Question

I have a simple demo with two buttons. They are laid out with a RelativeLayout at the top and bottom of the screen.
When I click one of them, I want them to switch places.
What is the best way to do that?

This is my res/layout/main.xml :

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <ImageButton
        android:id="@+id/android_button_1"
        android:layout_width="200dip"
        android:layout_height="wrap_content"
        android:src="@drawable/icon"
        android:layout_alignParentTop="true" />

    <ImageButton
        android:id="@+id/android_button_2"
        android:layout_width="200dip"
        android:layout_height="wrap_content"
        android:src="@drawable/icon2"
        android:layout_alignParentBottom="true" />

</RelativeLayout>

And this is my Activity:

public class HelloButtons extends Activity {

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        final ImageButton button1 = (ImageButton) findViewById(R.id.android_button_1);
        final ImageButton button2 = (ImageButton) findViewById(R.id.android_button_2);
        button1.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                // Perform action on clicks
                Toast.makeText(HelloButtons.this, "Beep Bop", Toast.LENGTH_SHORT).show();
            }
        });
        button2.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                // Perform action on clicks
                Toast.makeText(HelloButtons.this, "Beep Bop", Toast.LENGTH_SHORT).show();
            }
        });
    }
}

Answer 1

Use something along these lines

   RelativeLayout.LayoutParams lp1 = (LayoutParams) b1.getLayoutParams();
   RelativeLayout.LayoutParams lp2 = (LayoutParams) b2.getLayoutParams();

   lp2.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM, RelativeLayout.TRUE);
   lp2.addRule(RelativeLayout.ALIGN_PARENT_TOP, 0);
   lp1.addRule(RelativeLayout.ALIGN_PARENT_TOP, RelativeLayout.TRUE);
   lp1.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM, 0);

   b1.setLayoutParams(lp1);
   b2.setLayoutParams(lp2);

(and the opposite to revert them again) in you OnClickListeners