Add GtkActionBar

A widget intended to offer contextual actions for a given view.
It allows packing children into the start or end as well as offering
a single centered child box.

https://bugzilla.gnome.org/show_bug.cgi?id=721665

1 files changed, 1093 insertions, 0 deletions

diff --git a/gtk/gtkactionbar.c b/gtk/gtkactionbar.c
new file mode 100644
index 0000000000..02d3cdf838
--- /dev/null
+++ b/gtk/gtkactionbar.c
@@ -0,0 +1,1093 @@
+/*
+ * Copyright (c) 2013 - 2014 Red Hat, Inc.
+ *
+ * This program 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 program 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 License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include "config.h"
+
+#include "gtkactionbar.h"
+#include "gtkintl.h"
+#include "gtkprivate.h"
+#include "gtktypebuiltins.h"
+#include "gtkwidgetprivate.h"
+#include "gtkcontainerprivate.h"
+#include "gtkwindowprivate.h"
+#include "a11y/gtkcontaineraccessible.h"
+
+#include <string.h>
+
+/**
+ * SECTION:gtkactionbar
+ * @Short_description: A box with a centered child
+ * @Title: GtkActionBar
+ * @See_also: #GtkBox
+ *
+ * GtkActionBar is similar to a horizontal #GtkBox, it allows to place
+ * children at the start or the end. In addition, it contains an
+ * internal centered box which is centered with respect to the full
+ * width of the box, even if the children at either side take up
+ * different amounts of space.
+ *
+ */
+
+#define DEFAULT_SPACING 6
+
+struct _GtkActionBarPrivate
+{
+  GtkWidget *center_widget;
+  gint spacing;
+
+  GList *children;
+};
+
+typedef struct _Child Child;
+struct _Child
+{
+  GtkWidget *widget;
+  GtkPackType pack_type;
+};
+
+enum {
+  PROP_0,
+  PROP_CENTER_WIDGET,
+  PROP_SPACING,
+};
+
+enum {
+  CHILD_PROP_0,
+  CHILD_PROP_PACK_TYPE,
+  CHILD_PROP_POSITION
+};
+
+static void gtk_action_bar_buildable_init (GtkBuildableIface *iface);
+
+G_DEFINE_TYPE_WITH_CODE (GtkActionBar, gtk_action_bar, GTK_TYPE_CONTAINER,
+                         G_ADD_PRIVATE (GtkActionBar)
+                         G_IMPLEMENT_INTERFACE (GTK_TYPE_BUILDABLE,
+                                                gtk_action_bar_buildable_init));
+
+static void
+get_css_padding_and_border (GtkWidget *widget,
+                            GtkBorder *border)
+{
+  GtkStyleContext *context;
+  GtkStateFlags state;
+  GtkBorder tmp;
+
+  context = gtk_widget_get_style_context (widget);
+  state = gtk_widget_get_state_flags (widget);
+
+  gtk_style_context_get_padding (context, state, border);
+  gtk_style_context_get_border (context, state, &tmp);
+  border->top += tmp.top;
+  border->right += tmp.right;
+  border->bottom += tmp.bottom;
+  border->left += tmp.left;
+}
+
+static void
+construct_center_widget (GtkActionBar *bar)
+{
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (bar);
+
+  g_assert (priv->center_widget == NULL);
+
+  priv->center_widget = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
+  gtk_widget_set_valign (priv->center_widget, GTK_ALIGN_CENTER);
+  gtk_widget_show (priv->center_widget);
+  gtk_widget_set_parent (priv->center_widget, GTK_WIDGET (bar));
+}
+
+static void
+gtk_action_bar_init (GtkActionBar *bar)
+{
+  GtkStyleContext *context;
+  GtkActionBarPrivate *priv;
+
+  priv = gtk_action_bar_get_instance_private (bar);
+
+  gtk_widget_set_has_window (GTK_WIDGET (bar), FALSE);
+  gtk_widget_set_redraw_on_allocate (GTK_WIDGET (bar), FALSE);
+
+  priv->center_widget = NULL;
+  priv->children = NULL;
+  priv->spacing = DEFAULT_SPACING;
+
+  construct_center_widget (bar);
+
+  context = gtk_widget_get_style_context (GTK_WIDGET (bar));
+  gtk_style_context_add_class (context, "action-bar");
+  gtk_style_context_add_class (context, GTK_STYLE_CLASS_HORIZONTAL);
+}
+
+static gint
+count_visible_children (GtkActionBar *bar)
+{
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (bar);
+  GList *l;
+  Child *child;
