From c49bf9fe27e0632aa8da393ff007cf4577a1c9cd Mon Sep 17 00:00:00 2001
From: Friedemann Kleint <Friedemann.Kleint@qt.io>
Date: Tue, 9 Aug 2022 10:44:49 +0200
Subject: Documentation: Fix "Using Model Indexes" in Model View Programming
 guide to work

The code introduced by 54d5ca0c2766e915c960fa437cee6c20a324c1a7
did not work since the variables parentIndex/numRows
were local to the lambda and the outer code would not wait.
Move the widgets population into the lambda to fix this.

Modernize the remaining code a bit.

Pick-to: 6.4 6.3 6.2
Change-Id: I2a09878987df9edb9ff04f0ac4ad82af1a8b52c8
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
---
 src/widgets/doc/snippets/simplemodel-use/main.cpp | 56 +++++++++++++----------
 1 file changed, 31 insertions(+), 25 deletions(-)

(limited to 'src/widgets/doc/snippets/simplemodel-use/main.cpp')

diff --git a/src/widgets/doc/snippets/simplemodel-use/main.cpp b/src/widgets/doc/snippets/simplemodel-use/main.cpp
index 62739b1f991..5a3d6ecce00 100644
--- a/src/widgets/doc/snippets/simplemodel-use/main.cpp
+++ b/src/widgets/doc/snippets/simplemodel-use/main.cpp
@@ -7,55 +7,61 @@
   A simple example of how to access items from an existing model.
 */
 
-#include <QtGui>
+#include <QApplication>
+#include <QLabel>
+#include <QVBoxLayout>
+#include <QWidget>
+
+#include <QFileSystemModel>
+#include <QPalette>
+
+#include <QDir>
+#include <QModelIndex>
 
 /*!
     Create a default directory model and, using the index-based interface to
     the model and some QLabel widgets, populate the window's layout with the
     names of objects in the directory.
-
-    Note that we only want to read the filenames in the highest level of the
-    directory, so we supply a default (invalid) QModelIndex to the model in
-    order to indicate that we want top-level items.
 */
 
 int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
 
-    QWidget *window = new QWidget;
-    QVBoxLayout *layout = new QVBoxLayout(window);
-    QLabel *title = new QLabel("Some items from the directory model", window);
+    QWidget window;
+    auto *layout = new QVBoxLayout(&window);
+    auto *title = new QLabel("Some items from the directory model", &window);
     title->setBackgroundRole(QPalette::Base);
     title->setMargin(8);
     layout->addWidget(title);
 
 //! [0]
-    QFileSystemModel *model = new QFileSystemModel;
-    connect(model, &QFileSystemModel::directoryLoaded, [model](const QString &directory) {
-        QModelIndex parentIndex = model->index(directory);
-        int numRows = model->rowCount(parentIndex);
-    });
-    model->setRootPath(QDir::currentPath);
-//! [0]
+    auto *model = new QFileSystemModel;
 
+    auto onDirectoryLoaded = [model, layout, &window](const QString &directory) {
+        QModelIndex parentIndex = model->index(directory);
+        const int numRows = model->rowCount(parentIndex);
 //! [1]
-    for (int row = 0; row < numRows; ++row) {
-        QModelIndex index = model->index(row, 0, parentIndex);
+        for (int row = 0; row < numRows; ++row) {
+            QModelIndex index = model->index(row, 0, parentIndex);
 //! [1]
 
 //! [2]
-        QString text = model->data(index, Qt::DisplayRole).toString();
-        // Display the text in a widget.
+            QString text = model->data(index, Qt::DisplayRole).toString();
 //! [2]
-
-        QLabel *label = new QLabel(text, window);
-        layout->addWidget(label);
+            // Display the text in a widget.
+            auto *label = new QLabel(text, &window);
+            layout->addWidget(label);
 //! [3]
-    }
+        }
 //! [3]
+    };
+
+    QObject::connect(model, &QFileSystemModel::directoryLoaded, onDirectoryLoaded);
+    model->setRootPath(QDir::currentPath());
+//! [0]
 
-    window->setWindowTitle("A simple model example");
-    window->show();
+    window.setWindowTitle("A simple model example");
+    window.show();
     return app.exec();
 }
-- 
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