xcb: Add experimental legacy support for native X11 painting

This commit revives the old native QPixmap and QPaintEngine
implementations that were present in Qt4. The backing store supports
regular raster windows in this commit. Support for render-to-texture
widgets and OpenGL compositing will be added in a follow-up commit.

Change-Id: I80a9c4f0c42a6f68f571dfee930d95000d5dd950
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 118 insertions, 0 deletions

diff --git a/src/plugins/platforms/xcb/nativepainting/qpaintengine_x11_p.h b/src/plugins/platforms/xcb/nativepainting/qpaintengine_x11_p.h
new file mode 100644
index 0000000000..34b5d929d5
--- /dev/null
+++ b/src/plugins/platforms/xcb/nativepainting/qpaintengine_x11_p.h
@@ -0,0 +1,118 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QPAINTENGINE_X11_H
+#define QPAINTENGINE_X11_H
+
+#include <QtGui/QPaintEngine>
+
+typedef unsigned long XID;
+typedef XID Drawable;
+typedef struct _XGC *GC;
+
+QT_BEGIN_NAMESPACE
+
+extern "C" {
+Drawable qt_x11Handle(const QPaintDevice *pd);
+GC qt_x11_get_pen_gc(QPainter *);
+GC qt_x11_get_brush_gc(QPainter *);
+}
+
+class QX11PaintEnginePrivate;
+class QX11PaintEngine : public QPaintEngine
+{
+    Q_DECLARE_PRIVATE(QX11PaintEngine)
+public:
+    QX11PaintEngine();
+    ~QX11PaintEngine();
+
+    bool begin(QPaintDevice *pdev) Q_DECL_OVERRIDE;
+    bool end() Q_DECL_OVERRIDE;
+
+    void updateState(const QPaintEngineState &state) Q_DECL_OVERRIDE;
+
+    void updatePen(const QPen &pen);
+    void updateBrush(const QBrush &brush, const QPointF &pt);
+    void updateRenderHints(QPainter::RenderHints hints);
+    void updateFont(const QFont &font);
+    void updateMatrix(const QTransform &matrix);
+    void updateClipRegion_dev(const QRegion &region, Qt::ClipOperation op);
+
+    void drawLines(const QLine *lines, int lineCount) Q_DECL_OVERRIDE;
+    void drawLines(const QLineF *lines, int lineCount) Q_DECL_OVERRIDE;
+
+    void drawRects(const QRect *rects, int rectCount) Q_DECL_OVERRIDE;
+    void drawRects(const QRectF *rects, int rectCount) Q_DECL_OVERRIDE;
+
+    void drawPoints(const QPoint *points, int pointCount) Q_DECL_OVERRIDE;
+    void drawPoints(const QPointF *points, int pointCount) Q_DECL_OVERRIDE;
+
+    void drawEllipse(const QRect &r) Q_DECL_OVERRIDE;
+    void drawEllipse(const QRectF &r) Q_DECL_OVERRIDE;
+
+    virtual void drawPolygon(const QPointF *points, int pointCount, PolygonDrawMode mode) Q_DECL_OVERRIDE;
+    inline void drawPolygon(const QPoint *points, int pointCount, PolygonDrawMode mode) Q_DECL_OVERRIDE
+        { QPaintEngine::drawPolygon(points, pointCount, mode); }
+
+    void drawPixmap(const QRectF &r, const QPixmap &pm, const QRectF &sr) Q_DECL_OVERRIDE;
+    void drawTiledPixmap(const QRectF &r, const QPixmap &pixmap, const QPointF &s) Q_DECL_OVERRIDE;
+    void drawPath(const QPainterPath &path) Q_DECL_OVERRIDE;
+    void drawTextItem(const QPointF &p, const QTextItem &textItem) Q_DECL_OVERRIDE;
+    void drawImage(const QRectF &r, const QImage &img, const QRectF &sr,
+                   Qt::ImageConversionFlags flags = Qt::AutoColor) Q_DECL_OVERRIDE;
+
+    virtual Drawable handle() const;
+    inline Type type() const Q_DECL_OVERRIDE { return QPaintEngine::X11; }
+
+    QPainter::RenderHints supportedRenderHints() const;
+
+protected:
+    QX11PaintEngine(QX11PaintEnginePrivate &dptr);
+
+#if QT_CONFIG(fontconfig)
+    void drawFreetype(const QPointF &p, const QTextItemInt &ti);
+    bool drawCachedGlyphs(const QTransform &transform, const QTextItemInt &ti);
+#endif // QT_CONFIG(fontconfig)
+
+    friend class QPixmap;
+    friend class QFontEngineBox;
+    friend GC qt_x11_get_pen_gc(QPainter *);
+    friend GC qt_x11_get_brush_gc(QPainter *);
+
+private:
+    Q_DISABLE_COPY(QX11PaintEngine)
+};
+
+QT_END_NAMESPACE
+
+#endif // QPAINTENGINE_X11_H