+  gint n;
+
+  n = 0;
+  for (l = priv->children; l; l = l->next)
+    {
+      child = l->data;
+      if (gtk_widget_get_visible (child->widget))
+        n++;
+    }
+
+  return n;
+}
+
+static gboolean
+add_child_size (GtkWidget      *child,
+                GtkOrientation  orientation,
+                gint           *minimum,
+                gint           *natural)
+{
+  gint child_minimum, child_natural;
+
+  if (!gtk_widget_get_visible (child))
+    return FALSE;
+
+  if (orientation == GTK_ORIENTATION_HORIZONTAL)
+    gtk_widget_get_preferred_width (child, &child_minimum, &child_natural);
+  else
+    gtk_widget_get_preferred_height (child, &child_minimum, &child_natural);
+
+  if (GTK_ORIENTATION_HORIZONTAL == orientation)
+    {
+      *minimum += child_minimum;
+      *natural += child_natural;
+    }
+  else
+    {
+      *minimum = MAX (*minimum, child_minimum);
+      *natural = MAX (*natural, child_natural);
+    }
+
+  return TRUE;
+}
+
+static void
+gtk_action_bar_get_size (GtkWidget      *widget,
+                         GtkOrientation  orientation,
+                         gint           *minimum_size,
+                         gint           *natural_size)
+{
+  GtkActionBar *bar = GTK_ACTION_BAR (widget);
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (bar);
+  GList *l;
+  gint nvis_children;
+  gint minimum, natural;
+  GtkBorder css_borders;
+
+  minimum = natural = 0;
+  nvis_children = 0;
+
+  for (l = priv->children; l; l = l->next)
+    {
+      Child *child = l->data;
+
+      if (add_child_size (child->widget, orientation, &minimum, &natural))
+        nvis_children += 1;
+    }
+
+  if (priv->center_widget != NULL)
+    {
+      if (add_child_size (priv->center_widget, orientation, &minimum, &natural))
+        nvis_children += 1;
+    }
+
+  if (nvis_children > 0 && orientation == GTK_ORIENTATION_HORIZONTAL)
+    {
+      minimum += nvis_children * priv->spacing;
+      natural += nvis_children * priv->spacing;
+    }
+
+  get_css_padding_and_border (widget, &css_borders);
+
+  if (GTK_ORIENTATION_HORIZONTAL == orientation)
+    {
+      minimum += css_borders.left + css_borders.right;
+      natural += css_borders.left + css_borders.right;
+    }
+  else
+    {
+      minimum += css_borders.top + css_borders.bottom;
+      natural += css_borders.top + css_borders.bottom;
+    }
+
+  if (minimum_size)
+    *minimum_size = minimum;
+
+  if (natural_size)
+    *natural_size = natural;
+}
+
+static void
+gtk_action_bar_compute_size_for_orientation (GtkWidget *widget,
+                                             gint       avail_size,
+                                             gint      *minimum_size,
+                                             gint      *natural_size)
+{
+  GtkActionBar *bar = GTK_ACTION_BAR (widget);
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (bar);
+  GList *children;
+  gint required_size = 0;
+  gint required_natural = 0;
+  gint child_size;
+  gint child_natural;
+  gint nvis_children;
+  GtkBorder css_borders;
+
+  nvis_children = 0;
+
+  for (children = priv->children; children != NULL; children = children->next)
+    {
+      Child *child = children->data;
+
+      if (gtk_widget_get_visible (child->widget))
+        {
+          gtk_widget_get_preferred_width_for_height (child->widget,
+                                                     avail_size, &child_size, &child_natural);
+
+          required_size += child_size;
+          required_natural += child_natural;
+
+          nvis_children += 1;
+        }
+    }
+
+  if (priv->center_widget != NULL &&
+      gtk_widget_get_visible (priv->center_widget))
+    {
+      gtk_widget_get_preferred_width (priv->center_widget,
+                                      &child_size, &child_natural);
+      required_size += child_size;
+      required_natural += child_natural;
+    }
+
