Polish MapViewer example

This patch does some improvements to the MapViewer example.
Namely:

- sliders, which have been problematic in many ways, are now from
QtQuickControls 2, and this solves a couple of glitches.

- changing map provider now retains tilt, bearing and field of view,
if possible.

- High DPI scaling is enabled by default in main()

- the slider panel is open at start

Change-Id: I1cc380e3d05b89aa547139d912c142e4f0d266c9
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

4 files changed, 33 insertions, 23 deletions

diff --git a/examples/location/mapviewer/main.cpp b/examples/location/mapviewer/main.cpp
index 3eedd8dd..c44e3d9e 100644
--- a/examples/location/mapviewer/main.cpp
+++ b/examples/location/mapviewer/main.cpp
@@ -88,6 +88,7 @@ int main(int argc, char *argv[])
     for (const QByteArray &p : additionalLibraryPaths.split(':'))
         QCoreApplication::addLibraryPath(QString(p));
 
+    QGuiApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
     QGuiApplication application(argc, argv);
 
     QVariantMap parameters;
diff --git a/examples/location/mapviewer/map/MapComponent.qml b/examples/location/mapviewer/map/MapComponent.qml
index c3d5dfd2..c450a150 100644
--- a/examples/location/mapviewer/map/MapComponent.qml
+++ b/examples/location/mapviewer/map/MapComponent.qml
@@ -61,6 +61,7 @@ Map {
     property alias routeQuery: routeQuery
     property alias routeModel: routeModel
     property alias geocodeModel: geocodeModel
+    property alias slidersExpanded: sliders.expanded
 
     signal showGeocodeInfo()
     signal geocodeFinished()
diff --git a/examples/location/mapviewer/map/MapSliders.qml b/examples/location/mapviewer/map/MapSliders.qml
index 75e4f474..8e24481f 100644
--- a/examples/location/mapviewer/map/MapSliders.qml
+++ b/examples/location/mapviewer/map/MapSliders.qml
@@ -41,6 +41,7 @@
 import QtQuick 2.6
 import QtQuick.Controls 1.4
 import QtQuick.Controls.Styles 1.4
+import QtQuick.Controls 2.0 as C2
 
 Row {
     id: containerRow
@@ -49,6 +50,7 @@ Row {
     property real fontSize : 14
     property color labelBackground : "transparent"
     property int edge: Qt.RightEdge
+    property alias expanded: sliderToggler.checked
 
     function rightEdge() {
         return (containerRow.edge === Qt.RightEdge);
@@ -65,7 +67,7 @@ Row {
         width: 32
         height: 96
         checkable: true
-        checked: false
+        checked: true
         anchors.verticalCenter: parent.verticalCenter
 
         transform:  Scale {
@@ -204,59 +206,53 @@ Row {
 
             // The sliders row
             Row {
-                spacing: 10
+                spacing: -10
                 id: sliderRow
                 height: sliderContainer.slidersHeight
 
-                Slider {
+                C2.Slider {
                     id: zoomSlider
                     height: parent.height
                     orientation : Qt.Vertical
+                    from : containerRow.mapSource.minimumZoomLevel
+                    to : containerRow.mapSource.maximumZoomLevel
+                    value : containerRow.mapSource.zoomLevel
                     onValueChanged: {
                             containerRow.mapSource.zoomLevel = value
                     }
-                    Component.onCompleted: {
-                        minimumValue = Qt.binding(function() { return containerRow.mapSource.minimumZoomLevel; })
-                        maximumValue = Qt.binding(function() { return containerRow.mapSource.maximumZoomLevel; })
-                        value = Qt.binding(function() { return containerRow.mapSource.zoomLevel; })
-                    }
                 }
-                Slider {
+                C2.Slider {
                     id: bearingSlider
                     height: parent.height
-                    minimumValue: 0
-                    maximumValue: 360
+                    from: 0
+                    to: 360
                     orientation : Qt.Vertical
                     value: containerRow.mapSource.bearing
                     onValueChanged: {
                         containerRow.mapSource.bearing = value;
                     }
                 }
-                Slider {
+                C2.Slider {
                     id: tiltSlider
                     height: parent.height
                     orientation : Qt.Vertical
+                    from: containerRow.mapSource.minimumTilt;
+                    to: containerRow.mapSource.maximumTilt
+                    value: containerRow.mapSource.tilt
                     onValueChanged: {
                         containerRow.mapSource.tilt = value;
                     }
-                    Component.onCompleted: {
-                        minimumValue = Qt.binding(function() { return containerRow.mapSource.minimumTilt; })
-                        maximumValue = Qt.binding(function() { return containerRow.mapSource.maximumTilt; })
-                        value = Qt.binding(function() { return containerRow.mapSource.tilt; })
-                    }
                 }
-                Slider {
+                C2.Slider {
                     id: fovSlider
                     height: parent.height
                     orientation : Qt.Vertical
+                    from: containerRow.mapSource.minimumFieldOfView
+                    to: containerRow.mapSource.maximumFieldOfView
+                    value: containerRow.mapSource.fieldOfView
                     onValueChanged: {
                         containerRow.mapSource.fieldOfView = value;
                     }
-                    Component.onCompleted: {
-                        minimumValue = Qt.binding(function() { return containerRow.mapSource.minimumFieldOfView; })
-                        maximumValue = Qt.binding(function() { return containerRow.mapSource.maximumFieldOfView; })
-                        value = Qt.binding(function() { return containerRow.mapSource.fieldOfView; })
-                    }
                 }
             } // Row sliders
 
diff --git a/examples/location/mapviewer/mapviewer.qml b/examples/location/mapviewer/mapviewer.qml
index 21348919..debc329f 100644
--- a/examples/location/mapviewer/mapviewer.qml
+++ b/examples/location/mapviewer/mapviewer.qml
@@ -73,10 +73,18 @@ ApplicationWindow {
         }
 
         var zoomLevel = null
+        var tilt = null
+        var bearing = null
+        var fov = null
         var center = null
+        var panelExpanded = null
         if (map) {
             zoomLevel = map.zoomLevel
+            tilt = map.tilt
+            bearing = map.bearing
+            fov = map.fieldOfView
             center = map.center
+            panelExpanded = map.slidersExpanded
             map.destroy()
         }
 
@@ -84,8 +92,12 @@ ApplicationWindow {
         map.plugin = plugin;
 
         if (zoomLevel != null) {
+            map.tilt = tilt
+            map.bearing = bearing
+            map.fieldOfView = fov
             map.zoomLevel = zoomLevel
             map.center = center
+            map.slidersExpanded = panelExpanded
         } else {
             // Use an integer ZL to enable nearest interpolation, if possible.
             map.zoomLevel = Math.floor((map.maximumZoomLevel - map.minimumZoomLevel)/2)