implement Checkbox paintEvent

components/checkbox.cpp

@@ -1,10 +1,13 @@
 #include <QWidget>
 #include <QPainter>
+#include <QStylePainter>
+#include <QStyleOptionButton>
 #include "checkbox.h"
 
 Checkbox::Checkbox(QWidget *parent)
-    : QWidget(parent)
+    : QAbstractButton(parent)
 {
+    setFixedSize(200, 200);
 }
 
 Checkbox::~Checkbox()
@@ -13,19 +16,52 @@ Checkbox::~Checkbox()
 
 void Checkbox::mousePressEvent(QMouseEvent *event)
 {
-    QWidget::mousePressEvent(event);
+    QAbstractButton::mousePressEvent(event);
 }
 
 void Checkbox::mouseReleaseEvent(QMouseEvent *event)
 {
-    QWidget::mouseReleaseEvent(event);
+    QAbstractButton::mouseReleaseEvent(event);
 }
 
 void Checkbox::paintEvent(QPaintEvent *event)
 {
-    QPainter painter(this);
+    Q_UNUSED(event)
 
-    painter.drawRect(0, 0, 50, 50);
+    QStylePainter p(this);
+    QStyleOptionButton opt;
+    initStyleOption(&opt);
+    p.drawControl(QStyle::CE_CheckBox, opt);
 
-    QWidget::paintEvent(event);
+    p.drawRect(rect().adjusted(0, 0, -1, -1));        // tmp
+}
+
+void Checkbox::initStyleOption(QStyleOptionButton *option) const
+{
+    if (!option)
+        return;
+    //Q_D(const QCheckBox);
+    option->initFrom(this);
+    /*
+    if (d->down)
+        option->state |= QStyle::State_Sunken;
+    if (d->tristate && d->noChange)
+        option->state |= QStyle::State_NoChange;
+    else
+        option->state |= d->checked ? QStyle::State_On : QStyle::State_Off;
+    */
+    if (testAttribute(Qt::WA_Hover) && underMouse()) {
+        /*
+        if (d->hovering)
+            option->state |= QStyle::State_MouseOver;
+        else
+            option->state &= ~QStyle::State_MouseOver;
+            */
+    }
+    option->text = "Label label";
+    /*
+    option->text = d->text;
+    option->icon = d->icon;
+    option->iconSize = iconSize();
+    */
 }

components/checkbox.h

@@ -1,9 +1,11 @@
 #ifndef CHECKBOX_H
 #define CHECKBOX_H
 
-#include <QWidget>
+#include <QAbstractButton>
 
-class Checkbox : public QWidget
+class QStyleOptionButton;
+
+class Checkbox : public QAbstractButton
 {
     Q_OBJECT
 
@@ -15,6 +17,8 @@ protected:
     void mousePressEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
     void mouseReleaseEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
     void paintEvent(QPaintEvent *event) Q_DECL_OVERRIDE;
+
+    void initStyleOption(QStyleOptionButton *option) const;
 };
 
 #endif // CHECKBOX_H

main.cpp

@@ -6,8 +6,6 @@ int main(int argc, char *argv[])
 {
     QApplication a(argc, argv);
 
-    //a.setStyle(new Style);
-
     MainWindow w;
     w.show();