/////////////////////////////////////////////////////////////////////////////
// Name:        scrolwin.cpp
// Purpose:     wxScrolledWindow implementation
// Author:      Julian Smart
// Modified by:
// Created:     01/02/97
// RCS-ID:      $Id$
// Copyright:   (c) Julian Smart and Markus Holzem
// Licence:   	wxWindows license
/////////////////////////////////////////////////////////////////////////////

#ifdef __GNUG__
#pragma implementation
#pragma implementation "scrolwin.h"
#endif

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#include "wx/utils.h"
#include "wx/dcclient.h"

#ifdef __WXMSW__
#include "windows.h"
#endif

#ifdef __BORLANDC__
#pragma hdrstop
#endif

#include "wx/generic/scrolwin.h"

#if !USE_SHARED_LIBRARY
BEGIN_EVENT_TABLE(wxScrolledWindow, wxWindow)
  EVT_SCROLL(wxScrolledWindow::OnScroll)
  EVT_SIZE(wxScrolledWindow::OnSize)
  EVT_PAINT(wxScrolledWindow::OnPaint)
END_EVENT_TABLE()

IMPLEMENT_DYNAMIC_CLASS(wxScrolledWindow, wxWindow)
#endif

wxScrolledWindow::wxScrolledWindow(void)
{
  m_xScrollPixelsPerLine = 0;
  m_yScrollPixelsPerLine = 0;
  m_xScrollingEnabled = TRUE;
  m_yScrollingEnabled = TRUE;
  m_xScrollPosition = 0;
  m_yScrollPosition = 0;
  m_xScrollLines = 0;
  m_yScrollLines = 0;
  m_xScrollLinesPerPage = 0;
  m_yScrollLinesPerPage = 0;
}

bool wxScrolledWindow::Create(wxWindow *parent, wxWindowID id,
           const wxPoint& pos,
           const wxSize& size,
           long style,
           const wxString& name)
{
  m_xScrollPixelsPerLine = 0;
  m_yScrollPixelsPerLine = 0;
  m_xScrollingEnabled = TRUE;
  m_yScrollingEnabled = TRUE;
  m_xScrollPosition = 0;
  m_yScrollPosition = 0;
  m_xScrollLines = 0;
  m_yScrollLines = 0;
  m_xScrollLinesPerPage = 0;
  m_yScrollLinesPerPage = 0;

  return wxWindow::Create(parent, id, pos, size, style, name);
}

/*
 * pixelsPerUnitX/pixelsPerUnitY: number of pixels per unit (e.g. pixels per text line)
 * noUnitsX/noUnitsY:        : no. units per scrollbar
 */
void wxScrolledWindow::SetScrollbars (int pixelsPerUnitX, int pixelsPerUnitY,
	       int noUnitsX, int noUnitsY,
	       int xPos, int yPos, bool noRefresh )
{
  bool do_refresh =
     (
      (noUnitsX != 0 && m_xScrollLines == 0) ||
      (noUnitsX < m_xScrollPosition) ||
      (noUnitsY != 0 && m_yScrollLines == 0) ||
      (noUnitsY < m_yScrollPosition) ||
      (xPos != m_xScrollPosition) ||
      (yPos != m_yScrollPosition) ||
      (pixelsPerUnitX != m_xScrollPixelsPerLine) ||
      (pixelsPerUnitY != m_yScrollPixelsPerLine)
     );
      
      m_xScrollPixelsPerLine = pixelsPerUnitX;
      m_yScrollPixelsPerLine = pixelsPerUnitY;
      m_xScrollPosition = xPos;
      m_yScrollPosition = yPos;
      m_xScrollLines = noUnitsX;
      m_yScrollLines = noUnitsY;
      
   AdjustScrollbars();
   
   if (do_refresh && !noRefresh) Refresh();
   
#ifdef __WXMSW__
    UpdateWindow ((HWND) GetHWND());
#endif
}

void wxScrolledWindow::OnScroll(wxScrollEvent& event)
{
  int orient = event.GetOrientation();

  int nScrollInc = CalcScrollInc(event);
  if (nScrollInc == 0)
    return;

    // TODO: should we store the scroll position here as well as in wxWindow?
  if (orient == wxHORIZONTAL)
  {
    int newPos = m_xScrollPosition + nScrollInc;
    SetScrollPos(wxHORIZONTAL, newPos, TRUE );
  }
  else
  {
    int newPos = m_yScrollPosition + nScrollInc;
    SetScrollPos(wxVERTICAL, newPos, TRUE );
  }

