[evince] libview: Use GtkBindings for caret navigation

[Carlos Garcia Campos <carlosgc src gnome org>]

commit 1206ff1777d97f626853c0bbb3011259f43eeac2
Author: Carlos Garcia Campos <carlosgc gnome org>
Date:   Wed Jun 19 12:10:56 2013 +0200

    libview: Use GtkBindings for caret navigation
    
    This allows themes to override the key bindings and API users to move
    the caret cursor programmatically using g_signal_emit_by_name.

 libview/ev-view-marshal.list |    1 +
 libview/ev-view-private.h    |   36 +++++++-----
 libview/ev-view.c            |  120 +++++++++++++++++++++++++++++++----------
 3 files changed, 112 insertions(+), 45 deletions(-)
---
diff --git a/libview/ev-view-marshal.list b/libview/ev-view-marshal.list
index fad4924..0ead402 100644
--- a/libview/ev-view-marshal.list
+++ b/libview/ev-view-marshal.list
@@ -1,2 +1,3 @@
 VOID:ENUM,ENUM
 VOID:INT,INT
+BOOLEAN:ENUM,INT
diff --git a/libview/ev-view-private.h b/libview/ev-view-private.h
index a681c8d..5a39b93 100644
--- a/libview/ev-view-private.h
+++ b/libview/ev-view-private.h
@@ -175,6 +175,9 @@ struct _EvView {
        /* Common for button press handling */
        int pressed_button;
 
+       /* Key bindings propagation */
+       gboolean key_binding_handled;
+
        /* Information for middle clicking and dragging around. */
        DragInfo drag_info;
        
@@ -220,21 +223,24 @@ struct _EvView {
 struct _EvViewClass {
        GtkContainerClass parent_class;
 
-       void    (*scroll)                 (EvView         *view,
-                                          GtkScrollType   scroll,
-                                          GtkOrientation  orientation);
-       void    (*handle_link)            (EvView         *view,
-                                          EvLink         *link);
-       void    (*external_link)          (EvView         *view,
-                                          EvLinkAction   *action);
-       void    (*popup_menu)             (EvView         *view,
-                                          GList          *items);
-       void    (*selection_changed)      (EvView         *view);
-       void    (*sync_source)            (EvView         *view,
-                                          EvSourceLink   *link);
-       void    (*annot_added)            (EvView         *view,
-                                          EvAnnotation   *annot);
-       void    (*layers_changed)         (EvView         *view);
+        void     (*scroll)            (EvView         *view,
+                                      GtkScrollType   scroll,
+                                      GtkOrientation  orientation);
+        void     (*handle_link)       (EvView         *view,
+                                      EvLink         *link);
+        void     (*external_link)     (EvView         *view,
+                                      EvLinkAction   *action);
+        void     (*popup_menu)        (EvView         *view,
+                                      GList          *items);
+        void     (*selection_changed) (EvView         *view);
+        void     (*sync_source)       (EvView         *view,
+                                      EvSourceLink   *link);
+        void     (*annot_added)       (EvView         *view,
+                                      EvAnnotation   *annot);
+        void     (*layers_changed)    (EvView         *view);
+        gboolean (*move_cursor)       (EvView         *view,
+                                      GtkMovementStep step,
+                                      gint            count);
 };
 
 void _get_page_size_for_scale_and_rotation (EvDocument *document,
diff --git a/libview/ev-view.c b/libview/ev-view.c
index 49eb0ba..0d1d440 100644
--- a/libview/ev-view.c
+++ b/libview/ev-view.c
@@ -57,6 +57,7 @@ enum {
        SIGNAL_SYNC_SOURCE,
        SIGNAL_ANNOT_ADDED,
        SIGNAL_LAYERS_CHANGED,
+       SIGNAL_MOVE_CURSOR,
        N_SIGNALS
 };
 
@@ -928,6 +929,9 @@ ev_view_scroll (EvView        *view,
        gboolean first_page = FALSE;
        gboolean last_page = FALSE;
 
