Qt 5.7 | Qt Quick | Qt Quick Examples - Touch Interaction

Qt 5.7.1 Reference Documentation

# Qt Quick Examples - Touch Interaction

Touch Interaction is a collection of small QML examples relating to touch interaction methods. For more information, visit Important Concepts In Qt Quick - User Input.

## 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.

## Multipoint Flames Example

Multipoint Flames demonstrates distinguishing different fingers in a MultiPointTouchArea, by assigning a different colored flame to each touch point.

The MultipointTouchArea sets up multiple touch points:

          MultiPointTouchArea {
              anchors.fill: parent
              minimumTouchPoints: 1
              maximumTouchPoints: 5
              touchPoints: [
                  TouchPoint { id: touch1 },
                  TouchPoint { id: touch2 },
                  TouchPoint { id: touch11 },
                  TouchPoint { id: touch21 },
                  TouchPoint { id: touch31 }
              ]
          }

The flames are then simply bound to the coordinates of the touch point, and whether it is currently pressed, as follows:

          ParticleFlame {
              color: "red"
              emitterX: touch1.x
              emitterY: touch1.y
              emitting: touch1.pressed
          }

## Bear-Whack Example

Bear-Whack demonstrates using MultiPointTouchArea to add multiple finger support to a simple game. The interaction with the game is done through a SpriteGoal that follows the TouchPoint. The TouchPoints added to the MultiPointTouchArea are a component with the relevant logic embedded into it:

      TouchPoint {
          id: container
          property ParticleSystem system
          onPressedChanged: {
              if (pressed) {
                  timer.restart();
                  child.enabled = true;
                  system.explode(x,y);
              }
          }
          property QtObject obj: Timer {
              id: timer
              interval: 100
              running: false
              repeat: false
              onTriggered: child.enabled = false
          }
          property Item child: SpriteGoal {
              enabled: false
              x: container.area.x - 16
              y: container.area.y - 16
              width: container.area.width + 32
              height: container.area.height + 32 //+32 so it doesn't have to hit the exact center
              system: container.system
              parent: container.system
              goalState: "falling"
          }
      }

## Flick Resize Example

Flick Resize uses a PinchArea to implement a pinch-to-resize behavior. This is easily achieved by listening to the PinchArea signals and responding to user input.

      onPinchStarted: {
          initialWidth = flick.contentWidth
          initialHeight = flick.contentHeight
      }

      onPinchUpdated: {
          // adjust content pos due to drag
          flick.contentX += pinch.previousCenter.x - pinch.center.x
          flick.contentY += pinch.previousCenter.y - pinch.center.y

          // resize content
          flick.resizeContent(initialWidth * pinch.scale, initialHeight * pinch.scale, pinch.center)
      }

      onPinchFinished: {
          // Move its content within bounds.
          flick.returnToBounds()
      }

## Flickable Example

Flickable is a simple example demonstrating the Flickable type.

      Rectangle {
      width: 320
      height: 480
      Flickable {
          anchors.fill: parent
          contentWidth: 1200
          contentHeight: 1200
          Rectangle {
              width: 1000
              height: 1000

## Corkboards Example

Corkboards shows another use for Flickable, with QML types within the flickable object that respond to mouse and keyboard interaction. This behavior does not require special code as the Qt Quick types already cooperate with the Flickable type for accepting touch events.

Files:

- touchinteraction/touchinteraction.qml
- touchinteraction/flickable/basic-flickable.qml
- touchinteraction/flickable/corkboards.qml
- touchinteraction/flickable/content/Panel.qml
- touchinteraction/multipointtouch/bearwhack.qml
- touchinteraction/multipointtouch/multiflame.qml
- touchinteraction/multipointtouch/content/AugmentedTouchPoint.qml
- touchinteraction/multipointtouch/content/BearWhackParticleSystem.qml
- touchinteraction/multipointtouch/content/ParticleFlame.qml
- touchinteraction/pincharea/flickresize.qml
- touchinteraction/main.cpp
- touchinteraction/touchinteraction.pro
- touchinteraction/touchinteraction.qmlproject
- touchinteraction/touchinteraction.qrc