How to create Custom Ratings bar in Android

Question

Hello all i need to perform Ratings in my application... SO i need to create custom Ratings bar... Can Anyone Help me in this?

Answer 1

Making the custom rating bar with layer list and selectors is complex, it is better to override the RatingBar class and create a custom RatingBar. createBackgroundDrawableShape() is the function where you should put your empty state png and createProgressDrawableShape() is the function where you should put your filled state png.

Note: This code will not work with svg for now.

public class CustomRatingBar extends RatingBar {

    @Nullable
    private Bitmap mSampleTile;

    public ShapeDrawableRatingBar(final Context context, final AttributeSet attrs) {
        super(context, attrs);
        setProgressDrawable(createProgressDrawable());
    }

    @Override
    protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        if (mSampleTile != null) {
            final int width = mSampleTile.getWidth() * getNumStars();
            setMeasuredDimension(resolveSizeAndState(width, widthMeasureSpec, 0), getMeasuredHeight());
        }
    }

    protected LayerDrawable createProgressDrawable() {
        final Drawable backgroundDrawable = createBackgroundDrawableShape();
        LayerDrawable layerDrawable = new LayerDrawable(new Drawable[]{
            backgroundDrawable,
            backgroundDrawable,
            createProgressDrawableShape()
        });

        layerDrawable.setId(0, android.R.id.background);
        layerDrawable.setId(1, android.R.id.secondaryProgress);
        layerDrawable.setId(2, android.R.id.progress);
        return layerDrawable;
    }

    protected Drawable createBackgroundDrawableShape() {
        final Bitmap tileBitmap = drawableToBitmap(getResources().getDrawable(R.drawable.ic_star_empty));
        if (mSampleTile == null) {
            mSampleTile = tileBitmap;
        }
        final ShapeDrawable shapeDrawable = new ShapeDrawable(getDrawableShape());
        final BitmapShader bitmapShader = new BitmapShader(tileBitmap, Shader.TileMode.REPEAT, Shader.TileMode.CLAMP);
        shapeDrawable.getPaint().setShader(bitmapShader);
        return shapeDrawable;
    }

    protected Drawable createProgressDrawableShape() {
        final Bitmap tileBitmap = drawableToBitmap(getResources().getDrawable(R.drawable.ic_star_full));
        final ShapeDrawable shapeDrawable = new ShapeDrawable(getDrawableShape());
        final BitmapShader bitmapShader = new BitmapShader(tileBitmap, Shader.TileMode.REPEAT, Shader.TileMode.CLAMP);
        shapeDrawable.getPaint().setShader(bitmapShader);
        return new ClipDrawable(shapeDrawable, Gravity.LEFT, ClipDrawable.HORIZONTAL);
    }

    Shape getDrawableShape() {
        final float[] roundedCorners = new float[]{5, 5, 5, 5, 5, 5, 5, 5};
        return new RoundRectShape(roundedCorners, null, null);
    }

    public static Bitmap drawableToBitmap(Drawable drawable) {
        if (drawable instanceof BitmapDrawable) {
            return ((BitmapDrawable) drawable).getBitmap();
        }

        int width = drawable.getIntrinsicWidth();
        width = width > 0 ? width : 1;
        int height = drawable.getIntrinsicHeight();
        height = height > 0 ? height : 1;

        final Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        final Canvas canvas = new Canvas(bitmap);
        drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
        drawable.draw(canvas);

        return bitmap;
    }
}