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Qt/C++ - Tutorial 086. Using QSequentialAnimationGroup and QPropertyAnimation to move a button

QSequentialAnimationGroup, cpp, Qt, C++, QPropertyAnimation

Let's write a small example of an application in which a button will be moved using property animations. To do this, we use the QSequentialAnimationGroup and QPropertyAnimation classes.

QSequentialAnimationGroup is a class that combines several animations into one group, which allows you to automatically start one animation when the previous QPropertyAnimation has completed.

Animation will be launched by pressing the button and this button will move in the window as shown in the image.

We will create the project by default in Qt Creator, and all changes will apply only to the Widget class. You will need to add a QPushButton button through a graphic designer.

Widget.h

And here is an example in the code

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>

#include <QSequentialAnimationGroup>

namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = nullptr);
    ~Widget();

private slots:
    void onClickButton();

private:
    Ui::Widget *ui;

    // Button animation group
    QSequentialAnimationGroup* animationGroup;
};

#endif // WIDGET_H

Widget.cpp

The important point is that we create QPropertyAnimation with an indication of the property that we want to animate. In this case, it is "geometry". A property can be animated if it is declared in a class as Q_PROPERTY. Then smooth change of values of this property is performed.

#include "widget.h"
#include "ui_widget.h"

#include <QPropertyAnimation>
#include <QDebug>

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);

    // Create an animation group
    animationGroup = new QSequentialAnimationGroup(this);

    // Create an animation of the motion property from left-top to right-top.
    QPropertyAnimation* leftTopToRightTop = new QPropertyAnimation(ui->pushButton, "geometry");
    leftTopToRightTop->setDuration(1000); // Animation duration
    leftTopToRightTop->setStartValue(ui->pushButton->geometry()); // Starting position and animation geometry
    leftTopToRightTop->setEndValue(ui->pushButton->geometry().translated(100, 0)); // End position and geometry of animation
    animationGroup->addAnimation(leftTopToRightTop); // Add animation to the group

    // Right-top Bottom-right
    QPropertyAnimation* rightTopToRightBottom = new QPropertyAnimation(ui->pushButton, "geometry");
    rightTopToRightBottom->setDuration(1000);
    rightTopToRightBottom->setStartValue(leftTopToRightTop->endValue());
    rightTopToRightBottom->setEndValue(leftTopToRightTop->endValue().toRect().translated(0, 100));
    animationGroup->addAnimation(rightTopToRightBottom);

    // Bottom right to left down
    QPropertyAnimation* rightBottomToLeftBottom = new QPropertyAnimation(ui->pushButton, "geometry");
    rightBottomToLeftBottom->setDuration(1000);
    rightBottomToLeftBottom->setStartValue(rightTopToRightBottom->endValue());
    rightBottomToLeftBottom->setEndValue(rightTopToRightBottom->endValue().toRect().translated(-100, 0));
    animationGroup->addAnimation(rightBottomToLeftBottom);

    // Left-bottom top-left
    QPropertyAnimation* leftBottomToLeftTop = new QPropertyAnimation(ui->pushButton, "geometry");
    leftBottomToLeftTop->setDuration(1000);
    leftBottomToLeftTop->setStartValue(rightBottomToLeftBottom->endValue());
    leftBottomToLeftTop->setEndValue(rightBottomToLeftBottom->endValue().toRect().translated(0, -100));
    animationGroup->addAnimation(leftBottomToLeftTop);

    // We connect button pressing to the slot to the button handler.
    connect(ui->pushButton, &QPushButton::clicked, this, &Widget::onClickButton);
}

Widget::~Widget()
{
    delete ui;
}

void Widget::onClickButton()
{
    // Run the animation
    animationGroup->start();
}

Conclusion

Thus, it is possible to configure the most varied animations for object properties, which are marked with the Q_PROPERTY macro and have set and get methods.

Git Repository Link




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P
Feb. 18, 2019, 3:39 p.m.
Poyar

C++ - Test 001. The first program and data types

  • Result:73points,
  • Rating points1
НБ
Feb. 15, 2019, 1:03 p.m.
Николай Булахтин

C++ - Test 002. Constants

  • Result:25points,
  • Rating points-10
Last comments
V
Feb. 14, 2019, 6:41 p.m.
Vlad15007

Спасибо огромное! Заработало!
А
Feb. 12, 2019, 9:26 a.m.
Александр90

Сам разборался, спасибо.
А
Feb. 12, 2019, 8:19 a.m.
Александр90

День добрый! Можешь выложить форму mainwindow.ui от урока? Заранее спасибо
Feb. 11, 2019, 10:51 a.m.
Евгений Легоцкой

Нет, у меня проблема с жёстким диском случилась, занимался восстановлением ПК, ещё пару вечеров придётся этим заниматься, увы.
Now discuss on the forum
Feb. 17, 2019, 5:28 p.m.
Евгений Легоцкой

Добрый день. Очень извиняюсь за долгий ответ Первое, что нашёл, так это необходимость перерисовать чекбокс. void CheckBoxDelegate::paint(QPainter *painter, const QStyleOptionViewItem ...
Feb. 15, 2019, 3:36 p.m.
Евгений Легоцкой

Ну я тут нашёл одно решение, но сам его не проверял. Вам нужно помещать фамилии скорее всего в ячейки заголовка, и потом просто перерисовывать их QHeaderView * header = m_ui->tableWidget...
Feb. 15, 2019, 7:53 a.m.
Евгений Легоцкой

Добрый день! Не работал с remoteobjects, поэтому глянул документацию, чтобы рассмотреть, что это за зверь. После просмотра документации сложилось стойкой впечатление, что это вполне возм...
m
Feb. 14, 2019, 6:28 p.m.
mr_roman

Нашел решение на Java. Удалось интегрировать в проект сервиса на Qt, теперь из Qt запускаю Java-код акселерометра.
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