Cleanup QtWidgets (widgets) examples

Cleanup QtWidgets widgets 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

Change-Id: Ib56bb507eb2ef885f1ddc664050d3c7af92adb70
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

3 files changed, 14 insertions, 12 deletions

diff --git a/examples/widgets/widgets/codeeditor/codeeditor.cpp b/examples/widgets/widgets/codeeditor/codeeditor.cpp
index 8e29860669..e93a0251e5 100644
--- a/examples/widgets/widgets/codeeditor/codeeditor.cpp
+++ b/examples/widgets/widgets/codeeditor/codeeditor.cpp
@@ -48,10 +48,11 @@
 **
 ****************************************************************************/
 
-#include <QtWidgets>
-
 #include "codeeditor.h"
 
+#include <QPainter>
+#include <QTextBlock>
+
 //![constructor]
 
 CodeEditor::CodeEditor(QWidget *parent) : QPlainTextEdit(parent)
@@ -157,8 +158,8 @@ void CodeEditor::lineNumberAreaPaintEvent(QPaintEvent *event)
 //![extraAreaPaintEvent_1]
     QTextBlock block = firstVisibleBlock();
     int blockNumber = block.blockNumber();
-    int top = (int) blockBoundingGeometry(block).translated(contentOffset()).top();
-    int bottom = top + (int) blockBoundingRect(block).height();
+    int top = qRound(blockBoundingGeometry(block).translated(contentOffset()).top());
+    int bottom = top + qRound(blockBoundingRect(block).height());
 //![extraAreaPaintEvent_1]
 
 //![extraAreaPaintEvent_2]
@@ -172,7 +173,7 @@ void CodeEditor::lineNumberAreaPaintEvent(QPaintEvent *event)
 
         block = block.next();
         top = bottom;
-        bottom = top + (int) blockBoundingRect(block).height();
+        bottom = top + qRound(blockBoundingRect(block).height());
         ++blockNumber;
     }
 }
diff --git a/examples/widgets/widgets/codeeditor/codeeditor.h b/examples/widgets/widgets/codeeditor/codeeditor.h
index 5a48abafc4..283a4e0bdf 100644
--- a/examples/widgets/widgets/codeeditor/codeeditor.h
+++ b/examples/widgets/widgets/codeeditor/codeeditor.h
@@ -80,7 +80,7 @@ protected:
 private slots:
     void updateLineNumberAreaWidth(int newBlockCount);
     void highlightCurrentLine();
-    void updateLineNumberArea(const QRect &, int);
+    void updateLineNumberArea(const QRect &rect, int dy);
 
 private:
     QWidget *lineNumberArea;
@@ -92,16 +92,17 @@ private:
 class LineNumberArea : public QWidget
 {
 public:
-    LineNumberArea(CodeEditor *editor) : QWidget(editor) {
-        codeEditor = editor;
-    }
+    LineNumberArea(CodeEditor *editor) : QWidget(editor), codeEditor(editor)
+    {}
 
-    QSize sizeHint() const override {
+    QSize sizeHint() const override
+    {
         return QSize(codeEditor->lineNumberAreaWidth(), 0);
     }
 
 protected:
-    void paintEvent(QPaintEvent *event) override {
+    void paintEvent(QPaintEvent *event) override
+    {
         codeEditor->lineNumberAreaPaintEvent(event);
     }
 
diff --git a/examples/widgets/widgets/codeeditor/main.cpp b/examples/widgets/widgets/codeeditor/main.cpp
index e17acb87cd..72d186553a 100644
--- a/examples/widgets/widgets/codeeditor/main.cpp
+++ b/examples/widgets/widgets/codeeditor/main.cpp
@@ -48,7 +48,7 @@
 **
 ****************************************************************************/
 
-#include <QtWidgets>
+#include <QApplication>
 
 #include "codeeditor.h"