Implement removeAt() for layout classes to clean up item removal. Also

clean up qmlAttachedProperties() implementation and improve QML example

8 files changed, 70 insertions, 36 deletions

diff --git a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/.main.cpp.swo b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/.main.cpp.swo
index c742274..cbd3b3e 100644
--- a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/.main.cpp.swo
+++ b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/.main.cpp.swo
diff --git a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/gridlayout.cpp b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/gridlayout.cpp
index 728c225..1792696 100644
--- a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/gridlayout.cpp
+++ b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/gridlayout.cpp
@@ -131,13 +131,23 @@ void QGraphicsGridLayoutObject::addLayoutItem(QGraphicsLayoutItem *item)
             setAlignment(item, alignment);
         QObject::connect(obj, SIGNAL(alignmentChanged(QGraphicsLayoutItem*, Qt::Alignment)),
                          this, SLOT(updateAlignment(QGraphicsLayoutItem*, Qt::Alignment)));
-        //### need to disconnect when widget is removed? Re-implement removeAt()?
     }
 }
 
+void QGraphicsGridLayoutObject::removeAt(int index)
+{
+    QGraphicsLayoutItem *item = itemAt(index);
+    if (item) {
+        GridLayoutAttached *obj = attachedProperties.value(item);
+        obj->disconnect(this);
+        attachedProperties.remove(item);
+    }
+    QGraphicsGridLayout::removeAt(index);
+}
+
 void QGraphicsGridLayoutObject::clearChildren()
 {
-    //### do I need to delete the removed items? And/or removed them from attachedProperties?
+    // do not delete the removed items; they will be deleted by the QML engine
     while (count() > 0)
         removeAt(count()-1);
 }
@@ -146,7 +156,7 @@ qreal QGraphicsGridLayoutObject::spacing() const
 {
     if (verticalSpacing() == horizontalSpacing())
         return verticalSpacing();
-    return -1;  //###
+    return -1; 
 }
 
 qreal QGraphicsGridLayoutObject::contentsMargin() const
@@ -170,11 +180,9 @@ void QGraphicsGridLayoutObject::updateAlignment(QGraphicsLayoutItem *item, Qt::A
 
 GridLayoutAttached *QGraphicsGridLayoutObject::qmlAttachedProperties(QObject *obj)
 {
-    // ### This is not allowed - you must attach to any object
-    if (!qobject_cast<QGraphicsLayoutItem*>(obj))
-        return 0;
     GridLayoutAttached *rv = new GridLayoutAttached(obj);
-    attachedProperties.insert(qobject_cast<QGraphicsLayoutItem*>(obj), rv);
+    if (qobject_cast<QGraphicsLayoutItem*>(obj))
+        attachedProperties.insert(qobject_cast<QGraphicsLayoutItem*>(obj), rv);
     return rv;
 }
 
diff --git a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/gridlayout.h b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/gridlayout.h
index 04f0148..cb8d9b7 100644
--- a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/gridlayout.h
+++ b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/gridlayout.h
@@ -69,6 +69,8 @@ public:
     qreal contentsMargin() const;
     void setContentsMargin(qreal);
 
+    void removeAt(int index);
+
     static GridLayoutAttached *qmlAttachedProperties(QObject *);
 
 private slots:
diff --git a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/qgraphicsgridlayout.qml b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/qgraphicsgridlayout.qml
index c3edf1d..5cb011f 100644
--- a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/qgraphicsgridlayout.qml
+++ b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicsgridlayout/qgraphicsgridlayout.qml
@@ -49,46 +49,48 @@ Item {
         size.width: parent.width
         size.height: parent.height
 
