Qt Designer: Fix the documentation code snippets

Fix the .pro files to compile, fix the #includes and update the code.

Task-number: QTBUG-110447
Change-Id: I5eddd42ba4b6fc1697ca96303c943e385b680856
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
(cherry picked from commit 441a54653804b6f70afd6818169f6517f61232f6)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

13 files changed, 26 insertions, 23 deletions

diff --git a/src/designer/src/designer/doc/snippets/autoconnection/autoconnection.pro b/src/designer/src/designer/doc/snippets/autoconnection/autoconnection.pro
index fba94debf..6937e8e54 100644
--- a/src/designer/src/designer/doc/snippets/autoconnection/autoconnection.pro
+++ b/src/designer/src/designer/doc/snippets/autoconnection/autoconnection.pro
@@ -1,4 +1,5 @@
 TEMPLATE    = app
+QT          += widgets
 FORMS       = imagedialog.ui
 HEADERS     = imagedialog.h
 SOURCES     = imagedialog.cpp \
diff --git a/src/designer/src/designer/doc/snippets/autoconnection/imagedialog.cpp b/src/designer/src/designer/doc/snippets/autoconnection/imagedialog.cpp
index 8c3012b43..8776e38cd 100644
--- a/src/designer/src/designer/doc/snippets/autoconnection/imagedialog.cpp
+++ b/src/designer/src/designer/doc/snippets/autoconnection/imagedialog.cpp
@@ -1,7 +1,7 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
 
-#include <QtGui>
+#include <QMessageBox>
 
 #include "imagedialog.h"
 
@@ -19,14 +19,15 @@ ImageDialog::ImageDialog(QWidget *parent)
     colorDepthCombo->addItem(tr("65536 colors (16 bits per pixel)"));
     colorDepthCombo->addItem(tr("16 million colors (24 bits per pixel)"));
 
-    connect(cancelButton, SIGNAL(clicked()), this, SLOT(reject()));
+    connect(cancelButton, &QAbstractButton::clicked, this, &QDialog::reject);
 }
 
 void ImageDialog::on_okButton_clicked()
 {
-    if (nameLineEdit->text().isEmpty())
-        (void) QMessageBox::information(this, tr("No Image Name"),
+    if (nameLineEdit->text().isEmpty()) {
+        QMessageBox::information(this, tr("No Image Name"),
             tr("Please supply a name for the image."), QMessageBox::Cancel);
-    else
+    } else {
         accept();
+    }
 }
diff --git a/src/designer/src/designer/doc/snippets/autoconnection/imagedialog.h b/src/designer/src/designer/doc/snippets/autoconnection/imagedialog.h
index ca1afb77a..64d6b4e88 100644
--- a/src/designer/src/designer/doc/snippets/autoconnection/imagedialog.h
+++ b/src/designer/src/designer/doc/snippets/autoconnection/imagedialog.h
@@ -12,7 +12,7 @@ class ImageDialog : public QDialog, private Ui::ImageDialog
     Q_OBJECT
 
 public:
-    ImageDialog(QWidget *parent = 0);
+    explicit ImageDialog(QWidget *parent = nullptr);
 
 private slots:
     void on_okButton_clicked();
diff --git a/src/designer/src/designer/doc/snippets/imagedialog/imagedialog.pro b/src/designer/src/designer/doc/snippets/imagedialog/imagedialog.pro
index 164a7b2cb..c0afe036d 100644
--- a/src/designer/src/designer/doc/snippets/imagedialog/imagedialog.pro
+++ b/src/designer/src/designer/doc/snippets/imagedialog/imagedialog.pro
@@ -1,3 +1,4 @@
 TEMPLATE    = app
+QT          += widgets
 FORMS       = imagedialog.ui
 SOURCES     = main.cpp
diff --git a/src/designer/src/designer/doc/snippets/multipleinheritance/imagedialog.cpp b/src/designer/src/designer/doc/snippets/multipleinheritance/imagedialog.cpp
index d9f65e0d5..1c34df2bb 100644
--- a/src/designer/src/designer/doc/snippets/multipleinheritance/imagedialog.cpp
+++ b/src/designer/src/designer/doc/snippets/multipleinheritance/imagedialog.cpp
@@ -1,8 +1,6 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
 
