Merge remote-tracking branch 'qt/5.6' into 5.7

Change-Id: Iada0e076ee33e8d39ecc4f40edfd9764ba610c03

src/plugins/platforms/wayland/client.pro

@@ -1,18 +1,9 @@
 TARGET = QtWaylandClient
+MODULE = waylandclient
+
 QT += core-private gui-private
 QT_FOR_PRIVATE += platformsupport-private
 
-MODULE=waylandclient
-MODULE_PLUGIN_TYPES = \
-            wayland-graphics-integration-client \
-            wayland-inputdevice-integration \
-            wayland-decoration-client \
-            wayland-shell-integration
-
-CONFIG += generated_privates
-
-load(qt_module)
-
 # We have a bunch of C code with casts, so we can't have this option
 QMAKE_CXXFLAGS_WARN_ON -= -Wcast-qual
 
@@ -25,19 +16,19 @@ CONFIG += link_pkgconfig qpa/genericunixfontdatabase wayland-scanner
 
 config_xkbcommon {
     !contains(QT_CONFIG, no-pkg-config) {
-        PKGCONFIG += xkbcommon
+        PKGCONFIG_PRIVATE += xkbcommon
     } else {
-        LIBS += -lxkbcommon
+        LIBS_PRIVATE += -lxkbcommon
     }
 } else {
     DEFINES += QT_NO_WAYLAND_XKB
 }
 
 !contains(QT_CONFIG, no-pkg-config) {
-    PKGCONFIG += wayland-client wayland-cursor
+    PKGCONFIG_PRIVATE += wayland-client wayland-cursor
     contains(QT_CONFIG, glib): PKGCONFIG_PRIVATE += glib-2.0
 } else {
-    LIBS += -lwayland-client -lwayland-cursor $$QT_LIBS_GLIB
+    LIBS_PRIVATE += -lwayland-client -lwayland-cursor $$QT_LIBS_GLIB
 }
 
 INCLUDEPATH += $$PWD/../shared
@@ -82,6 +73,7 @@ SOURCES +=  qwaylandintegration.cpp \
             qwaylandinputcontext.cpp \
             qwaylanddatadevice.cpp \
             qwaylandshm.cpp \
+            qwaylandbuffer.cpp \
 
 HEADERS +=  qwaylandintegration_p.h \
             qwaylandnativeinterface_p.h \
@@ -119,3 +111,11 @@ HEADERS +=  qwaylandintegration_p.h \
 include(hardwareintegration/hardwareintegration.pri)
 include(shellintegration/shellintegration.pri)
 include(inputdeviceintegration/inputdeviceintegration.pri)
+
+CONFIG += generated_privates
+MODULE_PLUGIN_TYPES = \
+            wayland-graphics-integration-client \
+            wayland-inputdevice-integration \
+            wayland-decoration-client \
+            wayland-shell-integration
+load(qt_module)

src/plugins/platforms/wayland/plugins/decorations/bradient/bradient.pro

@@ -1,6 +1,3 @@
-PLUGIN_TYPE = wayland-decoration-client
-load(qt_plugin)
-
 QT += waylandclient-private
 
 OTHER_FILES += \
@@ -15,3 +12,5 @@ contains(QT_CONFIG, no-pkg-config) {
     PKGCONFIG += wayland-client
 }
 
+PLUGIN_TYPE = wayland-decoration-client
+load(qt_plugin)

src/plugins/platforms/wayland/plugins/hardwareintegration/brcm-egl/brcm-egl.pro

@@ -1,6 +1,3 @@
-PLUGIN_TYPE = wayland-graphics-integration-client
-load(qt_plugin)
-
 QT += waylandclient-private
 
 include(../../../../hardwareintegration/client/brcm-egl/brcm-egl.pri)
@@ -10,3 +7,5 @@ OTHER_FILES += \
 
 SOURCES += main.cpp
 
+PLUGIN_TYPE = wayland-graphics-integration-client
+load(qt_plugin)

src/plugins/platforms/wayland/plugins/hardwareintegration/drm-egl-server/drm-egl-server.pro

