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android – Common class for click listener

Posted by: admin June 15, 2020 Leave a comment

Questions:

I have 7 buttons in all my 6 activities. All 6 buttons have the same functionality in all activities. How can I perform a common click event lisnter for these 6 buttons.

How to&Answers:

You can create a new class that implements View.OnClickListener like this:

public class MyClickListener implements View.OnClickListener {
    @Override
    public void onClick(View view) {
         // TODO handle the click   
    }
}

In all your activities you can then set the click listener like this:

button.setOnClickListener(new MyClickListener());

You could even save the context in the class for displaying Toasts etc.

public class MyClickListener implements View.OnClickListener {
    private Context context;

    public MyClickListener(Context context) {
        this.context = context;
    }

    @Override
    public void onClick(View view) {
         Button button = (Button) view;
         Toast.makeText(this.context, button.getText().toString(), Toast.LENGTH_SHORT).show();
    }
}

Answer:

Have a class like this:

public class OnClickMaker{
    public static View.OnClickListener getOnClick(){
         return new View.OnClickListener(){
              public void on click(View v){
                  //do stuff
              }
          };
    }
}

And then in your other class, do this

button.setOnClickListener(OnClickMaker.getOnClick());

Answer:

Putting more words in Sagar’s answer given above.

Assumption:

As you have said you have 7 buttons in your 6 activities, I assume all the 7 buttons have same functionality/code.

Solution:

Step 1: Include android:click="btnFirstClick" in <Button> inside your XML layouts.

Step 2: Define abstract BaseActivity class by extending Activity and include methods with the same name you have given in android:onClick attribute.

abstract public class BaseActivity extends Activity {

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

   public void btnFirstClick(View v) {
   }

   public void btnSecondClick(View v) {
   }

   .....
   .....
  // same for other buttons
}

Step 3: Now extends this BaseActivity to all your 6 activities.

For example:

public class FirstActivity extends BaseActivity {

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

Answer:

Make a Function in a Class and put that class in the same package where all other classes are there. Simply just call that function in 6 onclicklisteners .

Answer:

You can do this,

Put the click events in the XML files android:click="clickMe"

Create this function in a Activity say

public void clickMe(View view) {
...//You handling code
}

and extend this Activity by all your activities.

Answer:

You can do like following

create a base activity

class BaseActivity extends Activity{
    public void onSpecificEvent(View v){
        // do your tasks
    }
}

now extends your activities from this one

class Activity1 extends BaseActivity
class Activity2 extends BaseActivity

In which buttons you need to implement the onClick use following in xml

android:onClick="onSpecificEvent"

Answer:

If you are in the same situation like me, I have a linear layout with undetermined number of buttons in it (generated dynamically) and you want a common listener for all of the button (log out their text for example), you can do like this

for (int i = 0; i < linearLayout.getChildCount(); i++)
    {
        final Button b = (Button) linearLayout.getChildAt(i);
        b.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Commons.log(b.getText().toString());
                //your other code here
            }
        });
    }

Now all the children (buttons) of the linear layout have same click listener