Doc: Fix warnings in StocQt Qt Quick demo

Fix a number of warnings from QML engine by adding
some boundary & sanity checks for properties. Also
address UI update issues by having XMLHTTPRequest
calls to trigger by a timer, instead of directly
binding them to multiple change notifier signals.

Task-number: QTBUG-33867
Change-Id: I48f573050b5dc3e3fe6e75bc423fe86ecc4a2469
Reviewed-by: Geir Vattekar <geir.vattekar@digia.com>
Reviewed-by: Alan Alpert <aalpert@blackberry.com>

4 files changed, 22 insertions, 10 deletions

diff --git a/examples/quick/demos/stocqt/content/StockChart.qml b/examples/quick/demos/stocqt/content/StockChart.qml
index 8235b5a632..f7e0d0206b 100644
--- a/examples/quick/demos/stocqt/content/StockChart.qml
+++ b/examples/quick/demos/stocqt/content/StockChart.qml
@@ -48,8 +48,8 @@ Rectangle {
 
     property var _months: [ "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December" ]
     property var stockModel: null
-    property var startDate
-    property var endDate
+    property var startDate: new Date()
+    property var endDate: new Date()
     property var settings
 
     function update() {
@@ -228,6 +228,7 @@ Rectangle {
 
             last = stockModel.indexOf(chart.endDate)
             first = last - (chart.endDate.getTime() - chart.startDate.getTime())/86400000;
+            first = Math.max(first, 0);
             console.log("painting...  first:" + first + ", last:" + last);
 
             var highestPrice = stockModel.highestPrice;
diff --git a/examples/quick/demos/stocqt/content/StockModel.qml b/examples/quick/demos/stocqt/content/StockModel.qml
index d127afc5c5..f9ed9c87d4 100644
--- a/examples/quick/demos/stocqt/content/StockModel.qml
+++ b/examples/quick/demos/stocqt/content/StockModel.qml
@@ -122,11 +122,14 @@ ListModel {
     }
 
     function updateStock() {
-       var xhr = new XMLHttpRequest;
-
         var req = requestUrl();
 
-        xhr.open("GET", req);
+        if (!req)
+            return;
+
+        var xhr = new XMLHttpRequest;
+
+        xhr.open("GET", req, true);
 
         model.ready = false;
         model.clear();
@@ -145,7 +148,7 @@ ListModel {
                     if (model.count > 0) {
                         model.ready = true;
                         model.stockPrice = model.get(0).adjusted;
-                        model.stockPriceChanged = Math.round((model.stockPrice - model.get(2).adjusted) * 100) / 100;
+                        model.stockPriceChanged = model.count > 1 ? (Math.round((model.stockPrice - model.get(1).close) * 100) / 100) : 0;
                         model.dataReady(); //emit signal
                     }
                 }
diff --git a/examples/quick/demos/stocqt/content/StockView.qml b/examples/quick/demos/stocqt/content/StockView.qml
index eefcf0aeb4..ce55fdf3d3 100644
--- a/examples/quick/demos/stocqt/content/StockView.qml
+++ b/examples/quick/demos/stocqt/content/StockView.qml
@@ -53,6 +53,8 @@ Rectangle {
     signal settingsClicked
 
     function update() {
+        if (!settings)
+            return;
         chart.endDate = settings.endDate
         chart.update()
     }
diff --git a/examples/quick/demos/stocqt/stocqt.qml b/examples/quick/demos/stocqt/stocqt.qml
index 9bcffd972f..3e231ab8bf 100644
--- a/examples/quick/demos/stocqt/stocqt.qml
+++ b/examples/quick/demos/stocqt/stocqt.qml
@@ -52,17 +52,23 @@ ListView {
     boundsBehavior: Flickable.StopAtBounds
     currentIndex: 1
 
+    Timer {
+        id: updateTimer
+        interval: 500
+        onTriggered: stock.updateStock()
+    }
+
     StockModel {
         id: stock
         stockId: listView.currentStockId
         stockName: listView.currentStockName
         startDate: settings.startDate
         endDate: settings.endDate
-        onStockIdChanged: updateStock()
-        onStartDateChanged: updateStock()
-        onEndDateChanged: updateStock()
+        onStockIdChanged: updateTimer.restart()
+        onStartDateChanged: updateTimer.restart()
+        onEndDateChanged: updateTimer.restart()
         onDataReady: {
-            root.currentIndex = 1
+            root.positionViewAtIndex(1, ListView.SnapPosition)
             stockView.update()
         }
     }