don't crash in UnselectAll() if the tree has no root

[wxWidgets.git] / src / os2 / dcclient.cpp

/////////////////////////////////////////////////////////////////////////////
// Name:        dcclient.cpp
// Purpose:     wxClientDC class
// Author:      David Webster
// Modified by:
// Created:     09/21/99
// RCS-ID:      $Id$
// Copyright:   (c) David Webster
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

// ===========================================================================
// declarations
// ===========================================================================

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

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

#include "wx/string.h"
#include "wx/log.h"
#include "wx/window.h"
#include "wx/app.h"

#include "wx/os2/private.h"

#include "wx/dcclient.h"

// ----------------------------------------------------------------------------
// array/list types
// ----------------------------------------------------------------------------

struct WXDLLEXPORT wxPaintDCInfo
{
    wxPaintDCInfo( wxWindow* pWin
                  ,wxDC*     pDC
                 )
    {
        m_hWnd = pWin->GetHWND();
        m_hDC = pDC->GetHDC();
        m_nCount = 1;
    }

    WXHWND                          m_hWnd;   // window for this DC
    WXHDC                           m_hDC;    // the DC handle
    size_t                          m_nCount; // usage count
}; // end of wxPaintDCInfot

#include "wx/arrimpl.cpp"

WX_DEFINE_OBJARRAY(wxArrayDCInfo);

// ----------------------------------------------------------------------------
// macros
// ----------------------------------------------------------------------------

    IMPLEMENT_DYNAMIC_CLASS(wxWindowDC, wxDC)
    IMPLEMENT_DYNAMIC_CLASS(wxClientDC, wxWindowDC)
    IMPLEMENT_DYNAMIC_CLASS(wxPaintDC, wxWindowDC)

// ----------------------------------------------------------------------------
// global variables
// ----------------------------------------------------------------------------

static RECT        g_paintStruct;

#ifdef __WXDEBUG__
    // a global variable which we check to verify that wxPaintDC are only
    // created in resopnse to WM_PAINT message - doing this from elsewhere is a
    // common programming error among wxWindows programmers and might lead to
    // very subtle and difficult to debug refresh/repaint bugs.
    int g_isPainting = 0;
#endif // __WXDEBUG__

// ===========================================================================
// implementation
// ===========================================================================

// ----------------------------------------------------------------------------
// wxWindowDC
// ----------------------------------------------------------------------------

wxWindowDC::wxWindowDC()
{
    m_pCanvas = NULL;
}

wxWindowDC::wxWindowDC(
  wxWindow*                         pTheCanvas
)
{
    ERRORID                         vError;
    wxString                        sError;

    m_pCanvas = pTheCanvas;
    m_hDC = (WXHDC) ::WinOpenWindowDC(GetWinHwnd(pTheCanvas) );

    //
    // default under PM is that Window and Client DC's are the same
    // so we offer a separate Presentation Space to use for the
    // entire window.  Otherwise, calling BeginPaint will just create
    // chached-micro client presentation space
    //
     m_hPS = ::GpiCreatePS( vHabmain
                           ,m_hDC
                           ,&m_PageSize
                           ,PU_PELS | GPIF_LONG | GPIA_ASSOC
                          );
    ::GpiAssociate(m_hPS, NULLHANDLE);
    ::GpiAssociate(m_hPS, m_hDC);

    //
    // Set the wxWindows color table
    //
    if (!::GpiCreateLogColorTable( m_hPS
                                  ,0L
                                  ,LCOLF_CONSECRGB
                                  ,0L
                                  ,(LONG)wxTheColourDatabase->m_nSize
                                  ,(PLONG)wxTheColourDatabase->m_palTable
                                 ))
    {
        vError = ::WinGetLastError(vHabmain);
        sError = wxPMErrorToStr(vError);
        wxLogError("Unable to set current color table. Error: %s\n", sError);
    }
    ::GpiCreateLogColorTable( m_hPS
                             ,0L
                             ,LCOLF_RGB
                             ,0L
                             ,0L
                             ,NULL
                            );
    ::WinQueryWindowRect( GetWinHwnd(m_pCanvas)
                         ,&m_vRclPaint
                        );
    InitDC();
} // end of wxWindowDC::wxWindowDC

void wxWindowDC::InitDC()
{
    wxColour                        vColor;

    vColor.InitFromName("BLACK");
    m_pen.SetColour(vColor);
    vColor.Set("WHITE");
    m_brush.SetColour(vColor);
    //
    // The background mode is only used for text background and is set in
    // DrawText() to OPAQUE as required, otherwise always TRANSPARENT,
    //
    ::GpiSetBackMix(GetHPS(), BM_LEAVEALONE);

    //
    // Default bg colour is pne of the window
    //
    SetBackground(wxBrush(m_pCanvas->GetBackgroundColour(), wxSOLID));
} // end of wxWindowDC::InitDC

// ----------------------------------------------------------------------------
// wxClientDC
// ----------------------------------------------------------------------------

wxClientDC::wxClientDC()
{
    m_pCanvas = NULL;
}

wxClientDC::wxClientDC(
  wxWindow*                         pTheCanvas
)
{
    SIZEL                           vSizl = { 0,0};
    ERRORID                         vError;
    wxString                        sError;

    m_pCanvas = pTheCanvas;

    //
    // default under PM is that Window and Client DC's are the same
    //
    m_hDC = (WXHDC) ::WinOpenWindowDC(GetWinHwnd(pTheCanvas));
    m_hPS = ::GpiCreatePS( wxGetInstance()
                          ,m_hDC
                          ,&vSizl
                          ,PU_PELS | GPIF_LONG | GPIA_ASSOC
                         );

