qwt_plot_canvas.cpp

00001 /* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
00002  * Qwt Widget Library
00003  * Copyright (C) 1997   Josef Wilgen
00004  * Copyright (C) 2002   Uwe Rathmann
00005  *
00006  * This library is free software; you can redistribute it and/or
00007  * modify it under the terms of the Qwt License, Version 1.0
00008  *****************************************************************************/
00009 
00010 // vim: expandtab
00011 
00012 #include <qpainter.h>
00013 #include <qstyle.h>
00014 #if QT_VERSION >= 0x040000
00015 #include <qstyleoption.h>
00016 #include <qpaintengine.h>
00017 #ifdef Q_WS_X11
00018 #include <qx11info_x11.h>
00019 #endif
00020 #endif
00021 #include <qevent.h>
00022 #include "qwt_painter.h"
00023 #include "qwt_math.h"
00024 #include "qwt_plot.h"
00025 #include "qwt_paint_buffer.h"
00026 #include "qwt_plot_canvas.h"
00027 
00028 class QwtPlotCanvas::PrivateData
00029 {
00030 public:
00031     PrivateData():
00032         focusIndicator(NoFocusIndicator),
00033         paintAttributes(0),
00034         cache(NULL)
00035     {
00036     }
00037 
00038     ~PrivateData()
00039     {
00040         delete cache;
00041     }
00042 
00043     FocusIndicator focusIndicator;
00044     int paintAttributes;
00045     QPixmap *cache;
00046 };
00047 
00049 
00050 QwtPlotCanvas::QwtPlotCanvas(QwtPlot *plot):
00051     QFrame(plot)
00052 {
00053     d_data = new PrivateData;
00054 
00055 #if QT_VERSION >= 0x040100
00056     setAutoFillBackground(true);
00057 #endif
00058 
00059 #if QT_VERSION < 0x040000
00060     setWFlags(Qt::WNoAutoErase);
00061 #ifndef QT_NO_CURSOR
00062     setCursor(Qt::crossCursor);
00063 #endif
00064 #else
00065 #ifndef QT_NO_CURSOR
00066     setCursor(Qt::CrossCursor);
00067 #endif
00068 #endif // >= 0x040000
00069 
00070     setPaintAttribute(PaintCached, true);
00071     setPaintAttribute(PaintPacked, true);
00072 }
00073 
00075 QwtPlotCanvas::~QwtPlotCanvas()
00076 {
00077     delete d_data;
00078 }
00079 
00090 void QwtPlotCanvas::setPaintAttribute(PaintAttribute attribute, bool on)
00091 {
00092     if ( bool(d_data->paintAttributes & attribute) == on )
00093         return;
00094 
00095     if ( on )
00096         d_data->paintAttributes |= attribute;
00097     else
00098         d_data->paintAttributes &= ~attribute;
00099 
00100     switch(attribute)
00101     {
00102         case PaintCached:
00103         {
00104             if ( on )
00105             {
00106                 if ( d_data->cache == NULL )
00107                     d_data->cache = new QPixmap();
00108 
00109                 if ( isVisible() )
00110                 {
00111                     const QRect cr = contentsRect();
00112                     *d_data->cache = QPixmap::grabWidget(this,
00113                         cr.x(), cr.y(), cr.width(), cr.height() );
00114                 }
00115             }
00116             else
00117             {
00118                 delete d_data->cache;
00119                 d_data->cache = NULL;
00120             }
00121             break;
00122         }
00123         case PaintPacked:
00124         {
00125             /*
00126               If not visible, changing of the background mode
00127               is delayed until it becomes visible. This tries to avoid 
00128               looking through the canvas when the canvas is shown the first 
00129               time.