+       if (view->key_binding_handled)
+               return;
+
        view->jump_to_find_result = FALSE;
 
        if (view->sizing_mode == EV_SIZING_FIT_PAGE) {
@@ -4955,48 +4959,61 @@ cursor_forward_line (EvView *view)
 }
 
 static gboolean
-caret_key_press_event (EvView      *view,
-                      GdkEventKey *event)
+ev_view_move_cursor (EvView         *view,
+                    GtkMovementStep step,
+                    gint            count)
 {
        gint prev_offset;
        gint prev_page;
 
-       /* Disable caret navigation on rotated pages */
-       if (view->rotation != 0)
+       if (!view->caret_enabled || view->rotation != 0)
                return FALSE;
 
+       view->key_binding_handled = TRUE;
        view->cursor_blink_time = 0;
 
        prev_offset = view->cursor_offset;
        prev_page = view->cursor_page;
 
-       switch (event->keyval) {
-       case GDK_KEY_Left:
-               if (event->state & GDK_CONTROL_MASK)
-                       cursor_backward_word_start (view);
-               else
+       switch (step) {
+       case GTK_MOVEMENT_VISUAL_POSITIONS:
+               while (count > 0) {
+                       cursor_forward_char (view);
+                       count--;
+               }
+               while (count < 0) {
                        cursor_backward_char (view);
+                       count++;
+               }
                break;
-       case GDK_KEY_Right:
-               if (event->state & GDK_CONTROL_MASK)
+       case GTK_MOVEMENT_WORDS:
+               while (count > 0) {
                        cursor_forward_word_end (view);
-               else
-                       cursor_forward_char (view);
-               break;
-       case GDK_KEY_Up:
-               cursor_backward_line (view);
-               break;
-       case GDK_KEY_Down:
-               cursor_forward_line (view);
+                       count--;
+               }
+               while (count < 0) {
+                       cursor_backward_word_start (view);
+                       count++;
+               }
                break;
-       case GDK_KEY_Home:
-               cursor_go_to_line_start (view);
+       case GTK_MOVEMENT_DISPLAY_LINES:
+               while (count > 0) {
+                       cursor_forward_line (view);
+                       count--;
+               }
+               while (count < 0) {
+                       cursor_backward_line (view);
+                       count++;
+               }
                break;
-       case GDK_KEY_End:
-               cursor_go_to_line_end (view);
+       case GTK_MOVEMENT_DISPLAY_LINE_ENDS:
+               if (count > 0)
+                       cursor_go_to_line_end (view);
+               else if (count < 0)
+                       cursor_go_to_line_start (view);
                break;
        default:
-               return FALSE;
+               g_assert_not_reached ();
        }
 
        ev_view_pend_cursor_blink (view);
@@ -5005,7 +5022,7 @@ caret_key_press_event (EvView      *view,
        if (prev_offset != view->cursor_offset || prev_page != view->cursor_page) {
                GdkRectangle view_rect;
 
-               /* scroll to view the text caret */
+               /* scroll to view the caret cursor */
                if (!get_caret_cursor_rect_from_offset (view, view->cursor_offset, view->cursor_page, 
&view_rect))
                        return TRUE;
 
@@ -5021,18 +5038,23 @@ static gboolean
 ev_view_key_press_event (GtkWidget   *widget,
                         GdkEventKey *event)
 {
-       EvView *view = EV_VIEW (widget);
+       EvView  *view = EV_VIEW (widget);
+       gboolean retval;
 
        if (!view->document)
                return FALSE;
 
-       if (view->caret_enabled && caret_key_press_event (view, event))
-               return TRUE;
-
        if (!gtk_widget_has_focus (widget))
                return ev_view_forward_key_event_to_focused_child (view, event);
 
