[eog] EogScrollView: Add overlay buttons to switch images

[Felix Riemann <friemann src gnome org>]

commit c3f1ba2a6317dd3698492964efdaae688c41a911
Author: Felix Riemann <friemann gnome org>
Date:   Sat Jan 24 17:38:01 2015 +0100

    EogScrollView: Add overlay buttons to switch images
    
    Revealing and hiding is not yet active.

 data/eog.css          |    9 +++++
 src/eog-scroll-view.c |   93 +++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 100 insertions(+), 2 deletions(-)
---
diff --git a/data/eog.css b/data/eog.css
index d8ea878..4d4be3c 100644
--- a/data/eog.css
+++ b/data/eog.css
@@ -9,3 +9,12 @@ GtkScrollbar#eog-image-gallery-scrollbar {
 GtkLabel#eog-sidebar-title {
        font-weight: bold;
 }
+
+EogScrollView GtkOverlay GtkButton {
+       opacity: 0.7;
+}
+
+EogScrollView GtkOverlay GtkButton:hover,
+EogScrollView GtkOverlay GtkButton:prelight {
+       opacity: 1.0;
+}
diff --git a/src/eog-scroll-view.c b/src/eog-scroll-view.c
index 72cb25e..6ed49d7 100644
--- a/src/eog-scroll-view.c
+++ b/src/eog-scroll-view.c
@@ -33,6 +33,9 @@
 #define CHECK_LIGHT "#cccccc"
 #define CHECK_WHITE "#ffffff"
 
+/* Time used for the realing animation of the overlaid buttons */
+#define OVERLAY_REVEAL_ANIM_TIME (500U) /* ms */
+
 #if 0
 /* Progressive loading state */
 typedef enum {
@@ -174,6 +177,11 @@ struct _EogScrollViewPrivate {
        gdouble initial_zoom;
        EogRotationState rotate_state;
        EogPanAction pan_action;
+
+       GtkWidget *overlay;
+       GtkWidget *left_revealer;
+       GtkWidget *right_revealer;
+       GtkWidget *bottom_revealer;
 };
 
 static void scroll_by (EogScrollView *view, int xofs, int yofs);
@@ -2703,6 +2711,10 @@ eog_scroll_view_init (EogScrollView *view)
                          view);
 
        priv->vbar = gtk_scrollbar_new (GTK_ORIENTATION_VERTICAL, priv->vadj);
+
+       priv->overlay = gtk_overlay_new ();
+       gtk_grid_attach (GTK_GRID (view), priv->overlay, 0, 0, 1, 1);
+
        priv->display = g_object_new (GTK_TYPE_DRAWING_AREA,
                                      "can-focus", TRUE,
                                      NULL);
@@ -2749,8 +2761,8 @@ eog_scroll_view_init (EogScrollView *view)
        g_signal_connect (G_OBJECT (priv->display), "drag-begin",
                          G_CALLBACK (view_on_drag_begin_cb), view);
 
-       gtk_grid_attach (GTK_GRID (view), priv->display,
-                        0, 0, 1, 1);
+       gtk_container_add (GTK_CONTAINER (priv->overlay), priv->display);
+
        gtk_widget_set_hexpand (priv->display, TRUE);
        gtk_widget_set_vexpand (priv->display, TRUE);
        gtk_grid_attach (GTK_GRID (view), priv->hbar,
@@ -2812,6 +2824,83 @@ eog_scroll_view_init (EogScrollView *view)
                                           TRUE);
        gtk_event_controller_set_propagation_phase (GTK_EVENT_CONTROLLER (priv->pan_gesture),
                                                    GTK_PHASE_CAPTURE);
+
+       /* left revealer */
+       priv->left_revealer = gtk_revealer_new ();
+       gtk_revealer_set_transition_type (GTK_REVEALER (priv->left_revealer),
+                                         GTK_REVEALER_TRANSITION_TYPE_CROSSFADE);
+       gtk_revealer_set_transition_duration (GTK_REVEALER (priv->left_revealer),
+                                             OVERLAY_REVEAL_ANIM_TIME);
+       gtk_widget_set_halign (priv->left_revealer, GTK_ALIGN_START);
+       gtk_widget_set_valign (priv->left_revealer, GTK_ALIGN_CENTER);
+       gtk_widget_set_margin_start(priv->left_revealer, 12);
+       gtk_overlay_add_overlay (GTK_OVERLAY (priv->overlay),
+                                priv->left_revealer);
+
+       /* right revealer */
+       priv->right_revealer = gtk_revealer_new ();
+       gtk_revealer_set_transition_type (GTK_REVEALER (priv->right_revealer),
+                                         GTK_REVEALER_TRANSITION_TYPE_CROSSFADE);
+       gtk_revealer_set_transition_duration (GTK_REVEALER (priv->right_revealer),
+                                             OVERLAY_REVEAL_ANIM_TIME);
+       gtk_widget_set_halign (priv->right_revealer, GTK_ALIGN_END);
+       gtk_widget_set_valign (priv->right_revealer, GTK_ALIGN_CENTER);
+       gtk_widget_set_margin_end (priv->right_revealer, 12);
+       gtk_overlay_add_overlay(GTK_OVERLAY (priv->overlay),
+                               priv->right_revealer);
+
+       /* bottom revealer */
+       priv->bottom_revealer = gtk_revealer_new ();
+       gtk_revealer_set_transition_type (GTK_REVEALER (priv->bottom_revealer),
+                                         GTK_REVEALER_TRANSITION_TYPE_CROSSFADE);
+       gtk_revealer_set_transition_duration (GTK_REVEALER (priv->bottom_revealer),
+                                             OVERLAY_REVEAL_ANIM_TIME);
+       gtk_widget_set_halign (priv->bottom_revealer, GTK_ALIGN_CENTER);
+       gtk_widget_set_valign (priv->bottom_revealer, GTK_ALIGN_END);
+       gtk_widget_set_margin_bottom (priv->bottom_revealer, 12);
+       gtk_overlay_add_overlay (GTK_OVERLAY (priv->overlay),
+                                priv->bottom_revealer);
+
+       /* buttons */
+
+       GtkWidget *button = gtk_button_new_from_icon_name ("go-next-symbolic",
+                                                             GTK_ICON_SIZE_BUTTON);
+
+       gtk_container_add(GTK_CONTAINER (priv->right_revealer), button);
+       gtk_actionable_set_action_name(GTK_ACTIONABLE (button), "win.go-next");
+
+
+       button = gtk_button_new_from_icon_name("go-previous-symbolic",
+                                              GTK_ICON_SIZE_BUTTON);
+
+       gtk_container_add(GTK_CONTAINER (priv->left_revealer), button);
+       gtk_actionable_set_action_name (GTK_ACTIONABLE(button),
+                                       "win.go-previous");
+
+
+       /* group rotate buttons into a box */
+       GtkWidget* bottomBox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
+
+       button = gtk_button_new_from_icon_name ("object-rotate-left-symbolic",
+                                               GTK_ICON_SIZE_BUTTON);
+       gtk_actionable_set_action_name (GTK_ACTIONABLE (button),
+                                       "win.rotate-270");
+       gtk_container_add (GTK_CONTAINER (bottomBox), button);
+
+       button = gtk_button_new_from_icon_name ("object-rotate-right-symbolic",
+                                               GTK_ICON_SIZE_BUTTON);
+       gtk_actionable_set_action_name (GTK_ACTIONABLE (button),
+                                       "win.rotate-90");
+       gtk_container_add (GTK_CONTAINER (bottomBox), button);
+
+       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);
 }
 
 static void