FreeformGestureDetector

:raised_hand: Multi-touch transform gesture detector for Android.

Sample

sample repo

Usage

The FreeformGestureDetector class acts like a regular gesture detector. It receives a stream of MotionEvents and outputs a stream of transformation matrices.

Create an instance for your View. The callback implements FreeformGestureDetector.OnGestureListener.

FreeformGestureDetector freeformGestureDetector = new FreeformGestureDetector(getContext(), callback);

In the View's touch event handler, unconditionally call freeformGestureDetector.onTouchEvent(MotionEvent).

@Override
public boolean onTouch(View v, MotionEvent e) {
    freeformGestureDetector.onTouchEvent(e);
    // ...
}

The callback will be executed for each resulting transform event. The transformation is based on touch movements.

The transform parameter contains the accumulated transformation since the last call that the callback has returned true (Similar behavior as ScaleGestureDetector).

@Override
public boolean onTransform(MotionEvent ev, Matrix transform) {
    // Handle transform events here
    myMatrix.postConcat(transform);
    return true;
}

Installation

Add JitPack to your root build.gradle's repositories.

allprojects {
    repositories {
        ...
        maven { url 'https://jitpack.io' }
    }
}

In your app's build.gradle dependencies:

dependencies {
    implementation 'com.github.Kalabasa:FreeformGestureDetector:1.0.0'
}

You can check the latest version in the Releases tab.

License

MIT.

See LICENSE file