How to sequentially animate through different QStates after single button click

  • I have an image displayed on a QGraphicsView and I'm trying to make it move using a state machine. After clicking the image I want it to move down by 200px and then across to the right another 200px. This is the code I have so far but the issue is that instead of the image moving in the L shape as desired it moves diagonally i.e. instead of the animation transitioning from state 1 to state 2 and then to state 3, the animation transitions state 1 to state 3 skipping state 2.

    @stateMachine = new QStateMachine(this);

    QState *state_01 = new QState(stateMachine);
    QState *state_02 = new QState(stateMachine);
    QState *state_03 = new QState(stateMachine);

    state_01->assignProperty(pixmap, "pos", QPointF(0, 0));
    state_02->assignProperty(pixmap, "pos", QPointF(0, 200));
    state_03->assignProperty(pixmap, "pos", QPointF(200, 200));

    QAbstractTransition *transition_01 = state_01->addTransition(pixmap, SIGNAL(pixmapPressed()), state_02);
    QAbstractTransition *transition_02 = state_02->addTransition(state_03);

    transition_01->addAnimation(new QPropertyAnimation(pixmap, "pos"));
    transition_02->addAnimation(new QPropertyAnimation(pixmap, "pos"));


    I think I'm probably misusing the statement for the transition of state 2 to state 3 but I've tried other methods without success. The only other idea I haven't tried would be to check if the image has reached it's position for state 2 and somehow emit a signal to start the next transition to state 3 but I feel that maybe what I'm asking for can all be done with the state machine framework. How can I get the image to animate through the 3 states after clicking on the image only once to start the entire process?

  • Qt Champions 2017

    Welcome to the forum.

    You need to make the two animations separately for L shape movement. Create one animation to move down and another animation to move right. Place these animations in QSequentialAnimationGroup.

    @QSequentialAnimationGroup *group = new QSequentialAnimationGroup;


    Regarding the transition to state 3, you have added unconditional transition from State 2 to State 3. What is the trigger for State2 and State 3. If you have add the appropriate trigger like Signal, then it will work.

Log in to reply

Looks like your connection to Qt Forum was lost, please wait while we try to reconnect.