Capture the 'virtual keyboard show/hide' event in Android

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<com.danbistudio.apps.view.ResizeRelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/layout_contain"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/white"
    android:orientation="vertical" >
  
    <!-- contain -->
    
</com.danbistudio.apps.view.ResizeRelativeLayout>

MainActivity.java

public class MainActivity extends Activity
		implements ResizeRelativeLayout.OnResizeLayout{
	//...
	private ResizeRelativeLayout layout;
	
	@Override
	public void onCreate(Bundle savedInstanceState) {
		  super.onCreate(savedInstanceState);
		  setContainView(R.layout.activity_main);
		  //...
		  layout = (ResizeRelativeLayout) findViewById(R.id.layout_contain);
		  layout.setOnResizeLayout(this);
	}
	@Override
	public void onSoftKeyboardHide() {
		//...
	}

	@Override
	public void onSoftKeyboardShow() {
		//...
	}
}

ResizeRelativeLayout.java

package com.danbistudio.apps.view;

import android.content.Context;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.view.View;
import android.view.ViewTreeObserver;
import android.widget.RelativeLayout;

/**
 * Created by quangdh on 8/13/15.
 */
public class ResizeRelativeLayout extends RelativeLayout
        implements ViewTreeObserver.OnGlobalLayoutListener{

    OnResizeLayout mOnResizeLayout = null;
    private boolean isKeyboardShown = false;
    private int currentHeight = Integer.MAX_VALUE;

    public void setOnResizeLayout(OnResizeLayout mOnResizeLayout){
        this.mOnResizeLayout = mOnResizeLayout;
    }

    public ResizeRelativeLayout(Context context) {
        super(context);
        getViewTreeObserver().addOnGlobalLayoutListener(this);
    }

    public ResizeRelativeLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
        getViewTreeObserver().addOnGlobalLayoutListener(this);
    }

    public ResizeRelativeLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        getViewTreeObserver().addOnGlobalLayoutListener(this);
    }

    public ResizeRelativeLayout(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        getViewTreeObserver().addOnGlobalLayoutListener(this);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        final int proposedheight = MeasureSpec.getSize(heightMeasureSpec);
        final int actualHeight = getHeight();
        Log.i("ResizeRelativeLayout","onMeasure()... "+proposedheight+" "+ actualHeight);
        if(mOnResizeLayout != null) {
            if (actualHeight > proposedheight) {
                if (!isKeyboardShown) {
                    isKeyboardShown = true;
                    mOnResizeLayout.onSoftKeyboardShow();
                }
            }
        }
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    @Override
    public boolean dispatchKeyEventPreIme(KeyEvent event) {
        if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
            if(mOnResizeLayout != null) {
                if (isKeyboardShown) {
                    isKeyboardShown = false;
                    mOnResizeLayout.onSoftKeyboardHide();
                }
            }
        }
        return super.dispatchKeyEventPreIme(event);
    }

    @Override
    public void onGlobalLayout() {
        int rootViewHeight = getRootView().getHeight();
        Log.i("ResizeRelativeLayout","onGlobalLayout()... "+rootViewHeight + " ... " +currentHeight);
        if(rootViewHeight > currentHeight){
            if(mOnResizeLayout != null) {
                if (isKeyboardShown) {
                    isKeyboardShown = false;
                    mOnResizeLayout.onSoftKeyboardHide();
                }
            }
        }
        currentHeight = rootViewHeight;

    }

    public interface OnResizeLayout{
        public void onSoftKeyboardShow();
        public void onSoftKeyboardHide();
    }

}