Remove the editor's default state. Now the editor has a decorator property.

+ Removed Editor::setDefaultState.
+ Removed EditorState::getDecorator.
+ Added Editor::get/setDecorator.
+ Added EditorStatesHistory class and Editor::backToPreviousState() method.
+ Added EditorState::onBeforePopState event.

src/CMakeLists.txt

@@ -310,6 +310,7 @@ add_library(aseprite-library
   widgets/editor/drawing_state.cpp
   widgets/editor/editor.cpp
   widgets/editor/editor_listeners.cpp
+  widgets/editor/editor_states_history.cpp
   widgets/editor/editor_view.cpp
   widgets/editor/keys.cpp
   widgets/editor/moving_cel_state.cpp

src/commands/cmd_canvas_size.cpp

@@ -74,12 +74,12 @@ public:
     m_top   ->EntryChange.connect(Bind<void>(&CanvasSizeFrame::onEntriesChange, this));
     m_bottom->EntryChange.connect(Bind<void>(&CanvasSizeFrame::onEntriesChange, this));
 
-    m_editor->setDefaultState(m_selectBoxState);
+    m_editor->setState(m_selectBoxState);
   }
 
   ~CanvasSizeFrame()
   {
-    m_editor->setDefaultState(EditorStatePtr(new StandbyState));
+    m_editor->backToPreviousState();
   }
 
   bool pressedOk() { return get_killer() == m_ok; }

src/commands/cmd_import_sprite_sheet.cpp

@@ -275,16 +275,18 @@ private:
     if (m_document && !m_editor) {
       m_rect = gfx::Rect(0, 0, 16, 16);
       m_editor = current_editor;
-      m_editor->setDefaultState(EditorStatePtr(new SelectBoxState(this, m_rect,
-								  SelectBoxState::PaintRulers |
-								  SelectBoxState::PaintGrid)));
+
+      EditorStatePtr newState(new SelectBoxState(this, m_rect,
+						 SelectBoxState::PaintRulers |
+						 SelectBoxState::PaintGrid));
+      m_editor->setState(newState);
     }
   }
 
   void releaseEditor()
   {
     if (m_editor) {
-      m_editor->setDefaultState(EditorStatePtr(new StandbyState));
+      m_editor->backToPreviousState();
       m_editor = NULL;
     }
   }

src/widgets/editor/drawing_state.cpp

@@ -80,7 +80,7 @@ bool DrawingState::onMouseDown(Editor* editor, Message* msg)
     m_toolLoopManager = NULL;
 
     // Change to standby state
-    editor->setState(editor->getDefaultState());
+    editor->backToPreviousState();
     editor->releaseMouse();
   }
 
@@ -98,7 +98,7 @@ bool DrawingState::onMouseUp(Editor* editor, Message* msg)
   m_toolLoopManager->releaseLoop(pointer_from_msg(msg));
 
   // Back to standby state.
-  editor->setState(editor->getDefaultState());
+  editor->backToPreviousState();
   editor->releaseMouse();
   return true;
 }

src/widgets/editor/editor.cpp

@@ -117,10 +117,13 @@ private:
 
 Editor::Editor()
   : Widget(editor_type())
-  , m_defaultState(EditorStatePtr(new StandbyState()))
-  , m_state(m_defaultState)
+  , m_state(new StandbyState())
+  , m_decorator(NULL)
   , m_customizationDelegate(NULL)
 {
+  // Add the first state into the history.
+  m_statesHistory.push(m_state);
+
   m_document = NULL;
   m_sprite = NULL;
   m_zoom = 0;
@@ -171,22 +174,31 @@ int editor_type()
   return type;
 }
 
-void Editor::setDefaultState(const EditorStatePtr& newState)
-{
-  m_defaultState = newState;
-  setState(newState);
-}
-
-void Editor::setState(const EditorStatePtr& newState)
+void Editor::setStateInternal(const EditorStatePtr& newState)
 {
   hideDrawingCursor();
 
   // Fire before change state event, set the state, and fire after
   // change state event.
-  m_state->onBeforeChangeState(this);
+  bool keepInHistory = m_state->onBeforeChangeState(this);
+
+  // Push a new state
+  if (newState) {
+    if (!keepInHistory)
+      m_statesHistory.pop();
+
+    m_statesHistory.push(newState);
+    m_state = newState;
+  }
+  // Go to previous state
+  else {
+    m_state->onBeforePopState(this);
+
+    m_statesHistory.pop();
+    m_state = m_statesHistory.top();
+  }
 
   // Change to the new state.
-  m_state = newState;
   m_state->onAfterChangeState(this);
 
