Cleanup QtWidgets (tools) examples

Cleanup QtWidgets tools examples:
 - use member-init (clang-tidy)
 - fix includes/don't include QtWidgets globally
 - include own header first
 - use nullptr (clang-tidy)
 - avoid c-style casts
 - use QVector instead QList
 - use QItemDelegate instead QStyledItemDelegate

Change-Id: Ibe9440cdf711e5cc2138c054864edebe1fc95731
Reviewed-by: Paul Wicking <paul.wicking@qt.io>

4 files changed, 23 insertions, 19 deletions

diff --git a/examples/widgets/tools/customcompleter/mainwindow.cpp b/examples/widgets/tools/customcompleter/mainwindow.cpp
index 39f5f39617..b8072b505c 100644
--- a/examples/widgets/tools/customcompleter/mainwindow.cpp
+++ b/examples/widgets/tools/customcompleter/mainwindow.cpp
@@ -48,13 +48,20 @@
 **
 ****************************************************************************/
 
-#include <QtWidgets>
 #include "mainwindow.h"
 #include "textedit.h"
 
+#include <QAction>
+#include <QApplication>
+#include <QCompleter>
+#include <QFile>
+#include <QMenuBar>
+#include <QMessageBox>
+#include <QStringListModel>
+
 //! [0]
 MainWindow::MainWindow(QWidget *parent)
-    : QMainWindow(parent), completer(0)
+    : QMainWindow(parent)
 {
     createMenu();
 
@@ -83,10 +90,10 @@ void MainWindow::createMenu()
     connect(aboutAct, &QAction::triggered, this, &MainWindow::about);
     connect(aboutQtAct, &QAction::triggered, qApp, &QApplication::aboutQt);
 
-    QMenu* fileMenu = menuBar()->addMenu(tr("File"));
+    QMenu *fileMenu = menuBar()->addMenu(tr("File"));
     fileMenu->addAction(exitAction);
 
-    QMenu* helpMenu = menuBar()->addMenu(tr("About"));
+    QMenu *helpMenu = menuBar()->addMenu(tr("About"));
     helpMenu->addAction(aboutAct);
     helpMenu->addAction(aboutQtAct);
 }
@@ -107,7 +114,7 @@ QAbstractItemModel *MainWindow::modelFromFile(const QString& fileName)
     while (!file.atEnd()) {
         QByteArray line = file.readLine();
         if (!line.isEmpty())
-            words << line.trimmed();
+            words << QString::fromUtf8(line.trimmed());
     }
 
 #ifndef QT_NO_CURSOR
diff --git a/examples/widgets/tools/customcompleter/mainwindow.h b/examples/widgets/tools/customcompleter/mainwindow.h
index 436377cce7..cde553e291 100644
--- a/examples/widgets/tools/customcompleter/mainwindow.h
+++ b/examples/widgets/tools/customcompleter/mainwindow.h
@@ -55,11 +55,7 @@
 
 QT_BEGIN_NAMESPACE
 class QAbstractItemModel;
-class QComboBox;
 class QCompleter;
-class QLabel;
-class QLineEdit;
-class QProgressBar;
 QT_END_NAMESPACE
 class TextEdit;
 
@@ -69,7 +65,7 @@ class MainWindow : public QMainWindow
     Q_OBJECT
 
 public:
-    MainWindow(QWidget *parent = 0);
+    MainWindow(QWidget *parent = nullptr);
 
 private slots:
     void about();
@@ -78,7 +74,7 @@ private:
     void createMenu();
     QAbstractItemModel *modelFromFile(const QString& fileName);
 
-    QCompleter *completer;
+    QCompleter *completer = nullptr;
     TextEdit *completingTextEdit;
 };
 //! [0]
diff --git a/examples/widgets/tools/customcompleter/textedit.cpp b/examples/widgets/tools/customcompleter/textedit.cpp
index d42f7b38bb..0d536fea3c 100644
--- a/examples/widgets/tools/customcompleter/textedit.cpp
+++ b/examples/widgets/tools/customcompleter/textedit.cpp
@@ -60,7 +60,7 @@
 
 //! [0]
 TextEdit::TextEdit(QWidget *parent)
-: QTextEdit(parent), c(0)
+    : QTextEdit(parent)
 {
     setPlainText(tr("This TextEdit provides autocompletions for words that have more than"
                     " 3 characters. You can trigger autocompletion using ") +
@@ -78,7 +78,7 @@ TextEdit::~TextEdit()
 void TextEdit::setCompleter(QCompleter *completer)
 {
     if (c)
-        QObject::disconnect(c, 0, this, 0);
+        c->disconnect(this);
 
     c = completer;
 
@@ -101,7 +101,7 @@ QCompleter *TextEdit::completer() const
 //! [3]
 
 //! [4]
-void TextEdit::insertCompletion(const QString& completion)
+void TextEdit::insertCompletion(const QString &completion)
 {
     if (c->widget() != this)
         return;
@@ -150,18 +150,19 @@ void TextEdit::keyPressEvent(QKeyEvent *e)
        }
     }
 
-    bool isShortcut = ((e->modifiers() & Qt::ControlModifier) && e->key() == Qt::Key_E); // CTRL+E
+    const bool isShortcut = (e->modifiers().testFlag(Qt::ControlModifier) && e->key() == Qt::Key_E); // CTRL+E
     if (!c || !isShortcut) // do not process the shortcut when we have a completer
         QTextEdit::keyPressEvent(e);
 //! [7]
 
 //! [8]
-    const bool ctrlOrShift = e->modifiers() & (Qt::ControlModifier | Qt::ShiftModifier);
+    const bool ctrlOrShift = e->modifiers().testFlag(Qt::ControlModifier) ||
+                             e->modifiers().testFlag(Qt::ShiftModifier);
     if (!c || (ctrlOrShift && e->text().isEmpty()))
         return;
 
     static QString eow("~!@#$%^&*()_+{}|:\"<>?,./;'[]\\-="); // end of word
-    bool hasModifier = (e->modifiers() != Qt::NoModifier) && !ctrlOrShift;
+    const bool hasModifier = (e->modifiers() != Qt::NoModifier) && !ctrlOrShift;
     QString completionPrefix = textUnderCursor();
 
     if (!isShortcut && (hasModifier || e->text().isEmpty()|| completionPrefix.length() < 3
diff --git a/examples/widgets/tools/customcompleter/textedit.h b/examples/widgets/tools/customcompleter/textedit.h
index d0636ab670..788cb74ae1 100644
--- a/examples/widgets/tools/customcompleter/textedit.h
+++ b/examples/widgets/tools/customcompleter/textedit.h
@@ -63,7 +63,7 @@ class TextEdit : public QTextEdit
     Q_OBJECT
 
 public:
-    TextEdit(QWidget *parent = 0);
+    TextEdit(QWidget *parent = nullptr);
     ~TextEdit();
 
     void setCompleter(QCompleter *c);
@@ -80,7 +80,7 @@ private:
     QString textUnderCursor() const;
 
 private:
-    QCompleter *c;
+    QCompleter *c = nullptr;
 };
 //! [0]