-       return gtk_bindings_activate_event (G_OBJECT (widget), event);
+       /* I expected GTK+ do this for me, but it doesn't cancel
+        * the propagation of bindings handled for the same binding set
+        */
+       view->key_binding_handled = FALSE;
+       retval = gtk_bindings_activate_event (G_OBJECT (widget), event);
+       view->key_binding_handled = FALSE;
+
+       return retval;
 }
 
 static gint
@@ -5633,6 +5655,25 @@ ev_view_screen_changed (GtkWidget *widget,
 }
 
 static void
+add_move_binding_keypad (GtkBindingSet  *binding_set,
+                        guint           keyval,
+                        GdkModifierType modifiers,
+                        GtkMovementStep step,
+                        gint            count)
+{
+       guint keypad_keyval = keyval - GDK_KEY_Left + GDK_KEY_KP_Left;
+
+       gtk_binding_entry_add_signal (binding_set, keyval, modifiers,
+                                     "move-cursor", 2,
+                                     GTK_TYPE_MOVEMENT_STEP, step,
+                                     G_TYPE_INT, count);
+       gtk_binding_entry_add_signal (binding_set, keypad_keyval, modifiers,
+                                     "move-cursor", 2,
+                                     GTK_TYPE_MOVEMENT_STEP, step,
+                                     G_TYPE_INT, count);
+}
+
+static void
 ev_view_class_init (EvViewClass *class)
 {
        GObjectClass *object_class = G_OBJECT_CLASS (class);
@@ -5671,6 +5712,7 @@ ev_view_class_init (EvViewClass *class)
        container_class->forall = ev_view_forall;
 
        class->scroll = ev_view_scroll_internal;
+       class->move_cursor = ev_view_move_cursor;
 
        g_object_class_install_property (object_class,
                                         PROP_IS_LOADING,
@@ -5768,9 +5810,27 @@ ev_view_class_init (EvViewClass *class)
                         g_cclosure_marshal_VOID__VOID,
                         G_TYPE_NONE, 0,
                         G_TYPE_NONE);
+       signals[SIGNAL_MOVE_CURSOR] = g_signal_new ("move-cursor",
+                        G_TYPE_FROM_CLASS (object_class),
+                        G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
+                        G_STRUCT_OFFSET (EvViewClass, move_cursor),
+                        NULL, NULL,
+                        ev_view_marshal_BOOLEAN__ENUM_INT,
+                        G_TYPE_BOOLEAN, 2,
+                        GTK_TYPE_MOVEMENT_STEP,
+                        G_TYPE_INT);
 
        binding_set = gtk_binding_set_by_class (class);
 
+       add_move_binding_keypad (binding_set, GDK_KEY_Left,  0, GTK_MOVEMENT_VISUAL_POSITIONS, -1);
+       add_move_binding_keypad (binding_set, GDK_KEY_Right, 0, GTK_MOVEMENT_VISUAL_POSITIONS, 1);
+       add_move_binding_keypad (binding_set, GDK_KEY_Left,  GDK_CONTROL_MASK, GTK_MOVEMENT_WORDS, -1);
+       add_move_binding_keypad (binding_set, GDK_KEY_Right, GDK_CONTROL_MASK, GTK_MOVEMENT_WORDS, 1);
+       add_move_binding_keypad (binding_set, GDK_KEY_Up,    0, GTK_MOVEMENT_DISPLAY_LINES, -1);
+       add_move_binding_keypad (binding_set, GDK_KEY_Down,  0, GTK_MOVEMENT_DISPLAY_LINES, 1);
+       add_move_binding_keypad (binding_set, GDK_KEY_Home,  0, GTK_MOVEMENT_DISPLAY_LINE_ENDS, -1);
+       add_move_binding_keypad (binding_set, GDK_KEY_End,   0, GTK_MOVEMENT_DISPLAY_LINE_ENDS, 1);
+
         add_scroll_binding_keypad (binding_set, GDK_KEY_Left,  0, GTK_SCROLL_STEP_BACKWARD, 
GTK_ORIENTATION_HORIZONTAL);
         add_scroll_binding_keypad (binding_set, GDK_KEY_Right, 0, GTK_SCROLL_STEP_FORWARD, 
GTK_ORIENTATION_HORIZONTAL);
         add_scroll_binding_keypad (binding_set, GDK_KEY_Left,  GDK_MOD1_MASK, GTK_SCROLL_STEP_DOWN, 
GTK_ORIENTATION_HORIZONTAL);