1// Copyright (C) 2016 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
3
4#ifndef QPAINTDEVICE_H
5#define QPAINTDEVICE_H
6
7#include <QtGui/qtguiglobal.h>
8#include <QtGui/qwindowdefs.h>
9#include <QtCore/qrect.h>
10
11QT_BEGIN_NAMESPACE
12
13
14
15class QPaintEngine;
16
17class Q_GUI_EXPORT QPaintDevice // device for QPainter
18{
19public:
20 enum PaintDeviceMetric {
21 PdmWidth = 1,
22 PdmHeight,
23 PdmWidthMM,
24 PdmHeightMM,
25 PdmNumColors,
26 PdmDepth,
27 PdmDpiX,
28 PdmDpiY,
29 PdmPhysicalDpiX,
30 PdmPhysicalDpiY,
31 PdmDevicePixelRatio,
32 PdmDevicePixelRatioScaled,
33 PdmDevicePixelRatioF_EncodedA,
34 PdmDevicePixelRatioF_EncodedB,
35 };
36
37 virtual ~QPaintDevice();
38
39 virtual int devType() const;
40 bool paintingActive() const;
41 virtual QPaintEngine *paintEngine() const = 0;
42
43 int width() const { return metric(metric: PdmWidth); }
44 int height() const { return metric(metric: PdmHeight); }
45 int widthMM() const { return metric(metric: PdmWidthMM); }
46 int heightMM() const { return metric(metric: PdmHeightMM); }
47 int logicalDpiX() const { return metric(metric: PdmDpiX); }
48 int logicalDpiY() const { return metric(metric: PdmDpiY); }
49 int physicalDpiX() const { return metric(metric: PdmPhysicalDpiX); }
50 int physicalDpiY() const { return metric(metric: PdmPhysicalDpiY); }
51 qreal devicePixelRatio() const;
52 qreal devicePixelRatioF() const { return devicePixelRatio(); }
53 int colorCount() const { return metric(metric: PdmNumColors); }
54 int depth() const { return metric(metric: PdmDepth); }
55
56 static inline qreal devicePixelRatioFScale() { return 0x10000; }
57 static inline int encodeMetricF(PaintDeviceMetric metric, double value);
58protected:
59 QPaintDevice() noexcept;
60 virtual int metric(PaintDeviceMetric metric) const;
61 virtual void initPainter(QPainter *painter) const;
62 virtual QPaintDevice *redirected(QPoint *offset) const;
63 virtual QPainter *sharedPainter() const;
64 double getDecodedMetricF(PaintDeviceMetric metricA, PaintDeviceMetric metricB) const;
65
66 ushort painters; // refcount
67private:
68 Q_DISABLE_COPY(QPaintDevice)
69
70 friend class QPainter;
71 friend class QPainterPrivate;
72 friend class QFontEngineMac;
73 friend class QX11PaintEngine;
74 friend Q_GUI_EXPORT int qt_paint_device_metric(const QPaintDevice *device, PaintDeviceMetric metric);
75};
76
77/*****************************************************************************
78 Inline functions
79 *****************************************************************************/
80
81inline int QPaintDevice::devType() const
82{ return QInternal::UnknownDevice; }
83
84inline bool QPaintDevice::paintingActive() const
85{ return painters != 0; }
86
87inline int QPaintDevice::encodeMetricF(PaintDeviceMetric metric, double value)
88{
89 qint32 buf[2];
90 Q_STATIC_ASSERT(sizeof(buf) == sizeof(double));
91 memcpy(dest: buf, src: &value, n: sizeof(buf));
92 return buf[metric & 1];
93}
94
95QT_END_NAMESPACE
96
97#endif // QPAINTDEVICE_H
98

source code of qtbase/src/gui/painting/qpaintdevice.h