Libgdx使用ShapeRenderer自定义Actor，无法接收到Touch事件

今天在项目中实现了一个效果，主要是画一个圆。为了后续使用方便，将这个圆封装在一个自定义Actor(CircleActot)中，后续想显示一个圆的时候，只要创建一个CircleActor中即可。 部分代码如下所示：

package com.ef.smallstar.unitmap.widget;

import android.content.res.Resources;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.g2d.Batch;
import com.badlogic.gdx.graphics.g2d.BitmapFont;
import com.badlogic.gdx.graphics.glutils.ShapeRenderer;
import com.badlogic.gdx.scenes.scene2d.Actor;
import com.ef.smallstar.EFApplication;
import com.ef.smallstar.R;

/**
 * Created by ext.danny.jiang on 17/4/17.
 *
 * A Widget currently used in the UnitMap, shown as a CIRCLE shape
 * if text not null, there would be a text drawn in the center of the circle
 */

public class CircleActor extends Actor {

private float centerX;
private float centerY;
private String text;
private float radius;

private ShapeRenderer sr;
private BitmapFont bitmapFont;

public CircleActor(float x, float y, float radius) {
this(x, y, radius, null);
    }

public CircleActor(float x, float y, float radius, String text) {
this.centerX = x;
this.centerY = y;
this.radius = radius;
this.text = text;

        sr = new ShapeRenderer();
    }

@Override
public void act(float delta) {
super.act(delta);
    }

@Override
public void draw(Batch batch, float parentAlpha) {
        ...

        batch.end();

        sr.setProjectionMatrix(batch.getProjectionMatrix());
        sr.setTransformMatrix(batch.getTransformMatrix());

        sr.begin(ShapeRenderer.ShapeType.Filled);

        sr.circle(centerX, centerY, radius);

        sr.end();

        batch.begin();

        ...
    }

然后创建一个Stage对象，并将CircleActor对象添加到Stage中即可显示。 但是无法给此CircleActor对象添加一个ClickLitener监听。例如如下代码：

Stage stage = new Stage();

CircleActor ca = new CircleActor(100, 100, 50, "Hello World");
ca.addListener(new ClickListener(){
public void click(){
        Gdx.app.log("TAG", "ca is clicked");
    }
})

stage.add(ca);

上述代码中的click方法永远无法被调用！ 后续调了大半天之后终于弄清楚了原因：虽然在CircleActor的draw方法中通过ShapeRenderer.circle方法将一个圆画到了屏幕上的某一位置，但是此ShapeRenderer其实和Actor之间并没有太多的联系。唯一的联系就是以下两句代码, 意思应该是将ShapeRenderer的camera和Actor对象一致。

sr.setProjectionMatrix(batch.getProjectionMatrix());
sr.setTransformMatrix(batch.getTransformMatrix());

但是此时，CircleActor并没有设置真正的大小与位置， 因此解决上述问题，需要在构造器中将CircleActor的大小和位置与ShapeRenderer做到一致 !!

如下代码所示，只要添加两行代码即可：

public EfCircle(float x, float y, float radius, String text) {
this.centerX = x;
this.centerY = y;
this.radius = radius;
this.text = text;

//解决ShapeRenderer无法获取Touch事件
        setPosition(centerX - radius, centerY - radius);
        setSize(radius * 2, radius * 2);

        sr = new ShapeRenderer();
    }