QmlProfiler: Consistently clear when clear button pressed

Several QML properties need extra treatment to avoid stale data
after clearing. Toggling the visibility of the timeline renderer
doesn't really help there.

Task-number: QTCREATORBUG-11833

Change-Id: I1903d7bd69d6fe31ecc4cadca8e30fa2104fa09a
Reviewed-by: Christian Stenger <christian.stenger@digia.com>
Reviewed-by: Kai Koehne <kai.koehne@digia.com>

src/plugins/qmlprofiler/qml/MainView.qml

@@ -82,16 +82,14 @@ Rectangle {
         onStateChanged: {
             // Clear if model is empty.
             if (qmlProfilerModelProxy.getState() === 0)
-                root.clearAll();
+                root.clear();
         }
         onDataAvailable: {
             view.clearData();
-            zoomControl.setRange(0,0);
-            view.visible = true;
-            view.requestPaint();
             zoomControl.setRange(qmlProfilerModelProxy.traceStartTime(),
                                  qmlProfilerModelProxy.traceStartTime() +
                                  qmlProfilerModelProxy.traceDuration()/10);
+            view.requestPaint();
         }
     }
 
@@ -106,21 +104,18 @@ Rectangle {
         }
     }
 
-    function clearData() {
+    function clear() {
+        flick.contentY = 0;
+        flick.contentX = 0;
+        flick.contentWidth = 0;
         view.clearData();
+        view.startTime = view.endTime = 0;
         hideRangeDetails();
         selectionRangeMode = false;
         updateRangeButton();
         zoomControl.setRange(0,0);
-    }
-
-    function clearDisplay() {
-        clearData();
-        view.visible = false;
-    }
-
-    function clearAll() {
-        clearDisplay();
+        zoomSlider.externalUpdate = true;
+        zoomSlider.value = zoomSlider.minimumValue;
     }
 
     function nextEvent() {

src/plugins/qmlprofiler/qml/Overview.qml

@@ -43,7 +43,7 @@ Canvas {
     property real endTime : 0
 
     // ***** functions
-    function clearDisplay()
+    function clear()
     {
         dataReady = false;
         requestPaint();

src/plugins/qmlprofiler/qml/TimeDisplay.qml

@@ -37,7 +37,6 @@ Canvas {
 
     property real startTime : 0
     property real endTime : 0
-    property real timePerPixel: 0
 
     Connections {
         target: zoomControl
@@ -55,7 +54,7 @@ Canvas {
         context.fillRect(0, 0, width, height);
 
         var realWidth = width - 1; // account for left border
-        var totalTime = endTime - startTime;
+        var totalTime = Math.max(1, endTime - startTime);
         var spacing = realWidth / totalTime;
 
         var initialBlockLength = 120;
@@ -67,7 +66,7 @@ Canvas {
         var realStartTime = Math.floor(startTime/timePerBlock) * timePerBlock;
         var realStartPos = (startTime - realStartTime) * spacing - 1;
 
-        timePerPixel = timePerBlock/pixelsPerBlock;
+        var timePerPixel = timePerBlock/pixelsPerBlock;
 
         var initialColor = Math.floor(realStartTime/timePerBlock) % 2;
 
@@ -100,6 +99,12 @@ Canvas {
         context.fillRect(0, 0, 1, height);
     }
 
+    function clear()
+    {
+        startTime = endTime = 0;
+        requestPaint();
+    }
+
     function prettyPrintTime( t )
     {
         var round = 1;

src/plugins/qmlprofiler/qmlprofilertraceview.cpp

@@ -292,13 +292,11 @@ qint64 QmlProfilerTraceView::selectionEnd() const
     return 0;
 }
 
-void QmlProfilerTraceView::clearDisplay()
+void QmlProfilerTraceView::clear()
 {
-    d->m_zoomControl->setRange(0,0);
-    d->m_mainView->rootObject()->setProperty("scrollY", QVariant(0));
-
-    QMetaObject::invokeMethod(d->m_mainView->rootObject(), "clearAll");
-    QMetaObject::invokeMethod(d->m_overview->rootObject(), "clearDisplay");
+    QMetaObject::invokeMethod(d->m_mainView->rootObject(), "clear");
+    QMetaObject::invokeMethod(d->m_overview->rootObject(), "clear");
+    QMetaObject::invokeMethod(d->m_timebar->rootObject(), "clear");
 }
 
 void QmlProfilerTraceView::selectNextEventByHash(const QString &hash)

src/plugins/qmlprofiler/qmlprofilertraceview.h

@@ -78,7 +78,7 @@ public:
     void showContextMenu(QPoint position);
 
 public slots:
-    void clearDisplay();
+    void clear();
     void selectNextEventByHash(const QString &eventHash);
     void selectNextEventByLocation(const QString &filename, const int line, const int column);
 

src/plugins/qmlprofiler/qmlprofilerviewmanager.cpp

@@ -170,7 +170,7 @@ void QmlProfilerViewManager::getStatisticsInRange(qint64 rangeStart, qint64 rang
 
 void QmlProfilerViewManager::clear()
 {
-    d->traceView->clearDisplay();
+    d->traceView->clear();
     d->eventsView->clear();
     d->v8profilerView->clear();
 }