ResizeMode support for QGraphicsWidgets created with QDeclarativeView

Task-number: QTBUG-8814
Reviewed-by: alexis

2 files changed, 180 insertions, 88 deletions

diff --git a/src/declarative/util/qdeclarativeview.cpp b/src/declarative/util/qdeclarativeview.cpp
index f786898..5cfa0e8 100644
--- a/src/declarative/util/qdeclarativeview.cpp
+++ b/src/declarative/util/qdeclarativeview.cpp
@@ -59,10 +59,14 @@
 #include <qfontdatabase.h>
 #include <qicon.h>
 #include <qurl.h>
-#include <qboxlayout.h>
+#include <qlayout.h>
+#include <qwidget.h>
+#include <qgraphicswidget.h>
 #include <qbasictimer.h>
 #include <QtCore/qabstractanimation.h>
 #include <private/qgraphicsview_p.h>
+#include <private/qdeclarativeitem_p.h>
+#include <private/qdeclarativeitemchangelistener_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -124,19 +128,23 @@ void FrameBreakAnimation::updateCurrentTime(int msecs)
     server->frameBreak();
 }
 
-class QDeclarativeViewPrivate
+class QDeclarativeViewPrivate : public QDeclarativeItemChangeListener
 {
 public:
     QDeclarativeViewPrivate(QDeclarativeView *view)
-        : q(view), root(0), component(0), resizeMode(QDeclarativeView::SizeViewToRootObject) {}
+        : q(view), root(0), declarativeItemRoot(0), graphicsWidgetRoot(0), component(0), resizeMode(QDeclarativeView::SizeViewToRootObject) {}
     ~QDeclarativeViewPrivate() { delete root; }
-
     void execute();
+    void itemGeometryChanged(QDeclarativeItem *item, const QRectF &newGeometry, const QRectF &oldGeometry);
+    void initResize();
+    void updateSize();
+    inline QSize rootObjectSize();
 
     QDeclarativeView *q;
 
     QDeclarativeGuard<QGraphicsObject> root;
-    QDeclarativeGuard<QDeclarativeItem> qmlRoot;
+    QDeclarativeGuard<QDeclarativeItem> declarativeItemRoot;
+    QDeclarativeGuard<QGraphicsWidget> graphicsWidgetRoot;
 
     QUrl source;
 
@@ -144,7 +152,6 @@ public:
     QDeclarativeComponent *component;
     QBasicTimer resizetimer;
 
-    mutable QSize initialSize;
     QDeclarativeView::ResizeMode resizeMode;
     QTime frameTimer;
 
@@ -155,18 +162,32 @@ public:
 
 void QDeclarativeViewPrivate::execute()
 {
-    delete root;
-    delete component;
-    initialSize = QSize();
-    component = new QDeclarativeComponent(&engine, source, q);
-
-    if (!component->isLoading()) {
-        q->continueExecute();
-    } else {
-        QObject::connect(component, SIGNAL(statusChanged(QDeclarativeComponent::Status)), q, SLOT(continueExecute()));
+    if (root) {
+        delete root;
+        root = 0;
+    }
+    if (component) {
+        delete component;
+        component = 0;
+    }
+    if (!source.isEmpty()) {
+        component = new QDeclarativeComponent(&engine, source, q);
+        if (!component->isLoading()) {
+            q->continueExecute();
+        } else {
+            QObject::connect(component, SIGNAL(statusChanged(QDeclarativeComponent::Status)), q, SLOT(continueExecute()));
+        }
     }
 }
 
+void QDeclarativeViewPrivate::itemGeometryChanged(QDeclarativeItem *resizeItem, const QRectF &newGeometry, const QRectF &oldGeometry)
+{
+    if (resizeItem == root && resizeMode == QDeclarativeView::SizeViewToRootObject) {
+        // wait for both width and height to be changed
+        resizetimer.start(0,q);
+    }
+    QDeclarativeItemChangeListener::itemGeometryChanged(resizeItem, newGeometry, oldGeometry);
+}
 
 /*!
     \class QDeclarativeView
@@ -332,7 +353,6 @@ QDeclarativeContext* QDeclarativeView::rootContext()
 
 /*!
   \enum QDeclarativeView::Status
-
     Specifies the loading status of the QDeclarativeView.
 
