Adding button listener in ArrayList

Question

I am adding OnClickListener in loop for buttons, the problem is it the i variable needs to be final, but then a can`t increase him.

My code:

ArrayList<Button> buttonList  = new ArrayList<Button>();
buttonList.add((Button)findViewById(R.id.mov1_btn));
buttonList.add((Button)findViewById(R.id.mov2_btn));
buttonList.add((Button)findViewById(R.id.mov3_btn));
buttonList.add((Button)findViewById(R.id.mov4_btn));
buttonList.add((Button)findViewById(R.id.mov5_btn));
buttonList.add((Button)findViewById(R.id.mov6_btn));

for(int i = 0;i<buttonList.size();i++) 
    {
        buttonList.get(i).setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    buttonList.get(movCnt).setBackgroundResource(R.drawable.mov1n);
                    buttonList.get(i).setBackgroundResource(R.drawable.mov1o);  
                    movCnt = i;

                }
            });
    }

Vladimir Mironov · Accepted Answer · 2013-03-18 15:57:36Z

5

Since i can't be final, you have to declare another variable.

for (int i = 0; i < buttonList.size(); i++) {
    final int current = i;  

    buttonList.get(i).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            buttonList.get(movCnt).setBackgroundResource(R.drawable.mov1n);
            buttonList.get(current).setBackgroundResource(R.drawable.mov1o);
            movCnt = current;
        }
    });
}

edited Mar 18, 2013 at 15:57

answered Mar 18, 2013 at 15:45

Vladimir Mironov

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Comments

Sababado · Accepted Answer · 2013-03-18 15:45:46Z

1

Don't set the variable i to final, instead just set a tag to the view. This way the value can always stay with the view and can be used whenever needed.

for(int i = 0;i<buttonList.size();i++) 
{
    buttonList.setTag(i);
    buttonList.get(i).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                buttonList.get(movCnt).setBackgroundResource(R.drawable.mov1n);
                buttonList.get(i).setBackgroundResource(R.drawable.mov1o);  
                movCnt = (Integer)v.getTag();

            }
        });
}

answered Mar 18, 2013 at 15:45

Sababado

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Comments

Ostap Andrusiv · Accepted Answer · 2013-03-18 15:47:10Z

1

//...
for(int i = 0;i<buttonList.size();i++) 
{
    final int current = i;

    buttonList.get(ii).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                buttonList.get(movCnt).setBackgroundResource(R.drawable.mov1n);
                buttonList.get(current).setBackgroundResource(R.drawable.mov1o);  
                movCnt = current;

            }
        });
}

answered Mar 18, 2013 at 15:47

Ostap Andrusiv

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Comments

Bob Yaris · Accepted Answer · 2013-03-18 15:49:35Z

You need to make the button final not the i, Here is an example for it should be done:

ArrayList<Button> list = new ArrayList<Button>();

        list.add((Button) findViewById(R.id.BTN_login));
        list.add((Button) findViewById(R.id.BTN_login));
        list.add((Button) findViewById(R.id.BTN_login));
        list.add((Button) findViewById(R.id.BTN_login));
        for (int i = 0; i < list.size(); i++)
        {
            final Button tempButton = list.get(i);
            tempButton.setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View v) {

                     tempButton.setBackgroundResource(R.drawable.mov1n);
                     tempButton.setBackgroundResource(R.drawable.mov1o);  


                }
            });

        }

Hope it helps.

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