Welcome: Store examples search text in settings

in QtCreator.ini under "WelcomePage/ExamplesSearchString".
The installer pre-set that setting, and in that way pre-
select a set of examples.

Change-Id: I8ac5a38ad0bd3f33875ef1997ccbf0352410dcc3
Reviewed-by: Thomas Hartmann <Thomas.Hartmann@digia.com>

share/qtcreator/welcomescreen/examples.qml

@@ -56,8 +56,13 @@ Rectangle {
         anchors.right: parent.right
         anchors.leftMargin: 18
 
+        text: examplesModel.readSearchStringsFromSettings()
+
         placeholderText: qsTr("Search in Examples...")
-        onTextChanged: examplesModel.parseSearchString(text)
+        onTextChanged: {
+            examplesModel.parseSearchString(text);
+            examplesModel.writeSearchStringToSettings(text);
+        }
     }
 
     ComboBox {

src/plugins/qtsupport/exampleslistmodel.cpp

@@ -54,6 +54,7 @@ static bool debugExamples()
 }
 
 static const char kSelectedExampleSetKey[] = "WelcomePage/SelectedExampleSet";
+static const char kExamplesSearchStringKey[] = "WelcomePage/ExamplesSearchString";
 
 void ExampleSetModel::writeCurrentIdToSettings(int currentIndex) const
 {
@@ -841,6 +842,16 @@ void ExamplesListModelFilter::filterForExampleSet(int index)
     m_sourceModel->selectExampleSet(index);
 }
 
+void ExamplesListModelFilter::writeSearchStringToSettings(const QString &string)
+{
+    Core::ICore::settings()->setValue(QLatin1String(kExamplesSearchStringKey), string);
+}
+
+QString ExamplesListModelFilter::readSearchStringsFromSettings()
+{
+    return Core::ICore::settings()->value(QLatin1String(kExamplesSearchStringKey)).toString();
+}
+
 void ExamplesListModelFilter::setShowTutorialsOnly(bool showTutorialsOnly)
 {
     m_showTutorialsOnly = showTutorialsOnly;

src/plugins/qtsupport/exampleslistmodel.h

@@ -185,6 +185,8 @@ public:
     QAbstractItemModel* exampleSetModel();
 
     Q_INVOKABLE void filterForExampleSet(int index);
+    Q_INVOKABLE void writeSearchStringToSettings(const QString &string);
+    Q_INVOKABLE QString readSearchStringsFromSettings();
 
 public slots:
     void setFilterTags(const QStringList &arg)