     \value Null This QDeclarativeView has no source set.
@@ -373,7 +393,6 @@ QList<QDeclarativeError> QDeclarativeView::errors() const
     return QList<QDeclarativeError>();
 }
 
-
 /*!
     \property QDeclarativeView::resizeMode
     \brief whether the view should resize the canvas contents
@@ -394,16 +413,92 @@ void QDeclarativeView::setResizeMode(ResizeMode mode)
     if (d->resizeMode == mode)
         return;
 
+    if (d->declarativeItemRoot) {
+        if (d->resizeMode == SizeViewToRootObject) {
+            QDeclarativeItemPrivate *p =
+                static_cast<QDeclarativeItemPrivate *>(QGraphicsItemPrivate::get(d->declarativeItemRoot));
+            p->removeItemChangeListener(d, QDeclarativeItemPrivate::Geometry);
+        }
+    } else if (d->graphicsWidgetRoot) {
+         if (d->resizeMode == QDeclarativeView::SizeViewToRootObject) {
+             d->graphicsWidgetRoot->removeEventFilter(this);
+         }
+    }
+
     d->resizeMode = mode;
-    if (d->qmlRoot) {
-        if (d->resizeMode == SizeRootObjectToView) {
-            d->qmlRoot->setWidth(width());
-            d->qmlRoot->setHeight(height());
-        } else {
-            d->qmlRoot->setWidth(d->initialSize.width());
-            d->qmlRoot->setHeight(d->initialSize.height());
+    if (d->root) {
+        d->initResize();
+    }
+}
+
+void QDeclarativeViewPrivate::initResize()
+{
+    if (declarativeItemRoot) {
+        if (resizeMode == QDeclarativeView::SizeViewToRootObject) {
+            QDeclarativeItemPrivate *p =
+                static_cast<QDeclarativeItemPrivate *>(QGraphicsItemPrivate::get(declarativeItemRoot));
+            p->addItemChangeListener(this, QDeclarativeItemPrivate::Geometry);
+        }
+    } else if (graphicsWidgetRoot) {
+        if (resizeMode == QDeclarativeView::SizeViewToRootObject) {
+            graphicsWidgetRoot->installEventFilter(q);
+        }
+    }
+    updateSize();
+}
+
+void QDeclarativeViewPrivate::updateSize()
+{
+    if (!root)
+        return;
+    if (declarativeItemRoot) {
+        if (resizeMode == QDeclarativeView::SizeViewToRootObject) {
+            QSize newSize = QSize(declarativeItemRoot->width(), declarativeItemRoot->height());
+            if (newSize.isValid() && newSize != q->size()) {
+                q->resize(newSize);
+            }
+        } else if (resizeMode == QDeclarativeView::SizeRootObjectToView) {
+            if (!qFuzzyCompare(q->width(), declarativeItemRoot->width()))
+                declarativeItemRoot->setWidth(q->width());
+            if (!qFuzzyCompare(q->height(), declarativeItemRoot->height()))
+                declarativeItemRoot->setHeight(q->height());
         }
+    } else if (graphicsWidgetRoot) {
+        if (resizeMode == QDeclarativeView::SizeViewToRootObject) {
+            QSize newSize = QSize(graphicsWidgetRoot->size().width(), graphicsWidgetRoot->size().height());
+            if (newSize.isValid() && newSize != q->size()) {
+                q->resize(newSize);
+            }
+        } else if (resizeMode == QDeclarativeView::SizeRootObjectToView) {
+            QSizeF newSize = QSize(q->size().width(), q->size().height());
+            if (newSize.isValid() && newSize != graphicsWidgetRoot->size()) {
+                graphicsWidgetRoot->resize(newSize);
+            }
+        }
+    }
+    q->updateGeometry();
+}
+
+QSize QDeclarativeViewPrivate::rootObjectSize()
+{
+    QSize rootObjectSize(0,0);
+    int widthCandidate = -1;
+    int heightCandidate = -1;
+    if (declarativeItemRoot) {
+        widthCandidate = declarativeItemRoot->width();
+        heightCandidate = declarativeItemRoot->height();
+    } else if (root) {
+        QSizeF size = root->boundingRect().size();
+        widthCandidate = size.width();
+        heightCandidate = size.height();
+    }
+    if (widthCandidate > 0) {
+        rootObjectSize.setWidth(widthCandidate);
     }
+    if (heightCandidate > 0) {
+        rootObjectSize.setHeight(heightCandidate);
+    }
+    return rootObjectSize;
 }
 
