create animation on TextField

components/textfield.cpp

@@ -1,18 +1,55 @@
+#include <QPropertyAnimation>
 #include <QWidget>
 #include <QPainter>
+#include <QDebug>
 #include "textfield.h"
 #include "style.h"
 
 TextField::TextField(QWidget *parent)
-    : QLineEdit(parent)
+    : QLineEdit(parent),
+      _animation(new QPropertyAnimation(this)),
+      _progress(1)
 {
     setStyle(&Style::instance());
+
+    _animation->setPropertyName("progress");
+    _animation->setTargetObject(this);
+    _animation->setEasingCurve(QEasingCurve::InCubic);
+    _animation->setDuration(350);
+    _animation->setStartValue(1);
+    _animation->setEndValue(0);
 }
 
 TextField::~TextField()
 {
 }
 
+void TextField::setProgress(qreal progress)
+{
+    if (_progress == progress)
+        return;
+    _progress = progress;
+
+    emit progressChanged(progress);
+    update();
+}
+
+void TextField::focusInEvent(QFocusEvent *event)
+{
+    _animation->setDirection(QAbstractAnimation::Forward);
+    _animation->start();
+
+    QLineEdit::focusInEvent(event);
+}
+
+void TextField::focusOutEvent(QFocusEvent *event)
+{
+    _animation->setDirection(QAbstractAnimation::Backward);
+    _animation->start();
+
+    QLineEdit::focusOutEvent(event);
+}
+
 void TextField::mousePressEvent(QMouseEvent *event)
 {
     QLineEdit::mousePressEvent(event);
@@ -28,5 +65,17 @@ void TextField::paintEvent(QPaintEvent *event)
     QLineEdit::paintEvent(event);
 
     QPainter painter(this);
-    painter.drawRect(0, 0, 50, 50);
+
+    QBrush brush;
+    brush.setStyle(Qt::SolidPattern);
+
+    if (!qFuzzyCompare(1, _progress)) {
+
+        painter.setPen(Qt::NoPen);
+        painter.setBrush(brush);
+
+        int w = _progress*static_cast<qreal>(width()/2);
+
+        painter.drawRect(w, height()-2, width()-w*2, 2);
+    }
 }

components/textfield.h

@@ -3,18 +3,34 @@
 
 #include <QLineEdit>
 
+class QPropertyAnimation;
+
 class TextField : public QLineEdit
 {
     Q_OBJECT
 
+    Q_PROPERTY(qreal progress WRITE setProgress READ progress NOTIFY progressChanged)
+
 public:
     explicit TextField(QWidget *parent = 0);
     ~TextField();
 
+    void setProgress(qreal progress);
+    inline qreal progress() const { return _progress; }
+
+signals:
+    void progressChanged(qreal);
+
 protected:
+    void focusInEvent(QFocusEvent *event) Q_DECL_OVERRIDE;
+    void focusOutEvent(QFocusEvent *event) Q_DECL_OVERRIDE;
     void mousePressEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
     void mouseReleaseEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
     void paintEvent(QPaintEvent *event) Q_DECL_OVERRIDE;
+
+private:
+    QPropertyAnimation *const _animation;
+    qreal                     _progress;
 };
 
 #endif // TEXTFIELD_H