@@ -1,6 +1,3 @@
-PLUGIN_TYPE = wayland-graphics-integration-client
-load(qt_plugin)
-
 # We have a bunch of C code with casts, so we can't have this option
 QMAKE_CXXFLAGS_WARN_ON -= -Wcast-qual
 
@@ -13,3 +10,5 @@ OTHER_FILES += \
 
 SOURCES += main.cpp
 
+PLUGIN_TYPE = wayland-graphics-integration-client
+load(qt_plugin)

src/plugins/platforms/wayland/plugins/hardwareintegration/libhybris-egl-server/libhybris-egl-server.pro

@@ -1,6 +1,3 @@
-PLUGIN_TYPE = wayland-graphics-integration-client
-load(qt_plugin)
-
 QT += waylandclient-private
 
 include(../../../../hardwareintegration/client/libhybris-egl-server/libhybris-egl-server.pri)
@@ -10,3 +7,5 @@ OTHER_FILES += \
 
 SOURCES += main.cpp
 
+PLUGIN_TYPE = wayland-graphics-integration-client
+load(qt_plugin)

src/plugins/platforms/wayland/plugins/hardwareintegration/wayland-egl/wayland-egl.pro

@@ -1,6 +1,3 @@
-PLUGIN_TYPE = wayland-graphics-integration-client
-load(qt_plugin)
-
 QT += waylandclient-private
 
 include(../../../../hardwareintegration/client/wayland-egl/wayland-egl.pri)
@@ -10,3 +7,5 @@ OTHER_FILES += \
 
 SOURCES += main.cpp
 
+PLUGIN_TYPE = wayland-graphics-integration-client
+load(qt_plugin)

src/plugins/platforms/wayland/plugins/hardwareintegration/xcomposite-egl/xcomposite-egl.pro

@@ -1,6 +1,3 @@
-PLUGIN_TYPE = wayland-graphics-integration-client
-load(qt_plugin)
-
 # We have a bunch of C code with casts, so we can't have this option
 QMAKE_CXXFLAGS_WARN_ON -= -Wcast-qual
 
@@ -13,3 +10,5 @@ OTHER_FILES += xcomposite-egl.json
 SOURCES += \
     main.cpp
 
+PLUGIN_TYPE = wayland-graphics-integration-client
+load(qt_plugin)

src/plugins/platforms/wayland/plugins/hardwareintegration/xcomposite-glx/xcomposite-glx.pro

@@ -1,6 +1,3 @@
-PLUGIN_TYPE = wayland-graphics-integration-client
-load(qt_plugin)
-
 QT += waylandclient-private
 
 include(../../../../hardwareintegration/client/xcomposite-glx/xcomposite-glx.pri)
@@ -10,3 +7,5 @@ OTHER_FILES += xcomposite-glx.json
 SOURCES += \
     main.cpp
 
+PLUGIN_TYPE = wayland-graphics-integration-client
+load(qt_plugin)

src/plugins/platforms/wayland/qwaylandbuffer.cpp

@@ -0,0 +1,72 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Copyright (C) 2015 Giulio Camuffo.
+** 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qwaylandbuffer_p.h"
+
+#include <QDebug>
+
+QT_BEGIN_NAMESPACE
+
+namespace QtWaylandClient {
+
+QWaylandBuffer::QWaylandBuffer()
+              : mBuffer(0)
+              , mBusy(false)
+{
+}
+
+QWaylandBuffer::~QWaylandBuffer()
+{
+    if (mBuffer)
+        wl_buffer_destroy(mBuffer);
+}
+
+void QWaylandBuffer::init(wl_buffer *buf)
+{
+    mBuffer = buf;
+    wl_buffer_add_listener(buf, &listener, this);
+}
+
+void QWaylandBuffer::release(void *data, wl_buffer *)
+{
+    static_cast<QWaylandBuffer *>(data)->mBusy = false;
+}
+
+const wl_buffer_listener QWaylandBuffer::listener = {
+    QWaylandBuffer::release
+};
+
+}
+
+QT_END_NAMESPACE

