Add mode support to QWaylandOutput

Outputs usually have more than one mode, add an API to support them.

When sizeFollowsWindow is true, modes are replaced by one with the
window size and refresh rate.  In that circumstance the mode changes
when the window is resized.

The sizeFollowsWindow property default value is no longer true.

The setGeometry() method is gone as it doesn't make sense now, the
setWidth() and setHeight() methods are now private slots to resize
the resolution as the window resizes (and sizeFollowsWindow is true).

Refresh rate is expressed in mHz rather than Hz just like the
Wayland protocol.

A compositor implementation may choose to add modes if it has access
to hardware information, it will call addMode() for each mode and
then invoke the setCurrentMode() method that sends the modes list
to the client. The preferred mode is indicated with a boolean
parameter to the addMode() method.

Change-Id: Iffed4784ccef695c276ebd800172957f4cff3324
Task-number: QTBUG-49814
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>
Reviewed-by: Johan Helsing <johan.helsing@qt.io>

1 files changed, 168 insertions, 101 deletions

diff --git a/src/compositor/compositor_api/qwaylandoutput.cpp b/src/compositor/compositor_api/qwaylandoutput.cpp
index 40cd9798c..19e17bb32 100644
--- a/src/compositor/compositor_api/qwaylandoutput.cpp
+++ b/src/compositor/compositor_api/qwaylandoutput.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2014-2015 Pier Luigi Fiorini <pierluigi.fiorini@gmail.com>
+** Copyright (C) 2014-2016 Pier Luigi Fiorini <pierluigi.fiorini@gmail.com>
 ** Copyright (C) 2013 Klarälvdalens Datakonsult AB (KDAB).
 ** Contact: http://www.qt.io/licensing/
 **
@@ -48,6 +48,7 @@
 #include <QtCore/QtMath>
 #include <QtGui/QWindow>
 #include <QtGui/QExposeEvent>
+#include <QtGui/QScreen>
 #include <private/qobject_p.h>
 
 QT_BEGIN_NAMESPACE
@@ -102,16 +103,14 @@ QWaylandOutputPrivate::QWaylandOutputPrivate()
     : QtWaylandServer::wl_output()
     , compositor(Q_NULLPTR)
     , window(Q_NULLPTR)
+    , currentMode(-1)
+    , preferredMode(-1)
     , subpixel(QWaylandOutput::SubpixelUnknown)
     , transform(QWaylandOutput::TransformNormal)
     , scaleFactor(1)
-    , sizeFollowsWindow(true)
+    , sizeFollowsWindow(false)
     , initialized(false)
 {
-    mode.size = QSize();
-    mode.refreshRate = 60;
-
-    qRegisterMetaType<QWaylandOutput::Mode>("WaylandOutput::Mode");
 }
 
 QWaylandOutputPrivate::~QWaylandOutputPrivate()
@@ -120,15 +119,10 @@ QWaylandOutputPrivate::~QWaylandOutputPrivate()
 
 void QWaylandOutputPrivate::output_bind_resource(Resource *resource)
 {
-    send_geometry(resource->handle,
-                  position.x(), position.y(),
-                  physicalSize.width(), physicalSize.height(),
-                  toWlSubpixel(subpixel), manufacturer, model,
-                  toWlTransform(transform));
+    sendGeometry(resource);
 
-    send_mode(resource->handle, mode_current | mode_preferred,
-              mode.size.width(), mode.size.height(),
-              mode.refreshRate * 1000);
+    for (const QWaylandOutputMode &mode : modes)
+        sendMode(resource, mode);
 
     if (resource->version() >= 2) {
         send_scale(resource->handle, scaleFactor);
@@ -136,19 +130,46 @@ void QWaylandOutputPrivate::output_bind_resource(Resource *resource)
     }
 }
 
+void QWaylandOutputPrivate::sendGeometry(const Resource *resource)
+{
+    send_geometry(resource->handle,
+                  position.x(), position.y(),
+                  physicalSize.width(), physicalSize.height(),
+                  toWlSubpixel(subpixel), manufacturer, model,
+                  toWlTransform(transform));
+}
+
 void QWaylandOutputPrivate::sendGeometryInfo()
 {
-    Q_FOREACH (Resource *resource, resourceMap().values()) {
-        send_geometry(resource->handle,
-                      position.x(), position.y(),
-                      physicalSize.width(), physicalSize.height(),
-                      toWlSubpixel(subpixel), manufacturer, model,
-                      toWlTransform(transform));
+    for (const Resource *resource : resourceMap().values()) {
+        sendGeometry(resource);
         if (resource->version() >= 2)
             send_done(resource->handle);
     }
 }
 