+  if (nvis_children > 0)
+    {
+      required_size += nvis_children * priv->spacing;
+      required_natural += nvis_children * priv->spacing;
+    }
+
+  get_css_padding_and_border (widget, &css_borders);
+
+  required_size += css_borders.left + css_borders.right;
+  required_natural += css_borders.left + css_borders.right;
+
+  if (minimum_size)
+    *minimum_size = required_size;
+
+  if (natural_size)
+    *natural_size = required_natural;
+}
+
+static void
+gtk_action_bar_compute_size_for_opposing_orientation (GtkWidget *widget,
+                                                      gint       avail_size,
+                                                      gint      *minimum_size,
+                                                      gint      *natural_size)
+{
+  GtkActionBar *bar = GTK_ACTION_BAR (widget);
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (bar);
+  Child *child;
+  GList *children;
+  gint nvis_children;
+  gint computed_minimum = 0;
+  gint computed_natural = 0;
+  GtkRequestedSize *sizes;
+  GtkPackType packing;
+  gint size = 0;
+  gint i;
+  gint child_size;
+  gint child_minimum;
+  gint child_natural;
+  GtkBorder css_borders;
+
+  nvis_children = count_visible_children (bar);
+
+  if (nvis_children <= 0)
+    return;
+
+  sizes = g_newa (GtkRequestedSize, nvis_children);
+
+  /* Retrieve desired size for visible children */
+  for (i = 0, children = priv->children; children; children = children->next)
+    {
+      child = children->data;
+
+      if (gtk_widget_get_visible (child->widget))
+        {
+          gtk_widget_get_preferred_width (child->widget,
+                                          &sizes[i].minimum_size,
+                                          &sizes[i].natural_size);
+
+          size -= sizes[i].minimum_size;
+          sizes[i].data = child;
+          i += 1;
+        }
+    }
+
+  /* Bring children up to size first */
+  size = gtk_distribute_natural_allocation (MAX (0, avail_size), nvis_children, sizes);
+
+  /* Allocate child positions. */
+  for (packing = GTK_PACK_START; packing <= GTK_PACK_END; ++packing)
+    {
+      for (i = 0, children = priv->children; children; children = children->next)
+        {
+          child = children->data;
+
+          /* If widget is not visible, skip it. */
+          if (!gtk_widget_get_visible (child->widget))
+            continue;
+
+          /* If widget is packed differently skip it, but still increment i,
+           * since widget is visible and will be handled in next loop
+           * iteration.
+           */
+          if (child->pack_type != packing)
+            {
+              i++;
+              continue;
+            }
+
+          child_size = sizes[i].minimum_size;
+
+          gtk_widget_get_preferred_height_for_width (child->widget,
+                                                     child_size, &child_minimum, &child_natural);
+
+          computed_minimum = MAX (computed_minimum, child_minimum);
+          computed_natural = MAX (computed_natural, child_natural);
+        }
+      i += 1;
+    }
+
+  if (priv->center_widget != NULL &&
+      gtk_widget_get_visible (priv->center_widget))
+    {
+      gtk_widget_get_preferred_height (priv->center_widget,
+                                       &child_minimum, &child_natural);
+      computed_minimum = MAX (computed_minimum, child_minimum);
+      computed_natural = MAX (computed_natural, child_natural);
+    }
+
+  get_css_padding_and_border (widget, &css_borders);
+
+  computed_minimum += css_borders.top + css_borders.bottom;
+  computed_natural += css_borders.top + css_borders.bottom;
+
+  if (minimum_size)
+    *minimum_size = computed_minimum;
+
+  if (natural_size)
+    *natural_size = computed_natural;
+}
+
+static void
+gtk_action_bar_get_preferred_width (GtkWidget *widget,
+                                    gint      *minimum_size,
