Android studio SurfaceView onTouchEvent-CodePudding

I have a SurfaceView in my activity xml and I want to get some informations when the SurfaceView is clicked. For that I have a class like below

class ImageTable extends SurfaceView implements SurfaceHolder.Callback {

 public ImageTable(Context context, SurfaceView surfaceView) {
        super(context);

        surfaceHolder =  surfaceView.getHolder();//getHolder();//
        surfaceHolder.addCallback(this);
        this.context = context;
        setFocusable(true);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        Log.i(TAG,String.valueOf( event.getAction()) "asd");
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                
                break;
            case MotionEvent.ACTION_MOVE:
                
                break;

            case MotionEvent.ACTION_UP:

                break;
        }
    return true;
    }
}

my activity is


public class SubmitActivity extends AppCompatActivity {

SurfaceView test;

protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_submit);
        test = findViewById(R.id.cylindersImage);
        context = this;

        imageTable = new ImageTable(this,test);
}
}

and xml file


<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">


    <SurfaceView
        android:id="@ id/cylindersImage"
        android:layout_width="358dp"
        android:layout_height="219dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.49"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.05">

    </SurfaceView>
</androidx.constraintlayout.widget.ConstraintLayout>

onTouchEvent does not work with this way but if I set it by test.setOnTouchListener(...) it works. I think I should relate SurfaceView test with ImageTable but I don't know how to do. I also some drawing codes in ImageTable and they work properly, everything is drawn in SurfaceView test

If I don't declare any SurfaceView on xml file and do setContenView(new ImageTable(...)) and set surfaceHolder as SurfaceHolder surfaceHolder = getHolder() the event works.

CodePudding user response：

First of all implement View.OnTouchListener interface on view class. After that connect view and listener. Also don't forget about ACTION_CANCEL case

public class SubmitActivity extends AppCompatActivity implements View.OnTouchListener // implement interface {

SurfaceView test;

protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_submit);
        test = findViewById(R.id.cylindersImage);
        context = this;

        imageTable = new ImageTable(this,test);
        imageTable.setOnTouchListener(this) // connect interface and view
}

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        Log.i(TAG,String.valueOf( event.getAction()) "asd");
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                
                break;
            case MotionEvent.ACTION_MOVE:
                
                break;

            case MotionEvent.ACTION_UP:

                break;
            case MotionEvent.ACTION_CANCEL:
                // usually handles when you make fast moves with finger
                // don't forget about it, it handles often
                break;
        }
    return true;
    }

}

class ImageTable extends SurfaceView implements SurfaceHolder.Callback {

 public ImageTable(Context context, SurfaceView surfaceView) {
        super(context);

        surfaceHolder =  surfaceView.getHolder();//getHolder();//
        surfaceHolder.addCallback(this);
        this.context = context;
        setFocusable(true);
    }
}

So If your want to implement it in ImageTable class, then try to do like this

class ImageTable extends SurfaceView implements SurfaceHolder.Callback, View.OnTouchListener {

 public ImageTable(Context context, SurfaceView surfaceView) {
        super(context);

        surfaceHolder =  surfaceView.getHolder();//getHolder();//
        surfaceHolder.addCallback(this);
        this.context = context;
        setFocusable(true);


        surfaceView.setOnTouchListener(this);
    }
}

@Override
    public boolean onTouchEvent(MotionEvent event) {
    ...implement event....