[gimp] app: simplify GimpTool::undo() and ::redo()

[Michael Natterer <mitch src gnome org>]

commit 6a312a71f3359a7f609f1b28beab781198349409
Author: Michael Natterer <mitch gimp org>
Date:   Sun Jul 9 17:22:06 2017 +0200

    app: simplify GimpTool::undo() and ::redo()
    
    Check for gimp_tool_can_undo() and can_redo() in gimptool.c, before
    calling undo() and redo(), instead of doing the same in each tool
    individually.

 app/tools/gimpblendtool.c            |   12 +-------
 app/tools/gimpforegroundselecttool.c |   48 ++++++++++++---------------------
 app/tools/gimpiscissorstool.c        |   10 +-----
 app/tools/gimptool.c                 |    4 +-
 app/tools/gimptransformtool.c        |   17 +++---------
 app/tools/gimpwarptool.c             |   11 --------
 6 files changed, 28 insertions(+), 74 deletions(-)
---
diff --git a/app/tools/gimpblendtool.c b/app/tools/gimpblendtool.c
index 6c1e30c..a3aa248 100644
--- a/app/tools/gimpblendtool.c
+++ b/app/tools/gimpblendtool.c
@@ -443,9 +443,8 @@ gimp_blend_tool_can_undo (GimpTool    *tool,
                           GimpDisplay *display)
 {
   GimpBlendTool *blend_tool = GIMP_BLEND_TOOL (tool);
-  GimpDrawTool  *draw_tool  = GIMP_DRAW_TOOL (tool);
 
-  if (display != draw_tool->display || ! blend_tool->undo_stack)
+  if (! blend_tool->undo_stack)
     return NULL;
 
   return _("Blend Step");
@@ -456,9 +455,8 @@ gimp_blend_tool_can_redo (GimpTool    *tool,
                           GimpDisplay *display)
 {
   GimpBlendTool *blend_tool = GIMP_BLEND_TOOL (tool);
-  GimpDrawTool  *draw_tool  = GIMP_DRAW_TOOL (tool);
 
-  if (display != draw_tool->display || ! blend_tool->redo_stack)
+  if (! blend_tool->redo_stack)
     return NULL;
 
   return _("Blend Step");
@@ -471,9 +469,6 @@ gimp_blend_tool_undo (GimpTool    *tool,
   GimpBlendTool *blend_tool = GIMP_BLEND_TOOL (tool);
   BlendInfo     *info;
 
-  if (! gimp_blend_tool_can_undo (tool, display))
-    return FALSE;
-
   info = blend_info_new (blend_tool->start_x,
                          blend_tool->start_y,
                          blend_tool->end_x,
@@ -502,9 +497,6 @@ gimp_blend_tool_redo (GimpTool    *tool,
   GimpBlendTool *blend_tool = GIMP_BLEND_TOOL (tool);
   BlendInfo     *info;
 
-  if (! gimp_blend_tool_can_redo (tool, display))
-    return FALSE;
-
   info = blend_info_new (blend_tool->start_x,
                          blend_tool->start_y,
                          blend_tool->end_x,
diff --git a/app/tools/gimpforegroundselecttool.c b/app/tools/gimpforegroundselecttool.c
index 4aa51d0..2f036e5 100644
--- a/app/tools/gimpforegroundselecttool.c
+++ b/app/tools/gimpforegroundselecttool.c
@@ -713,25 +713,19 @@ gimp_foreground_select_tool_undo (GimpTool    *tool,
                                   GimpDisplay *display)
 {
   GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+  StrokeUndo               *undo      = fg_select->undo_stack->data;
 
-  if (fg_select->undo_stack)
-    {
-      StrokeUndo *undo = fg_select->undo_stack->data;
-
-      gimp_foreground_select_undo_pop (undo, fg_select->trimap);
+  gimp_foreground_select_undo_pop (undo, fg_select->trimap);
 
-      fg_select->undo_stack = g_list_remove (fg_select->undo_stack, undo);
-      fg_select->redo_stack = g_list_prepend (fg_select->redo_stack, undo);
+  fg_select->undo_stack = g_list_remove (fg_select->undo_stack, undo);
+  fg_select->redo_stack = g_list_prepend (fg_select->redo_stack, undo);
 