-#include <QtGui>
-
 #include "imagedialog.h"
 
 ImageDialog::ImageDialog(QWidget *parent)
@@ -17,6 +15,6 @@ ImageDialog::ImageDialog(QWidget *parent)
     colorDepthCombo->addItem(tr("65536 colors (16 bits per pixel)"));
     colorDepthCombo->addItem(tr("16 million colors (24 bits per pixel)"));
 
-    connect(okButton, SIGNAL(clicked()), this, SLOT(accept()));
-    connect(cancelButton, SIGNAL(clicked()), this, SLOT(reject()));
+    connect(okButton, &QAbstractButton::clicked, this, &QDialog::accept);
+    connect(cancelButton, &QAbstractButton::clicked, this, &QDialog::reject);
 }
diff --git a/src/designer/src/designer/doc/snippets/multipleinheritance/imagedialog.h b/src/designer/src/designer/doc/snippets/multipleinheritance/imagedialog.h
index 67fc4d330..f6bc3b62c 100644
--- a/src/designer/src/designer/doc/snippets/multipleinheritance/imagedialog.h
+++ b/src/designer/src/designer/doc/snippets/multipleinheritance/imagedialog.h
@@ -11,7 +11,7 @@ class ImageDialog : public QDialog, private Ui::ImageDialog
     Q_OBJECT
 
 public:
-    ImageDialog(QWidget *parent = 0);
+    explicit ImageDialog(QWidget *parent = nullptr);
 };
 
 #endif
diff --git a/src/designer/src/designer/doc/snippets/multipleinheritance/multipleinheritance.pro b/src/designer/src/designer/doc/snippets/multipleinheritance/multipleinheritance.pro
index fba94debf..6937e8e54 100644
--- a/src/designer/src/designer/doc/snippets/multipleinheritance/multipleinheritance.pro
+++ b/src/designer/src/designer/doc/snippets/multipleinheritance/multipleinheritance.pro
@@ -1,4 +1,5 @@
 TEMPLATE    = app
+QT          += widgets
 FORMS       = imagedialog.ui
 HEADERS     = imagedialog.h
 SOURCES     = imagedialog.cpp \
diff --git a/src/designer/src/designer/doc/snippets/noautoconnection/imagedialog.cpp b/src/designer/src/designer/doc/snippets/noautoconnection/imagedialog.cpp
index d5cbafbe8..e29c41095 100644
--- a/src/designer/src/designer/doc/snippets/noautoconnection/imagedialog.cpp
+++ b/src/designer/src/designer/doc/snippets/noautoconnection/imagedialog.cpp
@@ -1,7 +1,7 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
 
-#include <QtGui>
+#include <QMessageBox>
 
 #include "imagedialog.h"
 
@@ -21,19 +21,20 @@ ImageDialog::ImageDialog(QWidget *parent)
     colorDepthCombo->addItem(tr("65536 colors (16 bits per pixel)"));
     colorDepthCombo->addItem(tr("16 million colors (24 bits per pixel)"));
 
-    connect(cancelButton, SIGNAL(clicked()), this, SLOT(reject()));
+    connect(cancelButton, &QAbstractButton::clicked, this, &QDialog::reject);
 //! [1]
-    connect(okButton, SIGNAL(clicked()), this, SLOT(checkValues()));
+    connect(okButton, &QAbstractButton::clicked, this, &ImageDialog::checkValues);
 }
 //! [1]
 
