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.

Answer 1

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);
    }
}