-      if (fg_select->state == MATTING_STATE_PREVIEW_MASK)
-        gimp_foreground_select_tool_preview (fg_select);
-      else
-        gimp_foreground_select_tool_set_trimap (fg_select);
-
-      return TRUE;
-    }
+  if (fg_select->state == MATTING_STATE_PREVIEW_MASK)
+    gimp_foreground_select_tool_preview (fg_select);
+  else
+    gimp_foreground_select_tool_set_trimap (fg_select);
 
-  return FALSE;
+  return TRUE;
 }
 
 static gboolean
@@ -739,25 +733,19 @@ gimp_foreground_select_tool_redo (GimpTool    *tool,
                                   GimpDisplay *display)
 {
   GimpForegroundSelectTool *fg_select = GIMP_FOREGROUND_SELECT_TOOL (tool);
+  StrokeUndo               *undo      = fg_select->redo_stack->data;
 
-  if (fg_select->redo_stack)
-    {
-      StrokeUndo *undo = fg_select->redo_stack->data;
-
-      gimp_foreground_select_undo_pop (undo, fg_select->trimap);
-
-      fg_select->redo_stack = g_list_remove (fg_select->redo_stack, undo);
-      fg_select->undo_stack = g_list_prepend (fg_select->undo_stack, undo);
+  gimp_foreground_select_undo_pop (undo, fg_select->trimap);
 
-      if (fg_select->state == MATTING_STATE_PREVIEW_MASK)
-        gimp_foreground_select_tool_preview (fg_select);
-      else
-        gimp_foreground_select_tool_set_trimap (fg_select);
+  fg_select->redo_stack = g_list_remove (fg_select->redo_stack, undo);
+  fg_select->undo_stack = g_list_prepend (fg_select->undo_stack, undo);
 
-      return TRUE;
-    }
+  if (fg_select->state == MATTING_STATE_PREVIEW_MASK)
+    gimp_foreground_select_tool_preview (fg_select);
+  else
+    gimp_foreground_select_tool_set_trimap (fg_select);
 
-  return FALSE;
+  return TRUE;
 }
 
 static void
diff --git a/app/tools/gimpiscissorstool.c b/app/tools/gimpiscissorstool.c
index eafe7e2..a4df02f 100644
--- a/app/tools/gimpiscissorstool.c
+++ b/app/tools/gimpiscissorstool.c
@@ -1111,7 +1111,7 @@ gimp_iscissors_tool_can_undo (GimpTool    *tool,
 {
   GimpIscissorsTool *iscissors = GIMP_ISCISSORS_TOOL (tool);
 
-  if (display != tool->display || ! iscissors->undo_stack)
+  if (! iscissors->undo_stack)
     return NULL;
 
   return _("Modify Scissors Curve");
@@ -1123,7 +1123,7 @@ gimp_iscissors_tool_can_redo (GimpTool    *tool,
 {
   GimpIscissorsTool *iscissors = GIMP_ISCISSORS_TOOL (tool);
 
-  if (display != tool->display || ! iscissors->redo_stack)
+  if (! iscissors->redo_stack)
     return NULL;
 
   return _("Modify Scissors Curve");
@@ -1135,9 +1135,6 @@ gimp_iscissors_tool_undo (GimpTool    *tool,
 {
   GimpIscissorsTool *iscissors = GIMP_ISCISSORS_TOOL (tool);
 
-  if (! gimp_iscissors_tool_can_undo (tool, display))
-    return FALSE;
-
   gimp_draw_tool_pause (GIMP_DRAW_TOOL (tool));
 
   iscissors->redo_stack = g_list_prepend (iscissors->redo_stack,
@@ -1166,9 +1163,6 @@ gimp_iscissors_tool_redo (GimpTool    *tool,
 {
   GimpIscissorsTool *iscissors = GIMP_ISCISSORS_TOOL (tool);
 
-  if (! gimp_iscissors_tool_can_redo (tool, display))
-    return FALSE;
-
   gimp_draw_tool_pause (GIMP_DRAW_TOOL (tool));
 
   if (! iscissors->undo_stack)
diff --git a/app/tools/gimptool.c b/app/tools/gimptool.c
index 4500792..b61ecec 100644
--- a/app/tools/gimptool.c
+++ b/app/tools/gimptool.c
@@ -1202,7 +1202,7 @@ gimp_tool_undo (GimpTool    *tool,
   g_return_val_if_fail (GIMP_IS_TOOL (tool), FALSE);
   g_return_val_if_fail (GIMP_IS_DISPLAY (display), FALSE);
 
