[gthumb] image overview: fixed pointer grub

[Paolo Bacchilega <paobac src gnome org>]

commit 60c7ea0395b9db6b8a0f7d8a185137af8e8aebf0
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Sat Nov 9 19:30:26 2013 +0100

    image overview: fixed pointer grub

 gthumb/gth-image-overview.c |  155 ++++++++++++++++++++++++++++++++++++++-----
 1 files changed, 139 insertions(+), 16 deletions(-)
---
diff --git a/gthumb/gth-image-overview.c b/gthumb/gth-image-overview.c
index 9ee328b..39ddc05 100644
--- a/gthumb/gth-image-overview.c
+++ b/gthumb/gth-image-overview.c
@@ -59,6 +59,8 @@ struct _GthImageOverviewPrivate {
        gulong                   hadj_changed_id;
        gboolean                 scrolling_active;
        gboolean                 update_preview;
+       GdkDevice               *grab_pointer;
+       GdkDevice               *grab_keyboard;
 };
 
 
@@ -366,7 +368,9 @@ gth_image_overview_realize (GtkWidget *widget)
                                  | GDK_POINTER_MOTION_MASK
                                  | GDK_POINTER_MOTION_HINT_MASK
                                  | GDK_BUTTON_MOTION_MASK
-                                 | GDK_SCROLL_MASK);
+                                 | GDK_SCROLL_MASK
+                                 | GDK_KEY_PRESS_MASK
+                                 | GDK_KEY_RELEASE_MASK);
        attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL;
        window = gdk_window_new (gtk_widget_get_parent_window (widget), &attributes, attributes_mask);
        gtk_widget_register_window (widget, window);
@@ -376,6 +380,23 @@ gth_image_overview_realize (GtkWidget *widget)
 
 
 static void
+_gth_image_overview_ungrab_devices (GthImageOverview *self,
+                                   guint32           time);
+
+
+static void
+gth_image_overview_unmap (GtkWidget *widget)
+{
+       GthImageOverview *self;
+
+       self = GTH_IMAGE_OVERVIEW (widget);
+       _gth_image_overview_ungrab_devices (self, GDK_CURRENT_TIME);
+
+       GTK_WIDGET_CLASS (gth_image_overview_parent_class)->unmap (widget);
+}
+
+
+static void
 gth_image_overview_size_allocate (GtkWidget     *widget,
                                  GtkAllocation *allocation)
 {
@@ -597,6 +618,7 @@ gth_image_overview_class_init (GthImageOverviewClass *klass)
 
        widget_class = (GtkWidgetClass *) klass;
        widget_class->realize = gth_image_overview_realize;
+       widget_class->unmap = gth_image_overview_unmap;
        widget_class->size_allocate = gth_image_overview_size_allocate;
        widget_class->draw = gth_image_overview_draw;
        widget_class->button_press_event = gth_image_overview_button_press_event;
@@ -652,6 +674,11 @@ gth_image_overview_init (GthImageOverview *self)
        self->priv->hadj_changed_id = 0;
        self->priv->scrolling_active = FALSE;
        self->priv->update_preview = TRUE;
+       self->priv->grab_pointer = NULL;
+       self->priv->grab_keyboard = NULL;
+
+       gtk_widget_set_has_window (GTK_WIDGET (self), TRUE);
+       gtk_widget_set_can_focus (GTK_WIDGET (self), TRUE);
 
        g_signal_connect (self, "notify::visible", G_CALLBACK (notify_visible_cb), NULL);
 
@@ -699,6 +726,78 @@ gth_image_overview_get_visible_area (GthImageOverview      *self,
 }
 
