Determine event source in event listener

Last example demonstrate a "Simple example of Button and OnClickListener", with individual OnClickListener for each View. Alternatively, we can have a common OnClickListener for more than one View, then determine event source in event listener, and perform the correspond operation accordingly.

Determine event source in event listener


package com.example.androidbutton;

import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener{

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  LinearLayout myBackGround = (LinearLayout)findViewById(R.id.mybackground);
  myBackGround.setOnClickListener(this);
  
  TextView myWeb = (TextView)findViewById(R.id.myweb);
  myWeb.setOnClickListener(this);
  
  Button button1 = (Button)findViewById(R.id.button1);
  button1.setOnClickListener(this);
  
  Button button2 = (Button)findViewById(R.id.button2);
  button2.setOnClickListener(this);
  
  ImageView myImage =(ImageView)findViewById(R.id.myimage);
  myImage.setOnClickListener(this);
 }

 @Override
 public void onClick(View v) {
  if(v.getClass() == TextView.class){
   Toast.makeText(getApplicationContext(), 
     "It's TextView:\n" + ((TextView)v).getText(), 
     Toast.LENGTH_SHORT).show();
  }else if(v.getClass() == Button.class){
   Toast.makeText(getApplicationContext(), 
     "It's Button:\n" + ((Button)v).getText(), 
     Toast.LENGTH_SHORT).show();
  }else if(v.getClass() == ImageView.class){
   Toast.makeText(getApplicationContext(), 
     "It's ImageView:", 
     Toast.LENGTH_SHORT).show();
   
   //setRotation require API Level 11
   float rot = ((ImageView)v).getRotation() + 90;
   ((ImageView)v).setRotation(rot);
   
  }else{
   Toast.makeText(getApplicationContext(), 
     "Background clicked", 
     Toast.LENGTH_SHORT).show();
  }
 }

}


<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    tools:context=".MainActivity"
    android:id="@+id/mybackground" >

    <TextView
        android:id="@+id/myweb"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="android-er.blogspot.com" />
    
    <Button
        android:id="@+id/button1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Button 1"/>
    <Button
        android:id="@+id/button2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Button 2"/>
    <ImageView
        android:id="@+id/myimage"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/ic_launcher"/>
    
</LinearLayout>


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