[gimp] app: mask alternative click modifiers must not clash with…

[Jehan <jehanp src gnome org>]

commit f4d39f8c7286ac5172ff7f79fbaeaa2555134693
Author: Jehan <jehan girinstud io>
Date:   Mon Dec 14 01:37:19 2020 +0100

    app: mask alternative click modifiers must not clash with…
    
    … multi-selection modifiers. Also they will work from now on on the
    clicked mask only.
    
    Shift and Ctrl clicks are reserved for multi-selection. We do not want
    these to do other actions if you shift|ctrl-click on a mask (even more
    as these alternative actions are hardly discoverable so it would make
    for bug-like behavior to the person not knowing these alternative
    actions).
    So Alt-click is still used for showing/hiding the mask, but
    enabling/disabling changes from Ctrl-click to Alt-Ctrl-click.
    
    The second change is that these actions will not run the actions on
    selected layers' mask, but on the clicked layer mask. This will at least
    make these interaction different from the actions (e.g. with contextual
    menu) and therefore it's not even redundant anymore. We will now have a
    way to work on all selected layers vs a way to work on a clicked layer
    (without changing the existing selection).

 app/widgets/gimplayertreeview.c | 37 +++++++++++++++++++++++++++----------
 1 file changed, 27 insertions(+), 10 deletions(-)
---
diff --git a/app/widgets/gimplayertreeview.c b/app/widgets/gimplayertreeview.c
index 0789d4eb73..12f75ce4df 100644
--- a/app/widgets/gimplayertreeview.c
+++ b/app/widgets/gimplayertreeview.c
@@ -1652,17 +1652,34 @@ gimp_layer_tree_view_mask_clicked (GimpCellRendererViewable *cell,
 
       if (renderer)
         {
-          GimpLayer *layer = GIMP_LAYER (renderer->viewable);
-
-          if (state & GDK_MOD1_MASK)
-            gimp_action_group_set_action_active (group, "layers-mask-show",
-                                                 ! gimp_layer_get_show_mask (layer));
-          else if (state & gimp_get_toggle_behavior_mask ())
-            gimp_action_group_set_action_active (group, "layers-mask-disable",
-                                                 gimp_layer_get_apply_mask (layer));
+          GimpLayer       *layer     = GIMP_LAYER (renderer->viewable);
+          GdkModifierType  modifiers = gimp_get_all_modifiers_mask ();
+
+          if ((state & GDK_MOD1_MASK))
+            {
+              GimpImage *image;
+
+              image = gimp_item_get_image (GIMP_ITEM (layer));
+
+              if ((state & modifiers) == GDK_MOD1_MASK)
+                {
+                  /* Alt-click shows/hides a layer mask */
+                  gimp_layer_set_show_mask (layer, ! gimp_layer_get_show_mask (layer), TRUE);
+                  gimp_image_flush (image);
+                }
+              if ((state & modifiers) == (GDK_MOD1_MASK | GDK_CONTROL_MASK))
+                {
+                  /* Alt-Control-click enables/disables a layer mask */
+                  gimp_layer_set_apply_mask (layer, ! gimp_layer_get_apply_mask (layer), TRUE);
+                  gimp_image_flush (image);
+                }
+            }
           else if (! gimp_layer_get_edit_mask (layer))
-            gimp_action_group_set_action_active (group,
-                                                 "layers-mask-edit", TRUE);
+            {
+              /* Simple click selects the mask for edition. */
+              gimp_action_group_set_action_active (group,
+                                                   "layers-mask-edit", TRUE);
+            }
 
           g_object_unref (renderer);
         }