Android: How to handle right to left swipe gestures

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日久生厌 2020-11-21 06:18

I want my app to recognize when a user swipes from right to left on the phone screen.

How to do this?

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22条回答
  • 2020-11-21 06:58

    OnSwipeTouchListener.java:

    import android.content.Context;
    import android.view.GestureDetector;
    import android.view.GestureDetector.SimpleOnGestureListener;
    import android.view.MotionEvent;
    import android.view.View;
    import android.view.View.OnTouchListener;
    
    public class OnSwipeTouchListener implements OnTouchListener {
    
        private final GestureDetector gestureDetector;
    
        public OnSwipeTouchListener (Context ctx){
            gestureDetector = new GestureDetector(ctx, new GestureListener());
        }
    
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            return gestureDetector.onTouchEvent(event);
        }
    
        private final class GestureListener extends SimpleOnGestureListener {
    
            private static final int SWIPE_THRESHOLD = 100;
            private static final int SWIPE_VELOCITY_THRESHOLD = 100;
    
            @Override
            public boolean onDown(MotionEvent e) {
                return true;
            }
    
            @Override
            public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
                boolean result = false;
                try {
                    float diffY = e2.getY() - e1.getY();
                    float diffX = e2.getX() - e1.getX();
                    if (Math.abs(diffX) > Math.abs(diffY)) {
                        if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                            if (diffX > 0) {
                                onSwipeRight();
                            } else {
                                onSwipeLeft();
                            }
                            result = true;
                        }
                    }
                    else if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                        if (diffY > 0) {
                            onSwipeBottom();
                        } else {
                            onSwipeTop();
                        }
                        result = true;
                    }
                } catch (Exception exception) {
                    exception.printStackTrace();
                }
                return result;
            }
        }
    
        public void onSwipeRight() {
        }
    
        public void onSwipeLeft() {
        }
    
        public void onSwipeTop() {
        }
    
        public void onSwipeBottom() {
        }
    }
    

    Usage:

    imageView.setOnTouchListener(new OnSwipeTouchListener(MyActivity.this) {
        public void onSwipeTop() {
            Toast.makeText(MyActivity.this, "top", Toast.LENGTH_SHORT).show();
        }
        public void onSwipeRight() {
            Toast.makeText(MyActivity.this, "right", Toast.LENGTH_SHORT).show();
        }
        public void onSwipeLeft() {
            Toast.makeText(MyActivity.this, "left", Toast.LENGTH_SHORT).show();
        }
        public void onSwipeBottom() {
            Toast.makeText(MyActivity.this, "bottom", Toast.LENGTH_SHORT).show();
        }
    
    });
    
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  • 2020-11-21 06:58

    This code detects left and right swipes, avoids deprecated API calls, and has other miscellaneous improvements over earlier answers.

    /**
     * Detects left and right swipes across a view.
     */
    public class OnSwipeTouchListener implements OnTouchListener {
    
        private final GestureDetector gestureDetector;
    
        public OnSwipeTouchListener(Context context) {
            gestureDetector = new GestureDetector(context, new GestureListener());
        }
    
        public void onSwipeLeft() {
        }
    
        public void onSwipeRight() {
        }
    
        public boolean onTouch(View v, MotionEvent event) {
            return gestureDetector.onTouchEvent(event);
        }
    
        private final class GestureListener extends SimpleOnGestureListener {
    
            private static final int SWIPE_DISTANCE_THRESHOLD = 100;
            private static final int SWIPE_VELOCITY_THRESHOLD = 100;
    
            @Override
            public boolean onDown(MotionEvent e) {
                return true;
            }
    
            @Override
            public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
                float distanceX = e2.getX() - e1.getX();
                float distanceY = e2.getY() - e1.getY();
                if (Math.abs(distanceX) > Math.abs(distanceY) && Math.abs(distanceX) > SWIPE_DISTANCE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                    if (distanceX > 0)
                        onSwipeRight();
                    else
                        onSwipeLeft();
                    return true;
                }
                return false;
            }
        }
    }
    

    Use it like this:

    view.setOnTouchListener(new OnSwipeTouchListener(context) {
        @Override
        public void onSwipeLeft() {
            // Whatever
        }
    });
    
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  • 2020-11-21 06:58

    Here is simple Android Code for detecting gesture direction

    In MainActivity.java and activity_main.xml, write the following code:

