priv->children = g_slist_delete_link (priv->children, children);
g_slice_free (GtkOverlayChild, child);
removed = TRUE;
}
else if (removed)
gtk_widget_child_notify (child->widget, "index");
}
if (!removed)
GTK_CONTAINER_CLASS (gtk_overlay_parent_class)->remove (container, widget);
}
/**
* gtk_overlay_reorder_overlay:
* @overlay: a #GtkOverlay
* @child: the overlaid #GtkWidget to move
* @position: the new index for @child in the list of overlay children
* of @overlay, starting from 0. If negative, indicates the end of
* the list
*
* Moves @child to a new @index in the list of @overlay children.
* The list contains overlays in the order that these were
* added to @overlay.
*
* A widgets index in the @overlay children list determines which order
* the children are drawn if they overlap. The first child is drawn at
* the bottom. It also affects the default focus chain order.
*
* Since: 3.18
*/
void
gtk_overlay_reorder_overlay (GtkOverlay *overlay,
GtkWidget *child,
gint position)
{
GtkOverlayPrivate *priv;
GSList *old_link;
GSList *new_link;
GSList *l;
GtkOverlayChild *child_info = NULL;
gint old_index, i;
gint index;
g_return_if_fail (GTK_IS_OVERLAY (overlay));
g_return_if_fail (GTK_IS_WIDGET (child));
priv = GTK_OVERLAY (overlay)->priv;
old_link = priv->children;
old_index = 0;
while (old_link)
{
child_info = old_link->data;
if (child_info->widget == child)
break;
old_link = old_link->next;
old_index++;
}
g_return_if_fail (old_link != NULL);
if (position < 0)
{
new_link = NULL;
index = g_slist_length (priv->children) - 1;
}
else
{
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new_link = g_slist_nth (priv->children, position);
index = MIN (position, g_slist_length (priv->children) - 1);
}
if (index == old_index)
return;
priv->children = g_slist_delete_link (priv->children, old_link);
priv->children = g_slist_insert_before (priv->children, new_link, child_info);
for (i = 0, l = priv->children; l != NULL; l = l->next, i++)
{
GtkOverlayChild *info = l->data;
if ((i < index && i < old_index) ||
(i > index && i > old_index))
continue;
gtk_widget_child_notify (info->widget, "index");
}
if (new_link)
gtk_widget_insert_before (child, GTK_WIDGET (overlay), ((GtkOverlayChild *)new_link->data)->widget);
else
gtk_widget_insert_before (child, GTK_WIDGET (overlay), NULL);
}
static void
gtk_overlay_forall (GtkContainer *overlay,
GtkCallback callback,
gpointer callback_data)
{
GtkOverlayPrivate *priv = GTK_OVERLAY (overlay)->priv;
GtkOverlayChild *child;
GSList *children;
GtkWidget *main_widget;
main_widget = gtk_bin_get_child (GTK_BIN (overlay));
if (main_widget)
(* callback) (main_widget, callback_data);
children = priv->children;
while (children)
{
child = children->data;
children = children->next;
(* callback) (child->widget, callback_data);
}
}
static GtkOverlayChild *
gtk_overlay_get_overlay_child (GtkOverlay *overlay,
GtkWidget *child)
{
GtkOverlayPrivate *priv = GTK_OVERLAY (overlay)->priv;
GtkOverlayChild *child_info;
GSList *children;
for (children = priv->children; children; children = children->next)
{
child_info = children->data;
if (child_info->widget == child)
return child_info;
}
return NULL;
}
static void
gtk_overlay_set_child_property (GtkContainer *container,
GtkWidget *child,
guint property_id,
const GValue *value,
GParamSpec *pspec)
{
GtkOverlay *overlay = GTK_OVERLAY (container);
GtkOverlayChild *child_info;
GtkWidget *main_widget;
main_widget = gtk_bin_get_child (GTK_BIN (overlay));
if (child == main_widget)
child_info = NULL;
else
{
child_info = gtk_overlay_get_overlay_child (overlay, child);
if (child_info == NULL)
{
GTK_CONTAINER_WARN_INVALID_CHILD_PROPERTY_ID (container, property_id, pspec);
