Recognizing a button from a dynamic view

Question

I have written this code for a dynamic layout where I am using this loop to generate a pair of buttons (this is the part of code where I generate them)

  for(int i = 1; i <= 2 ; i++) {
        Button button1 = new Button(this);
        button1.setTag("age");
        button1.setId(i);
        layout.addView(button1);

        Button button2 = new Button(this);
        button2.setId(i);
        button2.setTag("country");
        button2.setEnabled(false);
        layout.addView(button2);

        button1.setOnClickListener(this);
        button2.setOnClickListener(this);
       }

What I wish to do is if button1 is clicked, button2 should get enabled (initially it is disabled).

This would be a very easy task to do if the buttons were created in xml as then they will have separate R.id.xxxxx names for each, but here I am unable to understand how to detect the other button in the OnClick(View v) method so that I can change if it is enabled or not, I have tried to add the tag for each button so that I have another parameter to recognize the buttons but I have no idea how to recognize the other button with the view information of the clicked button1.

i have a similar doubt. please help http://stackoverflow.com/questions/17061833/androidone-button-id-for-many-buttons-on-expandable-list-children — user2468835, Jun 14 '13 at 07:25

Ted Hopp · Accepted Answer · 2012-06-05T14:08:18.857

I assume that you are using the button tags in your click processing. To keep the tag data and add the needed wiring between buttons, you can create a data structure that would serve as a tag:

static class ButtonTag {
    String buttonType;
    Button partner;
    ButtonTag(String type, Button button) {
        buttonType = type;
        partner = button;
    }
}

Then you could reorganize your setup code:

for(int i = 1; i <= 2 ; i++) {
    Button button1 = new Button(this);
    button1.setId(i);
    layout.addView(button1);

    Button button2 = new Button(this);
    button2.setId(i);
    button2.setEnabled(false);
    button1.setTag(new ButtonTag("age", button2));
    button2.setTag(new ButtonTag("country", button1));
    layout.addView(button2);
}

The click processing will obviously need to be changed to cast getTag() to a ButtonTag instead of a String.

If you don't need the "age" and "country" information to distinguish button types, just set each button as the tag for the other.

EDIT:

With the latter scheme, here's how you would use this in a click listener:

public void onClick(View v) {
    Object tag = v.getTag();
    if (tag instanceof Button) {
        Button btn = (Button) tag;
        btn.setEnabled(true);
        v.setEnabled(false);
    }
}

If you needed the "age" and "country" part of the tag for other reasons, the code would be only a little different:

public void onClick(View v) {
    Object tag = v.getTag();
    if (tag instanceof ButtonTag) {
        ButtonTag bTag = (ButtonTag) tag;
        bTag.partner.setEnabled(true);
        v.setEnabled(false);
    }
}

Thank you sir .... but I still don't understand how to recognise the other button, .... can you please tell me what has to be written in the onClick listener such that when button1 is clicked, button2 get's enabled. — Sumit, Jun 05 '12 at 07:41
Ted I have posted an answer below do you think that answer is ok ? — Sumit, Jun 05 '12 at 11:04
@Sumit - Your code probably does what you want, but it's inefficient (requiring a search through all the buttons) and kind of elaborate. I've added sample code to my answer showing a more direct solution. — Ted Hopp, Jun 05 '12 at 14:09

score 2 · Answer 2 · edited May 23 '17 at 12:31

I got a solution to the problem after referring to this question here ( find button by ID or TAG ), it solves the problem I was facing as such !

public class DynmaicViewExperimentActivity extends Activity implements OnClickListener{

List<Button> buttons;

@Override
public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        buttons = new ArrayList<Button>();
        setDynamicContentViewOfThisPage();
    }

public void onClick(View v) {
    // TODO Auto-generated method stub
    int buttonType = 0;
    if (v.getTag()=="age")
            buttonType = 1;
    else if (v.getTag()=="country")
            buttonType = 2;
    switch (buttonType) {
        case 1:
            for(Button b: buttons) {
                if(b.getId() == v.getId() && b.getTag().equals("country")){
                    b.setEnabled(true);
                    v.setEnabled(false);
                    }
        case 2:
            for(Button b: buttons) {
                if(b.getId() == v.getId() && b.getTag().equals("age")){
                    b.setEnabled(true);
                    v.setEnabled(false);
                    }
                }
            }
        }


private void setDynamicContentViewOfThisPage() {
    // Defining the Scroll View and the LinearLayout
    ScrollView sv = new ScrollView(this);
    LinearLayout l = new LinearLayout(this);
    l.setOrientation(LinearLayout.VERTICAL);
    sv.addView(l);

                                for(int i = 1; i <= 2 ; i++) {

                                  Button button1 = new Button(this);
                                  button1.setId(i);
                                  button1.setTag("age");
                                  buttons.add(button1);
                                  l.addView(button1);

                                  Button button2 = new Button(this);
                                  button2.setId(i);
                                  button2.setTag("country");
                                  buttons.add(button2);
                                  l.addView(button2);

                                  button.setOnClickListener(this);
                                  button2.setOnClickListener(this);

    // Set the content View to this
        this.setContentView(sv);
    }
   }
 }

Recognizing a button from a dynamic view

2 Answers2

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