    MainActivity.java

    import java.util.ArrayList;
    
    import android.app.Activity;
    import android.gesture.Gesture;
    import android.gesture.GestureLibraries;
    import android.gesture.GestureLibrary;
    import android.gesture.GestureOverlayView;
    import android.gesture.GestureOverlayView.OnGesturePerformedListener;
    import android.gesture.GestureStroke;
    import android.gesture.Prediction;
    import android.os.Bundle;
    import android.widget.Toast;
    
    public class MainActivity extends Activity implements
            OnGesturePerformedListener {
    
        GestureOverlayView gesture;
        GestureLibrary lib;
        ArrayList<Prediction> prediction;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            lib = GestureLibraries.fromRawResource(MainActivity.this,
                    R.id.gestureOverlayView1);
            gesture = (GestureOverlayView) findViewById(R.id.gestureOverlayView1);
            gesture.addOnGesturePerformedListener(this);
        }
    
        @Override
        public void onGesturePerformed(GestureOverlayView overlay, Gesture gesture) {
            ArrayList<GestureStroke> strokeList = gesture.getStrokes();
            // prediction = lib.recognize(gesture);
            float f[] = strokeList.get(0).points;
            String str = "";
    
            if (f[0] < f[f.length - 2]) {
                str = "Right gesture";
            } else if (f[0] > f[f.length - 2]) {
                str = "Left gesture";
            } else {
                str = "no direction";
            }
            Toast.makeText(getApplicationContext(), str, Toast.LENGTH_LONG).show();
    
        }
    
    }
    

    activity_main.xml

    <android.gesture.GestureOverlayView xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        xmlns:android1="http://schemas.android.com/apk/res/android"
        xmlns:android2="http://schemas.android.com/apk/res/android"
        android:id="@+id/gestureOverlayView1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android1:orientation="vertical" >
    
        <TextView
            android:id="@+id/textView1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Draw gesture"
            android:textAppearance="?android:attr/textAppearanceMedium" />
    
    </android.gesture.GestureOverlayView>
    
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  • 2020-11-21 07:00

    In order to have Click Listener, DoubleClick Listener, OnLongPress Listener, Swipe Left, Swipe Right, Swipe Up, Swipe Down on Single View you need to setOnTouchListener. i.e,

    view.setOnTouchListener(new OnSwipeTouchListener(MainActivity.this) {
    
                @Override
                public void onClick() {
                    super.onClick();
                    // your on click here
                }
    
                @Override
                public void onDoubleClick() {
                    super.onDoubleClick();
                    // your on onDoubleClick here
                }
    
                @Override
                public void onLongClick() {
                    super.onLongClick();
                    // your on onLongClick here
                }
    
                @Override
                public void onSwipeUp() {
                    super.onSwipeUp();
                    // your swipe up here
                }
    
                @Override
                public void onSwipeDown() {
                    super.onSwipeDown();
                    // your swipe down here.
                }
    
                @Override
                public void onSwipeLeft() {
                    super.onSwipeLeft();
                    // your swipe left here.
                }
    
                @Override
                public void onSwipeRight() {
                    super.onSwipeRight();
                    // your swipe right here.
                }
            });
    
    }
    

    For this you need OnSwipeTouchListener class that implements OnTouchListener.

    public class OnSwipeTouchListener implements View.OnTouchListener {
    
    private GestureDetector gestureDetector;
    
    public OnSwipeTouchListener(Context c) {
        gestureDetector = new GestureDetector(c, new GestureListener());
    }
    
    public boolean onTouch(final View view, final MotionEvent motionEvent) {
        return gestureDetector.onTouchEvent(motionEvent);
    }
    
    private final class GestureListener extends GestureDetector.SimpleOnGestureListener {
    
        private static final int SWIPE_THRESHOLD = 100;
        private static final int SWIPE_VELOCITY_THRESHOLD = 100;
    
        @Override
        public boolean onDown(MotionEvent e) {
            return true;
        }
    
        @Override
        public boolean onSingleTapUp(MotionEvent e) {
            onClick();
            return super.onSingleTapUp(e);
        }
    
        @Override
        public boolean onDoubleTap(MotionEvent e) {
            onDoubleClick();
            return super.onDoubleTap(e);
        }
    
        @Override
        public void onLongPress(MotionEvent e) {
            onLongClick();
            super.onLongPress(e);
        }
    
