[gtk+/popovers: 1/17] window: Add lowlevel popovers API

[Carlos Garnacho <carlosg src gnome org>]

commit 2baa1b0a6467da582a601b0c8b39aeb3bc717013
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu Nov 7 23:49:21 2013 +0100

    window: Add lowlevel popovers API
    
    Popovers are transient floating widgets that are confined to the
    window space. These have their own GdkWindow that is set on top
    of the regular window contents, so they can be used for popup menu
    alike UIs with custom popup/popdown/grabs behavior.

 gtk/gtkwindow.c |  238 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 gtk/gtkwindow.h |   12 +++
 2 files changed, 250 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index 93aab3e..27c8d79 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -118,6 +118,15 @@
 #define MNEMONICS_DELAY 300 /* ms */
 
 typedef struct _GtkDeviceGrabInfo GtkDeviceGrabInfo;
+typedef struct _GtkWindowPopover GtkWindowPopover;
+
+struct _GtkWindowPopover
+{
+  GtkWidget *widget;
+  GdkWindow *window;
+  gint x;
+  gint y;
+};
 
 struct _GtkWindowPrivate
 {
@@ -132,6 +141,8 @@ struct _GtkWindowPrivate
   GdkScreen             *screen;
   GtkApplication        *application;
 
+  GHashTable            *popovers;
+
   GdkModifierType        mnemonic_modifier;
   GdkWindowTypeHint      gdk_type_hint;
 
@@ -1260,6 +1271,18 @@ gtk_window_close (GtkWindow *window)
 }
 
 static void
+popover_destroy (GtkWindowPopover *popover)
+{
+  if (popover->widget)
+    gtk_widget_unparent (popover->widget);
+
+  if (popover->window)
+    gdk_window_destroy (popover->window);
+
+  g_free (popover);
+}
+
+static void
 gtk_window_init (GtkWindow *window)
 {
   GtkStyleContext *context;
@@ -1309,6 +1332,8 @@ gtk_window_init (GtkWindow *window)
   priv->has_resize_grip = TRUE;
   priv->mnemonics_visible = TRUE;
   priv->focus_visible = TRUE;
+  priv->popovers = g_hash_table_new_full (NULL, NULL, NULL,
+                                          (GDestroyNotify) popover_destroy);
 
   g_object_ref_sink (window);
   priv->has_user_ref_count = TRUE;
@@ -5094,6 +5119,8 @@ gtk_window_finalize (GObject *object)
       priv->mnemonics_display_timeout_id = 0;
     }
 
+  g_hash_table_destroy (priv->popovers);
+
   G_OBJECT_CLASS (gtk_window_parent_class)->finalize (object);
 }
 
@@ -5476,6 +5503,19 @@ gtk_window_hide (GtkWidget *widget)
 }
 
 static void
+popover_map (GtkWidget        *widget,
+             GtkWindowPopover *popover)
+{
+  if (popover->window)
+    {
+      gdk_window_show (popover->window);
+
+      if (gtk_widget_get_visible (popover->widget))
+        gtk_widget_map (popover->widget);
+    }
+}
+
+static void
 gtk_window_map (GtkWidget *widget)
 {
   GtkWidget *child;
@@ -5585,6 +5625,8 @@ gtk_window_map (GtkWidget *widget)
     gtk_window_set_focus_visible (window, gtk_window_get_focus_visible (priv->transient_parent));
   else
     gtk_window_set_focus_visible (window, FALSE);
+
+  g_hash_table_foreach (priv->popovers, (GHFunc) popover_map, window);
 }
 
 static gboolean
@@ -5606,6 +5648,18 @@ gtk_window_map_event (GtkWidget   *widget,
 }
 
 static void
+popover_unmap (GtkWidget        *widget,
+               GtkWindowPopover *popover)
+{
+  if (popover->window)
+    {
+      if (gtk_widget_is_visible (popover->widget))
+        gtk_widget_unmap (popover->widget);
+      gdk_window_hide (popover->window);
+    }
+}
+
+static void
 gtk_window_unmap (GtkWidget *widget)
 {
   GtkWindow *window = GTK_WINDOW (widget);
@@ -5621,6 +5675,7 @@ gtk_window_unmap (GtkWidget *widget)
       return;
     }
 