/*
  // TODO We need to multiply the ScrollWindow amount by the scaling
  // factor, but how do we know what this is in wxWin 2.0???
  float scaleX = 1.0;
  float scaleY = 1.0;

  if ( this->IsKindOf(CLASSINFO(wxCanvas)) )
  {
    wxDC* dc = ((wxCanvas *)this)->GetDC();
    dc->GetUserScale(&scaleX, &scaleY);
  }
*/

  if (orient == wxHORIZONTAL)
  {
    m_xScrollPosition += nScrollInc;
  }
  else
  {
    m_yScrollPosition += nScrollInc;
  }
  
  if (orient == wxHORIZONTAL)
  {
    if (m_xScrollingEnabled)
      ScrollWindow(-m_xScrollPixelsPerLine * nScrollInc, 0, NULL);
    else
      Refresh();
  }
  else
  {
    if (m_yScrollingEnabled)
      ScrollWindow(0, -m_yScrollPixelsPerLine * nScrollInc, NULL);
    else
      Refresh();
  }

}

int wxScrolledWindow::CalcScrollInc(wxScrollEvent& event)
{
  int pos = event.GetPosition();
  int orient = event.GetOrientation();

  int nScrollInc = 0;
  switch (event.GetEventType())
  {
    case wxEVENT_TYPE_SCROLL_TOP:
    {
      if (orient == wxHORIZONTAL)
        nScrollInc = - m_xScrollPosition;
      else
        nScrollInc = - m_yScrollPosition;
      break;
    }
    case wxEVENT_TYPE_SCROLL_BOTTOM:
    {
      if (orient == wxHORIZONTAL)
        nScrollInc = m_xScrollLines - m_xScrollPosition;
      else
        nScrollInc = m_yScrollLines - m_yScrollPosition;
      break;
    }
    case wxEVENT_TYPE_SCROLL_LINEUP:
    {
      nScrollInc = -1;
      break;
    }
    case wxEVENT_TYPE_SCROLL_LINEDOWN:
    {
      nScrollInc = 1;
      break;
    }
    case wxEVENT_TYPE_SCROLL_PAGEUP:
    {
      if (orient == wxHORIZONTAL)
        nScrollInc = -GetScrollPageSize(wxHORIZONTAL);
      else
        nScrollInc = -GetScrollPageSize(wxVERTICAL);
      break;
    }
    case wxEVENT_TYPE_SCROLL_PAGEDOWN:
    {
      if (orient == wxHORIZONTAL)
        nScrollInc = GetScrollPageSize(wxHORIZONTAL);
      else
        nScrollInc = GetScrollPageSize(wxVERTICAL);
      break;
    }
    case wxEVENT_TYPE_SCROLL_THUMBTRACK:
    {
      if (orient == wxHORIZONTAL)
        nScrollInc = pos - m_xScrollPosition;
      else
        nScrollInc = pos - m_yScrollPosition;
      break;
    }
    default:
    {
      break;
    }
  }
  if (orient == wxHORIZONTAL)
  {
        int w, h;
		GetClientSize(&w, &h);

    	int nMaxWidth = m_xScrollLines*m_xScrollPixelsPerLine;
    	int noPositions = (int) ( ((nMaxWidth - w)/(float)m_xScrollPixelsPerLine) + 0.5 );
    	if (noPositions < 0)
      		noPositions = 0;

		if ( (m_xScrollPosition + nScrollInc) < 0 )
			nScrollInc = -m_xScrollPosition; // As -ve as we can go
		else if ( (m_xScrollPosition + nScrollInc) > noPositions )
			nScrollInc = noPositions - m_xScrollPosition; // As +ve as we can go

        return nScrollInc;
  }
  else
  {
        int w, h;
		GetClientSize(&w, &h);

    	int nMaxHeight = m_yScrollLines*m_yScrollPixelsPerLine;
    	int noPositions = (int) ( ((nMaxHeight - h)/(float)m_yScrollPixelsPerLine) + 0.5 );
    	if (noPositions < 0)
      		noPositions = 0;

		if ( (m_yScrollPosition + nScrollInc) < 0 )
			nScrollInc = -m_yScrollPosition; // As -ve as we can go
		else if ( (m_yScrollPosition + nScrollInc) > noPositions )
			nScrollInc = noPositions - m_yScrollPosition; // As +ve as we can go

        return nScrollInc;
  }
}

// Adjust the scrollbars - new version.
void wxScrolledWindow::AdjustScrollbars(void)
{
  int w, h;
  GetClientSize(&w, &h);

  // Recalculate scroll bar range and position
  if (m_xScrollLines > 0)
  {
    int nMaxWidth = m_xScrollLines*m_xScrollPixelsPerLine;
    int newRange = (int) ( ((nMaxWidth)/(float)m_xScrollPixelsPerLine) + 0.5 );
    if (newRange < 0)
      newRange = 0;

    m_xScrollPosition = wxMin(newRange, m_xScrollPosition);

	// Calculate page size i.e. number of scroll units you get on the
	// current client window
    int noPagePositions = (int) ( (w/(float)m_xScrollPixelsPerLine) + 0.5 );
    if (noPagePositions < 1)
      noPagePositions = 1;