+void QWaylandOutputPrivate::sendMode(const Resource *resource, const QWaylandOutputMode &mode)
+{
+    quint32 flags = 0;
+    if (currentMode == modes.indexOf(mode))
+        flags |= QtWaylandServer::wl_output::mode_current;
+    if (preferredMode == modes.indexOf(mode))
+        flags |= QtWaylandServer::wl_output::mode_preferred;
+
+    send_mode(resource->handle, flags,
+              mode.size().width(), mode.size().height(),
+              mode.refreshRate());
+}
+
+void QWaylandOutputPrivate::sendModesInfo()
+{
+    for (const Resource *resource : resourceMap().values()) {
+        for (const QWaylandOutputMode &mode : modes)
+            sendMode(resource, mode);
+        if (resource->version() >= 2)
+            send_done(resource->handle);
+    }
+}
 
 void QWaylandOutputPrivate::addView(QWaylandView *view, QWaylandSurface *surface)
 {
@@ -252,16 +273,23 @@ void QWaylandOutput::initialize()
     Q_ASSERT(d->compositor);
     Q_ASSERT(d->compositor->isCreated());
 
-    if (d->window)
-        d->mode.size = d->window->size();
-    else
-        d->sizeFollowsWindow = false;
+    // Replace modes with one that follows the window size and refresh rate,
+    // but only if window size is valid
+    if (d->window && d->sizeFollowsWindow) {
+        QWaylandOutputMode mode(d->window->size(),
+                                qFloor(d->window->screen()->refreshRate() * 1000));
+        if (mode.isValid()) {
+            d->modes.clear();
+            addMode(mode, true);
+            setCurrentMode(mode);
+        }
+    }
 
     QWaylandCompositorPrivate::get(d->compositor)->addOutput(this);
 
     if (d->window) {
-        QObject::connect(d->window, &QWindow::widthChanged, this, &QWaylandOutput::setWidth);
-        QObject::connect(d->window, &QWindow::heightChanged, this, &QWaylandOutput::setHeight);
+        QObject::connect(d->window, &QWindow::widthChanged, this, &QWaylandOutput::handleSetWidth);
+        QObject::connect(d->window, &QWindow::heightChanged, this, &QWaylandOutput::handleSetHeight);
         QObject::connect(d->window, &QObject::destroyed, this, &QWaylandOutput::handleWindowDestroyed);
     }
 
@@ -431,39 +459,75 @@ void QWaylandOutput::setPosition(const QPoint &pt)
 }
 
 /*!
- * \property QWaylandOutput::mode
- *
- * This property holds the output's size in pixels and refresh rate in Hz.
+ * Returns the list of modes.
  */
-QWaylandOutput::Mode QWaylandOutput::mode() const
+QList<QWaylandOutputMode> QWaylandOutput::modes() const
 {
-    return d_func()->mode;
+    Q_D(const QWaylandOutput);
+    return d->modes.toList();
 }
 
-void QWaylandOutput::setMode(const Mode &mode)
+/*!
+ * Adds the mode \a mode to the output and mark it as preferred
+ * if \a preferred is \c true.
+ * Please note there can only be one preferred mode.
+ */
+void QWaylandOutput::addMode(const QWaylandOutputMode &mode, bool preferred)
 {
     Q_D(QWaylandOutput);
-    if (d->mode.size == mode.size && d->mode.refreshRate == mode.refreshRate)
+
+    if (!mode.isValid()) {
+        qWarning("Cannot add an invalid mode");
         return;
+    }
 
-    d->mode = mode;
+    d->modes.append(mode);
 