+  g_hash_table_foreach (priv->popovers, (GHFunc) popover_unmap, window);
   gdk_window = gtk_widget_get_window (widget);
 
   gtk_widget_set_mapped (widget, FALSE);
@@ -5754,6 +5809,40 @@ gtk_window_get_remembered_size (GtkWindow *window,
 }
 
 static void
+popover_realize (GtkWidget        *widget,
+                 GtkWindowPopover *popover,
+                 GtkWindow        *window)
+{
+  GdkWindow *parent_window;
+  GdkWindowAttr attributes;
+  GtkAllocation allocation;
+  gint attributes_mask;
+
+  if (popover->window)
+    return;
+
+  gtk_widget_get_allocation (widget, &allocation);
+
+  attributes.window_type = GDK_WINDOW_CHILD;
+  attributes.wclass = GDK_INPUT_OUTPUT;
+  attributes.x = popover->x;
+  attributes.y = popover->y;
+  attributes.width = allocation.width;
+  attributes.height = allocation.height;
+  attributes.visual = gtk_widget_get_visual (widget);
+  attributes.event_mask = gtk_widget_get_events (popover->widget) |
+    GDK_EXPOSURE_MASK;
+  attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL;
+
+  parent_window = gtk_widget_get_window (GTK_WIDGET (window));
+  popover->window =
+    gdk_window_new (parent_window, &attributes, attributes_mask);
+  gtk_widget_register_window (GTK_WIDGET (window), popover->window);
+
+  gtk_widget_set_parent_window (popover->widget, popover->window);
+}
+
+static void
 gtk_window_realize (GtkWidget *widget)
 {
   GtkAllocation allocation;
@@ -5998,6 +6087,8 @@ gtk_window_realize (GtkWidget *widget)
   if (priv->has_resize_grip)
     resize_grip_create_window (window);
 
+  g_hash_table_foreach (priv->popovers, (GHFunc) popover_realize, window);
+
   old_scale = priv->scale;
   priv->scale = gtk_widget_get_scale_factor (widget);
   if (old_scale != priv->scale)
@@ -6005,6 +6096,15 @@ gtk_window_realize (GtkWidget *widget)
 }
 
 static void
+popover_unrealize (GtkWidget        *widget,
+                   GtkWindowPopover *popover)
+{
+  gtk_widget_unrealize (popover->widget);
+  gdk_window_destroy (popover->window);
+  popover->window = NULL;
+}
+
+static void
 gtk_window_unrealize (GtkWidget *widget)
 {
   GtkWindow *window = GTK_WINDOW (widget);
@@ -6054,6 +6154,8 @@ gtk_window_unrealize (GtkWidget *widget)
         }
     }
 
+  g_hash_table_foreach (priv->popovers, (GHFunc) popover_unrealize, window);
+
   GTK_WIDGET_CLASS (gtk_window_parent_class)->unrealize (widget);
 }
 
@@ -6772,6 +6874,52 @@ _gtk_window_set_allocation (GtkWindow           *window,
 }
 
 static void
+popover_size_allocate (GtkWidget        *widget,
+                       GtkWindowPopover *popover,
+                       GtkWindow        *window)
+{
+  GtkAllocation allocation, window_alloc;
+  GtkRequisition child_req;
+  gint x, y;
+
+  if (!popover->window)
+    return;
+
+  gtk_widget_get_allocation (GTK_WIDGET (window), &window_alloc);
+  gtk_widget_get_preferred_size (widget, &child_req, NULL);
+  allocation.x = allocation.y = 0;
+  allocation.width = child_req.width;
+  allocation.height = child_req.height;
+
+  x = popover->x;
+  y = popover->y;
+
+  if (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL)
+    x -= allocation.width;
+
+  x = CLAMP (x, 0, window_alloc.width - allocation.width);
+  y = CLAMP (y, 0, window_alloc.height - allocation.height);
+
+  if (gtk_widget_get_hexpand (widget))
+    {
+      if (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_LTR)
+        allocation.width = window_alloc.width - x;
+      else
+        {
+          allocation.width += x;
+          x = 0;
+        }
+    }
+
+  if (gtk_widget_get_vexpand (widget))
+    allocation.height = window_alloc.height - y;
+
+  gdk_window_move_resize (popover->window, x, y,
+                          allocation.width, allocation.height);
+  gtk_widget_size_allocate (widget, &allocation);
+}
+
+static void
 gtk_window_size_allocate (GtkWidget     *widget,
                           GtkAllocation *allocation)
 {
@@ -6784,6 +6932,9 @@ gtk_window_size_allocate (GtkWidget     *widget,
   child = gtk_bin_get_child (GTK_BIN (window));
   if (child && gtk_widget_get_visible (child))
     gtk_widget_size_allocate (child, &child_allocation);
+
+  g_hash_table_foreach (window->priv->popovers,
+                        (GHFunc) popover_size_allocate, widget);
 }
 
 static gint
@@ -9347,10 +9498,12 @@ gtk_window_draw (GtkWidget *widget,
                 cairo_t   *cr)
 {
   GtkWindowPrivate *priv = GTK_WINDOW (widget)->priv;
+  GtkWindowPopover *popover;
   GtkStyleContext *context;
   gboolean ret = FALSE;
   GtkAllocation allocation;
   GtkBorder window_border;
+  GHashTableIter iter;
   gint title_height;
 
   context = gtk_widget_get_style_context (widget);
@@ -9435,6 +9588,16 @@ gtk_window_draw (GtkWidget *widget,
       gtk_style_context_restore (context);
     }
 
