[gimp] Paint Select tool: add a temporary option to show painted scribbles

[Thomas Manni <tmanni src gnome org>]

commit 6a169e289fea8c9aad0f829ba309e1f012206f79
Author: Thomas Manni <thomas manni free fr>
Date:   Fri Dec 4 18:56:28 2020 +0100

    Paint Select tool: add a temporary option to show painted scribbles
    
    For debugging purpose, will be removed on the final tool.

 app/tools/gimppaintselectoptions.c | 21 +++++++++++++++++++++
 app/tools/gimppaintselectoptions.h |  1 +
 app/tools/gimppaintselecttool.c    | 36 +++++++++++++++++++++++++++++++++++-
 3 files changed, 57 insertions(+), 1 deletion(-)
---
diff --git a/app/tools/gimppaintselectoptions.c b/app/tools/gimppaintselectoptions.c
index 9c707036a4..902ffe8040 100644
--- a/app/tools/gimppaintselectoptions.c
+++ b/app/tools/gimppaintselectoptions.c
@@ -43,6 +43,7 @@ enum
   PROP_0,
   PROP_MODE,
   PROP_STROKE_WIDTH,
+  PROP_SHOW_SCRIBBLES,
 };
 
 
@@ -83,6 +84,13 @@ gimp_paint_select_options_class_init (GimpPaintSelectOptionsClass *klass)
                          _("Size of the brush used for refinements"),
                          1, 6000, 50,
                          GIMP_PARAM_STATIC_STRINGS);
+
+  GIMP_CONFIG_PROP_BOOLEAN  (object_class, PROP_SHOW_SCRIBBLES,
+                         "show-scribbles",
+                         _("Show scribbles"),
+                         _("Show scribbles"),
+                         FALSE,
+                         GIMP_PARAM_STATIC_STRINGS);
 }
 
 static void
@@ -108,6 +116,10 @@ gimp_paint_select_options_set_property (GObject      *object,
       options->stroke_width = g_value_get_int (value);
       break;
 
+    case PROP_SHOW_SCRIBBLES:
+      options->show_scribbles = g_value_get_boolean (value);
+      break;
+
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
       break;
@@ -132,6 +144,10 @@ gimp_paint_select_options_get_property (GObject    *object,
       g_value_set_int (value, options->stroke_width);
       break;
 
+    case PROP_SHOW_SCRIBBLES:
+      g_value_set_boolean (value, options->show_scribbles);
+      break;
+
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
       break;
@@ -184,5 +200,10 @@ gimp_paint_select_options_gui (GimpToolOptions *tool_options)
   gimp_help_set_help_data (button,
                            _("Reset stroke width native size"), NULL);
 
+  /* show scribbles */
+  button = gimp_prop_check_button_new (config, "show-scribbles", "Show scribbles");
+  gtk_box_pack_start (GTK_BOX (vbox), button, FALSE, FALSE, 0);
+  gtk_widget_show (button);
+
   return vbox;
 }
diff --git a/app/tools/gimppaintselectoptions.h b/app/tools/gimppaintselectoptions.h
index 7c5cb201b6..ee9dd4068f 100644
--- a/app/tools/gimppaintselectoptions.h
+++ b/app/tools/gimppaintselectoptions.h
@@ -40,6 +40,7 @@ struct _GimpPaintSelectOptions
 
   GimpPaintSelectMode    mode;
   gint                   stroke_width;
+  gboolean               show_scribbles;
 };
 
 struct _GimpPaintSelectOptionsClass
diff --git a/app/tools/gimppaintselecttool.c b/app/tools/gimppaintselecttool.c
index a80d4325b6..4cc0ff1d87 100644
--- a/app/tools/gimppaintselecttool.c
+++ b/app/tools/gimppaintselecttool.c
@@ -124,6 +124,7 @@ static void   gimp_paint_select_tool_init_buffers        (GimpPaintSelectTool  *
 static void   gimp_paint_select_tool_init_scribble       (GimpPaintSelectTool  *ps_tool);
 static void   gimp_paint_select_tool_create_graph        (GimpPaintSelectTool  *ps_tool);
 static gboolean gimp_paint_select_tool_paint_scribble    (GimpPaintSelectTool  *ps_tool);
+static void gimp_paint_select_tool_toggle_scribbles_visibility (GimpPaintSelectTool  *ps_tool);
 
 static gfloat euclidean_distance                         (gint                  x1,
                                                           gint                  y1,
@@ -499,6 +500,10 @@ gimp_paint_select_tool_options_notify (GimpTool         *tool,
       g_object_unref (ps_tool->scribble);
       ps_tool->scribble = NULL;
     }
+  else if (! strcmp (pspec->name, "show-scribbles"))
+    {
+      gimp_paint_select_tool_toggle_scribbles_visibility (ps_tool);
+    }
 }
 
 static void
@@ -517,7 +522,11 @@ gimp_paint_select_tool_halt (GimpPaintSelectTool *ps_tool)
   ps_tool->image_mask = NULL;
 
   if (tool->display)
-    gimp_image_flush (gimp_display_get_image (tool->display));
+    {
+      gimp_display_shell_set_mask (gimp_display_get_shell (tool->display),
+                                   NULL, 0, 0, NULL, FALSE);
+      gimp_image_flush (gimp_display_get_image (tool->display));
+    }
 
   tool->display   = NULL;
   g_list_free (tool->drawables);
@@ -688,6 +697,8 @@ gimp_paint_select_tool_paint_scribble (GimpPaintSelectTool  *ps_tool)
         }
     }
 
+  gimp_paint_select_tool_toggle_scribbles_visibility (ps_tool);
+
   return overlap;
 }
 
@@ -756,6 +767,29 @@ gimp_paint_select_tool_create_graph (GimpPaintSelectTool  *ps_tool)
   gegl_node_connect_to (t, "output", ps_tool->ps_node, "aux2");
 }
 
+static void
+gimp_paint_select_tool_toggle_scribbles_visibility (GimpPaintSelectTool  *ps_tool)
+{
+  GimpTool  *tool = GIMP_TOOL (ps_tool);
+  GimpPaintSelectOptions  *options = GIMP_PAINT_SELECT_TOOL_GET_OPTIONS (tool);
+
+  if (options->show_scribbles)
+    {
+      const GimpRGB black = {0.0, 0.0, 0.0, 1.0};
+      gimp_display_shell_set_mask (gimp_display_get_shell (tool->display),
+                                   ps_tool->trimap,
+                                   ps_tool->drawable_off_x,
+                                   ps_tool->drawable_off_y,
+                                   &black,
+                                   TRUE);
+    }
+  else
+    {
+      gimp_display_shell_set_mask (gimp_display_get_shell (tool->display),
+                                   NULL, 0, 0, NULL, FALSE);
+    }
+}
+
 static gfloat
 euclidean_distance (gint  x1,
                     gint  y1,