src/plugins/platforms/wayland/qwaylandbuffer_p.h

@@ -65,17 +65,25 @@ namespace QtWaylandClient {
 
 class Q_WAYLAND_CLIENT_EXPORT QWaylandBuffer {
 public:
-    QWaylandBuffer()
+    QWaylandBuffer();
-        : mBuffer(0)
+    virtual ~QWaylandBuffer();
-    {
+    void init(wl_buffer *buf);
-    }
+
-    virtual ~QWaylandBuffer() { }
     wl_buffer *buffer() {return mBuffer;}
     virtual QSize size() const = 0;
     virtual int scale() const { return 1; }
 
+    void setBusy() { mBusy = true; }
+    bool busy() const { return mBusy; }
+
 protected:
     struct wl_buffer *mBuffer;
+
+private:
+    bool mBusy;
+
+    static void release(void *data, wl_buffer *);
+    static const wl_buffer_listener listener;
 };
 
 }

src/plugins/platforms/wayland/qwaylandinputdevice.cpp

@@ -259,6 +259,8 @@ void QWaylandInputDevice::handleWindowDestroyed(QWaylandWindow *window)
         mKeyboard->mFocus = 0;
         mKeyboard->stopRepeat();
     }
+    if (mTouch && window == mTouch->mFocus)
+        mTouch->mFocus = 0;
 }
 
 void QWaylandInputDevice::setDataDevice(QWaylandDataDevice *device)
@@ -745,6 +747,9 @@ void QWaylandInputDevice::Touch::touch_down(uint32_t serial,
                                      wl_fixed_t x,
                                      wl_fixed_t y)
 {
+    if (!surface)
+        return;
+
     mParent->mTime = time;
     mParent->mSerial = serial;
     mFocus = QWaylandWindow::fromWlSurface(surface);

src/plugins/platforms/wayland/qwaylandshmbackingstore.cpp

@@ -46,6 +46,7 @@
 #include <QtCore/qdebug.h>
 #include <QtGui/QPainter>
 #include <QMutexLocker>
+#include <QLoggingCategory>
 
 #include <wayland-client.h>
 #include <wayland-client-protocol.h>
@@ -59,9 +60,14 @@ QT_BEGIN_NAMESPACE
 
 namespace QtWaylandClient {
 
+Q_DECLARE_LOGGING_CATEGORY(logCategory)
+
+Q_LOGGING_CATEGORY(logCategory, "qt.qpa.wayland.backingstore")
+
 QWaylandShmBuffer::QWaylandShmBuffer(QWaylandDisplay *display,
                      const QSize &size, QImage::Format format, int scale)
-    : mShmPool(0)
+    : QWaylandBuffer()
+    , mShmPool(0)
     , mMarginsImage(0)
 {
     int stride = size.width() * 4;
@@ -97,8 +103,8 @@ QWaylandShmBuffer::QWaylandShmBuffer(QWaylandDisplay *display,
     mImage.setDevicePixelRatio(qreal(scale));
 
     mShmPool = wl_shm_create_pool(shm->object(), fd, alloc);
-    mBuffer = wl_shm_pool_create_buffer(mShmPool,0, size.width(), size.height(),
+    init(wl_shm_pool_create_buffer(mShmPool,0, size.width(), size.height(),
-                                       stride, wl_format);
+                                       stride, wl_format));
     close(fd);
 }
 
@@ -107,8 +113,6 @@ QWaylandShmBuffer::~QWaylandShmBuffer(void)
     delete mMarginsImage;
     if (mImage.constBits())
         munmap((void *) mImage.constBits(), mImage.byteCount());
-    if (mBuffer)
-        wl_buffer_destroy(mBuffer);
     if (mShmPool)
         wl_shm_pool_destroy(mShmPool);
 }
@@ -146,9 +150,7 @@ QWaylandShmBackingStore::QWaylandShmBackingStore(QWindow *window)
     , mDisplay(QWaylandScreen::waylandScreenFromWindow(window)->display())
     , mFrontBuffer(0)
     , mBackBuffer(0)
-    , mFrontBufferIsDirty(false)
     , mPainting(false)
-    , mFrameCallback(0)
 {
 
