[gimp] app: add transform_valid member to GimpTransformTool

[N/A <ell src gnome org>]

commit 6d0190b7fd1825e4e183ec5a4344964cae4285c7
Author: Ell <ell_se yahoo com>
Date:   Sat Jan 27 04:29:03 2018 -0500

    app: add transform_valid member to GimpTransformTool
    
    ... which specifies whether the transform matrix is valid.
    Subclasses can then set this member to indicate that the current
    transformation is invalid (which can happen in the unified,
    perspective, and handle transform tools).  When the transform is
    invalid, GimpTransformTool doesn't apply it upon committing, and
    returns an error instead.
    
    This commit doesn't set the transform_valid member in any of the
    subclasses, so there's no effective change.  The next commit adds a
    GimpGenericTransformTool subclass, that will use the new member.

 app/tools/gimptransformtool.c |   34 ++++++++++++++++++++++++++++++++--
 app/tools/gimptransformtool.h |    1 +
 2 files changed, 33 insertions(+), 2 deletions(-)
---
diff --git a/app/tools/gimptransformtool.c b/app/tools/gimptransformtool.c
index 4980f26..2b1575d 100644
--- a/app/tools/gimptransformtool.c
+++ b/app/tools/gimptransformtool.c
@@ -219,6 +219,7 @@ gimp_transform_tool_init (GimpTransformTool *tr_tool)
   tr_tool->progress_text = _("Transforming");
 
   gimp_matrix3_identity (&tr_tool->transform);
+  tr_tool->transform_valid = TRUE;
 
   tr_tool->strokes = g_ptr_array_new ();
 }
@@ -617,7 +618,8 @@ gimp_transform_tool_options_notify (GimpTool         *tool,
         {
           gboolean show_preview;
 
-          show_preview = gimp_transform_options_show_preview (tr_options);
+          show_preview = gimp_transform_options_show_preview (tr_options) &&
+                         tr_tool->transform_valid;
 
           gimp_canvas_item_set_visible (tr_tool->preview, show_preview);
         }
@@ -646,7 +648,8 @@ gimp_transform_tool_draw (GimpDrawTool *draw_tool)
 
   if (tr_tool->widget)
     {
-      gboolean show_preview = gimp_transform_options_show_preview (options);
+      gboolean show_preview = gimp_transform_options_show_preview (options) &&
+                              tr_tool->transform_valid;
 
       tr_tool->preview =
         gimp_draw_tool_add_transform_preview (draw_tool,
@@ -690,6 +693,9 @@ gimp_transform_tool_draw (GimpDrawTool *draw_tool)
                                          0, 0);
           g_object_add_weak_pointer (G_OBJECT (tr_tool->boundary_in),
                                      (gpointer) &tr_tool->boundary_in);
+
+          gimp_canvas_item_set_visible (tr_tool->boundary_in,
+                                        tr_tool->transform_valid);
         }
 
       if (segs_out)
@@ -701,6 +707,9 @@ gimp_transform_tool_draw (GimpDrawTool *draw_tool)
                                          0, 0);
           g_object_add_weak_pointer (G_OBJECT (tr_tool->boundary_in),
                                      (gpointer) &tr_tool->boundary_out);
+
+          gimp_canvas_item_set_visible (tr_tool->boundary_out,
+                                        tr_tool->transform_valid);
         }
     }
   else if (options->type == GIMP_TRANSFORM_TYPE_PATH)
@@ -730,6 +739,8 @@ gimp_transform_tool_draw (GimpDrawTool *draw_tool)
                   g_object_weak_ref (G_OBJECT (item),
                                      (GWeakNotify) g_ptr_array_remove,
                                      tr_tool->strokes);
+
+                  gimp_canvas_item_set_visible (item, tr_tool->transform_valid);
                 }
 
               if (coords)
@@ -834,7 +845,11 @@ gimp_transform_tool_widget_changed (GimpToolWidget    *widget,
 
