//=========================================================
//  MusE
//  Linux Music Editor
//    $Id: canvas.h,v 1.3.2.8 2009/02/02 21:38:01 terminator356 Exp $
//  (C) Copyright 1999 Werner Schweer (ws@seh.de)
//  Additions, modifications (C) Copyright 2011-2013 Tim E. Real (terminator356 on users DOT sourceforge DOT net)
//
//  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; 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
//=========================================================

#ifndef __CANVAS_H__
#define __CANVAS_H__

#include "citem.h"
#include "view.h"
#include "tools.h"
#include "undo.h"

#include <QWheelEvent>
#include <QMouseEvent>
#include <QKeyEvent>

class QMenu;
class QPoint;

namespace MusEGui {

//---------------------------------------------------------
//   Canvas
//---------------------------------------------------------

class Canvas : public View {
      Q_OBJECT
      QTimer *scrollTimer;
      
      bool doScroll;
      int scrollSpeed;
      
      QPoint ev_pos;
      QPoint ev_global_pos;
      bool ignore_mouse_move;
      bool canScrollLeft;
      bool canScrollRight;
      bool canScrollUp;
      bool canScrollDown;

      CItem *findCurrentItem(const QPoint &cStart);
      
      // Whether we have grabbed the mouse.
      bool _mouseGrabbed;
      // The number of times we have called QApplication::setOverrideCursor().
      // This should always be one or zero, anything else is an error, but unforeseen 
      //  events might cause us to miss a decrement with QApplication::restoreOverrideCursor().
      int _cursorOverrideCount;
      
      // If show is true, calls QApplication::restoreOverrideCursor() until _cursorOverrideCount-- is <= 0.
      // If show is false, calls QApplication::setOverrideCursor with a blank cursor.
      void showCursor(bool show = true);
      // Sets or resets the _mouseGrabbed flag and grabs or releases the mouse.
      void setMouseGrab(bool grabbed = false);
      
   protected:
      enum DragMode {
            DRAG_OFF=0, DRAG_NEW,
            DRAG_MOVE_START, DRAG_MOVE,
            DRAG_COPY_START, DRAG_COPY,
            DRAG_CLONE_START, DRAG_CLONE,
            DRAGX_MOVE, DRAGY_MOVE,
            DRAGX_COPY, DRAGY_COPY,
            DRAGX_CLONE, DRAGY_CLONE,
            DRAG_DELETE,
            DRAG_RESIZE, DRAG_LASSO_START, DRAG_LASSO,
            DRAG_PAN, DRAG_ZOOM
            };

      enum DragType {
            MOVE_MOVE, MOVE_COPY, MOVE_CLONE
            };

      enum HScrollDir {
            HSCROLL_NONE, HSCROLL_LEFT, HSCROLL_RIGHT
            };
      enum VScrollDir {
            VSCROLL_NONE, VSCROLL_UP, VSCROLL_DOWN
            };
      
      enum MenuIdBase {
            TOOLS_ID_BASE=10000
            };
      enum ResizeDirection {
            RESIZE_TO_THE_LEFT,
            RESIZE_TO_THE_RIGHT
      };
            
      CItemList items;
      CItemList moving;
      CItem* newCItem;
      CItem* curItem;
      MusECore::Part* curPart;
      int curPartId;      

      int canvasTools;
      DragMode drag;
      QRect lasso;
      QPoint start;
      QPoint end;
      QPoint global_start;
      Tool _tool;
      unsigned pos[3];
      ResizeDirection resizeDirection;
      
      HScrollDir hscrollDir;
      VScrollDir vscrollDir;
      int button;
      Qt::KeyboardModifiers keyState;
      QMenu* itemPopupMenu;
      QMenu* canvasPopupMenu;

      bool supportsResizeToTheLeft;

      void resizeToTheLeft(const QPoint &pos);
      void setCursor();
      virtual void viewKeyPressEvent(QKeyEvent* event);
      virtual void viewKeyReleaseEvent(QKeyEvent* event);
      virtual void viewMousePressEvent(QMouseEvent* event);
      virtual void viewMouseMoveEvent(QMouseEvent*);
      virtual void viewMouseReleaseEvent(QMouseEvent*);
      virtual void draw(QPainter&, const QRect&);
      virtual void wheelEvent(QWheelEvent* e);