-    Q_FOREACH (QWaylandOutputPrivate::Resource *resource, d->resourceMap().values()) {
-        d->send_mode(resource->handle, d->mode_current,
-                  d->mode.size.width(), d->mode.size.height(),
-                  d->mode.refreshRate * 1000);
-        if (resource->version() >= 2)
-            d->send_done(resource->handle);
+    if (preferred)
+        d->preferredMode = d->modes.indexOf(mode);
+
+    emit modeAdded();
+}
+
+/*!
+ * Returns the output's size in pixels and refresh rate in mHz.
+ * If the current mode is not set it will return an invalid mode.
+ *
+ * \sa QWaylandOutput::modes
+ * \sa QWaylandOutputMode
+ */
+QWaylandOutputMode QWaylandOutput::currentMode() const
+{
+    Q_D(const QWaylandOutput);
+
+    if (d->currentMode >= 0 && d->currentMode <= d->modes.size() - 1)
+        return d->modes.at(d->currentMode);
+    return QWaylandOutputMode();
+}
+
+/*!
+ * Sets the current mode.
+ * The mode \a mode must have been previously added.
+ *
+ * \sa QWaylandOutput::modes
+ * \sa QWaylandOutputMode
+ */
+void QWaylandOutput::setCurrentMode(const QWaylandOutputMode &mode)
+{
+    Q_D(QWaylandOutput);
+
+    int index = d->modes.indexOf(mode);
+    if (index < 0) {
+        qWarning("Cannot set an unknown QWaylandOutput mode as current");
+        return;
     }
 
-    Q_EMIT modeChanged();
+    d->currentMode = index;
+
+    Q_EMIT currentModeChanged();
     Q_EMIT geometryChanged();
 
-    if (d->window) {
-        d->window->resize(mode.size);
-        d->window->setMinimumSize(mode.size);
-        d->window->setMaximumSize(mode.size);
-    }
+    d->sendModesInfo();
 }
 
 /*!
@@ -477,37 +541,12 @@ void QWaylandOutput::setMode(const Mode &mode)
  *
  * This property holds the geometry of the QWaylandOutput.
  *
- * \sa QWaylandOutput::mode
+ * \sa QWaylandOutput::currentMode
  */
 QRect QWaylandOutput::geometry() const
 {
     Q_D(const QWaylandOutput);
-    return QRect(d->position, d->mode.size);
-}
-
-void QWaylandOutput::setGeometry(const QRect &geometry)
-{
-    Q_D(QWaylandOutput);
-    if (d->position == geometry.topLeft() && d->mode.size == geometry.size())
-        return;
-
-    d->position = geometry.topLeft();
-    d->mode.size = geometry.size();
-
-    Q_FOREACH (QWaylandOutputPrivate::Resource *resource, d->resourceMap().values()) {
-        d->send_geometry(resource->handle,
-                      d->position.x(), d->position.y(),
-                      d->physicalSize.width(), d->physicalSize.height(),
-                      toWlSubpixel(d->subpixel), d->manufacturer, d->model,
-                      toWlTransform(d->transform));
-        d->send_mode(resource->handle, d->mode_current,
-                  d->mode.size.width(), d->mode.size.height(),
-                  d->mode.refreshRate * 1000);
-        if (resource->version() >= 2)
-            d->send_done(resource->handle);
-    }
-    Q_EMIT positionChanged();
-    Q_EMIT modeChanged();
+    return QRect(d->position, currentMode().size());
 }
 
 /*!
@@ -527,13 +566,14 @@ void QWaylandOutput::setGeometry(const QRect &geometry)
  * The available geometry is in output coordinates space, starts from 0,0 and it's as big
  * as the output by default.
  *
- * \sa QWaylandOutput::mode, QWaylandOutput::geometry
+ * \sa QWaylandOutput::currentMode, QWaylandOutput::geometry
  */
 QRect QWaylandOutput::availableGeometry() const
 {
     Q_D(const QWaylandOutput);
+
     if (!d->availableGeometry.isValid())
-        return QRect(QPoint(0, 0), d->mode.size);
+        return QRect(QPoint(0, 0), currentMode().size());
 
     return d->availableGeometry;
 }
@@ -565,7 +605,7 @@ void QWaylandOutput::setAvailableGeometry(const QRect &availableGeometry)
  *
  * This property holds the physical size of the QWaylandOutput in millimeters.
  *
- * \sa QWaylandOutput::geometry, QWaylandOutput::mode
+ * \sa QWaylandOutput::geometry, QWaylandOutput::currentMode
  */
 QSize QWaylandOutput::physicalSize() const
 {
@@ -755,7 +795,10 @@ void QWaylandOutput::setScaleFactor(int scale)
  * This property controls whether the size of the WaylandOutput matches the
  * size of its window.
  *
- * The default is \c true if this WaylandOutput has a window.
+ * If this property is true, all modes previously added are replaced by a
+ * mode that matches window size and screen refresh rate.
+ *
+ * The default is false.
  */
 