+        /*
+            Below we create a grid layout using the GraphicsGridLayout item 
+            (defined by the GraphicsGridLayoutObject class in gridlayout.h). 
+
+            The row, column etc. are set through attached properties on
+            GraphicsGridLayout, using the properties defined in the 
+            GridLayoutAttached class (also defined in gridlayout.h).
+        */
+
         layout: QGraphicsGridLayout {
-            objectName: "layout"
             LayoutItem {
                 QGraphicsGridLayout.row: 0
                 QGraphicsGridLayout.column: 0
-                QGraphicsGridLayout.alignment: Qt.AlignLeft
                 minimumSize: "100x100"
                 maximumSize: "300x300"
-                preferredSize: "100x100"
+                preferredSize: "200x200"
                 Rectangle { color: "red"; anchors.fill: parent }
             }
             LayoutItem {
-                QGraphicsGridLayout.row: 1
-                QGraphicsGridLayout.column: 0
+                QGraphicsGridLayout.row: 0
+                QGraphicsGridLayout.column: 1
                 minimumSize: "100x100"
                 maximumSize: "200x200"
-                preferredSize: "100x100"
+                preferredSize: "200x200"
                 Rectangle { color: "orange"; anchors.fill: parent }
             }
             LayoutItem {
-                QGraphicsGridLayout.row: 2
+                QGraphicsGridLayout.row: 1
                 QGraphicsGridLayout.column: 0
+                QGraphicsGridLayout.columnSpan: 2
                 minimumSize: "100x100"
-                maximumSize: "300x300"
-                preferredSize: "200x200"
                 Rectangle { color: "yellow"; anchors.fill: parent }
             }
             LayoutItem {
-                QGraphicsGridLayout.row: 0
-                QGraphicsGridLayout.column: 1
-                minimumSize: "100x100"
-                maximumSize: "200x200"
+                QGraphicsGridLayout.row: 2
+                QGraphicsGridLayout.column: 0
                 preferredSize: "200x200"
                 Rectangle { color: "green"; anchors.fill: parent }
             }
             LayoutItem {
-                QGraphicsGridLayout.row: 1
+                QGraphicsGridLayout.row: 2
                 QGraphicsGridLayout.column: 1
-                minimumSize: "100x100"
-                maximumSize: "400x400"
                 preferredSize: "200x200"
                 Rectangle { color: "blue"; anchors.fill: parent }
             }
diff --git a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslayouts.pro b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslayouts.pro
index d92a6f4..672120a 100644
--- a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslayouts.pro
+++ b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslayouts.pro
@@ -1,5 +1,6 @@
 TEMPLATE = subdirs
 
 SUBDIRS += \
-    graphicsLayouts \
-    layoutItem
+    layoutitem \
+    qgraphicsgridlayout \
+    qgraphicslinearlayout
diff --git a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslinearlayout/linearlayout.cpp b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslinearlayout/linearlayout.cpp
index 5cd35cb..080b6ce 100644
--- a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslinearlayout/linearlayout.cpp
+++ b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslinearlayout/linearlayout.cpp
@@ -44,7 +44,7 @@
 #include <QGraphicsLayoutItem>
 
 LinearLayoutAttached::LinearLayoutAttached(QObject *parent)
-: QObject(parent), m_stretch(1), m_alignment(Qt::AlignCenter), m_spacing(0)
+: QObject(parent), m_stretch(1), m_alignment(Qt::AlignTop), m_spacing(0)
 {
 }
 
@@ -98,7 +98,6 @@ void QGraphicsLinearLayoutObject::insertLayoutItem(int index, QGraphicsLayoutIte
 {
     insertItem(index, item);
 
-    //connect attached properties
     if (LinearLayoutAttached *obj = attachedProperties.value(item)) {
         setStretchFactor(item, obj->stretchFactor());
         setAlignment(item, obj->alignment());
@@ -109,12 +108,23 @@ void QGraphicsLinearLayoutObject::insertLayoutItem(int index, QGraphicsLayoutIte
                          this, SLOT(updateAlignment(QGraphicsLayoutItem*,Qt::Alignment)));
         QObject::connect(obj, SIGNAL(spacingChanged(QGraphicsLayoutItem*,int)),
                          this, SLOT(updateSpacing(QGraphicsLayoutItem*,int)));
-        //### need to disconnect when widget is removed?
     }
 }
 
