CODEWITHSUNDEEP
androiddrag-and-dropontouchlistener
yahya
yahya

Reputation: 4860

ACTION_UP doesn't work

I'm trying to do an app which user can move image... And when the user move it to a certain place, app should do something else... Kinda unlocking...

But the problem is when ACTION_UP statement doesn't work... Any suggestions?

Here's my codes:

public class Main extends Activity {

    private View selected_item = null;
    private int offset_x = 0;
    private int offset_y = 0;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        ViewGroup vg = (ViewGroup) findViewById(R.id.lout);
        vg.setOnTouchListener(new View.OnTouchListener() {

            @Override
            @SuppressWarnings("deprecation")
            public boolean onTouch(View v, MotionEvent event) {

                          switch (event.getActionMasked()) {
                case MotionEvent.ACTION_MOVE:
                    int x = (int) event.getX() - offset_x;
                    int y = (int) event.getY() - offset_y;
                    int w = getWindowManager().getDefaultDisplay().getWidth() - 100;
                    int h = getWindowManager().getDefaultDisplay().getHeight() - 100;
                    if (x > w)
                        x = w;
                    if (y > h)
                        y = h;
                    AbsoluteLayout.LayoutParams lp = new AbsoluteLayout.LayoutParams(
                            new ViewGroup.MarginLayoutParams(
                                    AbsoluteLayout.LayoutParams.WRAP_CONTENT,
                                    AbsoluteLayout.LayoutParams.WRAP_CONTENT));
                    lp.x = x;
                    lp.y = y;
                    selected_item.setLayoutParams(lp);
                    break;
                default:
                    break;
                }
                return true;
            }
        });

        ImageView img = (ImageView) findViewById(R.id.imageView1);
        img.setOnTouchListener(new View.OnTouchListener() {

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                switch (event.getActionMasked()) {
                case MotionEvent.ACTION_DOWN:
                    offset_x = (int) event.getX();
                    offset_y = (int) event.getY();
                    selected_item = v;
                    break;
                case MotionEvent.ACTION_UP:
                    if (offset_x < 150 && offset_x > 120 && offset_y < 230
                            && offset_y > 200)
                        startActivity(new Intent(
                                "com.yahya.GeneralTraining.UNLOCKED"));
                    break;
                default:
                    break;
                }
                return false;

            }
        });

    }
}

Upvotes: 1

Views: 4918

Answers (3)

Shailendra Singh Rajawat
Shailendra Singh Rajawat

Reputation: 8242

Seems like your implementation is not exactly what you are looking for, you should assign offset_x and offset_y values inside ACTION_UP instead of ACTION_DOWN. Right now it will work like if user started dragging from x(120 to 150) and y(200 to 230) and drop anywhere. Unlock intent will fire, but what you want is drag from anywhere and drop to x(120 to 150) and y(200 to 230).

So write:

@Override
public boolean onTouch(View v, MotionEvent event) {
    //Are you sure you want event.getActionMasked() ??
    //I use event.getAction() 
    switch (event.getAction()) {
       case MotionEvent.ACTION_DOWN:
       //I don't believe you really need anything to do here
       break;
       case MotionEvent.ACTION_UP:
           offset_x = (int) event.getX();
           offset_y = (int) event.getY();
           selected_item = v;
           if (offset_x < 150 && offset_x > 120 && offset_y < 230 && offset_y > 200)
               startActivity(new Intent("com.yahya.GeneralTraining.UNLOCKED"));
        break;
        default:
        break;
    }
    return false;
}
});

Upvotes: 1

FoamyGuy
FoamyGuy

Reputation: 46856

I think you need to return true in your imageView onTouch() callback. For some reason returning false after ACTION_DOWN causes you to not get another call with ACTION_UP.

Upvotes: 7

Luiz Alfredo Galiza
Luiz Alfredo Galiza

Reputation: 131

your onTouch function must return true. This avoid other listener to take control of the event and mess up your application.

Upvotes: 2

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