android - How To Use Multiple TouchDelegate

Question

i have two ImageButtons, each inside a RelativeLayout and these two RelativeLayouts are in another RelativeLayout, i want to set TouchDelegate for each ImageButton. If normally i add TouchDelegate to each ImageButton and it's parent RelativeLayout then just one ImageButton works properly, Another one doesn't extend it's clicking area. So PLease help me on how to use TouchDelegate in both ImageButtons. If it's not possible then what can be a effective way to extend the clicking area of a view? Thanks in advance ........

Here is my xml code:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout android:id="@+id/FrameContainer"
android:layout_width="fill_parent" android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<RelativeLayout android:layout_alignParentLeft="true"
    android:id="@+id/relativeLayout3" android:layout_width="wrap_content"
    android:layout_height="wrap_content">
    <RelativeLayout android:layout_alignParentLeft="true"
        android:id="@+id/relativeLayout1" android:layout_width="113dip"
        android:layout_height="25dip">
        <ImageButton android:id="@+id/tutorial1"
            android:layout_width="wrap_content" android:layout_height="wrap_content"
            android:background="@null" android:src="@drawable/tutorial" />
    </RelativeLayout>
    <RelativeLayout android:layout_alignParentLeft="true"
        android:id="@+id/relativeLayout2" android:layout_width="113dip"
        android:layout_height="25dip" android:layout_marginLeft="100dip">
        <ImageButton android:id="@+id/tutorial2"
            android:layout_width="wrap_content" android:layout_height="wrap_content"
            android:background="@null" android:src="@drawable/tutorial"
            android:layout_marginLeft="50dip" />
    </RelativeLayout>
</RelativeLayout>

My Activity class :

import android.app.Activity;
import android.graphics.Rect;
import android.os.Bundle;
import android.view.TouchDelegate;
import android.view.View;
import android.widget.ImageButton;
import android.widget.Toast;

public class TestTouchDelegate extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    View mParent1 = findViewById(R.id.relativeLayout1);
    mParent1.post(new Runnable() {
        @Override
        public void run() {
            Rect bounds1 = new Rect();
            ImageButton mTutorialButton1 = (ImageButton) findViewById(R.id.tutorial1);
            mTutorialButton1.setEnabled(true);
            mTutorialButton1.setOnClickListener(new View.OnClickListener() {
                public void onClick(View view) {
                    Toast.makeText(TestTouchDelegate.this, "Test TouchDelegate 1", Toast.LENGTH_SHORT).show();
                }
            });

            mTutorialButton1.getHitRect(bounds1);
            bounds1.right += 50;
            TouchDelegate touchDelegate1 = new TouchDelegate(bounds1, mTutorialButton1);

            if (View.class.isInstance(mTutorialButton1.getParent())) {
                ((View) mTutorialButton1.getParent()).setTouchDelegate(touchDelegate1);
            }
        }
    });

    //View mParent = findViewById(R.id.FrameContainer);
    View mParent2 = findViewById(R.id.relativeLayout2);
    mParent2.post(new Runnable() {
        @Override
        public void run() {
            Rect bounds2 = new Rect();
            ImageButton mTutorialButton2 = (ImageButton) findViewById(R.id.tutorial2);
            mTutorialButton2.setEnabled(true);
            mTutorialButton2.setOnClickListener(new View.OnClickListener() {
                public void onClick(View view) {
                    Toast.makeText(TestTouchDelegate.this, "Test TouchDelegate 2", Toast.LENGTH_SHORT).show();
                }
            });

            mTutorialButton2.getHitRect(bounds2);
            bounds2.left += 50;
            TouchDelegate touchDelegate2 = new TouchDelegate(bounds2, mTutorialButton2);

            if (View.class.isInstance(mTutorialButton2.getParent())) {
                ((View) mTutorialButton2.getParent()).setTouchDelegate(touchDelegate2);
            }
        }
    });

}

}

Answer 1

You can use composite pattern to be able to add more than one TouchDelegate to the View. Steps:

1. Create TouchDelegateComposite (no matter what view you'll pass as an argument, it's used just to get the Context)
2. Create necessary TouchDelegates and add them to composite

3. Add composite to view as they recommend here (via view.post(new Runnable))

   public class TouchDelegateComposite extends TouchDelegate {
   
       private final List<TouchDelegate> delegates = new ArrayList<TouchDelegate>();
       private static final Rect emptyRect = new Rect();
   
       public TouchDelegateComposite(View view) {
           super(emptyRect, view);
       }
   
       public void addDelegate(TouchDelegate delegate) {
           if (delegate != null) {
               delegates.add(delegate);
           }
       }
   
       @Override
       public boolean onTouchEvent(MotionEvent event) {
           boolean res = false;
           float x = event.getX();
           float y = event.getY();
           for (TouchDelegate delegate : delegates) {
               event.setLocation(x, y);
               res = delegate.onTouchEvent(event) || res;
           }
           return res;
       }
   
   }