+                                    gint      *natural_size)
+{
+  gtk_action_bar_get_size (widget, GTK_ORIENTATION_HORIZONTAL, minimum_size, natural_size);
+}
+
+static void
+gtk_action_bar_get_preferred_height (GtkWidget *widget,
+                                     gint      *minimum_size,
+                                     gint      *natural_size)
+{
+  gtk_action_bar_get_size (widget, GTK_ORIENTATION_VERTICAL, minimum_size, natural_size);
+}
+
+static void
+gtk_action_bar_get_preferred_width_for_height (GtkWidget *widget,
+                                               gint       height,
+                                               gint      *minimum_width,
+                                               gint      *natural_width)
+{
+  gtk_action_bar_compute_size_for_orientation (widget, height, minimum_width, natural_width);
+}
+
+static void
+gtk_action_bar_get_preferred_height_for_width (GtkWidget *widget,
+                                               gint       width,
+                                               gint      *minimum_height,
+                                               gint      *natural_height)
+{
+  gtk_action_bar_compute_size_for_opposing_orientation (widget, width, minimum_height, natural_height);
+}
+
+static void
+gtk_action_bar_size_allocate (GtkWidget     *widget,
+                              GtkAllocation *allocation)
+{
+  GtkActionBar *bar = GTK_ACTION_BAR (widget);
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (bar);
+  GtkRequestedSize *sizes;
+  gint width, height;
+  gint nvis_children;
+  gint center_minimum_size;
+  gint center_natural_size;
+  gint start_width, end_width;
+  gint side[2];
+  GList *l;
+  gint i;
+  Child *child;
+  GtkPackType packing;
+  GtkAllocation child_allocation;
+  gint x;
+  gint child_size;
+  GtkTextDirection direction;
+  GtkBorder css_borders;
+
+  gtk_widget_set_allocation (widget, allocation);
+
+  direction = gtk_widget_get_direction (widget);
+  nvis_children = count_visible_children (bar);
+  sizes = g_newa (GtkRequestedSize, nvis_children);
+
+  get_css_padding_and_border (widget, &css_borders);
+  width = allocation->width - nvis_children * priv->spacing - css_borders.left - css_borders.right;
+  height = allocation->height - css_borders.top - css_borders.bottom;
+
+  i = 0;
+  for (l = priv->children; l; l = l->next)
+    {
+      child = l->data;
+      if (!gtk_widget_get_visible (child->widget))
+        continue;
+
+      gtk_widget_get_preferred_width_for_height (child->widget,
+                                                 height,
+                                                 &sizes[i].minimum_size,
+                                                 &sizes[i].natural_size);
+      width -= sizes[i].minimum_size;
+      i++;
+    }
+
+  if (priv->center_widget)
+    {
+      gtk_widget_get_preferred_width_for_height (priv->center_widget,
+                                                 height,
+                                                 &center_minimum_size,
+                                                 &center_natural_size);
+    }
+
+  width -= center_natural_size;
+
+  start_width = 0;
+  end_width = 0;
+
+  width = gtk_distribute_natural_allocation (MAX (0, width), nvis_children, sizes);
+
+  side[0] = side[1] = 0;
+  for (packing = GTK_PACK_START; packing <= GTK_PACK_END; packing++)
+    {
+      child_allocation.y = allocation->y + css_borders.top;
+      child_allocation.height = height;
+      if (packing == GTK_PACK_START)
+        x = allocation->x + css_borders.left + start_width;
+      else
+        x = allocation->x + allocation->width - end_width - css_borders.right;
+
+      if (packing == GTK_PACK_START)
+        {
+          l = priv->children;
+          i = 0;
+        }
+      else
+        {
+          l = g_list_last (priv->children);
+          i = nvis_children - 1;
