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Qt Quick Examples - Animation

Animation is a collection of small QML examples relating to animation. Each example is a small QML file emphasizing a particular type or feature.

For more information about animations, visit Important Concepts in Qt Quick - States, Transitions and Animations.

Running the Example

To run the example from Qt Creator, open the Welcome mode and select the example from Examples. For more information, visit Building and Running an Example.

ColorAnimation

ColorAnimation uses color animations to fade a sky from day to night.

gradient: Gradient {
    GradientStop {
        position: 0.0
        SequentialAnimation on color {
            loops: Animation.Infinite
            ColorAnimation { from: "#14148c"; to: "#0E1533"; duration: 5000 }
            ColorAnimation { from: "#0E1533"; to: "#14148c"; duration: 5000 }
        }
    }
    GradientStop {
        position: 1.0
        SequentialAnimation on color {
            loops: Animation.Infinite
            ColorAnimation { from: "#14aaff"; to: "#437284"; duration: 5000 }
            ColorAnimation { from: "#437284"; to: "#14aaff"; duration: 5000 }
        }
    }
}

PropertyAnimation

PropertyAnimation uses number animations to bounce a circle up and down.

// Animate the y property. Setting loops to Animation.Infinite makes the
// animation repeat indefinitely, otherwise it would only run once.
SequentialAnimation on y {
    loops: Animation.Infinite

    // Move from minHeight to maxHeight in 300ms, using the OutExpo easing function
    NumberAnimation {
        from: smiley.minHeight; to: smiley.maxHeight
        easing.type: Easing.OutExpo; duration: 300
    }

    // Then move back to minHeight in 1 second, using the OutBounce easing function
    NumberAnimation {
        from: smiley.maxHeight; to: smiley.minHeight
        easing.type: Easing.OutBounce; duration: 1000
    }

    // Then pause for 500ms
    PauseAnimation { duration: 500 }
}

Animators

Animators uses animators to bounce an icon up and down.

SequentialAnimation {
    SequentialAnimation {
        ParallelAnimation {
            YAnimator {
                target: smiley;
                from: smiley.minHeight;
                to: smiley.maxHeight
                easing.type: Easing.OutExpo;
                duration: 300
            }
            ScaleAnimator {
                target: shadow
                from: 1
                to: 0.5
                easing.type: Easing.OutExpo;
                duration: 300
            }
        }
        ParallelAnimation {
            YAnimator {
                target: smiley;
                from: smiley.maxHeight;
                to: smiley.minHeight
                easing.type: Easing.OutBounce;
                duration: 1000
            }
            ScaleAnimator {
                target: shadow
                from: 0.5
                to: 1
                easing.type: Easing.OutBounce;
                duration: 1000
            }
        }
    }
    PauseAnimation { duration: 500 }
    running: true
    loops: Animation.Infinite
}

Behaviors

Behaviors uses behaviors to move a rectangle to where you click.

// Set an 'elastic' behavior on the focusRect's y property.
Behavior on y {
    NumberAnimation { easing.type: Easing.OutElastic; easing.amplitude: 3.0; easing.period: 2.0; duration: 300 }
}

Wiggly Text

Wiggly Text demonstrates using more complex behaviors to animate and wiggle some text around as you drag it. It does this by assigning a complex binding to each letter:

            x: follow ? follow.x + follow.width : container.width / 6
            y: follow ? follow.y : container.height / 2

Then, it uses behaviors to animate the movement of each letter:

            Behavior on x { enabled: container.animated; SpringAnimation { spring: 3; damping: 0.3; mass: 1.0 } }
            Behavior on y { enabled: container.animated; SpringAnimation { spring: 3; damping: 0.3; mass: 1.0 } }

Tv Tennis

Tv Tennis uses complex behaviors to make the paddles follow a ball to simulate an infinite tennis game. Again, a binding which depends on other values is applied to the position and a behavior provided the animation.

y: ball.direction == 'left' ? ball.y - 45 : page.height/2 -45;
Behavior on y { SpringAnimation{ velocity: 300 } }

Easing Curves

Easing Curves shows off all the easing curves available in Qt Quick animations.

States

States demonstrates how the properties of an item can vary between states.

It defines several states:

// In state 'middleRight', move the image to middleRightRect
State {
    name: "middleRight"
    PropertyChanges { target: userIcon; x: middleRightRect.x; y: middleRightRect.y }
},

// In state 'bottomLeft', move the image to bottomLeftRect
State {
    name: "bottomLeft"
    PropertyChanges { target: userIcon; x: bottomLeftRect.x; y: bottomLeftRect.y  }
}

Transitions

Transitions takes the States example and animates the property changes by setting transitions:

// Transitions define how the properties change when the item moves between each state
transitions: [

    // When transitioning to 'middleRight' move x,y over a duration of 1 second,
    // with OutBounce easing function.
    Transition {
        from: "*"; to: "middleRight"
        NumberAnimation { properties: "x,y"; easing.type: Easing.OutBounce; duration: 1000 }
    },

    // When transitioning to 'bottomLeft' move x,y over a duration of 2 seconds,
    // with InOutQuad easing function.
    Transition {
        from: "*"; to: "bottomLeft"
        NumberAnimation { properties: "x,y"; easing.type: Easing.InOutQuad; duration: 2000 }
    },

    // For any other state changes move x,y linearly over duration of 200ms.
    Transition {
        NumberAnimation { properties: "x,y"; duration: 200 }
    }

PathAnimation

PathAnimation animates an image along a bezier curve using a PathAnimation.

PathAnimation {
    id: pathAnim

    duration: 2000
    easing.type: Easing.InQuad

    target: box
    orientation: PathAnimation.RightFirst
    anchorPoint: Qt.point(box.width/2, box.height/2)
    path: Path {
        startX: 50; startY: 50

        PathCubic {
            x: window.width - 50
            y: window.height - 50

            control1X: x; control1Y: 50
            control2X: 50; control2Y: y
        }

        onChanged: canvas.requestPaint()
    }
}

PathInterpolator

PathInterpolator animates an image along the same bezier curve, using a PathInterpolator instead.

PathInterpolator {
    id: motionPath

    path: Path {
        startX: 50; startY: 50

        PathCubic {
            x: window.width - 50
            y: window.height - 50

            control1X: x; control1Y: 50
            control2X: 50; control2Y: y
        }

        onChanged: canvas.requestPaint()
    }

    SequentialAnimation on progress {
        running: true
        loops: -1
        PauseAnimation { duration: 1000 }
        NumberAnimation {
            id: progressAnim
            running: false
            from: 0; to: 1
            duration: 2000
            easing.type: Easing.InQuad
        }
    }
}

Files:

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