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How to make Drag & Drop Button in Android

Asked 2011-02-18T04:56:52.813
14

I want to make a drag and drop button. Drag it where you want it to do and it stays there. Below code only scales the button, doesn't change its position.

package com.dynamic;
import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.TextView;

import com.dynamic.R;
import com.dynamic.R.layout;


public class dy extends Activity {
     int status;
     private FrameLayout layout;
     ImageView image;
     Button b;
     LayoutParams params;
     public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.frm);
            final Button tv=(Button)findViewById(R.id.txt_birth);
            tv.setDrawingCacheEnabled(true);

            layout = (FrameLayout) findViewById(R.id.frm);
            params = new LayoutParams(100,100);


            params = new LayoutParams(LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);
            tv.setOnTouchListener(new View.OnTouchListener(){

        @Override
        public boolean onTouch(View v, MotionEvent me) {
            // TODO Auto-generated method stub

            if (me.getAction() == MotionEvent.ACTION_DOWN) {
                System.out.println("up");
                status = 0;

            }
            if (me.getAction() == MotionEvent.ACTION_UP) {
                status = 1;
                //Log.i("Drag", "Stopped Dragging");
            } else if (me.getAction() == MotionEvent.ACTION_MOVE) {
                if (status == 0) {
                    System.out.println("Dragging");

                    tv.setPadding((int) me.getRawX(), (int) me.getRawY(), 0, 0);
                //  b.setPadding(0,50,0,0);
                    tv.invalidate();

                }
            }
            return false;
android drag-and-drop
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1 Answer

10

I know this question is a little old, but I found it when trying to implement drag and drop for a button. Using FoamyGuy's method I was able to get drag and drop to work using a LinearLayout as the parent view by setting the margins of the view in the onTouch method.

dragBtn.setOnTouchListener(new View.OnTouchListener() {

        public boolean onTouch(View v, MotionEvent me) {
            if (me.getAction() == MotionEvent.ACTION_MOVE  ){
                 LayoutParams params = new LayoutParams(v.getWidth(),  v.getHeight());
                 //set the margins. Not sure why but multiplying the height by 1.5 seems to keep my finger centered on the button while it's moving
                 params.setMargins((int)me.getRawX() - v.getWidth()/2, (int)(me.getRawY() - v.getHeight()*1.5), (int)me.getRawX() - v.getWidth()/2, (int)(me.getRawY() - v.getHeight()*1.5));
                 v.setLayoutParams(params);
             }
             return true;
        }
    });

NOTE: This only works if the view that you are dragging is the last view in the hierarchy. Otherwise it moves all the other views in relation to the view that you are dragging.

answered 2012-09-10T17:14:48.013

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