// Filename: pgScrollFrame.h
// Created by:  drose (17Aug05)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) 2001 - 2004, Disney Enterprises, Inc.  All rights reserved
//
// All use of this software is subject to the terms of the Panda 3d
// Software license.  You should have received a copy of this license
// along with this source code; you will also find a current copy of
// the license at http://etc.cmu.edu/panda3d/docs/license/ .
//
// To contact the maintainers of this program write to
// panda3d-general@lists.sourceforge.net .
//
////////////////////////////////////////////////////////////////////

#ifndef PGSCROLLFRAME_H
#define PGSCROLLFRAME_H

#include "pandabase.h"

#include "pgVirtualFrame.h"
#include "pgSliderBarNotify.h"
#include "pgSliderBar.h"

////////////////////////////////////////////////////////////////////
//       Class : PGScrollFrame
// Description : This is a special kind of frame that pretends to be
//               much larger than it actually is.  You can scroll
//               through the frame, as if you're looking through a
//               window at the larger frame beneath.  All children of
//               this frame node are scrolled and clipped as if they
//               were children of the larger, virtual frame.
//
//               This is implemented as a specialization of
//               PGVirtualFrame, which handles the meat of the virtual
//               canvas.  This class adds automatic support for scroll
//               bars, and restricts the virtual transform to
//               translate only (no scale or rotate).
////////////////////////////////////////////////////////////////////
class EXPCL_PANDA PGScrollFrame : public PGVirtualFrame, public PGSliderBarNotify {
PUBLISHED:
  PGScrollFrame(const string &name = "");
  virtual ~PGScrollFrame();

protected:
  PGScrollFrame(const PGScrollFrame &copy);

public:
  virtual PandaNode *make_copy() const;
  virtual bool cull_callback(CullTraverser *trav, CullTraverserData &data);
  virtual void xform(const LMatrix4f &mat);

PUBLISHED:
  void setup(float width, float height,
             float left, float right, float bottom, float top,
             float slider_width, float bevel);

  INLINE void set_virtual_frame(float left, float right, float bottom, float top);
  INLINE void set_virtual_frame(const LVecBase4f &virtual_frame);
  INLINE const LVecBase4f &get_virtual_frame() const;
  INLINE bool has_virtual_frame() const;
  INLINE void clear_virtual_frame();

  INLINE void set_manage_pieces(bool manage_pieces);
  INLINE bool get_manage_pieces() const;

  INLINE void set_auto_hide(bool auto_hide);
  INLINE bool get_auto_hide() const;

  INLINE void set_horizontal_slider(PGSliderBar *horizontal_slider);
  INLINE void clear_horizontal_slider();
  INLINE PGSliderBar *get_horizontal_slider() const;

  INLINE void set_vertical_slider(PGSliderBar *vertical_slider);
  INLINE void clear_vertical_slider();
  INLINE PGSliderBar *get_vertical_slider() const;

  void remanage();
  INLINE void recompute();

protected:
  virtual void frame_changed();

  virtual void item_transform_changed(PGItem *item);
  virtual void item_frame_changed(PGItem *item);
  virtual void item_draw_mask_changed(PGItem *item);
  virtual void slider_bar_adjust(PGSliderBar *slider_bar);

private:
  void recompute_clip();

  void recompute_canvas();
  float interpolate_canvas(float clip_min, float clip_max, 
                           float canvas_min, float canvas_max,
                           PGSliderBar *slider_bar);

private:
  bool _needs_remanage;
  bool _needs_recompute_clip;
  bool _needs_recompute_canvas;

  LVecBase4f _orig_clip_frame;

  bool _has_virtual_frame;
  LVecBase4f _virtual_frame;

  bool _manage_pieces;
  bool _auto_hide;

  PT(PGSliderBar) _horizontal_slider;
  PT(PGSliderBar) _vertical_slider;

public:
  static TypeHandle get_class_type() {
    return _type_handle;
  }
  static void init_type() {
    PGVirtualFrame::init_type();
    register_type(_type_handle, "PGScrollFrame",
                  PGVirtualFrame::get_class_type());
  }
  virtual TypeHandle get_type() const {
    return get_class_type();
  }
  virtual TypeHandle force_init_type() {init_type(); return get_class_type();}

private:
  static TypeHandle _type_handle;
};

#include "pgScrollFrame.I"

#endif