return;
}
}
switch (property_id)
{
case CHILD_PROP_PASS_THROUGH:
/* Ignore value on main child */
if (child_info)
{
if (g_value_get_boolean (value) != child_info->pass_through)
{
child_info->pass_through = g_value_get_boolean (value);
gtk_widget_set_pass_through (child, child_info->pass_through);
gtk_container_child_notify (container, child, "pass-through");
}
}
break;
case CHILD_PROP_INDEX:
if (child_info != NULL)
gtk_overlay_reorder_overlay (GTK_OVERLAY (container),
child,
g_value_get_int (value));
break;
default:
GTK_CONTAINER_WARN_INVALID_CHILD_PROPERTY_ID (container, property_id, pspec);
break;
}
}
static void
gtk_overlay_get_child_property (GtkContainer *container,
GtkWidget *child,
guint property_id,
GValue *value,
GParamSpec *pspec)
{
GtkOverlay *overlay = GTK_OVERLAY (container);
GtkOverlayPrivate *priv = GTK_OVERLAY (overlay)->priv;
GtkOverlayChild *child_info;
GtkWidget *main_widget;
main_widget = gtk_bin_get_child (GTK_BIN (overlay));
if (child == main_widget)
child_info = NULL;
else
{
child_info = gtk_overlay_get_overlay_child (overlay, child);
if (child_info == NULL)
{
GTK_CONTAINER_WARN_INVALID_CHILD_PROPERTY_ID (container, property_id, pspec);
return;
}
}
switch (property_id)
{
case CHILD_PROP_PASS_THROUGH:
if (child_info)
g_value_set_boolean (value, child_info->pass_through);
else
g_value_set_boolean (value, FALSE);
break;
case CHILD_PROP_INDEX:
g_value_set_int (value, g_slist_index (priv->children, child_info));
break;
default:
GTK_CONTAINER_WARN_INVALID_CHILD_PROPERTY_ID (container, property_id, pspec);
break;
}
}
static void
gtk_overlay_class_init (GtkOverlayClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);
GtkContainerClass *container_class = GTK_CONTAINER_CLASS (klass);
widget_class->size_allocate = gtk_overlay_size_allocate;
container_class->add = gtk_overlay_add;
container_class->remove = gtk_overlay_remove;
container_class->forall = gtk_overlay_forall;
container_class->set_child_property = gtk_overlay_set_child_property;
container_class->get_child_property = gtk_overlay_get_child_property;
klass->get_child_position = gtk_overlay_get_child_position;
/**
* GtkOverlay:pass-through:
*
* Pass through input, does not affect main child.
*
* Since: 3.18
*/
gtk_container_class_install_child_property (container_class, CHILD_PROP_PASS_THROUGH,
g_param_spec_boolean ("pass-through", P_("Pass Through"), P_("Pass through input, does not affect main child"),
FALSE,
GTK_PARAM_READWRITE));
/**
* GtkOverlay:index:
*
* The index of the overlay in the parent, -1 for the main child.
*
* Since: 3.18
*/
gtk_container_class_install_child_property (container_class, CHILD_PROP_INDEX,
g_param_spec_int ("index",
P_("Index"),
P_("The index of the overlay in the parent, -1 for the main child"),
-1, G_MAXINT, 0,
GTK_PARAM_READWRITE));
/**
* GtkOverlay::get-child-position:
* @overlay: the #GtkOverlay
* @widget: the child widget to position
* @allocation: (type Gdk.Rectangle) (out caller-allocates): return
* location for the allocation
*
* The ::get-child-position signal is emitted to determine
* the position and size of any overlay child widgets. A
* handler for this signal should fill @allocation with
* the desired position and size for @widget, relative to
* the 'main' child of @overlay.
*
* The default handler for this signal uses the @widget's
* halign and valign properties to determine the position
* and gives the widget its natural size (except that an
* alignment of %GTK_ALIGN_FILL will cause the overlay to
* be full-width/height). If the main child is a
* #GtkScrolledWindow, the overlays are placed relative
* to its contents.
