Cleanup StarDelegate example

Cleanup the StarDelegate example:
 - use QStyledItemDelegate instead QItemDelegate
 - use nullptr and other useful c++11 constructs
 - include the correct headers

Change-Id: If2f65fe7cbdcdd4571d10ffa98d36eeab7836bbb
Reviewed-by: Sze Howe Koh <szehowe.koh@gmail.com>
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
Reviewed-by: Luca Beldi <v.ronin@yahoo.it>

7 files changed, 33 insertions, 43 deletions

diff --git a/examples/widgets/itemviews/stardelegate/main.cpp b/examples/widgets/itemviews/stardelegate/main.cpp
index 51ca30c73a..452976bba0 100644
--- a/examples/widgets/itemviews/stardelegate/main.cpp
+++ b/examples/widgets/itemviews/stardelegate/main.cpp
@@ -101,10 +101,7 @@ int main(int argc, char *argv[])
     tableWidget.setEditTriggers(QAbstractItemView::DoubleClicked
                                 | QAbstractItemView::SelectedClicked);
     tableWidget.setSelectionBehavior(QAbstractItemView::SelectRows);
-
-    QStringList headerLabels;
-    headerLabels << "Title" << "Genre" << "Artist" << "Rating";
-    tableWidget.setHorizontalHeaderLabels(headerLabels);
+    tableWidget.setHorizontalHeaderLabels({"Title", "Genre", "Artist", "Rating"});
 
     populateTableWidget(&tableWidget);
 
diff --git a/examples/widgets/itemviews/stardelegate/stardelegate.cpp b/examples/widgets/itemviews/stardelegate/stardelegate.cpp
index da5902a160..41ae5a920f 100644
--- a/examples/widgets/itemviews/stardelegate/stardelegate.cpp
+++ b/examples/widgets/itemviews/stardelegate/stardelegate.cpp
@@ -65,7 +65,7 @@ void StarDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
             painter->fillRect(option.rect, option.palette.highlight());
 
         starRating.paint(painter, option.rect, option.palette,
-                         StarRating::ReadOnly);
+                         StarRating::EditMode::ReadOnly);
     } else {
         QStyledItemDelegate::paint(painter, option, index);
     }
@@ -79,9 +79,8 @@ QSize StarDelegate::sizeHint(const QStyleOptionViewItem &option,
     if (index.data().canConvert<StarRating>()) {
         StarRating starRating = qvariant_cast<StarRating>(index.data());
         return starRating.sizeHint();
-    } else {
-        return QStyledItemDelegate::sizeHint(option, index);
     }
+    return QStyledItemDelegate::sizeHint(option, index);
 }
 //! [1]
 
@@ -96,9 +95,8 @@ QWidget *StarDelegate::createEditor(QWidget *parent,
         connect(editor, &StarEditor::editingFinished,
                 this, &StarDelegate::commitAndCloseEditor);
         return editor;
-    } else {
-        return QStyledItemDelegate::createEditor(parent, option, index);
     }
+    return QStyledItemDelegate::createEditor(parent, option, index);
 }
 //! [2]
 
diff --git a/examples/widgets/itemviews/stardelegate/stardelegate.h b/examples/widgets/itemviews/stardelegate/stardelegate.h
index ffc65fbedd..1fc31f8ee8 100644
--- a/examples/widgets/itemviews/stardelegate/stardelegate.h
+++ b/examples/widgets/itemviews/stardelegate/stardelegate.h
@@ -57,9 +57,8 @@
 class StarDelegate : public QStyledItemDelegate
 {
     Q_OBJECT
-
 public:
-    StarDelegate(QWidget *parent = 0) : QStyledItemDelegate(parent) {}
+    using QStyledItemDelegate::QStyledItemDelegate;
 
     void paint(QPainter *painter, const QStyleOptionViewItem &option,
                const QModelIndex &index) const override;
diff --git a/examples/widgets/itemviews/stardelegate/stareditor.cpp b/examples/widgets/itemviews/stardelegate/stareditor.cpp
index 19a4b54d9e..43706eeae0 100644
--- a/examples/widgets/itemviews/stardelegate/stareditor.cpp
+++ b/examples/widgets/itemviews/stardelegate/stareditor.cpp
@@ -48,11 +48,11 @@
 **
 ****************************************************************************/
 
-#include <QtWidgets>
-
 #include "stareditor.h"
 #include "starrating.h"
 
+#include <QtWidgets>
+
 //! [0]
 StarEditor::StarEditor(QWidget *parent)
     : QWidget(parent)
@@ -71,35 +71,37 @@ QSize StarEditor::sizeHint() const
 void StarEditor::paintEvent(QPaintEvent *)
 {
     QPainter painter(this);
-    myStarRating.paint(&painter, rect(), this->palette(),
-                       StarRating::Editable);
+    myStarRating.paint(&painter, rect(), palette(),
+                       StarRating::EditMode::Editable);
 }
 //! [1]
 
