Android: AutoCompleteTextView show suggestions when no text entered

Question

This is documented behavior:

When threshold is less than or equals 0, a threshold of 1 is applied.

You can manually show the drop-down via showDropDown(), so perhaps you can arrange to show it when you want. Or, subclass AutoCompleteTextView and override enoughToFilter(), returning true all of time.

Here is my class InstantAutoComplete. It's something between AutoCompleteTextView and Spinner.

import android.content.Context;  
import android.graphics.Rect;
import android.util.AttributeSet;
import android.widget.AutoCompleteTextView;

public class InstantAutoComplete extends AutoCompleteTextView {

    public InstantAutoComplete(Context context) {
        super(context);
    }

    public InstantAutoComplete(Context arg0, AttributeSet arg1) {
        super(arg0, arg1);
    }

    public InstantAutoComplete(Context arg0, AttributeSet arg1, int arg2) {
        super(arg0, arg1, arg2);
    }

    @Override
    public boolean enoughToFilter() {
        return true;
    }

    @Override
    protected void onFocusChanged(boolean focused, int direction,
            Rect previouslyFocusedRect) {
        super.onFocusChanged(focused, direction, previouslyFocusedRect);
        if (focused && getAdapter() != null) {
            performFiltering(getText(), 0);
        }
    }

}

Use it in your xml like this:

<your.namespace.InstantAutoComplete ... />

Easiest way:

Just use setOnTouchListener and showDropDown()

AutoCompleteTextView text;
.....
.....
text.setOnTouchListener(new View.OnTouchListener(){
   @Override
   public boolean onTouch(View v, MotionEvent event){
      text.showDropDown();
      return false;
   }
});

Destil's code works just great when there is only one InstantAutoComplete object. It didn't work with two though - no idea why. But when I put showDropDown() (just like CommonsWare advised) into onFocusChanged() like this:

@Override
protected void onFocusChanged(boolean focused, int direction,
        Rect previouslyFocusedRect) {
    super.onFocusChanged(focused, direction, previouslyFocusedRect);
    if (focused) {
        performFiltering(getText(), 0);
        showDropDown();
    }
}

it solved the problem.

It is just the two answers properly combined, but I hope it may save somebody some time.