Android RatingBar size

Question

I want to make a rating bar that can work and display properly at any dimentions given.

Android default RatingBar does not scale and any other solution i saw was to reduce or increase the RatingBar size with prededined drawables.

Is there any way to have a RatingBar that adapts to the dimentions givens and adapts to any dimentions?

Answer 1

Yes there is by creating a new widget that acts like a RatingBar.

There are some issues.

• Clipping path doesn't have AA
• And the coords of the stars are not ideal

but these issues can be fixed quite easily. Here is the code of the new RatingBar widget.

You can create as many starNumber as you want and they will adapt to it's layout dimentions.

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Path;
import android.util.AttributeSet;
import android.widget.SeekBar;

public class PRatingBar extends SeekBar {

    private int starNumber = 5;
    private float space;
    private int rating;
    private boolean firstTime = true;

    public PRatingBar(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        _init();
    }

    public PRatingBar(Context context, AttributeSet attrs) {
        super(context, attrs);
        _init();
    }

    public PRatingBar(Context context) {
        super(context);
        _init();

    }

    /**
     * @return the rating
     */
    public int getRating() {
        return rating;
    }

    /**
     * Sets the number of stars
     * 
     * @param starNumber
     */
    public void setStarNumber(int starNumber) {
        this.starNumber = starNumber;
    }

    private void _init() {
        setThumb(null);
        setOnSeekBarChangeListener(sbcl);
        post(new Runnable() {

            @Override
            public void run() {
                setProgress((int) space);
            }
        });
    }

    OnSeekBarChangeListener sbcl = new OnSeekBarChangeListener() {

        @Override
        public void onStopTrackingTouch(SeekBar seekBar) {
            rating = (int) (getProgress() / space) + 1;
            setProgress((int) (rating * space));
        }

        @Override
        public void onStartTrackingTouch(SeekBar seekBar) {
        }

        @Override
        public void onProgressChanged(SeekBar seekBar, int progress,
                boolean fromUser) {
        }
    };

    @Override
    protected synchronized void onDraw(Canvas canvas) {

        setMax(getWidth());
        canvas.clipPath(calculateStarPath());

        // TODO C'mon you can do better than that
        if (firstTime) {
            setProgress((int) space);
            firstTime = false;
        }

        super.onDraw(canvas);

    }

    private Path calculateStarPath() {
        Path path = new Path();

        space = getWidth() / starNumber;
        float centerY = (getHeight() / 2f) - (space / 2f);
        float step = space / 10;
        float startX;
        for (int i = 0; i < starNumber; i++) {
            startX = i * space;

            path.moveTo(startX + (step * 5), centerY + 0);

            path.lineTo(startX + (step * 3.3f), centerY + (step * 3.3f));

            path.lineTo(startX, centerY + (step * 4));

            path.lineTo(startX + (step * 2.3f), centerY + (step * 6.3f));

            path.lineTo(startX + +(step * 2), centerY + space);

            path.lineTo(startX + (step * 5), centerY + (step * 8.1f));

            path.lineTo(startX + +(step * 8), centerY + space);

            path.lineTo(startX + (step * 7.6f), centerY + (step * 6.3f));

            path.lineTo(startX + (step * 10), centerY + (step * 4));

            path.lineTo(startX + (step * 6.7f), centerY + (step * 3.3f));

            path.close();
        }
        return path;
    }

}