 }
@@ -158,16 +160,10 @@ QWaylandShmBackingStore::~QWaylandShmBackingStore()
     if (QWaylandWindow *w = waylandWindow())
         w->setBackingStore(Q_NULLPTR);
 
-    if (mFrameCallback)
-        wl_callback_destroy(mFrameCallback);
-
 //    if (mFrontBuffer == waylandWindow()->attached())
 //        waylandWindow()->attach(0);
 
-    if (mFrontBuffer != mBackBuffer)
+    qDeleteAll(mBuffers);
-        delete mFrontBuffer;
-
-    delete mBackBuffer;
 }
 
 QPaintDevice *QWaylandShmBackingStore::paintDevice()
@@ -180,16 +176,7 @@ void QWaylandShmBackingStore::beginPaint(const QRegion &)
     mPainting = true;
     ensureSize();
 
-    QWaylandWindow *window = waylandWindow();
+    waylandWindow()->setCanResize(false);
-    QWaylandSubSurface *sub = window->subSurfaceWindow();
-
-    bool waiting = window->attached() && mBackBuffer == window->attached() && mFrameCallback;
-    bool syncSubSurface = sub && sub->isSync();
-    if (waiting && !syncSubSurface) {
-        window->waitForFrameSync();
-    }
-
-    window->setCanResize(false);
 }
 
 void QWaylandShmBackingStore::endPaint()
@@ -200,11 +187,6 @@ void QWaylandShmBackingStore::endPaint()
 
 void QWaylandShmBackingStore::hidden()
 {
-    QMutexLocker lock(&mMutex);
-    if (mFrameCallback) {
-        wl_callback_destroy(mFrameCallback);
-        mFrameCallback = Q_NULLPTR;
-    }
 }
 
 void QWaylandShmBackingStore::ensureSize()
@@ -231,48 +213,15 @@ void QWaylandShmBackingStore::flush(QWindow *window, const QRegion &region, cons
 
     mFrontBuffer = mBackBuffer;
 
-    QWaylandWindow *w = waylandWindow();
-    bool synchModeSubSurface = w->subSurfaceWindow() && w->subSurfaceWindow()->isSync();
-
-    if (mFrameCallback) {
-        if (synchModeSubSurface) {
-            wl_callback_destroy(mFrameCallback);
-            mFrameCallback = Q_NULLPTR;
-        } else {
-            mFrontBufferIsDirty = true;
-            return;
-        }
-    }
-
-    // Dont acquire the frame callback as that will cause beginPaint
-    // to block in waiting for frame sync since the damage will trigger
-    // its own sync request
-    if (!synchModeSubSurface) {
-        mFrameCallback = w->frame();
-        wl_callback_add_listener(mFrameCallback, &frameCallbackListener, this);
-    }
-
     QMargins margins = windowDecorationMargins();
-    bool damageAll = false;
-    if (w->attached() != mFrontBuffer) {
-        delete w->attached();
-        damageAll = true;
-    }
-    w->attachOffset(mFrontBuffer);
 
-    if (damageAll) {
+    waylandWindow()->attachOffset(mFrontBuffer);
-        //need to damage it all, otherwise the attach offset may screw up
+    mFrontBuffer->setBusy();
-        w->damage(QRect(QPoint(0,0), window->size()));
+
-    } else {
     QVector<QRect> rects = region.rects();
-        for (int i = 0; i < rects.size(); i++) {
+    foreach (const QRect &rect, rects)
-            QRect rect = rects.at(i);
+        waylandWindow()->damage(rect.translated(margins.left(), margins.top()));
-            rect.translate(margins.left(),margins.top());
+    waylandWindow()->commit();
-            w->damage(rect);
-        }
-    }
-    w->commit();
-    mFrontBufferIsDirty = false;
 }
 
 void QWaylandShmBackingStore::resize(const QSize &size, const QRegion &)
@@ -280,22 +229,65 @@ void QWaylandShmBackingStore::resize(const QSize &size, const QRegion &)
     mRequestedSize = size;
 }
 
