#include "wx/msw/printdlg.h"
#include "wx/msw/private.h"
#include "wx/msw/dcprint.h"
+#include "wx/msw/enhmeta.h"
#include <stdlib.h>
wxDC *wxWindowsPrinter::PrintDialog(wxWindow *parent)
{
- wxDC *dc = (wxPrinterDC*) NULL;
+ wxDC *dc = NULL;
wxWindowsPrintDialog dialog(parent, & m_printDialogData);
int ret = dialog.ShowModal();
wxPrintDialogData *data)
: wxPrintPreviewBase(printout, printoutForPrinting, data)
{
-#if wxUSE_HIGH_QUALITY_PREVIEW
- m_hqPreviewFailed = false;
-#endif
DetermineScaling();
}
wxPrintData *data)
: wxPrintPreviewBase(printout, printoutForPrinting, data)
{
-#if wxUSE_HIGH_QUALITY_PREVIEW
- m_hqPreviewFailed = false;
-#endif
DetermineScaling();
}
m_previewScaleY = float(logPPIScreenY) / logPPIPrinterY;
}
-
-#if wxUSE_HIGH_QUALITY_PREVIEW
-
-// The preview, as implemented in wxPrintPreviewBase (and as used prior to wx3)
-// is inexact: it uses screen DC, which has much lower resolution and has
-// other properties different from printer DC, so the preview is not quite
-// right.
-//
-// To make matters worse, if the application depends heavily on GetTextExtent()
-// or does text layout itself, the output in preview and on paper can be very
-// different. In particular, wxHtmlEasyPrinting is affected and the preview
-// can be easily off by several pages.
-//
-// To fix this, we attempt to render the preview into high-resolution bitmap
-// using DC with same resolution etc. as the printer DC. This takes lot of
-// memory, so the code is more complicated than it could be, but the results
-// are much better.
-//
-// Finally, this code is specific to wxMSW, because it doesn't make sense to
-// bother with it on other platforms. Both OSX and modern GNOME/GTK+
-// environments have builtin accurate preview (that applications should use
-// instead) and the differences between screen and printer DC in wxGTK are so
-// large than this trick doesn't help at all.
-
-namespace
-{
-
-// If there's not enough memory, we need to render the preview in parts.
-// Unfortunately we cannot simply use wxMemoryDC, because it reports its size
-// as bitmap's size, and we need to use smaller bitmap while still reporting
-// original ("correct") DC size, because printing code frequently uses
-// GetSize() to determine scaling factor. This DC class handles this.
-
-class PageFragmentDCImpl : public wxMemoryDCImpl
-{
-public:
- PageFragmentDCImpl(wxMemoryDC *owner, wxDC *printer, const wxRect& rect)
- : wxMemoryDCImpl(owner, printer),
- m_rect(rect)
- {
- SetDeviceOrigin(0, 0);
- }
-
- virtual void SetDeviceOrigin(wxCoord x, wxCoord y)
- {
- wxMemoryDCImpl::SetDeviceOrigin(x - m_rect.x, y - m_rect.y);
- }
-
- virtual void DoGetDeviceOrigin(wxCoord *x, wxCoord *y) const
- {
- wxMemoryDCImpl::DoGetDeviceOrigin(x, y);
- if ( x ) *x += m_rect.x;
- if ( x ) *y += m_rect.y;
- }
-
- virtual void DoGetSize(int *width, int *height) const
- {
- if ( width )
- *width = m_rect.width;
- if ( height )
- *height = m_rect.height;
- }
-
-private:
- wxRect m_rect;
-};
-
-class PageFragmentDC : public wxDC
-{
-public:
- PageFragmentDC(wxDC* printer, wxBitmap& bmp, const wxRect& rect)
- : wxDC(new PageFragmentDCImpl((wxMemoryDC*)this, printer, rect))
- {
- wx_static_cast(PageFragmentDCImpl*, m_pimpl)->DoSelect(bmp);
- }
-};
-
-// estimate how big chunks we can render, given available RAM
-long ComputeFragmentSize(long printerDepth,
- long width,
- long height)
+bool wxWindowsPrintPreview::RenderPageIntoBitmap(wxBitmap& bmp, int pageNum)
{
- // Compute the amount of memory needed to generate the preview.