*
* Returns: %TRUE if the @allocation has been filled
*/
signals[GET_CHILD_POSITION] =
g_signal_new (I_("get-child-position"),
G_TYPE_FROM_CLASS (object_class),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (GtkOverlayClass, get_child_position),
_gtk_boolean_handled_accumulator, NULL,
_gtk_marshal_BOOLEAN__OBJECT_BOXED,
G_TYPE_BOOLEAN, 2,
GTK_TYPE_WIDGET,
GDK_TYPE_RECTANGLE | G_SIGNAL_TYPE_STATIC_SCOPE);
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gtk_widget_class_set_css_name (widget_class, "overlay");
}
static void
gtk_overlay_init (GtkOverlay *overlay)
{
overlay->priv = gtk_overlay_get_instance_private (overlay);
gtk_widget_set_has_window (GTK_WIDGET (overlay), FALSE);
}
static void
gtk_overlay_buildable_add_child (GtkBuildable *buildable,
GtkBuilder *builder,
GObject *child,
const gchar *type)
{
if (type && strcmp (type, "overlay") == 0)
gtk_overlay_add_overlay (GTK_OVERLAY (buildable), GTK_WIDGET (child));
else if (!type)
{
/* Make sure the main-child node is the first one */
gtk_widget_insert_after (GTK_WIDGET (child), GTK_WIDGET (buildable), NULL);
_gtk_bin_set_child (GTK_BIN (buildable), GTK_WIDGET (child));
}
else
GTK_BUILDER_WARN_INVALID_CHILD_TYPE (buildable, type);
}
static void
gtk_overlay_buildable_init (GtkBuildableIface *iface)
{
iface->add_child = gtk_overlay_buildable_add_child;
}
/**
* gtk_overlay_new:
*
* Creates a new #GtkOverlay.
*
* Returns: a new #GtkOverlay object.
*
* Since: 3.2
*/
GtkWidget *
gtk_overlay_new (void)
{
return g_object_new (GTK_TYPE_OVERLAY, NULL);
}
/**
* gtk_overlay_add_overlay:
* @overlay: a #GtkOverlay
* @widget: a #GtkWidget to be added to the container
*
* Adds @widget to @overlay.
*
* The widget will be stacked on top of the main widget
* added with gtk_container_add().
*
* The position at which @widget is placed is determined
* from its #GtkWidget:halign and #GtkWidget:valign properties.
*
* Since: 3.2
*/
void
gtk_overlay_add_overlay (GtkOverlay *overlay,
GtkWidget *widget)
{
GtkOverlayPrivate *priv;
GtkOverlayChild *child;
g_return_if_fail (GTK_IS_OVERLAY (overlay));
g_return_if_fail (GTK_IS_WIDGET (widget));
priv = overlay->priv;
child = g_slice_new0 (GtkOverlayChild);
child->widget = widget;
priv->children = g_slist_append (priv->children, child);
gtk_widget_insert_before (widget, GTK_WIDGET (overlay), NULL);
gtk_widget_child_notify (widget, "index");
}
/**
* gtk_overlay_set_overlay_pass_through:
* @overlay: a #GtkOverlay
* @widget: an overlay child of #GtkOverlay
* @pass_through: whether the child should pass the input through
*
* Convenience function to set the value of the #GtkOverlay:pass-through
* child property for @widget.
*
* Since: 3.18
*/
void
gtk_overlay_set_overlay_pass_through (GtkOverlay *overlay,
GtkWidget *widget,
gboolean pass_through)
{
g_return_if_fail (GTK_IS_OVERLAY (overlay));
g_return_if_fail (GTK_IS_WIDGET (widget));
gtk_container_child_set (GTK_CONTAINER (overlay), widget,
"pass-through", pass_through,
NULL);
}
/**
* gtk_overlay_get_overlay_pass_through:
* @overlay: a #GtkOverlay
* @widget: an overlay child of #GtkOverlay
*
* Convenience function to get the value of the #GtkOverlay:pass-through
* child property for @widget.
*
* Returns: whether the widget is a pass through child.
*
* Since: 3.18
*/
gboolean
gtk_overlay_get_overlay_pass_through (GtkOverlay *overlay,
GtkWidget *widget)
{
gboolean pass_through;
g_return_val_if_fail (GTK_IS_OVERLAY (overlay), FALSE);
g_return_val_if_fail (GTK_IS_WIDGET (widget), FALSE);
gtk_container_child_get (GTK_CONTAINER (overlay), widget,
"pass-through", &pass_through,
NULL);
return pass_through;
}