+QWaylandShmBuffer *QWaylandShmBackingStore::getBuffer(const QSize &size)
+{
+    foreach (QWaylandShmBuffer *b, mBuffers) {
+        if (!b->busy()) {
+            if (b->size() == size) {
+                return b;
+            } else {
+                mBuffers.removeOne(b);
+                if (mBackBuffer == b)
+                    mBackBuffer = 0;
+                delete b;
+            }
+        }
+    }
+
+    static const int MAX_BUFFERS = 5;
+    if (mBuffers.count() < MAX_BUFFERS) {
+        QImage::Format format = QPlatformScreen::platformScreenForWindow(window())->format();
+        QWaylandShmBuffer *b = new QWaylandShmBuffer(mDisplay, size, format, waylandWindow()->scale());
+        mBuffers.prepend(b);
+        return b;
+    }
+    return 0;
+}
+
 void QWaylandShmBackingStore::resize(const QSize &size)
 {
     QMargins margins = windowDecorationMargins();
     int scale = waylandWindow()->scale();
     QSize sizeWithMargins = (size + QSize(margins.left()+margins.right(),margins.top()+margins.bottom())) * scale;
 
-    QImage::Format format = QPlatformScreen::platformScreenForWindow(window())->format();
+    // We look for a free buffer to draw into. If the buffer is not the last buffer we used,
+    // that is mBackBuffer, and the size is the same we memcpy the old content into the new
+    // buffer so that QPainter is happy to find the stuff it had drawn before. If the new
+    // buffer has a different size it needs to be redrawn completely anyway, and if the buffer
+    // is the same the stuff is there already.
+    // You can exercise the different codepaths with weston, switching between the gl and the
+    // pixman renderer. With the gl renderer release events are sent early so we can effectively
+    // run single buffered, while with the pixman renderer we have to use two.
+    QWaylandShmBuffer *buffer = getBuffer(sizeWithMargins);
+    while (!buffer) {
+        qCDebug(logCategory, "QWaylandShmBackingStore: stalling waiting for a buffer to be released from the compositor...");
 
-    if (mBackBuffer != NULL && mBackBuffer->size() == sizeWithMargins)
+        mDisplay->blockingReadEvents();
-        return;
+        buffer = getBuffer(sizeWithMargins);
-
-    if (mBackBuffer != mFrontBuffer) {
-        delete mBackBuffer; //we delete the attached buffer when we flush
     }
 
-    mBackBuffer = new QWaylandShmBuffer(mDisplay, sizeWithMargins, format, scale);
+    int oldSize = mBackBuffer ? mBackBuffer->image()->byteCount() : 0;
+    // mBackBuffer may have been deleted here but if so it means its size was different so we wouldn't copy it anyway
+    if (mBackBuffer != buffer && oldSize == buffer->image()->byteCount()) {
+        memcpy(buffer->image()->bits(), mBackBuffer->image()->constBits(), buffer->image()->byteCount());
+    }
+    mBackBuffer = buffer;
+    // ensure the new buffer is at the beginning of the list so next time getBuffer() will pick
+    // it if possible
+    if (mBuffers.first() != buffer) {
+        mBuffers.removeOne(buffer);
+        mBuffers.prepend(buffer);
+    }
 
     if (windowDecoration() && window()->isVisible())
         windowDecoration()->update();
@@ -369,36 +361,6 @@ QImage QWaylandShmBackingStore::toImage() const
 }
 #endif // QT_NO_OPENGL
 