 /*!
@@ -764,7 +807,10 @@ void QWaylandOutput::setScaleFactor(int scale)
  * This property controls whether the size of the QWaylandOutput matches the
  * size of its window.
  *
- * The default is \c true if this QWaylandOutput has a window.
+ * If this property is true, all modes previously added are replaced by a
+ * mode that matches window size and screen refresh rate.
+ *
+ * The default is false.
  */
 bool QWaylandOutput::sizeFollowsWindow() const
 {
@@ -781,13 +827,6 @@ void QWaylandOutput::setSizeFollowsWindow(bool follow)
     }
 
     if (follow != d->sizeFollowsWindow) {
-        if (follow) {
-            QObject::connect(d->window, &QWindow::widthChanged, this, &QWaylandOutput::setWidth);
-            QObject::connect(d->window, &QWindow::heightChanged, this, &QWaylandOutput::setHeight);
-        } else {
-            QObject::disconnect(d->window, &QWindow::widthChanged, this, &QWaylandOutput::setWidth);
-            QObject::disconnect(d->window, &QWindow::heightChanged, this, &QWaylandOutput::setHeight);
-        }
         d->sizeFollowsWindow = follow;
         Q_EMIT sizeFollowsWindowChanged();
     }
@@ -882,35 +921,63 @@ void QWaylandOutput::surfaceLeave(QWaylandSurface *surface)
 }
 
 /*!
- * Sets the width of this QWaylandOutput to \a newWidth.
- *
- * \sa setHeight, QWaylandOutput::geometry
+ * \internal
  */
-void QWaylandOutput::setWidth(int newWidth)
+void QWaylandOutput::handleSetWidth(int newWidth)
 {
     Q_D(QWaylandOutput);
-    if (d->mode.size.width() == newWidth)
+
+    if (!d->window || !d->sizeFollowsWindow)
         return;
 
-    QSize s = d->mode.size;
-    s.setWidth(newWidth);
-    setGeometry(QRect(d->position, s));
+    if (d->currentMode <= d->modes.size() - 1) {
+        if (d->currentMode >= 0) {
+            QWaylandOutputMode mode = d->modes.at(d->currentMode);
+            mode.setWidth(newWidth);
+            d->modes.replace(d->currentMode, mode);
+            d->sendModesInfo();
+        } else {
+            // We didn't add a mode during the initialization because the window
+            // size was invalid, let's add it now
+            QWaylandOutputMode mode(d->window->size(),
+                                    qFloor(d->window->screen()->refreshRate() * 1000));
+            if (mode.isValid()) {
+                d->modes.clear();
+                addMode(mode, true);
+                setCurrentMode(mode);
+            }
+        }
+    }
 }
 
 /*!
- * Sets the height of this QWaylandOutput to \a newHeight.
- *
- * \sa setWidth, QWaylandOutput::geometry
+ * \internal
  */
-void QWaylandOutput::setHeight(int newHeight)
+void QWaylandOutput::handleSetHeight(int newHeight)
 {
     Q_D(QWaylandOutput);
-    if (d->mode.size.height() == newHeight)
+
+    if (!d->window || !d->sizeFollowsWindow)
         return;
 
-    QSize s = d->mode.size;
-    s.setHeight(newHeight);
-    setGeometry(QRect(d->position, s));
+    if (d->currentMode <= d->modes.size() - 1) {
+        if (d->currentMode >= 0) {
+            QWaylandOutputMode mode = d->modes.at(d->currentMode);
+            mode.setHeight(newHeight);
+            d->modes.replace(d->currentMode, mode);
+            d->sendModesInfo();
+        } else {
+            // We didn't add a mode during the initialization because the window
+            // size was invalid, let's add it now
+            QWaylandOutputMode mode(d->window->size(),
+                                    qFloor(d->window->screen()->refreshRate() * 1000));
+            if (mode.isValid()) {
+                d->modes.clear();
+                addMode(mode, true);
+                setCurrentMode(mode);
+            }
+        }
+    }
 }
 
 /*!