   // Redraw all the editors with the same document of this editor
@@ -205,13 +217,24 @@ void Editor::setState(const EditorStatePtr& newState)
   updateStatusBar();
 }
 
+void Editor::setState(const EditorStatePtr& newState)
+{
+  setStateInternal(newState);
+}
+
+void Editor::backToPreviousState()
+{
+  setStateInternal(EditorStatePtr(NULL));
+}
+
 void Editor::setDocument(Document* document)
 {
   //if (this->hasMouse())
   //jmanager_free_mouse();	// TODO Why is this here? Review this code
 
-  // Reset current state.
-  setDefaultState(EditorStatePtr(new StandbyState));
+  // Reset all states (back to standby).
+  m_statesHistory.clear();
+  setState(EditorStatePtr(new StandbyState));
 
   if (m_cursor_thick)
     editor_clean_cursor();
@@ -404,10 +427,10 @@ void Editor::drawSprite(int x1, int y1, int x2, int y2)
 
     if (rendered) {
       // Pre-render decorator.
-      if (EditorDecorator* decorator = m_defaultState->getDecorator()) {
+      if (m_decorator) {
       	EditorPreRenderImpl preRender(this, rendered,
       				      Point(-source_x, -source_y), m_zoom);
-      	decorator->preRenderDecorator(&preRender);
+	m_decorator->preRenderDecorator(&preRender);
       }
 
 #ifdef DRAWSPRITE_DOUBLEBUFFERED
@@ -446,9 +469,9 @@ void Editor::drawSprite(int x1, int y1, int x2, int y2)
 		   settings->getGridColor());
 
   // Post-render decorator.
-  if (EditorDecorator* decorator = m_defaultState->getDecorator()) {
+  if (m_decorator) {
     EditorPostRenderImpl postRender(this);
-    decorator->postRenderDecorator(&postRender);
+    m_decorator->postRenderDecorator(&postRender);
   }
 }
 

src/widgets/editor/editor.h

@@ -21,13 +21,13 @@
 
 #include "app/color.h"
 #include "base/compiler_specific.h"
-#include "base/shared_ptr.h"
 #include "base/signal.h"
 #include "document.h"
 #include "gui/base.h"
 #include "gui/widget.h"
 #include "widgets/editor/editor_listeners.h"
 #include "widgets/editor/editor_state.h"
+#include "widgets/editor/editor_states_history.h"
 
 #define MIN_ZOOM 0
 #define MAX_ZOOM 5
@@ -42,25 +42,26 @@ namespace tools {
   class Tool;
 }
 
-typedef SharedPtr<EditorState> EditorStatePtr;
-
 class Editor : public Widget
 {
 public:
-  // in editor.c
-
   Editor();
   ~Editor();
 
-  EditorStatePtr getDefaultState() { return m_defaultState; }
+  // Returns the current state.
   EditorStatePtr getState() { return m_state; }
 
-  // Changes the state of the editor and uses it as the default one.
-  void setDefaultState(const EditorStatePtr& newState);
-
   // Changes the state of the editor.
   void setState(const EditorStatePtr& newState);
 
+  // Backs to previous state.
+  void backToPreviousState();
+
+  // Gets/sets the current decorator. The decorator is not owned by
+  // the Editor, so it must be deleted by the caller.
+  EditorDecorator* getDecorator() { return m_decorator; }
+  void setDecorator(EditorDecorator* decorator) { m_decorator = decorator; }
+
   Document* getDocument() { return m_document; }
   void setDocument(Document* document);
 
@@ -145,15 +146,6 @@ public:
   static void editor_cursor_init();
   static void editor_cursor_exit();
 
-private:
-  void editor_update_quicktool();
-  void editor_draw_cursor(int x, int y, bool refresh = true);
-  void editor_move_cursor(int x, int y, bool refresh = true);
-  void editor_clean_cursor(bool refresh = true);
-  bool editor_cursor_is_subpixel();
-
-public:
-
   // click.c
 
   enum {
@@ -180,6 +172,13 @@ protected:
   }
 
 private:
+  void setStateInternal(const EditorStatePtr& newState);
+  void editor_update_quicktool();
+  void editor_draw_cursor(int x, int y, bool refresh = true);
+  void editor_move_cursor(int x, int y, bool refresh = true);
+  void editor_clean_cursor(bool refresh = true);
+  bool editor_cursor_is_subpixel();
+
   void drawGrid(const gfx::Rect& gridBounds, const Color& color);
 
   void editor_request_size(int *w, int *h);
@@ -189,15 +188,15 @@ private:
 			     int sprite_x, int sprite_y, int color,
 			     void (*pixel)(BITMAP *bmp, int x, int y, int color));
 
