Android Open Source - Android-Sessions Main Activity

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License

The source code is released under:
MIT License
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Java Source Code

package uk.ac.icappsoc.appsocone;
/*  ww  w  .  jav a2 s  .co m*/
import android.os.Bundle;
import android.app.Activity;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

/*
 * Activity - 
 * Application component that provides a screen with which users
 * can interact in order to do something.
 */
public class MainActivity extends Activity {
  
  // A reference to a TextView that we keep around after it is created in onCreate()
  TextView myText;

  // This part runs as soon as the application begins
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    
    // Inflate our layout (places all widgets from /res/layout/activity_main.xml onto the screen)
    setContentView(R.layout.activity_main);
    
    // Retrieve views that we want to make interactive from the screen
    final ImageView myImage = (ImageView) findViewById(R.id.imageView1);
    myText = (TextView) findViewById(R.id.textView1);
    final Button myButton = (Button) findViewById(R.id.button1);
    EditText myTextField = (EditText) findViewById(R.id.editText1);
    
    // Change the text in our TextView to something different
    myText.setText("Doughnuts please!");
    
    // Create an OnClickListener, which we will use for our Button
    OnClickListener myOnClickListener = new OnClickListener(){
      
      // This method runs when the View this listener is attached to is clicked
      @Override
      public void onClick(View view) {
        // Show a small pop-up with some text that will disappear after some time
        Toast.makeText(MainActivity.this, "You are an Android master!", Toast.LENGTH_SHORT).show();
        
        // Print something to LogCat
        Log.d("AppSocOne", "You are a debugging master!");
        
        // Change the image in our ImageView
        myImage.setImageResource(R.drawable.krispy);
        
        // Change the text in our TextView
        myText.setText("Thank you!");
        
        // Change the text in our Button
        myButton.setText("Stop clicking me");
      }
      
    };
    
    // Attach our OnClickListener to our Button, so it is called every time the Button is clicked
    myButton.setOnClickListener(myOnClickListener);
    
    // Create a TextWatcher, which we will use for our EditText
    TextWatcher myTextWatcher = new TextWatcher(){
      @Override
      public void afterTextChanged(Editable s) {
        // We don't do anything..
      }

      @Override
      public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        // We don't do anything..
      }

      @Override
      public void onTextChanged(CharSequence s, int start, int count,int after) {
        // Call a custom method in our Activity
        updateMyTextBox(s);
      }
    };
    
    // Attach our TextWatcher to our EditText, so it is called every time the EditText changes
    myTextField.addTextChangedListener(myTextWatcher);
  }
  
  // This is an unnecessary, custom method just to demonstrate how you can store references to Views (and use them) outside onCreate()
  private void updateMyTextBox(CharSequence newText){
    // Update our TextView with the new text in the EditText
    myText.setText(newText);
  }

  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
  }

}
Java Source Code List