 QDeclarativeView::ResizeMode QDeclarativeView::resizeMode() const
@@ -449,55 +544,46 @@ void QDeclarativeView::continueExecute()
 */
 void QDeclarativeView::setRootObject(QObject *obj)
 {
-    if (QDeclarativeItem *item = qobject_cast<QDeclarativeItem *>(obj)) {
-        d->scene.addItem(item);
-
-        d->root = item;
-        d->qmlRoot = item;
-        connect(item, SIGNAL(widthChanged()), this, SLOT(sizeChanged()));
-        connect(item, SIGNAL(heightChanged()), this, SLOT(sizeChanged()));
-        if (d->initialSize.height() <= 0 && d->qmlRoot->width() > 0)
-            d->initialSize.setWidth(d->qmlRoot->width());
-        if (d->initialSize.height() <= 0 && d->qmlRoot->height() > 0)
-            d->initialSize.setHeight(d->qmlRoot->height());
-        resize(d->initialSize);
-
-        if (d->resizeMode == SizeRootObjectToView) {
-            d->qmlRoot->setWidth(width());
-            d->qmlRoot->setHeight(height());
+    if (d->root == obj)
+        return;
+    if (QDeclarativeItem *declarativeItem = qobject_cast<QDeclarativeItem *>(obj)) {
+        d->scene.addItem(declarativeItem);
+        d->root = declarativeItem;
+        d->declarativeItemRoot = declarativeItem;
+    } else if (QGraphicsObject *graphicsObject = qobject_cast<QGraphicsObject *>(obj)) {
+        d->scene.addItem(graphicsObject);
+        d->root = graphicsObject;
+        if (graphicsObject->isWidget()) {
+            d->graphicsWidgetRoot = static_cast<QGraphicsWidget*>(graphicsObject);
         } else {
-            QSize sz(d->qmlRoot->width(),d->qmlRoot->height());
-            emit sceneResized(sz);
-            resize(sz);
+            qWarning() << "QDeclarativeView::resizeMode is not honored for components of type QGraphicsObject";
         }
-        updateGeometry();
-    } else if (QGraphicsObject *item = qobject_cast<QGraphicsObject *>(obj)) {
-        d->scene.addItem(item);
-        qWarning() << "QDeclarativeView::resizeMode is not honored for components of type QGraphicsObject";
-    } else if (QWidget *wid = qobject_cast<QWidget *>(obj)) {
-        window()->setAttribute(Qt::WA_OpaquePaintEvent, false);
-        window()->setAttribute(Qt::WA_NoSystemBackground, false);
-        if (!layout()) {
-            setLayout(new QVBoxLayout);
-            layout()->setContentsMargins(0, 0, 0, 0);
-        } else if (layout()->count()) {
-            // Hide the QGraphicsView in GV mode.
-            QLayoutItem *item = layout()->itemAt(0);
-            if (item->widget())
-                item->widget()->hide();
+    } else if (obj) {
+        qWarning() << "QDeclarativeView only supports loading of root objects that derive from QGraphicsObject";
+        if (QWidget* widget  = qobject_cast<QWidget *>(obj)) {
+            window()->setAttribute(Qt::WA_OpaquePaintEvent, false);
+            window()->setAttribute(Qt::WA_NoSystemBackground, false);
+            if (layout() && layout()->count()) {
+                // Hide the QGraphicsView in GV mode.
+                QLayoutItem *item = layout()->itemAt(0);
+                if (item->widget())
+                    item->widget()->hide();
+            }
+            widget->setParent(this);
+            if (isVisible()) {
+                widget->setVisible(true);
+            }
+            resize(widget->size());
         }
-        layout()->addWidget(wid);
-        emit sceneResized(wid->size());
     }
-}
 
