Polish the SimpleTreeModel example

- Fix/silence most clang-tidy/compiler warnings
  * unsigned/int comparison
  * Avoid repeating return / default parameter types
  * Make functions static/use static invocations
  * Use string literals everywhere
  * Use auto * for pointers
  * Streamline code, use ternary operators
  * Move constructor parameters
  * Observe rule of 5 by using Q_DISABLE_COPY_MOVE
- Add some bells && whistles, resize properly, expand all

Complements 25027444a9b53d61a6257dc5f5ce0ffdb3b06f98.

Pick-to: 6.6
Change-Id: I78f48d187981ecabf69a5d4d42715bad026fa9e6
Reviewed-by: Kai Köhne <kai.koehne@qt.io>

1 files changed, 13 insertions, 5 deletions

diff --git a/examples/widgets/itemviews/simpletreemodel/main.cpp b/examples/widgets/itemviews/simpletreemodel/main.cpp
index ee8edb7c13..5800c595c8 100644
--- a/examples/widgets/itemviews/simpletreemodel/main.cpp
+++ b/examples/widgets/itemviews/simpletreemodel/main.cpp
@@ -5,20 +5,28 @@
 
 #include <QApplication>
 #include <QFile>
+#include <QScreen>
 #include <QTreeView>
 
+using namespace Qt::StringLiterals;
+
 int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
 
-    QFile file(":/default.txt");
-    file.open(QIODevice::ReadOnly);
-    TreeModel model(file.readAll());
+    QFile file(":/default.txt"_L1);
+    file.open(QIODevice::ReadOnly | QIODevice::Text);
+    TreeModel model(QString::fromUtf8(file.readAll()));
     file.close();
 
     QTreeView view;
     view.setModel(&model);
-    view.setWindowTitle(QObject::tr("Simple Tree Model"));
+    view.setWindowTitle(TreeModel::tr("Simple Tree Model"));
+    for (int c = 0; c < model.columnCount(); ++c)
+        view.resizeColumnToContents(c);
+    view.expandAll();
+    const auto screenSize = view.screen()->availableSize();
+    view.resize({screenSize.width() / 2, screenSize.height() * 2 / 3});
     view.show();
-    return app.exec();
+    return QCoreApplication::exec();
 }