animate drop shadow on RaisedButton

components/raisedbutton.cpp

@@ -1,3 +1,7 @@
+#include <QDebug>
+#include <QPropertyAnimation>
+#include <QStylePainter>
+#include <QPaintEvent>
 #include "raisedbutton.h"
 #include "lib/customshadoweffect.h"
 
@@ -7,8 +11,55 @@ RaisedButton::RaisedButton(QWidget *parent)
     CustomShadowEffect *effect = new CustomShadowEffect;
     setGraphicsEffect(effect);
     setAutoFillBackground(true);
+
+    QPropertyAnimation *animation;
+
+    animation = new QPropertyAnimation;
+    animation->setTargetObject(effect);
+    animation->setPropertyName("distance");
+    animation->setStartValue(2);
+    animation->setEndValue(6);
+    animation->setDuration(100);
+    _group.addAnimation(animation);
+
+    animation = new QPropertyAnimation;
+    animation->setTargetObject(effect);
+    animation->setPropertyName("blurRadius");
+    animation->setStartValue(10);
+    animation->setEndValue(20);
+    animation->setDuration(100);
+    _group.addAnimation(animation);
+
+    connect(animation, SIGNAL(valueChanged(QVariant)), this, SLOT(update()));
 }
 
 RaisedButton::~RaisedButton()
 {
 }
+
+void RaisedButton::mousePressEvent(QMouseEvent *event)
+{
+    Q_UNUSED(event)
+
+    _group.setDirection(QAbstractAnimation::Forward);
+    _group.start();
+
+    FlatButton::mousePressEvent(event);
+}
+
+void RaisedButton::mouseReleaseEvent(QMouseEvent *event)
+{
+    Q_UNUSED(event)
+
+    _group.setDirection(QAbstractAnimation::Backward);
+    _group.start();
+
+    FlatButton::mouseReleaseEvent(event);
+}
+
+void RaisedButton::paintEvent(QPaintEvent *event)
+{
+    QStylePainter painter(this);
+
+    painter.drawControl(QStyle::CE_PushButton, getStyleOption());
+}

components/raisedbutton.h

@@ -1,8 +1,11 @@
 #ifndef RAISEDBUTTON_H
 #define RAISEDBUTTON_H
 
+#include <QParallelAnimationGroup>
 #include "flatbutton.h"
 
+class QPropertyAnimation;
+
 class RaisedButton : public FlatButton
 {
     Q_OBJECT
@@ -10,6 +13,14 @@ class RaisedButton : public FlatButton
 public:
     explicit RaisedButton(QWidget *parent = 0);
     ~RaisedButton();
+
+protected:
+    void mousePressEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
+    void mouseReleaseEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
+    void paintEvent(QPaintEvent *event) Q_DECL_OVERRIDE;
+
+private:
+    QParallelAnimationGroup _group;
 };
 
 #endif // RAISEDBUTTON_H