-  // Default state when the editor is in standby (generally
-  // StandbyState).  Transitory states should back to the default
-  // state (e.g. ScrollingState returns to the default state when the
-  // mouse button is released).
-  EditorStatePtr m_defaultState;
+  // Stack of states. The top element in the stack is the current state (m_state).
+  EditorStatesHistory m_statesHistory;
 
   // Current editor state (it can be shared between several editors to
   // the same document). This member cannot be NULL.
   EditorStatePtr m_state;
+
+  // Current decorator (to draw extra UI elements).
+  EditorDecorator* m_decorator;
   
   Document* m_document;		// Active document in the editor
   Sprite* m_sprite;		// Active sprite in the editor

src/widgets/editor/editor_state.h

@@ -20,6 +20,7 @@
 #define WIDGETS_EDITOR_EDITOR_STATE_H_INCLUDED
 
 #include "base/disable_copying.h"
+#include "base/shared_ptr.h"
 
 class Editor;
 class EditorDecorator;
@@ -36,14 +37,20 @@ public:
   EditorState() { }
   virtual ~EditorState() { }
 
-  // Called just before this state is deleted and replaced by a new
-  // state in the Editor::setState() method.
-  virtual void onBeforeChangeState(Editor* editor) { }
+  // Called just before this state is replaced by a new state in the
+  // Editor::setState() method.  Returns true if this state should be
+  // kept in the EditorStatesHistory.
+  virtual bool onBeforeChangeState(Editor* editor) { return true; }
 
   // Called when this instance is set as the new Editor's state when
   // Editor::setState() method is used.
   virtual void onAfterChangeState(Editor* editor) { }
 
+  // Called just before the state will be removed from the
+  // EditorStatesHistory.  This event is useful to remove the
+  // decorator from the editor.
+  virtual void onBeforePopState(Editor* editor) { }
+
   // Called when the current tool in the tool bar changes. It is
   // useful for states which depends on the selected current tool (as
   // MovingPixelsState which drops the pixels in case the user selects
@@ -80,11 +87,10 @@ public:
   // drawing cursor.
   virtual bool requirePenPreview() { return false; }
 
-  // Called after the sprite is painted.
-  virtual EditorDecorator* getDecorator() { return NULL; }
-
 private:
   DISABLE_COPYING(EditorState);
 };
 
+typedef SharedPtr<EditorState> EditorStatePtr;
+
 #endif	// WIDGETS_EDITOR_EDITOR_STATE_H_INCLUDED

src/widgets/editor/editor_states_history.cpp

@@ -0,0 +1,58 @@
+/* ASE - Allegro Sprite Editor
+ * Copyright (C) 2001-2011  David Capello
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "config.h"
+
+#include "widgets/editor/editor_states_history.h"
+
+EditorStatesHistory::EditorStatesHistory()
+{
+}
+
+EditorStatesHistory::~EditorStatesHistory()
+{
+  clear();
+}
+
+EditorStatePtr EditorStatesHistory::top()
+{
+  return (!m_states.empty() ? m_states.back(): EditorStatePtr(NULL));
+}
+
+void EditorStatesHistory::push(const EditorStatePtr& state)
+{
+  ASSERT(state != NULL);
+  m_states.push_back(state);
+}
+
+void EditorStatesHistory::pop()
+{
+  ASSERT(!m_states.empty());
+  m_states.pop_back();
+}
+
+void EditorStatesHistory::clear()
+{
+  // Free shared pointers in reverse order
+  std::vector<EditorStatePtr>::reverse_iterator it = m_states.rbegin();
+  std::vector<EditorStatePtr>::reverse_iterator end = m_states.rend();
+  for (; it != end; ++it)
+    (*it).reset();
+
+  m_states.clear();
+}

src/widgets/editor/editor_states_history.h

@@ -0,0 +1,52 @@
+/* ASE - Allegro Sprite Editor
+ * Copyright (C) 2001-2011  David Capello
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef WIDGETS_EDITOR_STATES_HISTORY_H_INCLUDED
+#define WIDGETS_EDITOR_STATES_HISTORY_H_INCLUDED
+
+#include "widgets/editor/editor_state.h"
+
+#include <vector>
+
+// Stack of states in the editor. The top state is the current state
+// of the editor.
+class EditorStatesHistory
+{
+public:
+  EditorStatesHistory();
+  ~EditorStatesHistory();
+
+  // Gets the current state.
+  EditorStatePtr top();
+
+  // Adds a new state in the history.
+  void push(const EditorStatePtr& state);
+
+  // Removes a state from the history (you should keep a reference of
+  // the state with top() if you want to keep it in memory).
+  void pop();
+
+  // Deletes all the history.
+  void clear();
+
+private:
+  // Stack of states (the back of the vector is the top of the stack).
+  std::vector<EditorStatePtr> m_states;
+};
+
+#endif

src/widgets/editor/moving_cel_state.cpp

@@ -102,7 +102,7 @@ bool MovingCelState::onMouseUp(Editor* editor, Message* msg)
     document->generateMaskBoundaries();
   }
 
