Question

I’ve been trying to create a custom view that is to be used to indicate the battery level of a proprietary device.

So when the battery level of the device is read the method setPercentage(int batteryLevel) is called on the custom view :

The problem is that regardless of what value I set nothing seems to change in the custom view.

Here is the class :

public class RectangleView extends LinearLayout {
    private ArrayList<ImageView> views = new ArrayList<ImageView>();

    public RectangleView(Context context, AttributeSet attributeSet) {
        super(context, attributeSet);
        init(context);
    }

    public RectangleView(Context context) {
        super(context);
        init(context);
    }

    private void init(Context context) {
        this.setOrientation(LinearLayout.HORIZONTAL);
        for (int i = 0; i < 10; i++) {
            ImageView loadingPiece = new ImageView(context);
            loadingPiece.setBackgroundColor(Color.BLACK);
            this.addView(loadingPiece);
            LayoutParams layoutParams = (LayoutParams)loadingPiece.getLayoutParams();
            layoutParams.weight = 1.0f;
            layoutParams.height = this.getHeight();
            layoutParams.width = 0;
            loadingPiece.setLayoutParams(layoutParams);
            views.add(loadingPiece);
        }
    }

    public void setPercentage(int amountToShow) {
        for (int i = 0; i < views.size(); i++) 
            if (i < amountToShow)
                views.get(i).setVisibility(View.VISIBLE);
            else
                views.get(i).setVisibility(View.INVISIBLE);
    }
}

Caling setPersentage(5) should show 5 imageviews – However nothing is changed and the view itself seems empty.

Answer 1

I think that happens because of the LayoutParams you used(getHeight() returning 0 at that moment). See if this makes a difference:

    this.setOrientation(LinearLayout.HORIZONTAL);
    for (int i = 0; i < 10; i++) {
        ImageView loadingPiece = new ImageView(context);
        loadingPiece.setBackgroundColor(Color.BLACK);
        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(0,
            LinearLayout.LayoutParams.FILL_PARENT, 1.0f);
        this.addView(loadingPiece, lp);   
        views.add(loadingPiece);        
    }