+  g_hash_table_iter_init (&iter, priv->popovers);
+
+  while (g_hash_table_iter_next (&iter, NULL, (gpointer*) &popover))
+    {
+      if (popover->window && gtk_widget_is_visible (popover->widget) &&
+          gtk_cairo_should_draw_window (cr, popover->window))
+        gtk_container_propagate_draw (GTK_CONTAINER (widget),
+                                      popover->widget, cr);
+    }
+
   return ret;
 }
 
@@ -11681,3 +11844,78 @@ _gtk_window_handle_button_press_for_widget (GtkWidget      *widget,
 
   return FALSE;
 }
+
+void
+gtk_window_add_popover (GtkWindow *window,
+                        GtkWidget *popover)
+{
+  GtkWindowPrivate *priv;
+  GtkWindowPopover *data;
+
+  g_return_if_fail (GTK_IS_WINDOW (window));
+  g_return_if_fail (GTK_IS_WIDGET (popover));
+  g_return_if_fail (gtk_widget_get_parent (popover) == NULL);
+
+  priv = window->priv;
+
+  if (g_hash_table_contains (priv->popovers, popover))
+    return;
+
+  data = g_new0 (GtkWindowPopover, 1);
+  data->widget = popover;
+  g_hash_table_insert (priv->popovers, popover, data);
+
+  if (gtk_widget_get_realized (GTK_WIDGET (window)))
+    popover_realize (popover, data, window);
+
+  gtk_widget_set_parent (popover, GTK_WIDGET (window));
+}
+
+void
+gtk_window_remove_popover (GtkWindow *window,
+                           GtkWidget *popover)
+{
+  GtkWindowPrivate *priv;
+
+  g_return_if_fail (GTK_IS_WINDOW (window));
+  g_return_if_fail (GTK_IS_WIDGET (popover));
+
+  priv = window->priv;
+  g_hash_table_remove (priv->popovers, popover);
+}
+
+void
+gtk_window_set_popover_position (GtkWindow     *window,
+                                 GtkWidget     *popover,
+                                 gint           x,
+                                 gint           y)
+{
+  GtkWindowPopover *data = NULL;
+  GtkWindowPrivate *priv;
+
+  g_return_if_fail (GTK_IS_WINDOW (window));
+  g_return_if_fail (GTK_IS_WIDGET (popover));
+
+  priv = window->priv;
+  data = g_hash_table_lookup (priv->popovers, popover);
+
+  if (!data)
+    {
+      g_warning ("Widget %s(%p) is not a popover of window %s",
+                 gtk_widget_get_name (popover), popover,
+                 gtk_widget_get_name (GTK_WIDGET (window)));
+      return;
+    }
+
+  data->x = x;
+  data->y = y;
+
+  if (!data->window && gtk_widget_get_realized (GTK_WIDGET (window)))
+    popover_realize (popover, data, window);
+
+  if (data->window && gtk_widget_is_visible (GTK_WIDGET (window)))
+    {
+      popover_size_allocate (popover, data, window);
+      popover_map (popover, data);
+    }
+}
diff --git a/gtk/gtkwindow.h b/gtk/gtkwindow.h
index 4324cb7..86af6c9 100644
--- a/gtk/gtkwindow.h
+++ b/gtk/gtkwindow.h
@@ -467,6 +467,18 @@ GDK_AVAILABLE_IN_3_10
 void     gtk_window_set_titlebar           (GtkWindow    *window,
                                             GtkWidget    *titlebar);
 
+GDK_AVAILABLE_IN_3_12
+void     gtk_window_add_popover            (GtkWindow     *window,
+                                            GtkWidget     *popover);
+GDK_AVAILABLE_IN_3_12
+void     gtk_window_remove_popover         (GtkWindow     *window,
+                                            GtkWidget     *popover);
+GDK_AVAILABLE_IN_3_12
+void     gtk_window_set_popover_position   (GtkWindow     *window,
+                                            GtkWidget     *popover,
+                                            gint           x,
+                                            gint           y);
+
 G_END_DECLS
 
 #endif /* __GTK_WINDOW_H__ */