QT 之状态机小究

例子代码如下：

#include "hiveswitch.h"

HiveSwitch::HiveSwitch(QWidget *parent)

  : QWidget(parent)

{

  slot_pixmap.load(":/img/slot.png");

  slot_pixmap.setDevicePixelRatio(2.0);

  this->setFixedSize(slot_pixmap.width()/2,slot_pixmap.height()/2);

  switch_pixmap.load(":/img/switch.png");

  switch_pixmap.setDevicePixelRatio(2.0);

  switch_label = new QLabel(this);

  switch_label->setPixmap(switch_pixmap);

  QStateMachine *machine = new QStateMachine;

  QState *state1 = new QState(machine);

  state1->assignProperty(switch_label,"geometry",QRect(0,-16,switch_pixmap.width(), switch_pixmap.height()));

  machine->setInitialState(state1);

  QState *state2 = new QState(machine);

  state2->assignProperty(switch_label,"geometry",QRect(22,-16,switch_pixmap.width(), switch_pixmap.height()));

  QPropertyAnimation *animation=new QPropertyAnimation(switch_label,"geometry");

  animation->setDuration(100);

  animation->setEasingCurve(QEasingCurve::InCubic);

  QSignalTransition *transition1=state1->addTransition(this,SIGNAL(clicked()),state2);

  transition1->addAnimation(animation);

  QSignalTransition *transition2=state2->addTransition(this,SIGNAL(clicked()),state1);

  transition2->addAnimation(animation);

  machine->start();

}

HiveSwitch::~HiveSwitch()

{

}

void HiveSwitch::paintEvent(QPaintEvent *)

{

  QPainter painter(this);

  painter.drawPixmap(0,0,slot_pixmap);

}

void HiveSwitch::mouseReleaseEvent(QMouseEvent *event)

{

  emit clicked();

}

#ifndef HIVESWITCH_H

#define HIVESWITCH_H

#include <QWidget>

#include <QLabel>

#include <QStateMachine>

#include <QPropertyAnimation>

#include <QPainter>

#include <QSignalTransition>

class HiveSwitch : public QWidget

{

  Q_OBJECT

public:

  HiveSwitch(QWidget *parent = 0);

  ~HiveSwitch();

protected:

  void paintEvent(QPaintEvent*);

  void mouseReleaseEvent(QMouseEvent *event);

private:

  QPixmap slot_pixmap;

  QPixmap switch_pixmap;

  QLabel *switch_label;

signals:

  void clicked();

};

#endif // HIVESWITCH_H

效果如下：