A simple Android Rating View that extends LinearLayout and fill it with ImageViews

RatingView.java

package hco.widget;

import android.content.Context;
import android.graphics.Color;
import android.graphics.drawable.Drawable;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;

import hco.tools.SimplePool;

import static android.view.Gravity.CENTER;
import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
import static android.view.ViewGroup.LayoutParams.WRAP_CONTENT;
import static hco.utils.Uis.dp2px;
import static java.lang.Math.max;
import static java.lang.Math.min;
import static java.lang.Math.round;

public class RatingView extends LinearLayout {
private Drawable starEmptyDrawable;
private Drawable starFillDrawable;
private Drawable starHalfDrawable;
private int starImageSize = WRAP_CONTENT; // size<=0 (+ WRAP or MATH): add weight to star view
private boolean clickable = true;
private float rate = 0;
private OnRatingChangeListener onRatingChangeListener;

/** this simple pool I write from base you can use what pool you want */
private final SimplePool<ImageView> starViewPool = new SimplePool<ImageView>() {
	private final OnClickListener onClickListener = new OnClickListener() {
		@Override
		public void onClick(final View v) {
			if (clickable) {
				final int rate = RatingView.super.indexOfChild(v) + 1;
				setRate(rate);
				if (onRatingChangeListener != null)
					onRatingChangeListener.onRatingChange(rate);
			}
		}
	};

	@Override
	public ImageView newObject(final Object... params) {
		final ImageView item = new ImageView(getContext());
		item.setLayoutParams(new ViewGroup.LayoutParams(starImageSize, MATCH_PARENT));
		item.setPadding(0, 0, dp2px(2), 0);
		item.setImageDrawable(starEmptyDrawable);
		item.setOnClickListener(onClickListener);
		item.setAdjustViewBounds(true);
		item.setBackgroundColor(Color.RED);
		return item;
	}

	@Override
	protected void init(final ImageView item, final Object... params) {
		final LayoutParams layoutParams = item.getLayoutParams() instanceof LayoutParams ? (LayoutParams) item.getLayoutParams() : new LayoutParams(0, 0);
		layoutParams.width = starImageSize;
		layoutParams.height = MATCH_PARENT;
		layoutParams.weight = starImageSize > 0 ? 0 : 1;
		item.setLayoutParams(layoutParams);
	}
};

public RatingView(final Context context, final int starCount) {
	super(context);
	super.setGravity(CENTER);
	super.setOrientation(HORIZONTAL);
	super.setBackgroundColor(Color.BLACK);
	setStarCount(starCount);
}

/** I hate android xml based views */
public RatingView(final Context context) {
	this(context, 5);
}

public void setStarHalfDrawable(final Drawable starHalfDrawable) {
	this.starHalfDrawable = starHalfDrawable;
}

public void setOnRatingChangeListener(final OnRatingChangeListener onRatingChangeListener) {
	this.onRatingChangeListener = onRatingChangeListener;
}

public void setClickable(final boolean clickable) {
	this.clickable = clickable;
}

public void setStarFillDrawable(final Drawable starFillDrawable) {
	this.starFillDrawable = starFillDrawable;
}

public void setStarEmptyDrawable(final Drawable starEmptyDrawable) {
	this.starEmptyDrawable = starEmptyDrawable;
}

public void setStarImageSize(final int starImageSize) {
	this.starImageSize = starImageSize;
}

public void setStarCount(final int starCount) {
	if (super.getChildCount() == starCount)
		return;
	for (int i = 0; i < super.getChildCount(); i++)
		try {
			starViewPool.recycle((ImageView) getChildAt(i));
		} catch (final Throwable e) {
			e.printStackTrace();
		}
	super.removeAllViews();
	for (int i = 0; i < starCount; i++)
		super.addView(starViewPool.get());
	setRate();
}

public void setRate(float rate) {
	final int starCount = super.getChildCount();
	this.rate = rate = max(0, min(starCount, rate)); // [0,starCount]
	final int stars = round(rate);
	final boolean half = rate > stars; // x.y shows x.5 
	for (int i = 0; i < starCount; ++i)
		((ImageView) getChildAt(i)).setImageDrawable(i <= stars ? starFillDrawable : starEmptyDrawable);
	if (half)
		((ImageView) getChildAt(stars)).setImageDrawable(starHalfDrawable);
}

/** refresh rating */
public void setRate() {
	setRate(rate);
}

/** change stat listener */
public interface OnRatingChangeListener {
	void onRatingChange(final int RatingCount);
}
}