-/*!
-  \internal
- */
-void QDeclarativeView::sizeChanged()
-{
-    // delay, so we catch both width and height changing.
-    d->resizetimer.start(0,this);
+    if (d->root) {
+        QSize initialSize = d->rootObjectSize();
+        if (initialSize != size()) {
+            resize(initialSize);
+        }
+        d->initResize();
+    }
 }
 
 /*!
@@ -508,30 +594,36 @@ void QDeclarativeView::sizeChanged()
 void QDeclarativeView::timerEvent(QTimerEvent* e)
 {
     if (!e || e->timerId() == d->resizetimer.timerId()) {
-        if (d->qmlRoot) {
-            QSize sz(d->qmlRoot->width(),d->qmlRoot->height());
-            emit sceneResized(sz);
-            //if (!d->resizable)
-                //resize(sz);
-        }
+        d->updateSize();
         d->resizetimer.stop();
-        updateGeometry();
     }
 }
 
+bool QDeclarativeView::eventFilter(QObject *watched, QEvent *e)
+{
+    if (watched == d->root && d->resizeMode == SizeViewToRootObject) {
+        if (d->graphicsWidgetRoot) {
+            if (e->type() == QEvent::GraphicsSceneResize) {
+                d->updateSize();
+            }
+        }
+    }
+    return QGraphicsView::eventFilter(watched, e);
+}
+
 /*!
     \internal
-    The size hint is the size of the root item.
+    Preferred size follows the root object in
+    resize mode SizeViewToRootObject and
+    the view in resize mode SizeRootObjectToView.
 */
 QSize QDeclarativeView::sizeHint() const
 {
-    if (d->qmlRoot) {
-        if (d->initialSize.width() <= 0)
-            d->initialSize.setWidth(d->qmlRoot->width());
-        if (d->initialSize.height() <= 0)
-            d->initialSize.setHeight(d->qmlRoot->height());
+    if (d->resizeMode == SizeRootObjectToView) {
+        return size();
+    } else { // d->resizeMode == SizeViewToRootObject
+        return d->rootObjectSize();
     }
-    return d->initialSize;
 }
 
 /*!
@@ -549,17 +641,17 @@ QGraphicsObject *QDeclarativeView::rootObject() const
  */
 void QDeclarativeView::resizeEvent(QResizeEvent *e)
 {
-    if (d->resizeMode == SizeRootObjectToView && d->qmlRoot) {
-        d->qmlRoot->setWidth(width());
-        d->qmlRoot->setHeight(height());
+    if (d->resizeMode == SizeRootObjectToView) {
+        d->updateSize();
     }
-    if (d->qmlRoot) {
-        setSceneRect(QRectF(0, 0, d->qmlRoot->width(), d->qmlRoot->height()));
+    if (d->declarativeItemRoot) {
+        setSceneRect(QRectF(0, 0, d->declarativeItemRoot->width(), d->declarativeItemRoot->height()));
     } else if (d->root) {
         setSceneRect(d->root->boundingRect());
     } else {
         setSceneRect(rect());
     }
+    emit sceneResized(e->size());
     QGraphicsView::resizeEvent(e);
 }
 
diff --git a/src/declarative/util/qdeclarativeview.h b/src/declarative/util/qdeclarativeview.h
index 107f3f9..1807758 100644
--- a/src/declarative/util/qdeclarativeview.h
+++ b/src/declarative/util/qdeclarativeview.h
@@ -97,13 +97,13 @@ Q_SIGNALS:
 
 private Q_SLOTS:
     void continueExecute();
-    void sizeChanged();
 
 protected:
     virtual void resizeEvent(QResizeEvent *);
     virtual void paintEvent(QPaintEvent *event);
     virtual void timerEvent(QTimerEvent*);
     virtual void setRootObject(QObject *obj);
+    virtual bool eventFilter(QObject *watched, QEvent *e);
 
     friend class QDeclarativeViewPrivate;
     QDeclarativeViewPrivate *d;