    // Set the wxWindows color table
    if (!::GpiCreateLogColorTable( m_hPS
                                  ,0L
                                  ,LCOLF_CONSECRGB
                                  ,0L
                                  ,(LONG)wxTheColourDatabase->m_nSize
                                  ,(PLONG)wxTheColourDatabase->m_palTable
                                 ))
    {
        vError = ::WinGetLastError(vHabmain);
        sError = wxPMErrorToStr(vError);
        wxLogError("Unable to set current color table. Error: %s\n", sError);
    }
    ::GpiCreateLogColorTable( m_hPS
                             ,0L
                             ,LCOLF_RGB
                             ,0L
                             ,0L
                             ,NULL
                            );
    //
    // Set the DC/PS rectangle
    //
    ::WinQueryWindowRect( GetWinHwnd(m_pCanvas)
                         ,&m_vRclPaint
                        );
    InitDC();
} // end of wxClientDC::wxClientDC

void wxClientDC::InitDC()
{
    wxWindowDC::InitDC();

    // in wxUniv build we must manually do some DC adjustments usually
    // performed by Windows for us
#ifdef __WXUNIVERSAL__
    wxPoint ptOrigin = m_pCanvas->GetClientAreaOrigin();
    if ( ptOrigin.x || ptOrigin.y )
    {
        // no need to shift DC origin if shift is null
        SetDeviceOrigin(ptOrigin.x, ptOrigin.y);
    }

    // clip the DC to avoid overwriting the non client area
    SetClippingRegion(wxPoint(0, 0), m_pCanvas->GetClientSize());
#endif // __WXUNIVERSAL__
} // end of wxClientDC::InitDC

wxClientDC::~wxClientDC()
{
} // end of wxClientDC::~wxClientDC

// ----------------------------------------------------------------------------
// wxPaintDC
// ----------------------------------------------------------------------------

wxArrayDCInfo wxPaintDC::ms_cache;

wxPaintDC::wxPaintDC()
{
    m_pCanvas = NULL;
    m_hDC = 0;
}

wxPaintDC::wxPaintDC(
  wxWindow*                         pCanvas
)
{
    wxCHECK_RET(pCanvas, wxT("NULL canvas in wxPaintDC ctor"));

#ifdef __WXDEBUG__
    if (g_isPainting <= 0)
    {
        wxFAIL_MSG( wxT("wxPaintDC may be created only in EVT_PAINT handler!") );
        return;
    }
#endif // __WXDEBUG__

    m_pCanvas = pCanvas;

    //
    // Do we have a DC for this window in the cache?
    //
    wxPaintDCInfo*                  pInfo = FindInCache();

    if (pInfo)
    {
        m_hDC = pInfo->m_hDC;
        pInfo->m_nCount++;
    }
    else // not in cache, create a new one
    {
        HPS                         hPS;

        hPS = ::WinBeginPaint( GetWinHwnd(m_pCanvas)
                              ,NULLHANDLE
                              ,&g_paintStruct
                             );
        if(hPS)
        {
            m_hOldPS = m_hPS;
            m_hPS = hPS;
            ::GpiCreateLogColorTable( m_hPS
                                     ,0L
                                     ,LCOLF_CONSECRGB
                                     ,0L
                                     ,(LONG)wxTheColourDatabase->m_nSize
                                     ,(PLONG)wxTheColourDatabase->m_palTable
                                    );
            ::GpiCreateLogColorTable( m_hPS
                                     ,0L
                                     ,LCOLF_RGB
                                     ,0L
                                     ,0L
                                     ,NULL
                                    );

            ::WinFillRect(hPS, &g_paintStruct,  m_pCanvas->GetBackgroundColour().GetPixel());
            ::WinQueryWindowRect( GetWinHwnd(m_pCanvas)
                                 ,&m_vRclPaint
                                );
        }

        m_bIsPaintTime   = TRUE;
        m_hDC = (WXHDC) -1; // to satisfy those anonizmous efforts
        ms_cache.Add(new wxPaintDCInfo(m_pCanvas, this));
    }
    InitDC();
} // end of wxPaintDC::wxPaintDC

wxPaintDC::~wxPaintDC()
{
    if ( m_hDC )
    {
        SelectOldObjects(m_hDC);

        size_t                      nIndex;
        wxPaintDCInfo*              pInfo = FindInCache(&nIndex);

        wxCHECK_RET( pInfo, wxT("existing DC should have a cache entry") );

        if ( !--pInfo->m_nCount )
        {
            ::WinEndPaint(m_hPS);
            m_hPS          = m_hOldPS;
            m_bIsPaintTime = FALSE;
            ms_cache.RemoveAt(nIndex);
        }
        //else: cached DC entry is still in use

        // prevent the base class dtor from ReleaseDC()ing it again
        m_hDC = 0;
    }
}

wxPaintDCInfo* wxPaintDC::FindInCache(
  size_t*                           pIndex
) const
{
    wxPaintDCInfo*                  pInfo = NULL;
    size_t                          nCache = ms_cache.GetCount();

    for (size_t n = 0; n < nCache; n++)
    {
        pInfo = &ms_cache[n];
        if (pInfo->m_hWnd == m_pCanvas->GetHWND())
        {
            if (pIndex)
                *pIndex = n;
            break;
        }
    }
    return pInfo;
} // end of wxPaintDC::FindInCache

// find the entry for this DC in the cache (keyed by the window)
WXHDC wxPaintDC::FindDCInCache(
  wxWindow*                         pWin
)
{
    wxPaintDCInfo*                  pInfo = NULL;
    size_t                          nCache = ms_cache.GetCount();

    for (size_t n = 0; n < nCache; n++)
    {
        pInfo = &ms_cache[n];
        if (pInfo->m_hWnd == pWin->GetHWND())
        {
            return pInfo->m_hDC;
        }
    }
    return 0;
} // end of wxPaintDC::FindInCache