Fixes for the mapviewer QtLocation example

Currently identified problems with this example are:
- the map element loses focus upon provider switch, or opening some
other page (geocoding page, for example)
  - caused by changes in the StackView. Solved by forcing the focus
    upon map change
- selecting minimap causes segfault
  - caused by dereferencing a null pointer (m_flick.m_animation)
    in qquickgeomapgesturearea.cpp
- occasional (random) crashes with "QVector index out of bound" error
- the menus show up on the wrong screen most of the time if the window
spans multiple screens (but this is a broader qtquick problem)

This patch fixes the first two issues

Task-number: QTBUG-50519
Change-Id: Ic6b4a35e62e4651bd8003f47fade45f44a99d81c
Reviewed-by: Alex Blasche <alexander.blasche@theqtcompany.com>

1 files changed, 22 insertions, 12 deletions

diff --git a/examples/location/mapviewer/mapviewer.qml b/examples/location/mapviewer/mapviewer.qml
index bcc2c919..2cb4e0d0 100644
--- a/examples/location/mapviewer/mapviewer.qml
+++ b/examples/location/mapviewer/mapviewer.qml
@@ -63,26 +63,41 @@ ApplicationWindow {
         var plugin
 
         if (parameters && parameters.length>0)
-            plugin = Qt.createQmlObject ('import QtLocation 5.3; Plugin{ name:"' + provider + '"; parameters: appWindow.parameters}', appWindow)
+            plugin = Qt.createQmlObject ('import QtLocation 5.6; Plugin{ name:"' + provider + '"; parameters: appWindow.parameters}', appWindow)
         else
-            plugin = Qt.createQmlObject ('import QtLocation 5.3; Plugin{ name:"' + provider + '"}', appWindow)
+            plugin = Qt.createQmlObject ('import QtLocation 5.6; Plugin{ name:"' + provider + '"}', appWindow)
 
+        if (minimap) {
+            minimap.destroy()
+            minimap = null
+        }
+
+        var zoomLevel = null
+        var center = null
         if (map) {
+            zoomLevel = map.zoomLevel
+            center = map.center
             map.destroy()
-            minimap = null
         }
 
         map = mapComponent.createObject(page);
         map.plugin = plugin;
-        map.zoomLevel = (map.maximumZoomLevel - map.minimumZoomLevel)/2
+        if (zoomLevel != null) {
+            map.zoomLevel = zoomLevel
+            map.center = center
+        } else {
+            map.zoomLevel = (map.maximumZoomLevel - map.minimumZoomLevel)/2
+        }
+
+        map.forceActiveFocus()
     }
 
     function getPlugins()
     {
-        var plugin = Qt.createQmlObject ('import QtLocation 5.3; Plugin {}', appWindow)
+        var plugin = Qt.createQmlObject ('import QtLocation 5.6; Plugin {}', appWindow)
         var myArray = new Array()
         for (var i = 0; i<plugin.availableServiceProviders.length; i++) {
-            var tempPlugin = Qt.createQmlObject ('import QtLocation 5.3; Plugin {name: "' + plugin.availableServiceProviders[i]+ '"}', appWindow)
+            var tempPlugin = Qt.createQmlObject ('import QtLocation 5.6; Plugin {name: "' + plugin.availableServiceProviders[i]+ '"}', appWindow)
             if (tempPlugin.supportsMapping())
                 myArray.push(tempPlugin.name)
         }
@@ -94,7 +109,7 @@ ApplicationWindow {
     {
         var parameters = new Array()
         for (var prop in pluginParameters){
-            var parameter = Qt.createQmlObject('import QtLocation 5.3; PluginParameter{ name: "'+ prop + '"; value: "' + pluginParameters[prop]+'"}',appWindow)
+            var parameter = Qt.createQmlObject('import QtLocation 5.6; PluginParameter{ name: "'+ prop + '"; value: "' + pluginParameters[prop]+'"}',appWindow)
             parameters.push(parameter)
         }
         appWindow.parameters = parameters
@@ -156,11 +171,6 @@ ApplicationWindow {
                 providerMenu.items[i].checked = providerMenu.items[i].text === providerName
             }
 
-            if (minimap) {
-                minimap.destroy()
-                minimap = null
-            }
-
             createMap(providerName)
             if (map.error === Map.NoError) {
                 selectMapType(map.activeMapType)