   if (tr_tool->preview)
     {
+      gboolean show_preview = gimp_transform_options_show_preview (options) &&
+                              tr_tool->transform_valid;
+
       gimp_canvas_item_begin_change (tr_tool->preview);
+      gimp_canvas_item_set_visible (tr_tool->preview, show_preview);
       g_object_set (tr_tool->preview,
                     "transform", &matrix,
                     NULL);
@@ -844,6 +859,8 @@ gimp_transform_tool_widget_changed (GimpToolWidget    *widget,
   if (tr_tool->boundary_in)
     {
       gimp_canvas_item_begin_change (tr_tool->boundary_in);
+      gimp_canvas_item_set_visible (tr_tool->boundary_in,
+                                    tr_tool->transform_valid);
       g_object_set (tr_tool->boundary_in,
                     "transform", &matrix,
                     NULL);
@@ -853,6 +870,8 @@ gimp_transform_tool_widget_changed (GimpToolWidget    *widget,
   if (tr_tool->boundary_out)
     {
       gimp_canvas_item_begin_change (tr_tool->boundary_out);
+      gimp_canvas_item_set_visible (tr_tool->boundary_out,
+                                    tr_tool->transform_valid);
       g_object_set (tr_tool->boundary_out,
                     "transform", &matrix,
                     NULL);
@@ -864,6 +883,7 @@ gimp_transform_tool_widget_changed (GimpToolWidget    *widget,
       GimpCanvasItem *item = g_ptr_array_index (tr_tool->strokes, i);
 
       gimp_canvas_item_begin_change (item);
+      gimp_canvas_item_set_visible (item, tr_tool->transform_valid);
       g_object_set (item,
                     "transform", &matrix,
                     NULL);
@@ -955,6 +975,13 @@ gimp_transform_tool_commit (GimpTransformTool *tr_tool)
       return;
     }
 
+  if (! tr_tool->transform_valid)
+    {
+      gimp_tool_message_literal (tool, display,
+                                 _("The current transform is invalid"));
+      return;
+    }
+
   if (tr_tool->gui)
     gimp_tool_gui_hide (tr_tool->gui);
 
@@ -1283,6 +1310,7 @@ gimp_transform_tool_recalc_matrix (GimpTransformTool *tr_tool,
     GIMP_TRANSFORM_TOOL_GET_CLASS (tr_tool)->recalc_matrix (tr_tool, widget);
 
   gimp_transform_tool_dialog_update (tr_tool);
+  gimp_transform_tool_update_sensitivity (tr_tool);
 
   if (tr_tool->gui)
     gimp_tool_gui_show (tr_tool->gui);
@@ -1348,6 +1376,8 @@ gimp_transform_tool_update_sensitivity (GimpTransformTool *tr_tool)
   if (! tr_tool->gui)
     return;
 
+  gimp_tool_gui_set_response_sensitive (tr_tool->gui, GTK_RESPONSE_OK,
+                                        tr_tool->transform_valid);
   gimp_tool_gui_set_response_sensitive (tr_tool->gui, RESPONSE_RESET,
                                         g_list_next (tr_tool->undo_list) != NULL);
 }
diff --git a/app/tools/gimptransformtool.h b/app/tools/gimptransformtool.h
index a1ab98f..6273d86 100644
--- a/app/tools/gimptransformtool.h
+++ b/app/tools/gimptransformtool.h
@@ -51,6 +51,7 @@ struct _GimpTransformTool
   gint            x2, y2;             /*  lower right hand coords            */
 
   GimpMatrix3     transform;          /*  transformation matrix              */
+  gboolean        transform_valid;    /*  whether the matrix is valid        */
   TransInfo       trans_info;         /*  transformation info                */
   TransInfo      *old_trans_info;     /*  for resetting everything           */
   TransInfo      *prev_trans_info;    /*  the current finished state         */