Fix Export with resize + non-linear undo history (fix #1749)

src/app/commands/cmd_save_file.cpp

@@ -16,6 +16,8 @@
 #include "app/commands/params.h"
 #include "app/console.h"
 #include "app/context_access.h"
+#include "app/document.h"
+#include "app/document_undo.h"
 #include "app/file/file.h"
 #include "app/file/gif_format.h"
 #include "app/file_selector.h"
@@ -39,6 +41,7 @@
 #include "doc/sprite.h"
 #include "fmt/format.h"
 #include "ui/ui.h"
+#include "undo/undo_state.h"
 
 namespace app {
 
@@ -289,6 +292,10 @@ public:
 
 protected:
   void onExecute(Context* context) override;
+
+private:
+  void moveToUndoState(Document* doc,
+                       const undo::UndoState* state);
 };
 
 SaveFileCopyAsCommand::SaveFileCopyAsCommand()
@@ -365,7 +372,7 @@ void SaveFileCopyAsCommand::onExecute(Context* context)
   }
 
   // Apply scale
-  bool undoResize = false;
+  const undo::UndoState* undoState = nullptr;
   if (xscale != 1.0 || yscale != 1.0) {
     Command* resizeCmd = Commands::instance()->byId(CommandId::SpriteSize());
     ASSERT(resizeCmd);
@@ -378,6 +385,7 @@ void SaveFileCopyAsCommand::onExecute(Context* context)
       if (newHeight < 1) newHeight = 1;
       if (width != newWidth || height != newHeight) {
         doc->setInhibitBackup(true);
+        undoState = doc->undoHistory()->currentState();
 
         Params params;
         params.set("use-ui", "false");
@@ -385,7 +393,6 @@ void SaveFileCopyAsCommand::onExecute(Context* context)
         params.set("height", base::convert_to<std::string>(newHeight).c_str());
         params.set("resize-method", "nearest-neighbor"); // TODO add algorithm in the UI?
         context->executeCommand(resizeCmd, params);
-        undoResize = true;
       }
     }
   }
@@ -422,15 +429,27 @@ void SaveFileCopyAsCommand::onExecute(Context* context)
   }
 
   // Undo resize
-  if (undoResize) {
-    Command* undoCmd = Commands::instance()->byId(CommandId::Undo());
-    if (undoCmd)
-      context->executeCommand(undoCmd);
-
+  if (undoState &&
+      undoState != doc->undoHistory()->currentState()) {
+    moveToUndoState(doc, undoState);
     doc->setInhibitBackup(false);
   }
 }
 
+void SaveFileCopyAsCommand::moveToUndoState(Document* doc,
+                                            const undo::UndoState* state)
+{
+  try {
+    DocumentWriter writer(doc, 100);
+    doc->undoHistory()->moveToState(state);
+    doc->generateMaskBoundaries();
+    doc->notifyGeneralUpdate();
+  }
+  catch (const std::exception& ex) {
+    Console::showException(ex);
+  }
+}
+
 Command* CommandFactory::createSaveFileCommand()
 {
   return new SaveFileCommand;

src/app/commands/cmd_undo_history.cpp

@@ -159,11 +159,7 @@ private:
     view()->updateView();
   }
 
-  void onAfterUndo(DocumentUndo* history) override {
-    selectState(history->currentState());
-  }
-
-  void onAfterRedo(DocumentUndo* history) override {
+  void onCurrentUndoStateChange(DocumentUndo* history) override {
     selectState(history->currentState());
   }
 

src/app/document_undo.cpp

@@ -106,7 +106,7 @@ void DocumentUndo::undo()
   m_totalUndoSize -= cmd->memSize();
   {
     m_undoHistory.undo();
-    notify_observers(&DocumentUndoObserver::onAfterUndo, this);
+    notify_observers(&DocumentUndoObserver::onCurrentUndoStateChange, this);
   }
   m_totalUndoSize += cmd->memSize();
   if (m_totalUndoSize != oldSize)
@@ -122,7 +122,7 @@ void DocumentUndo::redo()
   m_totalUndoSize -= cmd->memSize();
   {
     m_undoHistory.redo();
-    notify_observers(&DocumentUndoObserver::onAfterRedo, this);
+    notify_observers(&DocumentUndoObserver::onCurrentUndoStateChange, this);
   }
   m_totalUndoSize += cmd->memSize();
   if (m_totalUndoSize != oldSize)
@@ -217,6 +217,7 @@ Cmd* DocumentUndo::lastExecutedCmd() const
 void DocumentUndo::moveToState(const undo::UndoState* state)
 {
   m_undoHistory.moveTo(state);
+  notify_observers(&DocumentUndoObserver::onCurrentUndoStateChange, this);
 
   // Recalculate the total undo size
   size_t oldSize = m_totalUndoSize;

src/app/document_undo_observer.h

@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2015-2017  David Capello
+// Copyright (C) 2015-2018  David Capello
 //
 // This program is distributed under the terms of
 // the End-User License Agreement for Aseprite.
@@ -22,8 +22,7 @@ class DocumentUndo;
     virtual void onAddUndoState(DocumentUndo* history) = 0;
     virtual void onDeleteUndoState(DocumentUndo* history,
                                    undo::UndoState* state) = 0;
-    virtual void onAfterUndo(DocumentUndo* history) = 0;
-    virtual void onAfterRedo(DocumentUndo* history) = 0;
+    virtual void onCurrentUndoStateChange(DocumentUndo* history) = 0;
     virtual void onClearRedo(DocumentUndo* history) = 0;
     virtual void onTotalUndoSizeChange(DocumentUndo* history) = 0;
   };