[eog] EogScrollView: Hide and reveal the overlay buttons by mouse movement

[Felix Riemann <friemann src gnome org>]

commit 09f08726398111c9e8fcf2c25ac43110a5f4c560
Author: Felix Riemann <friemann gnome org>
Date:   Sat Jan 24 18:39:56 2015 +0100

    EogScrollView: Hide and reveal the overlay buttons by mouse movement

 src/eog-scroll-view.c |   94 +++++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 88 insertions(+), 6 deletions(-)
---
diff --git a/src/eog-scroll-view.c b/src/eog-scroll-view.c
index 6ed49d7..4821b79 100644
--- a/src/eog-scroll-view.c
+++ b/src/eog-scroll-view.c
@@ -182,6 +182,7 @@ struct _EogScrollViewPrivate {
        GtkWidget *left_revealer;
        GtkWidget *right_revealer;
        GtkWidget *bottom_revealer;
+       GSource   *overlay_timeout_source;
 };
 
 static void scroll_by (EogScrollView *view, int xofs, int yofs);
@@ -2671,6 +2672,80 @@ sv_rgba_to_string_mapping (const GValue       *value,
 }
 
 static void
+_clear_overlay_timeout (EogScrollView *view)
+{
+       EogScrollViewPrivate *priv = view->priv;
+
+       if (priv->overlay_timeout_source != NULL) {
+               g_source_unref (priv->overlay_timeout_source);
+               g_source_destroy (priv->overlay_timeout_source);
+       }
+
+       priv->overlay_timeout_source = NULL;
+}
+static gboolean
+_overlay_timeout_cb (gpointer data)
+{
+       EogScrollView *view = EOG_SCROLL_VIEW (data);
+       EogScrollViewPrivate *priv = view->priv;
+
+       gtk_revealer_set_reveal_child (GTK_REVEALER (priv->left_revealer), FALSE);
+       gtk_revealer_set_reveal_child (GTK_REVEALER (priv->right_revealer), FALSE);
+       gtk_revealer_set_reveal_child (GTK_REVEALER (priv->bottom_revealer), FALSE);
+
+       _clear_overlay_timeout (view);
+
+       return FALSE;
+}
+static void
+_set_overlay_timeout (EogScrollView *view)
+{
+       GSource *source;
+
+       _clear_overlay_timeout (view);
+
+       source = g_timeout_source_new_seconds (2);
+       g_source_set_callback (source, _overlay_timeout_cb, view, NULL);
+
+       g_source_attach (source, NULL);
+
+       view->priv->overlay_timeout_source = source;
+}
+
+static gboolean
+_enter_overlay_event_cb (GtkWidget *widget,
+                        GdkEvent *event,
+                        gpointer user_data)
+{
+       EogScrollView *view = EOG_SCROLL_VIEW (user_data);
+
+       _clear_overlay_timeout (view);
+
+       return FALSE;
+}
+
+static gboolean
+_motion_notify_cb (GtkWidget *widget, GdkEventMotion *event, gpointer user_data)
+{
+       EogScrollView *view = EOG_SCROLL_VIEW (user_data);
+       EogScrollViewPrivate *priv = view->priv;
+       gboolean reveal_child;
+
+       reveal_child = gtk_revealer_get_reveal_child (GTK_REVEALER (priv->left_revealer));
+
+       if (!reveal_child) {
+               gtk_revealer_set_reveal_child (GTK_REVEALER (priv->left_revealer), TRUE);
+               gtk_revealer_set_reveal_child (GTK_REVEALER (priv->right_revealer), TRUE);
+               gtk_revealer_set_reveal_child (GTK_REVEALER (priv->bottom_revealer), TRUE);
+       }
+
+       /* reset timeout */
+       _set_overlay_timeout(view);
+
+       return FALSE;
+}
+
+static void
 eog_scroll_view_init (EogScrollView *view)
 {
        GSettings *settings;
@@ -2895,12 +2970,19 @@ eog_scroll_view_init (EogScrollView *view)
 
        gtk_container_add (GTK_CONTAINER (priv->bottom_revealer), bottomBox);
 
-       /* Workaround to keep the buttons visible until the right signals
-        * are wired up.
-        */
-       gtk_revealer_set_reveal_child (GTK_REVEALER (priv->left_revealer), TRUE);
-       gtk_revealer_set_reveal_child (GTK_REVEALER (priv->right_revealer), TRUE);
-       gtk_revealer_set_reveal_child (GTK_REVEALER (priv->bottom_revealer), TRUE);
+       /* Display overlay buttons on mouse movement */
+       g_signal_connect (priv->display,
+                         "motion-notify-event",
+                         G_CALLBACK (_motion_notify_cb),
+                         view);
+
+       /* Don't hide overlay buttons when above */
+       gtk_widget_add_events (GTK_WIDGET (priv->overlay),
+                              GDK_ENTER_NOTIFY_MASK);
+       g_signal_connect (priv->overlay,
+                         "enter-notify-event",
+                         G_CALLBACK (_enter_overlay_event_cb),
+                         view);
 }
 
 static void