+        }
+
+      for (; l != NULL; (packing == GTK_PACK_START) ? (l = l->next) : (l = l->prev))
+        {
+          child = l->data;
+          if (!gtk_widget_get_visible (child->widget))
+            continue;
+
+          if (child->pack_type != packing)
+            goto next;
+
+          child_size = sizes[i].minimum_size;
+
+          child_allocation.width = child_size;
+
+          if (packing == GTK_PACK_START)
+            {
+              child_allocation.x = x;
+              x += child_size;
+              x += priv->spacing;
+            }
+          else
+            {
+              x -= child_size;
+              child_allocation.x = x;
+              x -= priv->spacing;
+            }
+
+          side[packing] += child_size + priv->spacing;
+
+          if (direction == GTK_TEXT_DIR_RTL)
+            child_allocation.x = allocation->x + allocation->width - (child_allocation.x - allocation->x) - child_allocation.width;
+
+          gtk_widget_size_allocate (child->widget, &child_allocation);
+
+        next:
+          if (packing == GTK_PACK_START)
+            i++;
+          else
+            i--;
+        }
+    }
+
+  side[GTK_PACK_START] += start_width;
+  side[GTK_PACK_END] += end_width;
+
+  child_allocation.y = allocation->y + css_borders.top;
+  child_allocation.height = height;
+
+  width = MAX (side[0], side[1]);
+
+  if (allocation->width - 2 * width >= center_natural_size)
+    child_size = MIN (center_natural_size, allocation->width - 2 * width);
+  else if (allocation->width - side[0] - side[1] >= center_natural_size)
+    child_size = MIN (center_natural_size, allocation->width - side[0] - side[1]);
+  else
+    child_size = allocation->width - side[0] - side[1];
+
+  child_allocation.x = allocation->x + (allocation->width - child_size) / 2;
+  child_allocation.width = child_size;
+
+  if (allocation->x + side[0] > child_allocation.x)
+    child_allocation.x = allocation->x + side[0];
+  else if (allocation->x + allocation->width - side[1] < child_allocation.x + child_allocation.width)
+    child_allocation.x = allocation->x + allocation->width - side[1] - child_allocation.width;
+
+  if (direction == GTK_TEXT_DIR_RTL)
+    child_allocation.x = allocation->x + allocation->width - (child_allocation.x - allocation->x) - child_allocation.width;
+
+  if (priv->center_widget)
+    gtk_widget_size_allocate (priv->center_widget, &child_allocation);
+}
+
+/**
+ * gtk_action_bar_set_center_widget:
+ * @bar: a #GtkActionBar
+ * @center_widget: (allow-none): a widget to use for the center
+ *
+ * Sets the center widget for the #GtkActionBar.
+ *
+ * Since: 3.12
+ */
+void
+gtk_action_bar_set_center_widget (GtkActionBar *bar,
+                                  GtkWidget    *center_widget)
+{
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (bar);
+
+  g_return_if_fail (GTK_IS_ACTION_BAR (bar));
+  if (center_widget)
+    g_return_if_fail (GTK_IS_WIDGET (center_widget));
+
+  /* No need to do anything if the center widget stays the same */
+  if (priv->center_widget == center_widget)
+    return;
+
+  if (priv->center_widget)
+    {
+      GtkWidget *center = priv->center_widget;
+
+      priv->center_widget = NULL;
+      gtk_widget_unparent (center);
+    }
+
+  if (center_widget != NULL)
+    {
+      priv->center_widget = center_widget;
+
+      gtk_widget_set_parent (priv->center_widget, GTK_WIDGET (bar));
+      gtk_widget_set_valign (priv->center_widget, GTK_ALIGN_CENTER);
+      gtk_widget_show (center_widget);
+    }
+  else
+    {
+      construct_center_widget (bar);
+    }
+
+  gtk_widget_queue_resize (GTK_WIDGET (bar));
+
+  g_object_notify (G_OBJECT (bar), "center-widget");
+}
+
+/**
+ * gtk_action_bar_get_center_widget:
+ * @bar: a #GtkActionBar
+ *
+ * Retrieves the center box widget of the bar.
+ *
+ * Return value: (transfer none): the center #GtkBox.