+void QGraphicsLinearLayoutObject::removeAt(int index)
+{
+    QGraphicsLayoutItem *item = itemAt(index);
+    if (item) {
+        LinearLayoutAttached *obj = attachedProperties.value(item);
+        obj->disconnect(this);
+        attachedProperties.remove(item);
+    }
+    QGraphicsLinearLayout::removeAt(index);
+}
+
 void QGraphicsLinearLayoutObject::clearChildren()
 {
+    // do not delete the removed items; they will be deleted by the QML engine
     while (count() > 0)
         removeAt(count()-1);
 }
@@ -156,11 +166,9 @@ void QGraphicsLinearLayoutObject::updateAlignment(QGraphicsLayoutItem *item, Qt:
 QHash<QGraphicsLayoutItem*, LinearLayoutAttached*> QGraphicsLinearLayoutObject::attachedProperties;
 LinearLayoutAttached *QGraphicsLinearLayoutObject::qmlAttachedProperties(QObject *obj)
 {
-    // ### This is not allowed - you must attach to any object
-    if (!qobject_cast<QGraphicsLayoutItem*>(obj))
-        return 0;
     LinearLayoutAttached *rv = new LinearLayoutAttached(obj);
-    attachedProperties.insert(qobject_cast<QGraphicsLayoutItem*>(obj), rv);
+    if (qobject_cast<QGraphicsLayoutItem*>(obj))
+        attachedProperties.insert(qobject_cast<QGraphicsLayoutItem*>(obj), rv);
     return rv;
 }
 
diff --git a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslinearlayout/linearlayout.h b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslinearlayout/linearlayout.h
index 392f3f8..e6daf4d 100644
--- a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslinearlayout/linearlayout.h
+++ b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslinearlayout/linearlayout.h
@@ -74,11 +74,13 @@ public:
 
     QDeclarativeListProperty<QGraphicsLayoutItem> children() { return QDeclarativeListProperty<QGraphicsLayoutItem>(this, 0, children_append, children_count, children_at, children_clear); }
 
-    static LinearLayoutAttached *qmlAttachedProperties(QObject *);
-
     qreal contentsMargin() const;
     void setContentsMargin(qreal);
 
+    void removeAt(int index);
+
+    static LinearLayoutAttached *qmlAttachedProperties(QObject *);
+
 private slots:
     void updateStretch(QGraphicsLayoutItem*,int);
     void updateSpacing(QGraphicsLayoutItem*,int);
diff --git a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslinearlayout/qgraphicslinearlayout.qml b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslinearlayout/qgraphicslinearlayout.qml
index da77921..72cdeb6 100644
--- a/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslinearlayout/qgraphicslinearlayout.qml
+++ b/examples/declarative/cppextensions/qgraphicslayouts/qgraphicslinearlayout/qgraphicslinearlayout.qml
@@ -49,17 +49,28 @@ Item {
         size.width: parent.width
         size.height: parent.height
 
+        /*
+            Below we create a linear layout using the GraphicsLinearLayout item 
+            (defined by the GraphicsLinearLayoutObject class in linearlayout.h). 
+
+            The first LayoutItem uses 'GraphicsLinearLayout.spacing' to set the
+            item's spacing: this is an attached property, set using the 
+            properties defined in the LinearLayoutAttached class (also defined
+            in linearlayout.h).
+        */
+
         layout: QGraphicsLinearLayout {
             LayoutItem {
+                QGraphicsLinearLayout.spacing: 50
                 minimumSize: "100x100"
-                maximumSize: "300x300"
+                maximumSize: "200x200"
                 preferredSize: "100x100"
                 Rectangle { color: "yellow"; anchors.fill: parent }
             }
             LayoutItem {
                 minimumSize: "100x100"
                 maximumSize: "400x400"
-                preferredSize: "200x200"
+                preferredSize: "300x300"
                 Rectangle { color: "green"; anchors.fill: parent }
             }
         }