[gimp] Bug 315051 - Image preview in transforms keeps original version visible

[Michael Natterer <mitch src gnome org>]

commit f03051143831b9053c6d6c791886425f8bc688f8
Author: Michael Natterer <mitch gimp org>
Date:   Thu Apr 6 00:15:42 2017 +0200

    Bug 315051 - Image preview in transforms keeps original version visible
    
    If the transformed item is a layer, and we are transforming the entire
    layer (if there is now selection), hide the original layer during the
    interactive transform. Based on a 2.8 patch from saulgoode.

 app/tools/gimptransformtool.c |   43 +++++++++++++++++++++++++++++++++++++++++
 app/tools/gimptransformtool.h |    3 ++
 2 files changed, 46 insertions(+), 0 deletions(-)
---
diff --git a/app/tools/gimptransformtool.c b/app/tools/gimptransformtool.c
index 4b7366e..6059573 100644
--- a/app/tools/gimptransformtool.c
+++ b/app/tools/gimptransformtool.c
@@ -42,6 +42,7 @@
 #include "core/gimpitem-linked.h"
 #include "core/gimplayer.h"
 #include "core/gimpprogress.h"
+#include "core/gimpprojection.h"
 #include "core/gimptoolinfo.h"
 #include "core/gimp-transform-utils.h"
 #include "core/gimp-utils.h"
@@ -174,6 +175,9 @@ static GimpItem *gimp_transform_tool_check_active_item      (GimpTransformTool
                                                              GimpImage             *display,
                                                              gboolean               invisible_layer_ok,
                                                              GError               **error);
+static void      gimp_transform_tool_hide_active_item       (GimpTransformTool     *tr_tool,
+                                                             GimpItem              *item);
+static void      gimp_transform_tool_show_active_item       (GimpTransformTool     *tr_tool);
 
 static TransInfo * trans_info_new  (void);
 static void        trans_info_free (TransInfo *info);
@@ -300,6 +304,8 @@ gimp_transform_tool_initialize (GimpTool     *tool,
       tool->display  = display;
       tool->drawable = drawable;
 
+      gimp_transform_tool_hide_active_item (tr_tool, item);
+
       /*  Initialize the transform tool dialog */
       if (! tr_tool->gui)
         gimp_transform_tool_dialog (tr_tool);
@@ -1479,6 +1485,8 @@ gimp_transform_tool_halt (GimpTransformTool *tr_tool)
       tr_tool->prev_trans_info = NULL;
     }
 
+  gimp_transform_tool_show_active_item (tr_tool);
+
   tool->display  = NULL;
   tool->drawable = NULL;
  }
@@ -1877,6 +1885,41 @@ gimp_transform_tool_check_active_item (GimpTransformTool  *tr_tool,
   return item;
 }
 
+static void
+gimp_transform_tool_hide_active_item (GimpTransformTool *tr_tool,
+                                      GimpItem          *item)
+{
+  GimpTransformOptions *options = GIMP_TRANSFORM_TOOL_GET_OPTIONS (tr_tool);
+  GimpDisplay          *display = GIMP_TOOL (tr_tool)->display;
+  GimpImage            *image   = gimp_display_get_image (display);
+
+  if (options->type == GIMP_TRANSFORM_TYPE_LAYER &&
+      GIMP_IS_LAYER (item)                       &&
+      gimp_item_get_visible (item)               &&
+      gimp_channel_is_empty (gimp_image_get_mask (image)))
+    {
+      tr_tool->hidden_item = item;
+      gimp_item_set_visible (item, FALSE, FALSE);
+
+      gimp_projection_flush (gimp_image_get_projection (image));
+    }
+}
+
+static void
+gimp_transform_tool_show_active_item (GimpTransformTool *tr_tool)
+{
+  if (tr_tool->hidden_item)
+    {
+      GimpDisplay *display = GIMP_TOOL (tr_tool)->display;
+      GimpImage   *image   = gimp_display_get_image (display);
+
+      gimp_item_set_visible (tr_tool->hidden_item, TRUE, FALSE);
+      tr_tool->hidden_item = NULL;
+
+      gimp_image_flush (image);
+    }
+}
+
 static TransInfo *
 trans_info_new (void)
 {
diff --git a/app/tools/gimptransformtool.h b/app/tools/gimptransformtool.h
index 4d78099..df4e0e2 100644
--- a/app/tools/gimptransformtool.h
+++ b/app/tools/gimptransformtool.h
@@ -110,6 +110,9 @@ struct _GimpTransformTool
   GList          *redo_list;          /*  list of all undone states,
                                           NULL when nothing undone */
 
+  GimpItem       *hidden_item;        /*  the item that was hidden during
+                                          the transform                      */
+
   TransformAction function;           /*  current tool activity              */
 
   gboolean        use_grid;           /*  does the tool use the grid         */