+ *
+ * Since: 3.12
+ */
+GtkWidget *
+gtk_action_bar_get_center_widget (GtkActionBar *bar)
+{
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (bar);
+
+  g_return_val_if_fail (GTK_IS_ACTION_BAR (bar), NULL);
+
+  return priv->center_widget;
+}
+
+static void
+gtk_action_bar_finalize (GObject *object)
+{
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (GTK_ACTION_BAR (object));
+
+  g_list_free (priv->children);
+
+  G_OBJECT_CLASS (gtk_action_bar_parent_class)->finalize (object);
+}
+
+static void
+gtk_action_bar_get_property (GObject    *object,
+                             guint       prop_id,
+                             GValue     *value,
+                             GParamSpec *pspec)
+{
+  GtkActionBar *bar = GTK_ACTION_BAR (object);
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (bar);
+
+  switch (prop_id)
+    {
+    case PROP_SPACING:
+      g_value_set_int (value, priv->spacing);
+      break;
+
+    case PROP_CENTER_WIDGET:
+      g_value_set_object (value, priv->center_widget);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gtk_action_bar_set_property (GObject      *object,
+                             guint         prop_id,
+                             const GValue *value,
+                             GParamSpec   *pspec)
+{
+  GtkActionBar *bar = GTK_ACTION_BAR (object);
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (bar);
+
+  switch (prop_id)
+    {
+    case PROP_SPACING:
+      priv->spacing = g_value_get_int (value);
+      gtk_widget_queue_resize (GTK_WIDGET (bar));
+      break;
+
+    case PROP_CENTER_WIDGET:
+      gtk_action_bar_set_center_widget (bar, g_value_get_object (value));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gtk_action_bar_pack (GtkActionBar *bar,
+                     GtkWidget    *widget,
+                     GtkPackType   pack_type)
+{
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (bar);
+  Child *child;
+
+  g_return_if_fail (gtk_widget_get_parent (widget) == NULL);
+
+  child = g_new (Child, 1);
+  child->widget = widget;
+  child->pack_type = pack_type;
+
+  priv->children = g_list_append (priv->children, child);
+
+  gtk_widget_freeze_child_notify (widget);
+  gtk_widget_set_parent (widget, GTK_WIDGET (bar));
+  gtk_widget_child_notify (widget, "pack-type");
+  gtk_widget_child_notify (widget, "position");
+  gtk_widget_thaw_child_notify (widget);
+}
+
+static void
+gtk_action_bar_add (GtkContainer *container,
+                    GtkWidget    *child)
+{
+  gtk_action_bar_pack (GTK_ACTION_BAR (container), child, GTK_PACK_START);
+}
+
+static GList *
+find_child_link (GtkActionBar *bar,
+                 GtkWidget    *widget)
+{
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (bar);
+  GList *l;
+  Child *child;
+
+  for (l = priv->children; l; l = l->next)
+    {
+      child = l->data;
+      if (child->widget == widget)
+        return l;
+    }
+
+  return NULL;
+}
+
+static void
+gtk_action_bar_remove (GtkContainer *container,
+                       GtkWidget    *widget)
+{
+  GtkActionBar *bar = GTK_ACTION_BAR (container);
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (bar);
+  GList *l;
+  Child *child;
+
+  l = find_child_link (bar, widget);
+  if (l)
+    {
+      child = l->data;
+      gtk_widget_unparent (child->widget);
+      priv->children = g_list_delete_link (priv->children, l);
+      g_free (child);
+      gtk_widget_queue_resize (GTK_WIDGET (container));
+    }
+}
+
+static void
+gtk_action_bar_forall (GtkContainer *container,
+                       gboolean      include_internals,
+                       GtkCallback   callback,
+                       gpointer      callback_data)
+{
+  GtkActionBar *bar = GTK_ACTION_BAR (container);
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (bar);
+  Child *child;
+  GList *children;
+
+  children = priv->children;
+  while (children)
+    {
+      child = children->data;
+      children = children->next;
+      if (child->pack_type == GTK_PACK_START)
+        (* callback) (child->widget, callback_data);
+    }
+
+  if (priv->center_widget != NULL)
+    (* callback) (priv->center_widget, callback_data);
+
+  children = priv->children;
+  while (children)
+    {
+      child = children->data;
+      children = children->next;
+      if (child->pack_type == GTK_PACK_END)
+        (* callback) (child->widget, callback_data);
+    }
+}
+
+static GType
+gtk_action_bar_child_type (GtkContainer *container)
+{
+  return GTK_TYPE_WIDGET;
+}
+
+static void
+gtk_action_bar_get_child_property (GtkContainer *container,