 //! [2]
 void StarEditor::mouseMoveEvent(QMouseEvent *event)
 {
-    int star = starAtPosition(event->x());
+    const int star = starAtPosition(event->x());
 
     if (star != myStarRating.starCount() && star != -1) {
         myStarRating.setStarCount(star);
         update();
     }
+    QWidget::mouseMoveEvent(event);
 }
 //! [2]
 
 //! [3]
-void StarEditor::mouseReleaseEvent(QMouseEvent * /* event */)
+void StarEditor::mouseReleaseEvent(QMouseEvent *event)
 {
     emit editingFinished();
+    QWidget::mouseReleaseEvent(event);
 }
 //! [3]
 
 //! [4]
-int StarEditor::starAtPosition(int x)
+int StarEditor::starAtPosition(int x) const
 {
-    int star = (x / (myStarRating.sizeHint().width()
-                     / myStarRating.maxStarCount())) + 1;
+    const int star = (x / (myStarRating.sizeHint().width()
+                           / myStarRating.maxStarCount())) + 1;
     if (star <= 0 || star > myStarRating.maxStarCount())
         return -1;
 
diff --git a/examples/widgets/itemviews/stardelegate/stareditor.h b/examples/widgets/itemviews/stardelegate/stareditor.h
index 4a4c3a4954..8b1bf2efed 100644
--- a/examples/widgets/itemviews/stardelegate/stareditor.h
+++ b/examples/widgets/itemviews/stardelegate/stareditor.h
@@ -59,9 +59,8 @@
 class StarEditor : public QWidget
 {
     Q_OBJECT
-
 public:
-    StarEditor(QWidget *parent = 0);
+    StarEditor(QWidget *parent = nullptr);
 
     QSize sizeHint() const override;
     void setStarRating(const StarRating &starRating) {
@@ -78,7 +77,7 @@ protected:
     void mouseReleaseEvent(QMouseEvent *event) override;
 
 private:
-    int starAtPosition(int x);
+    int starAtPosition(int x) const;
 
     StarRating myStarRating;
 };
diff --git a/examples/widgets/itemviews/stardelegate/starrating.cpp b/examples/widgets/itemviews/stardelegate/starrating.cpp
index 845e474de9..15e14965e3 100644
--- a/examples/widgets/itemviews/stardelegate/starrating.cpp
+++ b/examples/widgets/itemviews/stardelegate/starrating.cpp
@@ -48,19 +48,18 @@
 **
 ****************************************************************************/
 
+#include "starrating.h"
+
 #include <QtWidgets>
 #include <cmath>
 
-#include "starrating.h"
-
-const int PaintingScaleFactor = 20;
+constexpr int PaintingScaleFactor = 20;
 
 //! [0]
 StarRating::StarRating(int starCount, int maxStarCount)
+    : myStarCount(starCount),
+      myMaxStarCount(maxStarCount)
 {
-    myStarCount = starCount;
-    myMaxStarCount = maxStarCount;
-
     starPolygon << QPointF(1.0, 0.5);
     for (int i = 1; i < 5; ++i)
         starPolygon << QPointF(0.5 + 0.5 * std::cos(0.8 * i * 3.14),
@@ -87,23 +86,19 @@ void StarRating::paint(QPainter *painter, const QRect &rect,
 
     painter->setRenderHint(QPainter::Antialiasing, true);
     painter->setPen(Qt::NoPen);
+    painter->setBrush(mode == EditMode::Editable ?
+                          palette.highlight() :
+                          palette.foreground());
 
-    if (mode == Editable) {
-        painter->setBrush(palette.highlight());
-    } else {
-        painter->setBrush(palette.foreground());
-    }
-
-    int yOffset = (rect.height() - PaintingScaleFactor) / 2;
+    const int yOffset = (rect.height() - PaintingScaleFactor) / 2;
     painter->translate(rect.x(), rect.y() + yOffset);
     painter->scale(PaintingScaleFactor, PaintingScaleFactor);
 
     for (int i = 0; i < myMaxStarCount; ++i) {
-        if (i < myStarCount) {
+        if (i < myStarCount)
             painter->drawPolygon(starPolygon, Qt::WindingFill);
-        } else if (mode == Editable) {
+        else if (mode == EditMode::Editable)
             painter->drawPolygon(diamondPolygon, Qt::WindingFill);
-        }
         painter->translate(1.0, 0.0);
     }
 
diff --git a/examples/widgets/itemviews/stardelegate/starrating.h b/examples/widgets/itemviews/stardelegate/starrating.h
index fa77311914..fc3028db58 100644
--- a/examples/widgets/itemviews/stardelegate/starrating.h
+++ b/examples/widgets/itemviews/stardelegate/starrating.h
@@ -51,15 +51,15 @@
 #ifndef STARRATING_H
 #define STARRATING_H
 
-#include <QMetaType>
-#include <QPointF>
-#include <QVector>
+#include <QPainter>
+#include <QPolygonF>
+#include <QSize>
 
 //! [0]
 class StarRating
 {
 public:
-    enum EditMode { Editable, ReadOnly };
+    enum class EditMode { Editable, ReadOnly };
 
     explicit StarRating(int starCount = 1, int maxStarCount = 5);