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, 160 insertions, 0 deletions

diff --git a/src/plugins/platforms/xcb/nativepainting/qpixmap_x11_p.h b/src/plugins/platforms/xcb/nativepainting/qpixmap_x11_p.h
new file mode 100644
index 0000000000..2cbd1fe3d0
--- /dev/null
+++ b/src/plugins/platforms/xcb/nativepainting/qpixmap_x11_p.h
@@ -0,0 +1,160 @@
+/****************************************************************************
+**
+** 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 QX11PLATFORMPIXMAP_H
+#define QX11PLATFORMPIXMAP_H
+
+#include <QBitmap>
+#include <QPixmap>
+
+#include <qpa/qplatformpixmap.h>
+#include "qxcbnativepainting.h"
+
+typedef unsigned long XID;
+typedef XID Drawable;
+typedef XID Picture;
+typedef XID Pixmap;
+
+QT_BEGIN_NAMESPACE
+
+class QX11PaintEngine;
+struct QXImageWrapper;
+
+class QX11PlatformPixmap : public QPlatformPixmap
+{
+public:
+    QX11PlatformPixmap(PixelType pixelType);
+    ~QX11PlatformPixmap();
+
+    QPlatformPixmap *createCompatiblePlatformPixmap() const Q_DECL_OVERRIDE;
+    void resize(int width, int height) Q_DECL_OVERRIDE;
+    void fromImage(const QImage &img, Qt::ImageConversionFlags flags) Q_DECL_OVERRIDE;
+    void copy(const QPlatformPixmap *data, const QRect &rect) Q_DECL_OVERRIDE;
+    bool scroll(int dx, int dy, const QRect &rect) Q_DECL_OVERRIDE;
+    int metric(QPaintDevice::PaintDeviceMetric metric) const Q_DECL_OVERRIDE;
+    void fill(const QColor &fillColor) Q_DECL_OVERRIDE;
+    QBitmap mask() const Q_DECL_OVERRIDE;
+    void setMask(const QBitmap &mask) Q_DECL_OVERRIDE;
+    bool hasAlphaChannel() const Q_DECL_OVERRIDE;
+    QPixmap transformed(const QTransform &matrix, Qt::TransformationMode mode) const Q_DECL_OVERRIDE;
+    QImage toImage() const Q_DECL_OVERRIDE;
+    QImage toImage(const QRect &rect) const Q_DECL_OVERRIDE;
+    QPaintEngine *paintEngine() const Q_DECL_OVERRIDE;
+    qreal devicePixelRatio() const Q_DECL_OVERRIDE;
+    void setDevicePixelRatio(qreal scaleFactor) Q_DECL_OVERRIDE;
+
+    inline Drawable handle() const { return hd; }
+    inline Picture x11PictureHandle() const { return picture; }
+    inline const QXcbX11Info *x11_info() const { return &xinfo; }
+
+    Pixmap x11ConvertToDefaultDepth();
+    static XID createBitmapFromImage(const QImage &image);
+
+#if QT_CONFIG(xrender)
+    void convertToARGB32(bool preserveContents = true);
+#endif
+
+private:
+    friend class QX11PaintEngine;
+    friend const QXcbX11Info &qt_x11Info(const QPixmap &pixmap);
+    friend void qt_x11SetScreen(QPixmap &pixmap, int screen);
+
+    void release();
+    QImage toImage(const QXImageWrapper &xi, const QRect &rect) const;
+    QBitmap mask_to_bitmap(int screen) const;
+    static Pixmap bitmap_to_mask(const QBitmap &, int screen);
+    void bitmapFromImage(const QImage &image);
+    bool canTakeQImageFromXImage(const QXImageWrapper &xi) const;
+    QImage takeQImageFromXImage(const QXImageWrapper &xi) const;
+
+    Pixmap hd = 0;
+
+    enum Flag {
+        NoFlags = 0x0,
+        Uninitialized = 0x1,
+        Readonly = 0x2,
+        InvertedWhenBoundToTexture = 0x4,
+        GlSurfaceCreatedWithAlpha = 0x8
+    };
+    uint flags;
+
+    QXcbX11Info xinfo;
+    Pixmap x11_mask;
+    Picture picture;
+    Picture mask_picture;
+    Pixmap hd2; // sorted in the default display depth
+    //QPixmap::ShareMode share_mode;
+    qreal dpr;
+
+    QX11PaintEngine *pengine;
+};
+
+inline QX11PlatformPixmap *qt_x11Pixmap(const QPixmap &pixmap)
+{
+    return (pixmap.handle() && pixmap.handle()->classId() == QPlatformPixmap::X11Class)
+            ? static_cast<QX11PlatformPixmap *>(pixmap.handle())
+            : Q_NULLPTR;
+}
+
+inline Picture qt_x11PictureHandle(const QPixmap &pixmap)
+{
+    if (QX11PlatformPixmap *pm = qt_x11Pixmap(pixmap))
+        return pm->x11PictureHandle();
+
+    return 0;
+}
+
+inline Pixmap qt_x11PixmapHandle(const QPixmap &pixmap)
+{
+    if (QX11PlatformPixmap *pm = qt_x11Pixmap(pixmap))
+        return pm->handle();
+
+    return 0;
+}
+
+inline const QXcbX11Info &qt_x11Info(const QPixmap &pixmap)
+{
+    if (QX11PlatformPixmap *pm = qt_x11Pixmap(pixmap)) {
+        return pm->xinfo;
+    } else {
+        static QXcbX11Info nullX11Info;
+        return nullX11Info;
+    }
+}
+
+int qt_x11SetDefaultScreen(int screen);
+void qt_x11SetScreen(QPixmap &pixmap, int screen);
+
+QT_END_NAMESPACE
+
+#endif // QX11PLATFORMPIXMAP_H