+                                   GtkWidget    *widget,
+                                   guint         property_id,
+                                   GValue       *value,
+                                   GParamSpec   *pspec)
+{
+  GtkActionBar *bar = GTK_ACTION_BAR (container);
+  GtkActionBarPrivate *priv = gtk_action_bar_get_instance_private (bar);
+  GList *l;
+  Child *child;
+
+  l = find_child_link (bar, widget);
+  if (l == NULL)
+    {
+      g_param_value_set_default (pspec, value);
+      return;
+    }
+
+  child = l->data;
+
+  switch (property_id)
+    {
+    case CHILD_PROP_PACK_TYPE:
+      g_value_set_enum (value, child->pack_type);
+      break;
+
+    case CHILD_PROP_POSITION:
+      g_value_set_int (value, g_list_position (priv->children, l));
+      break;
+
+    default:
+      GTK_CONTAINER_WARN_INVALID_CHILD_PROPERTY_ID (container, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gtk_action_bar_set_child_property (GtkContainer *container,
+                                   GtkWidget    *widget,
+                                   guint         property_id,
+                                   const GValue *value,
+                                   GParamSpec   *pspec)
+{
+  GList *l;
+  Child *child;
+
+  l = find_child_link (GTK_ACTION_BAR (container), widget);
+  child = l->data;
+
+  switch (property_id)
+    {
+    case CHILD_PROP_PACK_TYPE:
+      child->pack_type = g_value_get_enum (value);
+      break;
+    default:
+      GTK_CONTAINER_WARN_INVALID_CHILD_PROPERTY_ID (container, property_id, pspec);
+      break;
+    }
+}
+
+static GtkWidgetPath *
+gtk_action_bar_get_path_for_child (GtkContainer *container,
+                                   GtkWidget    *child)
+{
+  GtkActionBar *bar = GTK_ACTION_BAR (container);
+  GtkWidgetPath *path, *sibling_path;
+  GList *list, *children;
+
+  path = _gtk_widget_create_path (GTK_WIDGET (container));
+
+  if (gtk_widget_get_visible (child))
+    {
+      gint i, position;
+
+      sibling_path = gtk_widget_path_new ();
+
+      /* get_all_children works in reverse (!) visible order */
+      children = _gtk_container_get_all_children (container);
+      if (gtk_widget_get_direction (GTK_WIDGET (bar)) == GTK_TEXT_DIR_LTR)
+        children = g_list_reverse (children);
+
+      position = -1;
+      i = 0;
+      for (list = children; list; list = list->next)
+        {
+          if (!gtk_widget_get_visible (list->data))
+            continue;
+
+          gtk_widget_path_append_for_widget (sibling_path, list->data);
+
+          if (list->data == child)
+            position = i;
+          i++;
+        }
+      g_list_free (children);
+
+      if (position >= 0)
+        gtk_widget_path_append_with_siblings (path, sibling_path, position);
+      else
+        gtk_widget_path_append_for_widget (path, child);
+
+      gtk_widget_path_unref (sibling_path);
+    }
+  else
+    gtk_widget_path_append_for_widget (path, child);
+
+  return path;
+}
+
+static gint
+gtk_action_bar_draw (GtkWidget *widget,
+                     cairo_t   *cr)
+{
+  GtkStyleContext *context;
+
+  context = gtk_widget_get_style_context (widget);
+
+  gtk_render_background (context, cr, 0, 0,
+                         gtk_widget_get_allocated_width (widget),
+                         gtk_widget_get_allocated_height (widget));
+  gtk_render_frame (context, cr, 0, 0,
+                    gtk_widget_get_allocated_width (widget),
+                    gtk_widget_get_allocated_height (widget));
+
+
+  GTK_WIDGET_CLASS (gtk_action_bar_parent_class)->draw (widget, cr);
+
+  return TRUE;
+}
+
+static void
+gtk_action_bar_class_init (GtkActionBarClass *class)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
+  GtkContainerClass *container_class = GTK_CONTAINER_CLASS (class);
+
+  object_class->finalize = gtk_action_bar_finalize;
+  object_class->get_property = gtk_action_bar_get_property;
+  object_class->set_property = gtk_action_bar_set_property;
+
+  widget_class->size_allocate = gtk_action_bar_size_allocate;
+  widget_class->get_preferred_width = gtk_action_bar_get_preferred_width;
+  widget_class->get_preferred_height = gtk_action_bar_get_preferred_height;
+  widget_class->get_preferred_height_for_width = gtk_action_bar_get_preferred_height_for_width;
+  widget_class->get_preferred_width_for_height = gtk_action_bar_get_preferred_width_for_height;
+  widget_class->draw = gtk_action_bar_draw;
+
+  container_class->add = gtk_action_bar_add;
+  container_class->remove = gtk_action_bar_remove;
+  container_class->forall = gtk_action_bar_forall;