- // Memory requirements of RenderPageFragment() are as follows:
+ // The preview, as implemented in wxPrintPreviewBase (and as used prior to
+ // wx3) is inexact: it uses screen DC, which has much lower resolution and
+ // has other properties different from printer DC, so the preview is not
+ // quite right.
//
- // (memory DC - always)
- // width * height * printerDepth/8
- // (wxImage + wxDIB instance)
- // width * height * (3 + 4)
- // (this could be reduced to *3 if using wxGraphicsContext)
+ // To make matters worse, if the application depends heavily on
+ // GetTextExtent() or does text layout itself, the output in preview and on
+ // paper can be very different. In particular, wxHtmlEasyPrinting is
+ // affected and the preview can be easily off by several pages.
//
- // So, given amount of memory M, we can render at most
- //
- // height = M / (width * (printerDepth/8 + F))
- //
- // where F is 3 or 7 depending on whether wxGraphicsContext is used or not
-
- wxMemorySize memAvail = wxGetFreeMemory();
- if ( memAvail == -1 )
- {
- // we don't know; 10meg shouldn't be a problem hopefully
- memAvail = 10000000;
- }
- else
- {
- // limit ourselves to half of available RAM to have a margin for other
- // apps, for our rendering code, and for miscalculations
- memAvail /= 2;
- }
+ // To fix this, we render the preview into high-resolution enhanced
+ // metafile with properties identical to the printer DC. This guarantees
+ // metrics correctness while still being fast.
- const float perPixel = float(printerDepth)/8 + (3 + 4);
- const long perLine = long(width * perPixel);
- const long maxstep = (memAvail / perLine).GetValue();
- const long step = wxMin(height, maxstep);
-
- wxLogTrace("printing",
- "using %liMB of RAM (%li lines) for preview, %li %lipx fragments",
- long((memAvail >> 20).GetValue()),
- maxstep,
- (height+step-1) / step,
- step);
-
- return step;
-}
-
-} // anonymous namespace
-
-
-bool wxWindowsPrintPreview::RenderPageFragment(float scaleX, float scaleY,
- int *nextFinalLine,
- wxPrinterDC& printer,
- wxMemoryDC& finalDC,
- const wxRect& rect,
- int pageNum)
-{
- // compute 'rect' equivalent in the small final bitmap:
- const wxRect smallRect(wxPoint(0, *nextFinalLine),
- wxPoint(int(rect.GetRight() * scaleX),
- int(rect.GetBottom() * scaleY)));
- wxLogTrace("printing",
- "rendering fragment of page %i: [%i,%i,%i,%i] scaled down to [%i,%i,%i,%i]",
- pageNum,
- rect.x, rect.y, rect.GetRight(), rect.GetBottom(),
- smallRect.x, smallRect.y, smallRect.GetRight(), smallRect.GetBottom()
- );
-
- // create DC and bitmap compatible with printer DC:
- wxBitmap large(rect.width, rect.height, printer);
- if ( !large.IsOk() )
- return false;
-
- // render part of the page into it:
- {
- PageFragmentDC memoryDC(&printer, large, rect);
- if ( !memoryDC.IsOk() )
- return false;
-
- memoryDC.Clear();
-
- if ( !RenderPageIntoDC(memoryDC, pageNum) )
- return false;
- } // release bitmap from memoryDC
-
- // now scale the rendered part down and blit it into final output:
-
- wxImage img;
- {
- wxDIB dib(large);
- if ( !dib.IsOk() )
- return false;
- large = wxNullBitmap; // free memory a.s.a.p.
