[evince] libview: Activate current focused element on space/return key press

[Carlos Garcia Campos <carlosgc src gnome org>]

commit a183add784c52f09f7f25d77da29880e32b9ee6a
Author: Carlos Garcia Campos <carlosgc gnome org>
Date:   Thu Oct 10 11:21:23 2013 +0200

    libview: Activate current focused element on space/return key press
    
    Form field check and radio buttons are toggled and links are activated.
    We ignore space key presses for links for consistency with web browsers.
    Based on patches by Antía Puentes.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=706244

 libview/ev-view-private.h |    1 +
 libview/ev-view.c         |  101 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 102 insertions(+), 0 deletions(-)
---
diff --git a/libview/ev-view-private.h b/libview/ev-view-private.h
index e159348..3bb289b 100644
--- a/libview/ev-view-private.h
+++ b/libview/ev-view-private.h
@@ -244,6 +244,7 @@ struct _EvViewClass {
                                       GtkMovementStep step,
                                       gint            count,
                                       gboolean        extend_selection);
+       void     (*activate)          (EvView         *view);
 };
 
 void _get_page_size_for_scale_and_rotation (EvDocument *document,
diff --git a/libview/ev-view.c b/libview/ev-view.c
index a21ac11..389b532 100644
--- a/libview/ev-view.c
+++ b/libview/ev-view.c
@@ -56,6 +56,7 @@ enum {
        SIGNAL_LAYERS_CHANGED,
        SIGNAL_MOVE_CURSOR,
        SIGNAL_CURSOR_MOVED,
+       SIGNAL_ACTIVATE,
        N_SIGNALS
 };
 
@@ -5692,6 +5693,81 @@ ev_view_key_press_event (GtkWidget   *widget,
        return retval;
 }
 
+static gboolean
+ev_view_activate_form_field (EvView      *view,
+                            EvFormField *field)
+{
+       gboolean handled = FALSE;
+
+       if (field->is_read_only)
+               return handled;
+
+       if (field->activation_link) {
+               ev_view_handle_link (view, field->activation_link);
+               handled = TRUE;
+       }
+
+       if (EV_IS_FORM_FIELD_BUTTON (field)) {
+               ev_view_form_field_button_toggle (view, field);
+               handled = TRUE;
+       }
+
+       return handled;
+}
+
+static gboolean
+current_event_is_space_key_press (void)
+{
+       GdkEvent *current_event;
+       guint     keyval;
+       gboolean  is_space_key_press;
+
+       current_event = gtk_get_current_event ();
+       if (!current_event)
+               return FALSE;
+
+       is_space_key_press = current_event->type == GDK_KEY_PRESS &&
+               gdk_event_get_keyval (current_event, &keyval) &&
+               (keyval == GDK_KEY_space || keyval == GDK_KEY_KP_Space);
+       gdk_event_free (current_event);
+
+       return is_space_key_press;
+}
+
+static gboolean
+ev_view_activate_link (EvView *view,
+                      EvLink *link)
+{
+       /* Most of the GtkWidgets emit activate on both Space and Return key press,
+        * but we don't want to activate links on Space for consistency with the Web.
+        */
+       if (current_event_is_space_key_press ())
+               return FALSE;
+
+       ev_view_handle_link (view, link);
+
+       return TRUE;
+}
+
+static void
+ev_view_activate (EvView *view)
+{
+       if (!view->focused_element)
+               return;
+
+       if (EV_IS_DOCUMENT_FORMS (view->document) &&
+           EV_IS_FORM_FIELD (view->focused_element->data)) {
+               view->key_binding_handled = ev_view_activate_form_field (view, EV_FORM_FIELD 
(view->focused_element->data));
+               return;
+       }
+
+       if (EV_IS_DOCUMENT_LINKS (view->document) &&
+           EV_IS_LINK (view->focused_element->data)) {
+               view->key_binding_handled = ev_view_activate_link (view, EV_LINK 
(view->focused_element->data));
+               return;
+       }
+}
+
 static gint
 ev_view_focus_in (GtkWidget     *widget,
                  GdkEventFocus *event)
@@ -6342,6 +6418,7 @@ ev_view_class_init (EvViewClass *class)
 
        class->scroll = ev_view_scroll_internal;
        class->move_cursor = ev_view_move_cursor;
+       class->activate = ev_view_activate;
 
        g_object_class_install_property (object_class,
                                         PROP_IS_LOADING,
@@ -6468,6 +6545,15 @@ ev_view_class_init (EvViewClass *class)
                         G_TYPE_NONE, 2,
                         G_TYPE_INT,
                         G_TYPE_INT);
+       signals[SIGNAL_ACTIVATE] = g_signal_new ("activate",
+                        G_OBJECT_CLASS_TYPE (object_class),
+                        G_SIGNAL_RUN_FIRST | G_SIGNAL_ACTION,
+                        G_STRUCT_OFFSET (EvViewClass, activate),
+                        NULL, NULL,
+                        g_cclosure_marshal_VOID__VOID,
+                        G_TYPE_NONE, 0,
+                        G_TYPE_NONE);
+       widget_class->activate_signal = signals[SIGNAL_ACTIVATE];
 
        binding_set = gtk_binding_set_by_class (class);
 
@@ -6490,6 +6576,21 @@ ev_view_class_init (EvViewClass *class)
         add_scroll_binding_keypad (binding_set, GDK_KEY_Down,  GDK_MOD1_MASK, GTK_SCROLL_STEP_UP, 
GTK_ORIENTATION_VERTICAL);
        add_scroll_binding_keypad (binding_set, GDK_KEY_Page_Up, 0, GTK_SCROLL_PAGE_BACKWARD, 
GTK_ORIENTATION_VERTICAL);
        add_scroll_binding_keypad (binding_set, GDK_KEY_Page_Down, 0, GTK_SCROLL_PAGE_FORWARD, 
GTK_ORIENTATION_VERTICAL);
+
+       /* We can't use the bindings defined in GtkWindow for Space and Return,
+        * because we also have those bindings for scrolling.
+        */
+       gtk_binding_entry_add_signal (binding_set, GDK_KEY_space, 0,
+                                     "activate", 0);
+       gtk_binding_entry_add_signal (binding_set, GDK_KEY_KP_Space, 0,
+                                     "activate", 0);
+       gtk_binding_entry_add_signal (binding_set, GDK_KEY_Return, 0,
+                                     "activate", 0);
+       gtk_binding_entry_add_signal (binding_set, GDK_KEY_ISO_Enter, 0,
+                                     "activate", 0);
+       gtk_binding_entry_add_signal (binding_set, GDK_KEY_KP_Enter, 0,
+                                     "activate", 0);
+
        gtk_binding_entry_add_signal (binding_set, GDK_KEY_Return, 0, "scroll", 2,
                                      GTK_TYPE_SCROLL_TYPE, GTK_SCROLL_PAGE_FORWARD,
                                      GTK_TYPE_ORIENTATION, GTK_ORIENTATION_VERTICAL);