+  container_class->child_type = gtk_action_bar_child_type;
+  container_class->set_child_property = gtk_action_bar_set_child_property;
+  container_class->get_child_property = gtk_action_bar_get_child_property;
+  container_class->get_path_for_child = gtk_action_bar_get_path_for_child;
+  gtk_container_class_handle_border_width (container_class);
+
+  gtk_container_class_install_child_property (container_class,
+                                              CHILD_PROP_PACK_TYPE,
+                                              g_param_spec_enum ("pack-type",
+                                                                 P_("Pack type"),
+                                                                 P_("A GtkPackType indicating whether the child is packed with reference to the start or end of the parent"),
+                                                                 GTK_TYPE_PACK_TYPE, GTK_PACK_START,
+                                                                 GTK_PARAM_READWRITE));
+  gtk_container_class_install_child_property (container_class,
+                                              CHILD_PROP_POSITION,
+                                              g_param_spec_int ("position",
+                                                                P_("Position"),
+                                                                P_("The index of the child in the parent"),
+                                                                -1, G_MAXINT, 0,
+                                                                GTK_PARAM_READABLE));
+
+  g_object_class_install_property (object_class,
+                                   PROP_SPACING,
+                                   g_param_spec_int ("spacing",
+                                                     P_("Spacing"),
+                                                     P_("The amount of space between children"),
+                                                     0, G_MAXINT,
+                                                     DEFAULT_SPACING,
+                                                     GTK_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class,
+                                   PROP_CENTER_WIDGET,
+                                   g_param_spec_object ("center-widget",
+                                                        P_("Center Widget"),
+                                                        P_("Widget to display in center"),
+                                                        GTK_TYPE_WIDGET,
+                                                        G_PARAM_READWRITE |
+                                                        G_PARAM_CONSTRUCT |
+                                                        G_PARAM_STATIC_STRINGS));
+
+  gtk_widget_class_set_accessible_role (widget_class, ATK_ROLE_PANEL);
+}
+
+static void
+gtk_action_bar_buildable_add_child (GtkBuildable *buildable,
+                                    GtkBuilder   *builder,
+                                    GObject      *child,
+                                    const gchar  *type)
+{
+  if (type && strcmp (type, "center") == 0)
+    gtk_action_bar_set_center_widget (GTK_ACTION_BAR (buildable), GTK_WIDGET (child));
+  else if (!type)
+    gtk_container_add (GTK_CONTAINER (buildable), GTK_WIDGET (child));
+  else
+    GTK_BUILDER_WARN_INVALID_CHILD_TYPE (GTK_ACTION_BAR (buildable), type);
+}
+
+static void
+gtk_action_bar_buildable_init (GtkBuildableIface *iface)
+{
+  iface->add_child = gtk_action_bar_buildable_add_child;
+}
+
+/**
+ * gtk_action_bar_pack_start:
+ * @bar: A #GtkActionBar
+ * @child: the #GtkWidget to be added to @bar
+ *
+ * Adds @child to @box, packed with reference to the
+ * start of the @box.
+ *
+ * Since: 3.12
+ */
+void
+gtk_action_bar_pack_start (GtkActionBar *bar,
+                           GtkWidget    *child)
+{
+  gtk_action_bar_pack (bar, child, GTK_PACK_START);
+}
+
+/**
+ * gtk_action_bar_pack_end:
+ * @bar: A #GtkActionBar
+ * @child: the #GtkWidget to be added to @bar
+ *
+ * Adds @child to @box, packed with reference to the
+ * end of the @box.
+ *
+ * Since: 3.12
+ */
+void
+gtk_action_bar_pack_end (GtkActionBar *bar,
+                         GtkWidget    *child)
+{
+  gtk_action_bar_pack (bar, child, GTK_PACK_END);
+}
+
+/**
+ * gtk_action_bar_new:
+ *
+ * Creates a new #GtkActionBar widget.
+ *
+ * Returns: a new #GtkActionBar
+ *
+ * Since: 3.12
+ */
+GtkWidget *
+gtk_action_bar_new (void)
+{
+  return GTK_WIDGET (g_object_new (GTK_TYPE_ACTION_BAR, NULL));
+}