 //! [2]
 void ImageDialog::checkValues()
 {
-    if (nameLineEdit->text().isEmpty())
-        (void) QMessageBox::information(this, tr("No Image Name"),
+    if (nameLineEdit->text().isEmpty()) {
+        QMessageBox::information(this, tr("No Image Name"),
             tr("Please supply a name for the image."), QMessageBox::Cancel);
-    else
+    } else {
         accept();
+    }
 }
 //! [2]
diff --git a/src/designer/src/designer/doc/snippets/noautoconnection/imagedialog.h b/src/designer/src/designer/doc/snippets/noautoconnection/imagedialog.h
index f78d3f5f6..611b90119 100644
--- a/src/designer/src/designer/doc/snippets/noautoconnection/imagedialog.h
+++ b/src/designer/src/designer/doc/snippets/noautoconnection/imagedialog.h
@@ -12,7 +12,7 @@ class ImageDialog : public QDialog, private Ui::ImageDialog
     Q_OBJECT
 
 public:
-    ImageDialog(QWidget *parent = 0);
+    explicit ImageDialog(QWidget *parent = nullptr);
 
 private slots:
     void checkValues();
diff --git a/src/designer/src/designer/doc/snippets/noautoconnection/noautoconnection.pro b/src/designer/src/designer/doc/snippets/noautoconnection/noautoconnection.pro
index fba94debf..6937e8e54 100644
--- a/src/designer/src/designer/doc/snippets/noautoconnection/noautoconnection.pro
+++ b/src/designer/src/designer/doc/snippets/noautoconnection/noautoconnection.pro
@@ -1,4 +1,5 @@
 TEMPLATE    = app
+QT          += widgets
 FORMS       = imagedialog.ui
 HEADERS     = imagedialog.h
 SOURCES     = imagedialog.cpp \
diff --git a/src/designer/src/designer/doc/snippets/singleinheritance/imagedialog.cpp b/src/designer/src/designer/doc/snippets/singleinheritance/imagedialog.cpp
index 77bc97a01..4cf642d17 100644
--- a/src/designer/src/designer/doc/snippets/singleinheritance/imagedialog.cpp
+++ b/src/designer/src/designer/doc/snippets/singleinheritance/imagedialog.cpp
@@ -1,8 +1,6 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
 
-#include <QtGui>
-
 #include "imagedialog.h"
 
 ImageDialog::ImageDialog(QWidget *parent)
@@ -17,6 +15,6 @@ ImageDialog::ImageDialog(QWidget *parent)
     ui.colorDepthCombo->addItem(tr("65536 colors (16 bits per pixel)"));
     ui.colorDepthCombo->addItem(tr("16 million colors (24 bits per pixel)"));
 
-    connect(ui.okButton, SIGNAL(clicked()), this, SLOT(accept()));
-    connect(ui.cancelButton, SIGNAL(clicked()), this, SLOT(reject()));
+    connect(ui.okButton, &QAbstractButton::clicked, this, &QDialog::accept);
+    connect(ui.cancelButton, &QAbstractButton::clicked, this, &QDialog::reject);
 }
diff --git a/src/designer/src/designer/doc/snippets/singleinheritance/imagedialog.h b/src/designer/src/designer/doc/snippets/singleinheritance/imagedialog.h
index aa1e11334..6fd2df0e0 100644
--- a/src/designer/src/designer/doc/snippets/singleinheritance/imagedialog.h
+++ b/src/designer/src/designer/doc/snippets/singleinheritance/imagedialog.h
@@ -11,7 +11,7 @@ class ImageDialog : public QDialog
     Q_OBJECT
 
 public:
-    ImageDialog(QWidget *parent = 0);
+    explicit ImageDialog(QWidget *parent = nullptr);
 
 private:
     Ui::ImageDialog ui;
diff --git a/src/designer/src/designer/doc/snippets/singleinheritance/singleinheritance.pro b/src/designer/src/designer/doc/snippets/singleinheritance/singleinheritance.pro
index fba94debf..6937e8e54 100644
--- a/src/designer/src/designer/doc/snippets/singleinheritance/singleinheritance.pro
+++ b/src/designer/src/designer/doc/snippets/singleinheritance/singleinheritance.pro
@@ -1,4 +1,5 @@
 TEMPLATE    = app
+QT          += widgets
 FORMS       = imagedialog.ui
 HEADERS     = imagedialog.h
 SOURCES     = imagedialog.cpp \