    SetScrollbar(wxHORIZONTAL, m_xScrollPosition, noPagePositions, newRange);
    SetScrollPageSize(wxHORIZONTAL, noPagePositions);
  }
  // Robert Roebling
  else
  { 
    m_xScrollPosition = 0;
    SetScrollbar (wxHORIZONTAL, 0, 0, 0, FALSE);  
  }
    
  if (m_yScrollLines > 0)
  {
    int nMaxHeight = m_yScrollLines*m_yScrollPixelsPerLine;
    int newRange = (int) ( ((nMaxHeight)/(float)m_yScrollPixelsPerLine) + 0.5 );
    if (newRange < 0)
      newRange = 0;

    m_yScrollPosition = wxMin(newRange, m_yScrollPosition);

	// Calculate page size i.e. number of scroll units you get on the
	// current client window
    int noPagePositions = (int) ( (h/(float)m_yScrollPixelsPerLine) + 0.5 );
    if (noPagePositions < 1)
      noPagePositions = 1;

    SetScrollbar(wxVERTICAL, m_yScrollPosition, noPagePositions, newRange);
    SetScrollPageSize(wxVERTICAL, noPagePositions);
  }
  else
  {
    m_yScrollPosition = 0;
    SetScrollbar (wxVERTICAL, 0, 0, 0, FALSE);  // Robert Roebling
  }
  
}

// Default OnSize resets scrollbars, if any
void wxScrolledWindow::OnSize(wxSizeEvent& WXUNUSED(event))
{
#if USE_CONSTRAINTS
  if (GetAutoLayout())
    Layout();
#endif

  AdjustScrollbars();
}

// This calls OnDraw, having adjusted the origin according to the current
// scroll position
void wxScrolledWindow::OnPaint(wxPaintEvent& WXUNUSED(event))
{
	wxPaintDC dc(this);
	PrepareDC(dc);

	OnDraw(dc);
}

// Override this function if you don't want to have wxScrolledWindow
// automatically change the origin according to the scroll position.
void wxScrolledWindow::PrepareDC(wxDC& dc)
{
	dc.SetDeviceOrigin(- m_xScrollPosition * m_xScrollPixelsPerLine, - m_yScrollPosition * m_yScrollPixelsPerLine);
}

#if WXWIN_COMPATIBILITY
void wxScrolledWindow::GetScrollUnitsPerPage (int *x_page, int *y_page) const
{
      *x_page = GetScrollPageSize(wxHORIZONTAL);
      *y_page = GetScrollPageSize(wxVERTICAL);
}
#endif

void wxScrolledWindow::GetScrollPixelsPerUnit (int *x_unit, int *y_unit) const
{
      *x_unit = m_xScrollPixelsPerLine;
      *y_unit = m_yScrollPixelsPerLine;
}

int wxScrolledWindow::GetScrollPageSize(int orient) const
{
    if ( orient == wxHORIZONTAL )
        return m_xScrollLinesPerPage;
    else
        return m_yScrollLinesPerPage;
}

void wxScrolledWindow::SetScrollPageSize(int orient, int pageSize)
{
    if ( orient == wxHORIZONTAL )
        m_xScrollLinesPerPage = pageSize;
    else
        m_yScrollLinesPerPage = pageSize;
}

/*
 * Scroll to given position (scroll position, not pixel position)
 */
void wxScrolledWindow::Scroll (int x_pos, int y_pos)
{
  int old_x, old_y;
  ViewStart (&old_x, &old_y);
  if (((x_pos == -1) || (x_pos == old_x)) && ((y_pos == -1) || (y_pos == old_y)))
    return;

  if (x_pos > -1)
    {
      m_xScrollPosition = x_pos;
      SetScrollPos (wxHORIZONTAL, x_pos, TRUE);
    }
  if (y_pos > -1)
    {
      m_yScrollPosition = y_pos;
      SetScrollPos (wxVERTICAL, y_pos, TRUE);
    }
  Refresh();
#ifdef __WXMSW__
  ::UpdateWindow ((HWND) GetHWND());
#endif
}

void wxScrolledWindow::EnableScrolling (bool x_scroll, bool y_scroll)
{
  m_xScrollingEnabled = x_scroll;
  m_yScrollingEnabled = y_scroll;
}

void wxScrolledWindow::GetVirtualSize (int *x, int *y) const
{
      *x = m_xScrollPixelsPerLine * m_xScrollLines;
      *y = m_yScrollPixelsPerLine * m_yScrollLines;
}

// Where the current view starts from
void wxScrolledWindow::ViewStart (int *x, int *y) const
{
  *x = m_xScrollPosition;
  *y = m_yScrollPosition;
}

void wxScrolledWindow::CalcScrolledPosition(int x, int y, int *xx, int *yy) const
{
  *xx = x - m_xScrollPosition * m_xScrollPixelsPerLine;
  *yy = y - m_yScrollPosition * m_yScrollPixelsPerLine;
}

void wxScrolledWindow::CalcUnscrolledPosition(int x, int y, float *xx, float *yy) const
{
  *xx = (float)(x + m_xScrollPosition * m_xScrollPixelsPerLine);
  *yy = (float)(y + m_yScrollPosition * m_yScrollPixelsPerLine);
}