RangeSlider: use deferred execution

Task-number: QTBUG-50992
Change-Id: Ibbc946c3402c65f9b100fc74dde04e4d439c8535
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

2 files changed, 44 insertions, 6 deletions

diff --git a/src/quicktemplates2/qquickrangeslider.cpp b/src/quicktemplates2/qquickrangeslider.cpp
index 274c887d..44c00f68 100644
--- a/src/quicktemplates2/qquickrangeslider.cpp
+++ b/src/quicktemplates2/qquickrangeslider.cpp
@@ -36,6 +36,7 @@
 
 #include "qquickrangeslider_p.h"
 #include "qquickcontrol_p_p.h"
+#include "qquickdeferredexecute_p_p.h"
 
 #include <QtCore/qscopedpointer.h>
 #include <QtQuick/private/qquickwindow_p.h>
@@ -109,13 +110,15 @@ public:
     void setPosition(qreal position, bool ignoreOtherPosition = false);
     void updatePosition(bool ignoreOtherPosition = false);
 
+    void executeHandle(bool complete = false);
+
     static QQuickRangeSliderNodePrivate *get(QQuickRangeSliderNode *node);
 
     qreal value;
     bool isPendingValue;
     qreal pendingValue;
     qreal position;
-    QQuickItem *handle;
+    QQuickDeferredPointer<QQuickItem> handle;
     QQuickRangeSlider *slider;
     bool pressed;
     bool hovered;
@@ -149,6 +152,20 @@ void QQuickRangeSliderNodePrivate::updatePosition(bool ignoreOtherPosition)
     setPosition(pos, ignoreOtherPosition);
 }
 
+static inline QString handleName() { return QStringLiteral("handle"); }
+
+void QQuickRangeSliderNodePrivate::executeHandle(bool complete)
+{
+    Q_Q(QQuickRangeSliderNode);
+    if (handle.wasExecuted())
+        return;
+
+    if (!handle)
+        quickBeginDeferred(q, handleName(), handle);
+    if (complete)
+        quickCompleteDeferred(q, handleName(), handle);
+}
+
 QQuickRangeSliderNodePrivate *QQuickRangeSliderNodePrivate::get(QQuickRangeSliderNode *node)
 {
     return node->d_func();
@@ -227,7 +244,9 @@ qreal QQuickRangeSliderNode::visualPosition() const
 
 QQuickItem *QQuickRangeSliderNode::handle() const
 {
-    Q_D(const QQuickRangeSliderNode);
+    QQuickRangeSliderNodePrivate *d = const_cast<QQuickRangeSliderNodePrivate *>(d_func());
+    if (!d->handle)
+        d->executeHandle();
     return d->handle;
 }
 
@@ -237,7 +256,7 @@ void QQuickRangeSliderNode::setHandle(QQuickItem *handle)
     if (d->handle == handle)
         return;
 
-    QQuickControlPrivate::destroyDelegate(d->handle, d->slider);
+    delete d->handle;
     d->handle = handle;
     if (handle) {
         if (!handle->parentItem())
@@ -263,7 +282,8 @@ void QQuickRangeSliderNode::setHandle(QQuickItem *handle)
 
         handle->setActiveFocusOnTab(true);
     }
-    emit handleChanged();
+    if (!d->handle.isExecuting())
+        emit handleChanged();
 }
 
 bool QQuickRangeSliderNode::isPressed() const
@@ -1045,13 +1065,28 @@ void QQuickRangeSlider::mirrorChange()
     emit d->second->visualPositionChanged();
 }
 
-void QQuickRangeSlider::componentComplete()
+void QQuickRangeSlider::classBegin()
 {
     Q_D(QQuickRangeSlider);
-    QQuickControl::componentComplete();
+    QQuickControl::classBegin();
 
+    QQmlContext *context = qmlContext(this);
+    if (context) {
+        QQmlEngine::setContextForObject(d->first, context);
+        QQmlEngine::setContextForObject(d->second, context);
+    }
+}
+
+void QQuickRangeSlider::componentComplete()
+{
+    Q_D(QQuickRangeSlider);
     QQuickRangeSliderNodePrivate *firstPrivate = QQuickRangeSliderNodePrivate::get(d->first);
     QQuickRangeSliderNodePrivate *secondPrivate = QQuickRangeSliderNodePrivate::get(d->second);
+    firstPrivate->executeHandle(true);
+    secondPrivate->executeHandle(true);
+    d->executeBackground(true);
+
+    QQuickControl::componentComplete();
 
     if (firstPrivate->isPendingValue || secondPrivate->isPendingValue
         || !qFuzzyCompare(d->from, defaultFrom) || !qFuzzyCompare(d->to, defaultTo)) {
diff --git a/src/quicktemplates2/qquickrangeslider_p.h b/src/quicktemplates2/qquickrangeslider_p.h
index fc5a1d99..cc071974 100644
--- a/src/quicktemplates2/qquickrangeslider_p.h
+++ b/src/quicktemplates2/qquickrangeslider_p.h
@@ -67,6 +67,7 @@ class Q_QUICKTEMPLATES2_PRIVATE_EXPORT QQuickRangeSlider : public QQuickControl
     Q_PROPERTY(Qt::Orientation orientation READ orientation WRITE setOrientation NOTIFY orientationChanged FINAL)
     // 2.2 (Qt 5.9)
     Q_PROPERTY(bool live READ live WRITE setLive NOTIFY liveChanged FINAL REVISION 2)
+    Q_CLASSINFO("DeferredPropertyNames", "background")
 
 public:
     explicit QQuickRangeSlider(QQuickItem *parent = nullptr);
@@ -124,6 +125,7 @@ protected:
     void touchEvent(QTouchEvent *event) override;
 #endif
     void mirrorChange() override;
+    void classBegin() override;
     void componentComplete() override;
 
 #if QT_CONFIG(accessibility)
@@ -149,6 +151,7 @@ class Q_QUICKTEMPLATES2_PRIVATE_EXPORT QQuickRangeSliderNode : public QObject
     Q_PROPERTY(bool pressed READ isPressed WRITE setPressed NOTIFY pressedChanged FINAL)
     // 2.1 (Qt 5.8)
     Q_PROPERTY(bool hovered READ isHovered WRITE setHovered NOTIFY hoveredChanged FINAL REVISION 1)
+    Q_CLASSINFO("DeferredPropertyNames", "handle")
 
 public:
     explicit QQuickRangeSliderNode(qreal value, QQuickRangeSlider *slider);