 
+static gboolean
+_gth_image_overview_grab_devices (GthImageOverview     *self,
+                                 GdkDevice             *keyboard,
+                                 GdkDevice             *pointer,
+                                 GdkCursor             *cursor,
+                                 guint32                time)
+{
+       if (keyboard != NULL) {
+               if (gdk_device_grab (keyboard,
+                                    gtk_widget_get_window (GTK_WIDGET (self)),
+                                    GDK_OWNERSHIP_WINDOW,
+                                    FALSE,
+                                    (GDK_KEY_PRESS_MASK | GDK_KEY_RELEASE_MASK),
+                                    NULL,
+                                    time) != GDK_GRAB_SUCCESS)
+               {
+                       return FALSE;
+               }
+       }
+
+       if (pointer != NULL) {
+               if (gdk_device_grab (pointer,
+                                    gtk_widget_get_window (GTK_WIDGET (self)),
+                                    GDK_OWNERSHIP_WINDOW,
+                                    FALSE,
+                                    (GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK | 
GDK_POINTER_MOTION_MASK | GDK_SCROLL_MASK),
+                                    cursor,
+                                    time) != GDK_GRAB_SUCCESS)
+               {
+                       if (keyboard != NULL)
+                               gdk_device_ungrab (keyboard, time);
+
+                       return FALSE;
+               }
+       }
+
+       return TRUE;
+}
+
+
+static void
+_gth_image_overview_ungrab_devices (GthImageOverview *self,
+                                   guint32           time)
+{
+       if (self->priv->grab_pointer != NULL) {
+               gdk_device_ungrab (self->priv->grab_pointer, time);
+               gtk_device_grab_remove (GTK_WIDGET (self), self->priv->grab_pointer);
+               self->priv->grab_pointer = NULL;
+       }
+       if (self->priv->grab_keyboard != NULL) {
+               gdk_device_ungrab (self->priv->grab_keyboard, time);
+               self->priv->grab_keyboard = NULL;
+       }
+
+       self->priv->scrolling_active = FALSE;
+}
+
+
+static gboolean
+_gth_image_overview_grab_broken_event (GtkWidget          *widget,
+                                      GdkEventGrabBroken *event,
+                                      gpointer            user_data)
+{
+       GthImageOverview *self = user_data;
+
+       if (event->grab_window == NULL)
+               _gth_image_overview_ungrab_devices (self, GDK_CURRENT_TIME);
+
+       return TRUE;
+}
+
+
 void
 gth_image_overview_activate_scrolling (GthImageOverview        *self,
                                       gboolean          active,
@@ -706,30 +805,54 @@ gth_image_overview_activate_scrolling (GthImageOverview   *self,
 {
        g_return_if_fail (event != NULL);
 
+       if (! gtk_widget_get_realized (GTK_WIDGET (self)))
+               return;
+
        if (active && ! self->priv->scrolling_active) {
+               GdkDevice *device;
+               GdkDevice *pointer;
+               GdkDevice *keyboard;
                GdkCursor *cursor;
 
-               gtk_widget_realize (GTK_WIDGET (self));
-               gtk_grab_add (GTK_WIDGET (self));
+               if ((self->priv->grab_pointer != NULL) || (self->priv->grab_keyboard != NULL))
+                       return;
+
+               gtk_widget_grab_focus (GTK_WIDGET (self));
 
                /* capture mouse events */
 
+               device = gdk_event_get_device ((GdkEvent *) event);
+               if (gdk_device_get_source (device) == GDK_SOURCE_KEYBOARD) {
+                       keyboard = device;
+                       pointer = gdk_device_get_associated_device (device);
+               }
+               else {
+                       pointer = device;
+                       keyboard = gdk_device_get_associated_device (device);
+               }
+
                cursor = gdk_cursor_new_for_display (gtk_widget_get_display (GTK_WIDGET 
(self->priv->viewer)), GDK_FLEUR);
-               gdk_device_grab (gdk_event_get_device ((GdkEvent *) event),
-                                gtk_widget_get_window (GTK_WIDGET (self)),
-                                GDK_OWNERSHIP_WINDOW,
-                                FALSE,
-                                GDK_ALL_EVENTS_MASK,
-                                cursor,
-                                event->time);
-               g_object_unref (cursor);
 
-               gtk_widget_grab_focus (GTK_WIDGET (self));
-       }
-       else if (! active && self->priv->scrolling_active) {
-               gdk_device_ungrab (gdk_event_get_device ((GdkEvent *) event), event->time);
-               gtk_grab_remove (GTK_WIDGET (self));
+               if (_gth_image_overview_grab_devices (self,
+                                                     keyboard,
+                                                     pointer,
+                                                     cursor,
+                                                     event->time))
+               {
+                       self->priv->grab_pointer = pointer;
+                       self->priv->grab_keyboard = keyboard;
+                       gtk_device_grab_add (GTK_WIDGET (self), self->priv->grab_pointer, TRUE);
+
+                       g_signal_connect (self,
+                                         "grab-broken-event",
+                                         G_CALLBACK (_gth_image_overview_grab_broken_event),
+                                         self);
+               }
+
+               g_object_unref (cursor);
        }
+       else if (! active && self->priv->scrolling_active)
+               _gth_image_overview_ungrab_devices (self, event->time);
 
        self->priv->scrolling_active = active;
 }