CODEWITHSUNDEEP
androidviewandroid-activity
Phillip
Phillip

Reputation: 5656

Calling findViewById() from outside an activity

Is there any way to access a layout's view from a non-Activity-derived class? I'm creating an Accordion class and need to access some of the activity's UI elements. I'm passing in the activity's context to my accordion class's constructor, but the findViewById API is only available from the Activity class. I also don't want to pass in an instance of my activity since that seems to be frowned upon due to potential memory leaks.

Upvotes: 15

Views: 27002

Answers (4)

Nicco Simone
Nicco Simone

Reputation: 181

I'm pretty sure you can just pass an activity as a parameter, e.g.

public void initSouthViews(Activity activity) {
    for (int i = 0; i < southScores_.length; ++i) {
        southScores_[i] = (EditText) activity.findViewById(10);
    }
}

Upvotes: 18

Phillip
Phillip

Reputation: 5656

I passed in an instance of one of the Views into the class's constructor.

Upvotes: 1

Jordy Langen
Jordy Langen

Reputation: 3591

Here is something that might be helpful.

public interface IViewRequest {

    public View requestViewByID(int id);
}

public class MyActivity extends Activity {

    private IViewRequest viewRequest = new IViewRequest(){

    public View requestViewByID(int id){
        return findViewById(id);
    });
}

public class Accordion(){

    private IViewRequest viewRequest;

    public Accordion(IViewRequest viewRequest){
        this.viewRequest = viewRequest;
    }

    private View findViewById(int id){
        return viewRequest.requestViewByID(id);
    }
}

I have never tried something like this. I also don't know if it won't cuase any memory leaks. But it does what you asked :) "Calling findViewById() from outside an activity"

Upvotes: 3

LordTwaroog
LordTwaroog

Reputation: 1738

Activity's context is in fact the Activity class itself. Assuming that this object will live inside only one Activity, it should be safe to pass object of type Activity to it. Otherwise, think about reengineering your Accordion class.

Upvotes: 2

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