        // Determines the fling velocity and then fires the appropriate swipe event accordingly
        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
            boolean result = false;
            try {
                float diffY = e2.getY() - e1.getY();
                float diffX = e2.getX() - e1.getX();
                if (Math.abs(diffX) > Math.abs(diffY)) {
                    if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                        if (diffX > 0) {
                            onSwipeRight();
                        } else {
                            onSwipeLeft();
                        }
                    }
                } else {
                    if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                        if (diffY > 0) {
                            onSwipeDown();
                        } else {
                            onSwipeUp();
                        }
                    }
                }
            } catch (Exception exception) {
                exception.printStackTrace();
            }
            return result;
        }
    }
    
    public void onSwipeRight() {
    }
    
    public void onSwipeLeft() {
    }
    
    public void onSwipeUp() {
    }
    
    public void onSwipeDown() {
    }
    
    public void onClick() {
    
    }
    
    public void onDoubleClick() {
    
    }
    
    public void onLongClick() {
    
    }
    }
    
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  • 2020-11-21 07:01
    import android.content.Context
    import android.view.GestureDetector
    import android.view.GestureDetector.SimpleOnGestureListener
    import android.view.MotionEvent
    import android.view.View
    import android.view.View.OnTouchListener
    
    /**
     * Detects left and right swipes across a view.
     */
    class OnSwipeTouchListener(context: Context, onSwipeCallBack: OnSwipeCallBack?) : OnTouchListener {
    
        private var gestureDetector : GestureDetector
        private var onSwipeCallBack: OnSwipeCallBack?=null
    
        init {
    
            gestureDetector = GestureDetector(context, GestureListener())
            this.onSwipeCallBack = onSwipeCallBack!!
        }
        companion object {
    
            private val SWIPE_DISTANCE_THRESHOLD = 100
            private val SWIPE_VELOCITY_THRESHOLD = 100
        }
    
       /* fun onSwipeLeft() {}
    
        fun onSwipeRight() {}*/
    
        override fun onTouch(v: View, event: MotionEvent): Boolean {
    
    
            return gestureDetector.onTouchEvent(event)
        }
    
        private inner class GestureListener : SimpleOnGestureListener() {
    
            override fun onDown(e: MotionEvent): Boolean {
                return true
            }
    
            override fun onFling(eve1: MotionEvent?, eve2: MotionEvent?, velocityX: Float, velocityY: Float): Boolean {
                try {
                    if(eve1 != null&& eve2!= null) {
                        val distanceX = eve2?.x - eve1?.x
                        val distanceY = eve2?.y - eve1?.y
                        if (Math.abs(distanceX) > Math.abs(distanceY) && Math.abs(distanceX) > SWIPE_DISTANCE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                            if (distanceX > 0)
                                onSwipeCallBack!!.onSwipeLeftCallback()
                            else
                                onSwipeCallBack!!.onSwipeRightCallback()
                            return true
                        }
                    }
                }catch (exception:Exception){
                    exception.printStackTrace()
                }
    
                return false
            }
    
    
        }
    }
    
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  • 2020-11-21 07:05

    I've been doing similar things, but for horizontal swipes only

    import android.content.Context
    import android.view.GestureDetector
    import android.view.MotionEvent
    import android.view.View
    
    abstract class OnHorizontalSwipeListener(val context: Context) : View.OnTouchListener {    
    
        companion object {
             const val SWIPE_MIN = 50
             const val SWIPE_VELOCITY_MIN = 100
        }
    
        private val detector = GestureDetector(context, GestureListener())
    
        override fun onTouch(view: View, event: MotionEvent) = detector.onTouchEvent(event)    
    
        abstract fun onRightSwipe()
    
        abstract fun onLeftSwipe()
    
        private inner class GestureListener : GestureDetector.SimpleOnGestureListener() {    
    
            override fun onDown(e: MotionEvent) = true
    
            override fun onFling(e1: MotionEvent, e2: MotionEvent, velocityX: Float, velocityY: Float)
                : Boolean {
    
                val deltaY = e2.y - e1.y
                val deltaX = e2.x - e1.x
    
                if (Math.abs(deltaX) < Math.abs(deltaY)) return false
    
                if (Math.abs(deltaX) < SWIPE_MIN
                        && Math.abs(velocityX) < SWIPE_VELOCITY_MIN) return false
    
                if (deltaX > 0) onRightSwipe() else onLeftSwipe()
    
                return true
            }
        }
    }
    

    And then it can be used for view components

    private fun listenHorizontalSwipe(view: View) {
        view.setOnTouchListener(object : OnHorizontalSwipeListener(context!!) {
                override fun onRightSwipe() {
                    Log.d(TAG, "Swipe right")
                }
    
                override fun onLeftSwipe() {
                    Log.d(TAG, "Swipe left")
                }
    
            }
        )
    }
    
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