-  if (display == tool->display)
+  if (gimp_tool_can_undo (tool, display))
     return GIMP_TOOL_GET_CLASS (tool)->undo (tool, display);
 
   return FALSE;
@@ -1215,7 +1215,7 @@ gimp_tool_redo (GimpTool    *tool,
   g_return_val_if_fail (GIMP_IS_TOOL (tool), FALSE);
   g_return_val_if_fail (GIMP_IS_DISPLAY (display), FALSE);
 
-  if (display == tool->display)
+  if (gimp_tool_can_redo (tool, display))
     return GIMP_TOOL_GET_CLASS (tool)->redo (tool, display);
 
   return FALSE;
diff --git a/app/tools/gimptransformtool.c b/app/tools/gimptransformtool.c
index cd90d18..f8bc991 100644
--- a/app/tools/gimptransformtool.c
+++ b/app/tools/gimptransformtool.c
@@ -519,11 +519,9 @@ static const gchar *
 gimp_transform_tool_can_undo (GimpTool    *tool,
                               GimpDisplay *display)
 {
-  GimpTransformTool *tr_tool   = GIMP_TRANSFORM_TOOL (tool);
-  GimpDrawTool      *draw_tool = GIMP_DRAW_TOOL (tool);
+  GimpTransformTool *tr_tool = GIMP_TRANSFORM_TOOL (tool);
 
-  if (display != draw_tool->display || ! tr_tool->undo_list ||
-      ! tr_tool->undo_list->next)
+  if (! tr_tool->undo_list || ! tr_tool->undo_list->next)
     return NULL;
 
   return _("Transform Step");
@@ -533,10 +531,9 @@ static const gchar *
 gimp_transform_tool_can_redo (GimpTool    *tool,
                               GimpDisplay *display)
 {
-  GimpTransformTool *tr_tool   = GIMP_TRANSFORM_TOOL (tool);
-  GimpDrawTool      *draw_tool = GIMP_DRAW_TOOL (tool);
+  GimpTransformTool *tr_tool = GIMP_TRANSFORM_TOOL (tool);
 
-  if (display != draw_tool->display || ! tr_tool->redo_list)
+  if (! tr_tool->redo_list)
     return NULL;
 
   return _("Transform Step");
@@ -549,9 +546,6 @@ gimp_transform_tool_undo (GimpTool    *tool,
   GimpTransformTool *tr_tool = GIMP_TRANSFORM_TOOL (tool);
   GList             *item;
 
-  if (! gimp_transform_tool_can_undo (tool, display))
-    return FALSE;
-
   item = g_list_next (tr_tool->undo_list);
 
   /* Move prev_trans_info from undo_list to redo_list */
@@ -582,9 +576,6 @@ gimp_transform_tool_redo (GimpTool    *tool,
   GimpTransformTool *tr_tool = GIMP_TRANSFORM_TOOL (tool);
   GList             *item;
 
-  if (! gimp_transform_tool_can_redo (tool, display))
-    return FALSE;
-
   item = tr_tool->redo_list;
 
   /* Move prev_trans_info from redo_list to undo_list */
diff --git a/app/tools/gimpwarptool.c b/app/tools/gimpwarptool.c
index c23c67d..40765dc 100644
--- a/app/tools/gimpwarptool.c
+++ b/app/tools/gimpwarptool.c
@@ -504,16 +504,8 @@ gimp_warp_tool_undo (GimpTool    *tool,
   GimpWarpTool *wt = GIMP_WARP_TOOL (tool);
   GeglNode     *to_delete;
   GeglNode     *prev_node;
-  const gchar  *type;
-
-  if (! wt->render_node)
-    return FALSE;
 
   to_delete = gegl_node_get_producer (wt->render_node, "aux", NULL);
-  type = gegl_node_get_operation (to_delete);
-
-  if (strcmp (type, "gegl:warp"))
-    return FALSE;
 
   wt->redo_stack = g_list_prepend (wt->redo_stack, to_delete);
 
@@ -539,9 +531,6 @@ gimp_warp_tool_redo (GimpTool    *tool,
   GimpWarpTool *wt = GIMP_WARP_TOOL (tool);
   GeglNode     *to_add;
 
-  if (! wt->render_node || ! wt->redo_stack)
-    return FALSE;
-
   to_add = wt->redo_stack->data;
 
   gegl_node_connect_to (to_add,          "output",