Abstract expression and binding APIs

By splitting the interface through which the system interacts with bindings
away from a specific implementation, we can introduce highly specialized
implementations for specific optimizations.

This commit also includes a sample optimization for object properties being
assigned directly from a local id.

1 files changed, 61 insertions, 21 deletions

diff --git a/src/declarative/qml/qmlbinding.cpp b/src/declarative/qml/qmlbinding.cpp
index 41cef49..7c5b366 100644
--- a/src/declarative/qml/qmlbinding.cpp
+++ b/src/declarative/qml/qmlbinding.cpp
@@ -47,6 +47,8 @@
 #include <QVariant>
 #include <private/qfxperf_p.h>
 #include <QtCore/qdebug.h>
+#include <private/qmlcontext_p.h>
+#include <private/qmldeclarativedata_p.h>
 
 Q_DECLARE_METATYPE(QList<QObject *>);
 
@@ -55,7 +57,7 @@ QT_BEGIN_NAMESPACE
 QML_DEFINE_NOCREATE_TYPE(QmlBinding);
 
 QmlBindingPrivate::QmlBindingPrivate()
-: inited(false), updating(false), enabled(true), mePtr(0)
+: updating(false), enabled(false), mePtr(0)
 {
 }
 
@@ -92,25 +94,6 @@ QmlMetaProperty QmlBinding::property() const
    return d->property; 
 }
 
-void QmlBinding::init()
-{
-    Q_D(QmlBinding);
-
-    if (d->inited)
-        return;
-    d->inited = true;
-    update();
-}
-
-void QmlBinding::forceUpdate()
-{
-    Q_D(QmlBinding);
-    if (!d->inited)
-        init();
-    else
-        update();
-}
-
 void QmlBinding::update()
 {
     Q_D(QmlBinding);
@@ -118,7 +101,7 @@ void QmlBinding::update()
 #ifdef Q_ENABLE_PERFORMANCE_LOG
     QFxPerfTimer<QFxPerf::BindableValueUpdate> bu;
 #endif
-    if (!d->inited || !d->enabled)
+    if (!d->enabled)
         return;
 
     if (!d->updating) {
@@ -168,6 +151,20 @@ void QmlBinding::setEnabled(bool e)
     Q_D(QmlBinding);
     d->enabled = e;
     setTrackChange(e);
+
+    if (e) {
+        d->mePtr = 0;
+        addToObject(d->property.object());
+        update();
+    } else {
+        removeFromObject();
+    }
+}
+
+int QmlBinding::propertyIndex()
+{
+    Q_D(QmlBinding);
+    return d->property.coreIndex();
 }
 
 bool QmlBinding::enabled() const
@@ -177,4 +174,47 @@ bool QmlBinding::enabled() const
     return d->enabled;
 }
 
+QString QmlBinding::expression() const
+{
+    return QmlExpression::expression();
+}
+
+QmlAbstractBinding::QmlAbstractBinding()
+: m_prevBinding(0), m_nextBinding(0)
+{
+}
+
+QmlAbstractBinding::~QmlAbstractBinding()
+{
+    removeFromObject();
+}
+
+void QmlAbstractBinding::addToObject(QObject *object)
+{
+    removeFromObject();
+
+    if (object) {
+        QmlDeclarativeData *data = QmlDeclarativeData::get(object, true);
+        m_nextBinding = data->bindings;
+        if (m_nextBinding) m_nextBinding->m_prevBinding = &m_nextBinding;
+        m_prevBinding = &data->bindings;
+        data->bindings = this;
+    }
+}
+
+void QmlAbstractBinding::removeFromObject()
+{
+    if (m_prevBinding) {
+        *m_prevBinding = m_nextBinding;
+        if (m_nextBinding) m_nextBinding->m_prevBinding = m_prevBinding;
+        m_prevBinding = 0;
+        m_nextBinding = 0;
+    }
+}
+
+QString QmlAbstractBinding::expression() const
+{
+    return QLatin1String("<Unknown>");
+}
+
 QT_END_NAMESPACE