Android how to add swipe Gesture on LinearLayout without onDown true

Question

I'm working on Gesture activity in android I used class to detect the swipe action is

public class ActivitySwipeDetector  implements View.OnTouchListener {

    static final String logTag = "ActivitySwipeDetector";
    private Activity activity;
    static final int MIN_DISTANCE = 100;
    private float downX, downY, upX, upY;

    public ActivitySwipeDetector(Activity activity){
        this.activity = activity;
    }

    public void onRightToLeftSwipe(){
        Log.i(logTag, "RightToLeftSwipe!");
        Toast.makeText(activity, "RightToLeftSwipe", Toast.LENGTH_SHORT).show();
        //activity.doSomething();
    }

    public void onLeftToRightSwipe(){
        Log.i(logTag, "LeftToRightSwipe!");
        Toast.makeText(activity, "LeftToRightSwipe", Toast.LENGTH_SHORT).show();
        //activity.doSomething();
    }

    public void onTopToBottomSwipe(){
        Log.i(logTag, "onTopToBottomSwipe!");
        //Toast.makeText(activity, "onTopToBottomSwipe", Toast.LENGTH_SHORT).show();
        //activity.doSomething();
    }

    public void onBottomToTopSwipe(){
        Log.i(logTag, "onBottomToTopSwipe!");
        //Toast.makeText(activity, "onBottomToTopSwipe", Toast.LENGTH_SHORT).show();
        //activity.doSomething();
    }

    public boolean onTouch(View v, MotionEvent event) {
        switch(event.getAction()){
        case MotionEvent.ACTION_DOWN: {
            downX = event.getX();
            downY = event.getY();
            return true;
        }
        case MotionEvent.ACTION_UP: {
            upX = event.getX();
            upY = event.getY();

            float deltaX = downX - upX;
            float deltaY = downY - upY;

            // swipe horizontal?
                    if(Math.abs(deltaX) > MIN_DISTANCE){
                        // left or right
                        if(deltaX < 0) { this.onLeftToRightSwipe(); return true; }
                        if(deltaX > 0) { this.onRightToLeftSwipe(); return true; }
                    }
                    else {
                        Log.i(logTag, "Swipe was only " + Math.abs(deltaX) + " long, need at least " + MIN_DISTANCE);
                        return false; // We don't consume the event
                    }

                    // swipe vertical?
                    if(Math.abs(deltaY) > MIN_DISTANCE){
                        // top or down
                        if(deltaY < 0) { this.onTopToBottomSwipe(); return true; }
                        if(deltaY > 0) { this.onBottomToTopSwipe(); return true; }
                    }
                    else {
                        Log.i(logTag, "Swipe was only " + Math.abs(deltaX) + " long, need at least " + MIN_DISTANCE);
                        return false; // We don't consume the event
                    }

                    return true;
        }
        }
        return false;
    }

}

my xml file is

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/action_settings"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

</LinearLayout>

And in My activity I calling like this

ActivitySwipeDetector activitySwipeDetector = new ActivitySwipeDetector(this);
        LinearLayout lowestLayout = (LinearLayout)this.findViewById(R.id.action_settings);
        lowestLayout.setOnTouchListener(activitySwipeDetector);

I called ActivitySwipeDetector(this); so Its working fine with full activity. But how can I apply Swipe detector only to LinearLayout not to the Whole Activity. Please help me out.

Answer 1

Needed for me and best was your code, so I fixed a bit, need more fix, see the comment

public class RelativeLayoutTouchListener implements OnTouchListener {

    static final String logTag = "ActivitySwipeDetector";
    private Activity activity;
    static final int MIN_DISTANCE = 100;// TODO change this runtime based on screen resolution. for 1920x1080 is to small the 100 distance
    private float downX, downY, upX, upY;

    // private MainActivity mMainActivity;

    public RelativeLayoutTouchListener(MainActivity mainActivity) {
        activity = mainActivity;
    }

    public void onRightToLeftSwipe() {
        Log.i(logTag, "RightToLeftSwipe!");
        Toast.makeText(activity, "RightToLeftSwipe", Toast.LENGTH_SHORT).show();
        // activity.doSomething();
    }

    public void onLeftToRightSwipe() {
        Log.i(logTag, "LeftToRightSwipe!");
        Toast.makeText(activity, "LeftToRightSwipe", Toast.LENGTH_SHORT).show();
        // activity.doSomething();
    }

    public void onTopToBottomSwipe() {
        Log.i(logTag, "onTopToBottomSwipe!");
        Toast.makeText(activity, "onTopToBottomSwipe", Toast.LENGTH_SHORT).show();
        // activity.doSomething();
    }

    public void onBottomToTopSwipe() {
        Log.i(logTag, "onBottomToTopSwipe!");
        Toast.makeText(activity, "onBottomToTopSwipe", Toast.LENGTH_SHORT).show();
        // activity.doSomething();
    }

    public boolean onTouch(View v, MotionEvent event) {
        switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN: {
            downX = event.getX();
            downY = event.getY();
            return true;
        }
        case MotionEvent.ACTION_UP: {
            upX = event.getX();
            upY = event.getY();

            float deltaX = downX - upX;
            float deltaY = downY - upY;

            // swipe horizontal?
            if (Math.abs(deltaX) > MIN_DISTANCE) {
                // left or right
                if (deltaX < 0) {
                    this.onLeftToRightSwipe();
                    return true;
                }
                if (deltaX > 0) {
                    this.onRightToLeftSwipe();
                    return true;
                }
            } else {
                Log.i(logTag, "Swipe was only " + Math.abs(deltaX) + " long horizontally, need at least " + MIN_DISTANCE);
                // return false; // We don't consume the event
            }

            // swipe vertical?
            if (Math.abs(deltaY) > MIN_DISTANCE) {
                // top or down
                if (deltaY < 0) {
                    this.onTopToBottomSwipe();
                    return true;
                }
                if (deltaY > 0) {
                    this.onBottomToTopSwipe();
                    return true;
                }
            } else {
                Log.i(logTag, "Swipe was only " + Math.abs(deltaX) + " long vertically, need at least " + MIN_DISTANCE);
                // return false; // We don't consume the event
            }

            return false; // no swipe horizontally and no swipe vertically
        }// case MotionEvent.ACTION_UP:
        }
        return false;
    }

}

Usage:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    rlTop = (RelativeLayout) findViewById(R.id.rlTop);      
    rlTop.setOnTouchListener(new RelativeLayoutTouchListener(this));
}

Answer 2

I have had good results with the original code. But the listener needs to be added to a view, not a layout. We are extending View.OnTouchListener, after all.