00130              */
00131 
00132             if ( on == false || isVisible() )
00133                 QwtPlotCanvas::setSystemBackground(!on);
00134 
00135             break;
00136         }
00137     }
00138 }
00139 
00146 bool QwtPlotCanvas::testPaintAttribute(PaintAttribute attribute) const
00147 {
00148     return (d_data->paintAttributes & attribute) != 0;
00149 }
00150 
00152 QPixmap *QwtPlotCanvas::paintCache()
00153 {
00154     return d_data->cache;
00155 }
00156 
00158 const QPixmap *QwtPlotCanvas::paintCache() const
00159 {
00160     return d_data->cache;
00161 }
00162 
00164 void QwtPlotCanvas::invalidatePaintCache()
00165 {
00166     if ( d_data->cache )
00167         *d_data->cache = QPixmap();
00168 }
00169 
00175 void QwtPlotCanvas::setFocusIndicator(FocusIndicator focusIndicator)
00176 {
00177     d_data->focusIndicator = focusIndicator;
00178 }
00179 
00185 QwtPlotCanvas::FocusIndicator QwtPlotCanvas::focusIndicator() const
00186 {
00187     return d_data->focusIndicator;
00188 }
00189 
00190 void QwtPlotCanvas::hideEvent(QHideEvent *e)
00191 {
00192     QFrame::hideEvent(e);
00193 
00194     if ( d_data->paintAttributes & PaintPacked )
00195     {
00196         // enable system background to avoid the "looking through
00197         // the canvas" effect, for the next show
00198 
00199         setSystemBackground(true);
00200     }
00201 }
00202 
00203 void QwtPlotCanvas::paintEvent(QPaintEvent *event)
00204 {
00205 #if QT_VERSION >= 0x040000
00206     QPainter painter(this);
00207     
00208     if ( !contentsRect().contains( event->rect() ) ) 
00209     {
00210         painter.save();
00211         painter.setClipRegion( event->region() & frameRect() );
00212         drawFrame( &painter );
00213         painter.restore(); 
00214     }
00215 
00216     painter.setClipRegion(event->region() & contentsRect());
00217 
00218     drawContents( &painter );
00219 #else // QT_VERSION < 0x040000
00220     QFrame::paintEvent(event);
00221 #endif
00222 
00223     if ( d_data->paintAttributes & PaintPacked )
00224         setSystemBackground(false);
00225 }
00226 
00228 void QwtPlotCanvas::drawContents(QPainter *painter)
00229 {
00230     if ( d_data->paintAttributes & PaintCached && d_data->cache 
00231         && d_data->cache->size() == contentsRect().size() )
00232     {
00233         painter->drawPixmap(contentsRect().topLeft(), *d_data->cache);
00234     }
00235     else
00236         drawCanvas(painter);
00237 
00238     if ( hasFocus() && focusIndicator() == CanvasFocusIndicator )
00239         drawFocusIndicator(painter);
00240 }
00241 
00251 void QwtPlotCanvas::drawCanvas(QPainter *painter)
00252 {
00253     if ( !contentsRect().isValid() )
00254         return;
00255 
00256     QBrush bgBrush;
00257 #if QT_VERSION >= 0x040000
00258         bgBrush = palette().brush(backgroundRole());
00259 #else
00260     QColorGroup::ColorRole role = 
00261         QPalette::backgroundRoleFromMode( backgroundMode() );
00262     bgBrush = colorGroup().brush( role );
00263 #endif
00264 
00265     if ( d_data->paintAttributes & PaintCached && d_data->cache )
00266     {
00267         *d_data->cache = QPixmap(contentsRect().size());
00268 
00269 #ifdef Q_WS_X11
00270 #if QT_VERSION >= 0x040000
00271         if ( d_data->cache->x11Info().screen() != x11Info().screen() )
00272             d_data->cache->x11SetScreen(x11Info().screen());
00273 #else
00274         if ( d_data->cache->x11Screen() != x11Screen() )
00275             d_data->cache->x11SetScreen(x11Screen());
00276 #endif
00277 #endif
00278 
00279         if ( d_data->paintAttributes & PaintPacked )
00280         {
00281             QPainter bgPainter(d_data->cache);
00282             bgPainter.setPen(Qt::NoPen);
00283 
00284             bgPainter.setBrush(bgBrush);
00285             bgPainter.drawRect(d_data->cache->rect());
00286         }
00287         else
00288             d_data->cache->fill(this, d_data->cache->rect().topLeft());
00289 
00290         QPainter cachePainter(d_data->cache);
00291         cachePainter.translate(-contentsRect().x(),
00292             -contentsRect().y());
00293 
00294         ((QwtPlot *)parent())->drawCanvas(&cachePainter);
00295 
00296         cachePainter.end();
00297 
00298         painter->drawPixmap(contentsRect(), *d_data->cache);
00299     }
00300     else
00301     {
00302 #if QT_VERSION >= 0x040000
00303         if ( d_data->paintAttributes & PaintPacked )
00304 #endif
00305         {
00306             painter->save();
00307 
00308             painter->setPen(Qt::NoPen);
00309             painter->setBrush(bgBrush);
00310             painter->drawRect(contentsRect());
00311 
00312             painter->restore();
00313         }
00314 
00315         ((QwtPlot *)parent())->drawCanvas(painter);
00316     }
00317 }
00318 
00320 void QwtPlotCanvas::drawFocusIndicator(QPainter *painter)
00321 {
00322     const int margin = 1;
00323 
00324     QRect focusRect = contentsRect();
00325     focusRect.setRect(focusRect.x() + margin, focusRect.y() + margin,
00326         focusRect.width() - 2 * margin, focusRect.height() - 2 * margin);
00327 
00328     QwtPainter::drawFocusRect(painter, this, focusRect);
00329 }
00330 
00331 void QwtPlotCanvas::setSystemBackground(bool on)
00332 {
00333 #if QT_VERSION < 0x040000
00334     if ( backgroundMode() == Qt::NoBackground )
00335     {
00336         if ( on )
00337             setBackgroundMode(Qt::PaletteBackground);
00338     }
00339     else
00340     {
00341         if ( !on )
00342             setBackgroundMode(Qt::NoBackground);
00343     }
00344 #else
00345     if ( testAttribute(Qt::WA_NoSystemBackground) == on )
00346         setAttribute(Qt::WA_NoSystemBackground, !on);
00347 #endif
00348 }

Generated on Mon Feb 26 21:22:37 2007 for Qwt User's Guide by  doxygen 1.4.6