include/QtGui/qpaintdevice.h

0001 // Copyright (C) 2016 The Qt Company Ltd.
0002 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
0003
0004 #ifndef QPAINTDEVICE_H
0005 #define QPAINTDEVICE_H
0006
0007 #include <QtGui/qtguiglobal.h>
0008 #include <QtGui/qwindowdefs.h>
0009 #include <QtCore/qrect.h>
0010
0011 QT_BEGIN_NAMESPACE
0012
0013
0014
0015 class QPaintEngine;
0016
0017 class Q_GUI_EXPORT QPaintDevice                                // device for QPainter
0018 {
0019 public:
0020     enum PaintDeviceMetric {
0021         PdmWidth = 1,
0022         PdmHeight,
0023         PdmWidthMM,
0024         PdmHeightMM,
0025         PdmNumColors,
0026         PdmDepth,
0027         PdmDpiX,
0028         PdmDpiY,
0029         PdmPhysicalDpiX,
0030         PdmPhysicalDpiY,
0031         PdmDevicePixelRatio,
0032         PdmDevicePixelRatioScaled
0033     };
0034
0035     virtual ~QPaintDevice();
0036
0037     virtual int devType() const;
0038     bool paintingActive() const;
0039     virtual QPaintEngine *paintEngine() const = 0;
0040
0041     int width() const { return metric(PdmWidth); }
0042     int height() const { return metric(PdmHeight); }
0043     int widthMM() const { return metric(PdmWidthMM); }
0044     int heightMM() const { return metric(PdmHeightMM); }
0045     int logicalDpiX() const { return metric(PdmDpiX); }
0046     int logicalDpiY() const { return metric(PdmDpiY); }
0047     int physicalDpiX() const { return metric(PdmPhysicalDpiX); }
0048     int physicalDpiY() const { return metric(PdmPhysicalDpiY); }
0049     qreal devicePixelRatio() const { return metric(PdmDevicePixelRatioScaled) / devicePixelRatioFScale(); }
0050     qreal devicePixelRatioF()  const { return devicePixelRatio(); }
0051     int colorCount() const { return metric(PdmNumColors); }
0052     int depth() const { return metric(PdmDepth); }
0053
0054     static inline qreal devicePixelRatioFScale() { return 0x10000; }
0055 protected:
0056     QPaintDevice() noexcept;
0057     virtual int metric(PaintDeviceMetric metric) const;
0058     virtual void initPainter(QPainter *painter) const;
0059     virtual QPaintDevice *redirected(QPoint *offset) const;
0060     virtual QPainter *sharedPainter() const;
0061
0062     ushort        painters;                        // refcount
0063 private:
0064     Q_DISABLE_COPY(QPaintDevice)
0065
0066     friend class QPainter;
0067     friend class QPainterPrivate;
0068     friend class QFontEngineMac;
0069     friend class QX11PaintEngine;
0070     friend Q_GUI_EXPORT int qt_paint_device_metric(const QPaintDevice *device, PaintDeviceMetric metric);
0071 };
0072
0073 /*****************************************************************************
0074   Inline functions
0075  *****************************************************************************/
0076
0077 inline int QPaintDevice::devType() const
0078 { return QInternal::UnknownDevice; }
0079
0080 inline bool QPaintDevice::paintingActive() const
0081 { return painters != 0; }
0082
0083 QT_END_NAMESPACE
0084
0085 #endif // QPAINTDEVICE_H