- img = dib.ConvertToImage();
- } // free the DIB now that it's no longer needed, too
-
- if ( !img.IsOk() )
- return false;
-
- img.Rescale(smallRect.width, smallRect.height, wxIMAGE_QUALITY_HIGH);
- if ( !img.IsOk() )
- return false;
+ // print the preview into a metafile:
+ wxPrinterDC printerDC(m_printDialogData.GetPrintData());
+ wxEnhMetaFileDC metaDC(printerDC,
+ wxEmptyString,
+ printerDC.GetSize().x, printerDC.GetSize().y);
- wxBitmap bmp(img);
- if ( !bmp.IsOk() )
+ if ( !RenderPageIntoDC(metaDC, pageNum) )
return false;
- img = wxNullImage;
- finalDC.DrawBitmap(bmp, smallRect.x, smallRect.y);
- if ( bmp.IsOk() )
- {
- *nextFinalLine += smallRect.height;
- return true;
- }
-
- return false;
-}
-
-bool wxWindowsPrintPreview::RenderPageIntoBitmapHQ(wxBitmap& bmp, int pageNum)
-{
- wxLogTrace("printing", "rendering HQ preview of page %i", pageNum);
-
- wxPrinterDC printerDC(m_printDialogData.GetPrintData());
- if ( !printerDC.IsOk() )
+ wxEnhMetaFile *metafile = metaDC.Close();
+ if ( !metafile )
return false;
- // compute scale factor
- const float scaleX = float(bmp.GetWidth()) / float(m_pageWidth);
- const float scaleY = float(bmp.GetHeight()) / float(m_pageHeight);
-
+ // now render the metafile:
wxMemoryDC bmpDC;
bmpDC.SelectObject(bmp);
bmpDC.Clear();
- const int initialStep = ComputeFragmentSize(printerDC.GetDepth(),
- m_pageWidth, m_pageHeight);
+ wxRect outRect(0, 0, bmp.GetWidth(), bmp.GetHeight());
+ metafile->Play(&bmpDC, &outRect);
- wxRect todo(0, 0, m_pageWidth, initialStep); // rect to render
- int nextFinalLine = 0; // first not-yet-rendered output line
- while ( todo.y < m_pageHeight )
- {
- todo.SetBottom(wxMin(todo.GetBottom(), m_pageHeight - 1));
-
- if ( !RenderPageFragment(scaleX, scaleY,
- &nextFinalLine,
- printerDC,
- bmpDC,
- todo,
- pageNum) )
- {
- if ( todo.height < 20 )
- {
- // something is very wrong if we can't render even at this
- // slow space, let's bail out and fall back to low quality
- // preview
- wxLogTrace("printing",
- "it seems that HQ preview doesn't work at all");
- return false;
- }
-
- // it's possible our memory calculation was off, or conditions
- // changed, or there's not enough _bitmap_ resources; try if using
- // smaller bitmap would help:
- todo.height /= 2;
+ delete metafile;
- wxLogTrace("printing",
- "preview of fragment failed, reducing height to %ipx",
- todo.height);
-
- continue; // retry at the same position again
- }
-
- // move to the next segment
- todo.Offset(0, todo.height);
- }
+ // TODO: we should keep the metafile and reuse it when changing zoom level
return true;
}
-bool wxWindowsPrintPreview::RenderPageIntoBitmap(wxBitmap& bmp, int pageNum)
-{
- // try high quality rendering first:
- if ( !m_hqPreviewFailed )
- {
- if ( RenderPageIntoBitmapHQ(bmp, pageNum) )
- {
- return true;
- }
- else
- {
- wxLogTrace("printing",
- "high-quality preview failed, falling back to normal");
- m_hqPreviewFailed = true; // don't bother re-trying
- }
- }
-
- // if it fails, use the generic method that is less resource intensive,
- // but inexact
- return wxPrintPreviewBase::RenderPageIntoBitmap(bmp, pageNum);
-}
-
-#endif // wxUSE_HIGH_QUALITY_PREVIEW
/****************************************************************************
projects / wxWidgets.git / blobdiff