[gnome-control-center] keyboard: fix editing of custom shortcuts

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 147a1e814d7b221bcf2868f9b9af677ccd2adfd8
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Mon Jan 30 08:18:20 2017 -0200

    keyboard: fix editing of custom shortcuts
    
    After introducing the reset button to match the mockups [1], the
    shortcut editor dialog had some issues exposed. This is visible
    e.g. when the user tries to edit a custom shortcut's name and
    the shortcut is disabled.
    
    This happens because we assume there is always a shortcut set.
    When we open the dialog to edit a custom shortcut, however, nothing
    is actually set, and we end up saving the disabled shortcut when
    editing the shortcut's name or command.
    
    Fix that by initializing the shortcut's accelerators when editing a
    shortcut, and correcting the logic to validate the shortcut.
    
    [1] 
https://raw.githubusercontent.com/gnome-design-team/gnome-mockups/master/system-settings/keyboard/keyboard-wires.png
    
    https://bugzilla.gnome.org/show_bug.cgi?id=777845

 panels/keyboard/cc-keyboard-shortcut-editor.c |   22 ++++++++++++++++++----
 1 files changed, 18 insertions(+), 4 deletions(-)
---
diff --git a/panels/keyboard/cc-keyboard-shortcut-editor.c b/panels/keyboard/cc-keyboard-shortcut-editor.c
index 0540f03..647f22d 100644
--- a/panels/keyboard/cc-keyboard-shortcut-editor.c
+++ b/panels/keyboard/cc-keyboard-shortcut-editor.c
@@ -271,7 +271,7 @@ setup_custom_shortcut (CcKeyboardShortcutEditor *self)
   GtkShortcutLabel *shortcut_label;
   CcKeyboardItem *collision_item;
   HeaderMode mode;
-  gboolean is_custom;
+  gboolean is_custom, is_accel_empty;
   gboolean valid, accel_valid;
   gchar *accel;
 
@@ -279,7 +279,10 @@ setup_custom_shortcut (CcKeyboardShortcutEditor *self)
   accel_valid = is_valid_binding (self->custom_keyval, self->custom_mask, self->custom_keycode) &&
                 is_valid_accel (self->custom_keyval, self->custom_mask) &&
                 !self->custom_is_modifier;
-  if (is_empty_binding (self->custom_keyval, self->custom_mask, self->custom_keycode))
+
+  is_accel_empty = is_empty_binding (self->custom_keyval, self->custom_mask, self->custom_keycode);
+
+  if (is_accel_empty)
     accel_valid = TRUE;
   valid = accel_valid;
 
@@ -289,8 +292,12 @@ setup_custom_shortcut (CcKeyboardShortcutEditor *self)
       if (accel_valid)
         {
           gtk_stack_set_visible_child_name (GTK_STACK (self->stack), "custom");
-          gtk_stack_set_visible_child_name (GTK_STACK (self->custom_shortcut_stack), "label");
-          gtk_widget_show (self->reset_custom_button);
+
+          /* We have to check if the current accelerator is empty in order to
+           * decide if we show the "Set Shortcut" button or the accelerator label */
+          gtk_stack_set_visible_child_name (GTK_STACK (self->custom_shortcut_stack),
+                                            is_accel_empty ? "button" : "label");
+          gtk_widget_set_visible (self->reset_custom_button, !is_accel_empty);
         }
 
       valid = accel_valid &&
@@ -505,6 +512,13 @@ setup_keyboard_item (CcKeyboardShortcutEditor *self,
   is_custom = item->type == CC_KEYBOARD_ITEM_TYPE_GSETTINGS_PATH;
   accel = gtk_accelerator_name (item->keyval, item->mask);
 
+  /* To avoid accidentally thinking we unset the current keybinding, set the values
+   * of the keyboard item that is being edited */
+  self->custom_is_modifier = FALSE;
+  self->custom_keycode = item->keycode;
+  self->custom_keyval = item->keyval;
+  self->custom_mask = item->mask;
+
   /* Headerbar */
   gtk_header_bar_set_title (GTK_HEADER_BAR (self->headerbar),
                             is_custom ? _("Set Custom Shortcut") : _("Set Shortcut"));