-void QWaylandShmBackingStore::done(void *data, wl_callback *callback, uint32_t time)
-{
-    Q_UNUSED(time);
-    QWaylandShmBackingStore *self =
-            static_cast<QWaylandShmBackingStore *>(data);
-    if (callback != self->mFrameCallback) // others, like QWaylandWindow, may trigger callbacks too
-        return;
-    QMutexLocker lock(&self->mMutex);
-    QWaylandWindow *window = self->waylandWindow();
-    wl_callback_destroy(self->mFrameCallback);
-    self->mFrameCallback = 0;
-
-
-    if (self->mFrontBufferIsDirty && !self->mPainting) {
-        self->mFrontBufferIsDirty = false;
-        self->mFrameCallback = wl_surface_frame(window->object());
-        wl_callback_add_listener(self->mFrameCallback,&self->frameCallbackListener,self);
-        if (self->mFrontBuffer != window->attached()) {
-            delete window->attached();
-        }
-        window->attachOffset(self->mFrontBuffer);
-        window->damage(QRect(QPoint(0,0),window->geometry().size()));
-        window->commit();
-    }
-}
-
-const struct wl_callback_listener QWaylandShmBackingStore::frameCallbackListener = {
-    QWaylandShmBackingStore::done
-};
-
 }
 
 QT_END_NAMESPACE

src/plugins/platforms/wayland/qwaylandshmbackingstore_p.h

@@ -57,6 +57,7 @@
 #include <QtGui/QImage>
 #include <qpa/qplatformwindow.h>
 #include <QMutex>
+#include <QLinkedList>
 
 QT_BEGIN_NAMESPACE
 
@@ -113,22 +114,17 @@ public:
 
 private:
     void updateDecorations();
+    QWaylandShmBuffer *getBuffer(const QSize &size);
 
     QWaylandDisplay *mDisplay;
+    QLinkedList<QWaylandShmBuffer *> mBuffers;
     QWaylandShmBuffer *mFrontBuffer;
     QWaylandShmBuffer *mBackBuffer;
-    bool mFrontBufferIsDirty;
     bool mPainting;
     QMutex mMutex;
 
     QSize mRequestedSize;
     Qt::WindowFlags mCurrentWindowFlags;
-
-    static const struct wl_callback_listener frameCallbackListener;
-    static void done(void *data,
-             struct wl_callback *callback,
-             uint32_t time);
-    struct wl_callback *mFrameCallback;
 };
 
 }

src/plugins/platforms/wayland/qwaylandwindow.cpp

@@ -81,7 +81,6 @@ QWaylandWindow::QWaylandWindow(QWindow *window)
     , mMouseEventsInContentArea(false)
     , mMousePressedInContentArea(Qt::NoButton)
     , m_cursorShape(Qt::ArrowCursor)
-    , mBuffer(0)
     , mWaitingForFrameSync(false)
     , mFrameCallback(0)
     , mRequestResizeSent(false)
@@ -432,9 +431,8 @@ void QWaylandWindow::requestResize()
 
 void QWaylandWindow::attach(QWaylandBuffer *buffer, int x, int y)
 {
-    mBuffer = buffer;
+    if (buffer)
-    if (mBuffer)
+        attach(buffer->buffer(), x, y);
-        attach(mBuffer->buffer(), x, y);
     else
         QtWayland::wl_surface::attach(0, 0, 0);
 }
@@ -445,11 +443,6 @@ void QWaylandWindow::attachOffset(QWaylandBuffer *buffer)
     mOffset = QPoint();
 }
 
-QWaylandBuffer *QWaylandWindow::attached() const
-{
-    return mBuffer;
-}
-
 void QWaylandWindow::damage(const QRect &rect)
 {
     //We have to do sync stuff before calling damage, or we might
@@ -459,10 +452,8 @@ void QWaylandWindow::damage(const QRect &rect)
         wl_callback_add_listener(mFrameCallback,&QWaylandWindow::callbackListener,this);
         mWaitingForFrameSync = true;
     }
-    if (mBuffer) {
     damage(rect.x(), rect.y(), rect.width(), rect.height());
 }
-}
 
 const wl_callback_listener QWaylandWindow::callbackListener = {
     QWaylandWindow::frameCallback

src/plugins/platforms/wayland/qwaylandwindow_p.h

@@ -214,7 +214,6 @@ protected:
     Qt::MouseButtons mMousePressedInContentArea;
     Qt::CursorShape m_cursorShape;
 
-    QWaylandBuffer *mBuffer;
     WId mWindowId;
     bool mWaitingForFrameSync;
     struct wl_callback *mFrameCallback;