Android 监控FPS — Choreographer

package com.suzaku.ndk.anrtest;

import android.view.Choreographer;

/**
 * @Author: kai.xu
 * @CreateDate: 2022/5/19 3:49 下午
 * @Description:
 */
public class FPSWatcher {

    public interface Watcher {
        void watch(int fps);
    }

    private long mLastFrameTimeNanos = 0;
    private boolean isRunning = false;
    private Watcher watcher;

    private FPSWatcher() {
    }

    public void addWatcher(Watcher watcher) {
        this.watcher = watcher;
    }

    public void start() {
        if (isRunning) {
            return;
        }
        mLastFrameTimeNanos = 0;
        isRunning = true;
        Choreographer.getInstance().postFrameCallback(frameCallback);
    }

    public void stop() {
        mLastFrameTimeNanos = 0;
        isRunning = false;
    }

    Choreographer.FrameCallback frameCallback = new Choreographer.FrameCallback() {
        @Override
        public void doFrame(long frameTimeNanos) {
            //初始化时间
            if (mLastFrameTimeNanos != 0) {
                final long jitterNanos = frameTimeNanos - mLastFrameTimeNanos;
                if (jitterNanos != 0) {
                    int fps = (int) ((1000000000.0 / jitterNanos) + 0.999);
                    if (watcher != null) {
                        watcher.watch(fps);
                    }
                }
            }
            mLastFrameTimeNanos = frameTimeNanos;
            //注册下一帧
            if (isRunning) {
                Choreographer.getInstance().postFrameCallback(this);
            }
        }
    };

    static class Inner {
        private static final FPSWatcher watcher = new FPSWatcher();
    }

    public static FPSWatcher get() {
        return Inner.watcher;
    }
}