-  editor->setState(editor->getDefaultState());
+  editor->backToPreviousState();
   editor->releaseMouse();
   return true;
 }

src/widgets/editor/moving_pixels_state.cpp

@@ -80,7 +80,7 @@ MovingPixelsState::~MovingPixelsState()
   delete m_pixelsMovement;
 }
 
-void MovingPixelsState::onBeforeChangeState(Editor* editor)
+bool MovingPixelsState::onBeforeChangeState(Editor* editor)
 {
   ASSERT(m_pixelsMovement != NULL);
 
@@ -96,6 +96,7 @@ void MovingPixelsState::onBeforeChangeState(Editor* editor)
   editor->releaseMouse();
 
   app_get_statusbar()->hideMovePixelsOptions();
+  return false;			// Don't keep this state in history
 }
 
 void MovingPixelsState::onCurrentToolChange(Editor* editor)
@@ -274,6 +275,5 @@ void MovingPixelsState::dropPixels(Editor* editor)
 {
   // Just change to default state (StandbyState generally). We'll
   // receive an onBeforeChangeState event after this call.
-  editor->setState(editor->getDefaultState());
+  editor->backToPreviousState();
 }
-

src/widgets/editor/moving_pixels_state.h

@@ -33,7 +33,7 @@ public:
   MovingPixelsState(Editor* editor, Message* msg, Image* imge, int x, int y, int opacity);
   virtual ~MovingPixelsState();
 
-  virtual void onBeforeChangeState(Editor* editor) OVERRIDE;
+  virtual bool onBeforeChangeState(Editor* editor) OVERRIDE;
   virtual void onCurrentToolChange(Editor* editor) OVERRIDE;
   virtual bool onMouseDown(Editor* editor, Message* msg) OVERRIDE;
   virtual bool onMouseUp(Editor* editor, Message* msg) OVERRIDE;

src/widgets/editor/scrolling_state.cpp

@@ -45,7 +45,7 @@ bool ScrollingState::onMouseDown(Editor* editor, Message* msg)
 
 bool ScrollingState::onMouseUp(Editor* editor, Message* msg)
 {
-  editor->setState(editor->getDefaultState());
+  editor->backToPreviousState();
   editor->releaseMouse();
   return true;
 }

src/widgets/editor/select_box_state.cpp

@@ -56,6 +56,16 @@ void SelectBoxState::setBoxBounds(const gfx::Rect& box)
   m_rulers[V2] = Ruler(Ruler::Vertical, box.x+box.w);
 }
 
+void SelectBoxState::onAfterChangeState(Editor* editor)
+{
+  editor->setDecorator(this);
+}
+
+void SelectBoxState::onBeforePopState(Editor* editor)
+{
+  editor->setDecorator(NULL);
+}
+
 bool SelectBoxState::onMouseDown(Editor* editor, Message* msg)
 {
   if (msg->mouse.left || msg->mouse.right) {
@@ -135,11 +145,6 @@ bool SelectBoxState::onSetCursor(Editor* editor)
   return false;
 }
 
-EditorDecorator* SelectBoxState::getDecorator()
-{
-  return this;
-}
-
 void SelectBoxState::preRenderDecorator(EditorPreRender* render)
 {
   // Without black shadow?

src/widgets/editor/select_box_state.h

@@ -53,11 +53,12 @@ public:
   void setBoxBounds(const gfx::Rect& rc);
 
   // EditorState overrides
+  virtual void onAfterChangeState(Editor* editor) OVERRIDE;
+  virtual void onBeforePopState(Editor* editor) OVERRIDE;
   virtual bool onMouseDown(Editor* editor, Message* msg) OVERRIDE;
   virtual bool onMouseUp(Editor* editor, Message* msg) OVERRIDE;
   virtual bool onMouseMove(Editor* editor, Message* msg) OVERRIDE;
   virtual bool onSetCursor(Editor* editor) OVERRIDE;
-  virtual EditorDecorator* getDecorator() OVERRIDE;
 
   // Returns false as it overrides default standby state behavior &
   // look. This state uses normal arrow cursors.