      virtual void keyPress(QKeyEvent*);
      virtual void keyRelease(QKeyEvent*);
      virtual bool mousePress(QMouseEvent*) { return true; }
      virtual void mouseMove(QMouseEvent* event) = 0;
      virtual void mouseRelease(const QPoint&) {}
      virtual void drawCanvas(QPainter&, const QRect&) = 0;
      virtual void drawTopItem(QPainter& p, const QRect& rect) = 0;

      virtual void drawItem(QPainter&, const CItem*, const QRect&) = 0;
      virtual void drawMoving(QPainter&, const CItem*, const QRect&) = 0;
      virtual void updateSelection() = 0;
      virtual QPoint raster(const QPoint&) const = 0;
      virtual int y2pitch(int) const = 0; //CDW
      virtual int pitch2y(int) const = 0; //CDW
      virtual int y2height(int) const = 0; 
      virtual int yItemOffset() const = 0;

      virtual CItem* newItem(const QPoint&, int state) = 0;
      virtual void resizeItem(CItem*, bool noSnap=false, bool ctrl=false) = 0;
      virtual void newItem(CItem*, bool noSnap=false) = 0;
      virtual bool deleteItem(CItem*) = 0;

      /*!
         \brief Virtual member

         Implementing class is responsible for creating a popup to be shown when the user rightclicks an item on the Canvas
         \param item The canvas item that is rightclicked
         \return A QPopupMenu*
         */
      virtual QMenu* genItemPopup(CItem* /*item*/) { return 0; }

      /*!
         \brief Pure virtual member

         Implementing class is responsible for creating a popup to be shown when the user rightclicks an empty region of the canvas
         \return A QPopupMenu*
         */
      QMenu* genCanvasPopup(QMenu* menu = 0);

      /*!
         \brief Virtual member

         This is the function called when the user has selected an option in the popupmenu generated by genItemPopup()
         \param item the canvas item the whole thing is about
         \param n Command type
         \param pt I think this is the position of the pointer when right mouse button was pressed
         */
      virtual void itemPopup(CItem* /*item */, int /*n*/, const QPoint& /*pt*/) {}
      void canvasPopup(int);

      virtual void startDrag(CItem*, DragType) = 0;// {}

      // selection
      virtual void deselectAll();
      virtual void selectItem(CItem* e, bool);

      virtual void deleteItem(const QPoint&);

      // moving
      void startMoving(const QPoint&, DragType, bool rasterize = true);
      void moveItems(const QPoint&, int dir = 0, bool rasterize = true);
      virtual void endMoveItems(const QPoint&, DragType, int dir, bool rasterize = true) = 0;

      virtual void selectLasso(bool toggle);

      virtual void itemPressed(const CItem*) {}
      virtual void itemReleased(const CItem*, const QPoint&) {}
      virtual void itemMoved(const CItem*, const QPoint&) {}
      virtual void curPartChanged() { emit curPartHasChanged(curPart); }

   public slots:
      void setTool(int t);
      virtual void setPos(int, unsigned, bool adjustScrollbar);
      void scrollTimerDone(void);
      void redirectedWheelEvent(QWheelEvent*);

   signals:
      void followEvent(int);
      void toolChanged(int);
      void verticalScroll(unsigned);
      void horizontalScroll(unsigned);
      void horizontalScrollNoLimit(unsigned);
      void horizontalZoom(bool zoom_in, const QPoint& glob_pos);
      void horizontalZoom(int mag, const QPoint& glob_pos);
      void curPartHasChanged(MusECore::Part*);
      
   public:
      Canvas(QWidget* parent, int sx, int sy, const char* name = 0);
      virtual ~Canvas();
      // Whether we have grabbed the mouse.
      bool mouseGrabbed() const { return _mouseGrabbed; }
      bool isSingleSelection() const;
      int selectionSize() const;
      bool itemsAreSelected() const;
      Tool tool() const { return _tool; }
      MusECore::Part* part() const { return curPart; }
      void setCurrentPart(MusECore::Part*); 
      void setCanvasTools(int n) { canvasTools = n; }
      int getCurrentDrag();
      };

} // namespace MusEGui

#endif

