android 仿弹幕功能实现（小记）

上周无意在郭神的博客中发现一篇关于弹幕的文章，自己想动手试试

效果图如下：

首先第一步引入依赖：

compile 'com.github.ctiao:DanmakuFlameMaster:0.5.3'

android studio 升级为3.0以上的版本依赖添加可以换成：

implementation 'com.github.ctiao:DanmakuFlameMaster:0.5.3'

布局很简单一个videoView +上我们引入依赖的DanmakuView 即可

首先 xml侧代码：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">


    <VideoView
        android:id="@+id/vv"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <master.flame.danmaku.ui.widget.DanmakuView
        android:id="@+id/dan_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />


    <LinearLayout
        android:id="@+id/operation_layout"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:layout_alignParentBottom="true"
        android:background="#fff"
        android:visibility="gone">

        <EditText
            android:id="@+id/edit_text"
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:layout_weight="1"
            />

        <Button
            android:id="@+id/send"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:text="Send" />
    </LinearLayout>
</RelativeLayout>

注：郭神的里面设置的启动横屏，我的没有设置，横屏可参考郭神的博客:https://blog.youkuaiyun.com/guolin_blog/article/details/51933728

java侧代码：

package com.example.rxjavademo;

import android.graphics.Color;
import android.net.Uri;
import android.os.Build;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.VideoView;

import java.util.Random;

import master.flame.danmaku.controller.DrawHandler;
import master.flame.danmaku.danmaku.model.BaseDanmaku;
import master.flame.danmaku.danmaku.model.DanmakuTimer;
import master.flame.danmaku.danmaku.model.IDanmakus;
import master.flame.danmaku.danmaku.model.android.DanmakuContext;
import master.flame.danmaku.danmaku.model.android.Danmakus;
import master.flame.danmaku.danmaku.parser.BaseDanmakuParser;
import master.flame.danmaku.ui.widget.DanmakuView;

public class MainActivity extends AppCompatActivity {

    private boolean showDanmaku;

    private DanmakuView danmakuView;

    private DanmakuContext danmakuContext;

    private BaseDanmakuParser parser = new BaseDanmakuParser() {
        @Override
        protected IDanmakus parse() {
            return new Danmakus();
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        VideoView videoView =  findViewById(R.id.vv);

        final LinearLayout operationLayout =  findViewById(R.id.operation_layout);
        final Button send =  findViewById(R.id.send);
        final EditText editText =  findViewById(R.id.edit_text);

//        videoView.setVideoPath(Environment.getExternalStorageDirectory() + "/mnt/shared/Other/wildlife.mp4");
        videoView.setVideoURI(Uri.parse("android.resource://"+getPackageName()+"/"+R.raw.wildlife));
        videoView.start();

        danmakuView =  findViewById(R.id.dan_view);
        danmakuView.enableDanmakuDrawingCache(true);


        danmakuView.setCallback(new DrawHandler.Callback() {
            @Override
            public void prepared() {
                showDanmaku = true;
                danmakuView.start();
                generateSomeDanmaku();
            }

            @Override
            public void updateTimer(DanmakuTimer timer) {

            }

            @Override
            public void danmakuShown(BaseDanmaku danmaku) {

            }

            @Override
            public void drawingFinished() {

            }
        });
        danmakuContext = DanmakuContext.create();
        danmakuView.prepare(parser, danmakuContext);

        danmakuView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (operationLayout.getVisibility() == View.GONE) {
                    operationLayout.setVisibility(View.VISIBLE);
                } else {
                    operationLayout.setVisibility(View.GONE);
                }
            }
        });

        send.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String content = editText.getText().toString();
                if (!TextUtils.isEmpty(content)) {
                    addDanmaku(content, true);
                    editText.setText("");
                }
            }
        });

        getWindow().getDecorView().setOnSystemUiVisibilityChangeListener(new View.OnSystemUiVisibilityChangeListener() {
            @Override
            public void onSystemUiVisibilityChange(int visibility) {
                if (visibility == View.SYSTEM_UI_FLAG_VISIBLE) {
                    onWindowFocusChanged(true);
                }
            }
        });
    }

    /**
     * 向弹幕View中添加一条弹幕
     * @param content
     *          弹幕的具体内容
     * @param  withBorder
     *          弹幕是否有边框
     */
    private void addDanmaku(String content, boolean withBorder) {
        BaseDanmaku danmaku = danmakuContext.mDanmakuFactory.createDanmaku(BaseDanmaku.TYPE_SCROLL_RL);
        danmaku.text = content;
        danmaku.padding = 5;
        danmaku.textSize = sp2px(20);
        danmaku.textColor = Color.WHITE;
        danmaku.setTime(danmakuView.getCurrentTime());
        if (withBorder) {
            danmaku.borderColor = Color.GREEN;
        }
        danmakuView.addDanmaku(danmaku);
    }


    /**
     * 随机生成一些弹幕内容以供测试
     */
    private void generateSomeDanmaku() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                while(showDanmaku) {
                    int time = new Random().nextInt(300);
                    String content = "" + time + time;
                    addDanmaku(content, false);
                    try {
                        Thread.sleep(time);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        }).start();
    }

    /**
     * sp转px的方法。
     */
    public int sp2px(float spValue) {
        final float fontScale = getResources().getDisplayMetrics().scaledDensity;
        return (int) (spValue * fontScale + 0.5f);
    }

    @Override
    protected void onPause() {
        super.onPause();
        if (danmakuView != null && danmakuView.isPrepared()) {
            danmakuView.pause();
        }
    }

    @Override
    protected void onResume() {
        super.onResume();
        if (danmakuView != null && danmakuView.isPrepared() && danmakuView.isPaused()) {
            danmakuView.resume();
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        showDanmaku = false;
        if (danmakuView != null) {
            danmakuView.release();
            danmakuView = null;
        }
    }

    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        super.onWindowFocusChanged(hasFocus);
        if (hasFocus && Build.VERSION.SDK_INT >= 19) {
            View decorView = getWindow().getDecorView();
            decorView.setSystemUiVisibility(
                    View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                            | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                            | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                            | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
                            | View.SYSTEM_UI_FLAG_FULLSCREEN
                            | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY);
        }
    }
}

视频资源我这边就不提供了你们可以随意去下载个视频加入到项目中即可。

参考博客：https://blog.youkuaiyun.com/guolin_blog/article/details/51933728

model下载：https://download.youkuaiyun.com/download/qq_36636969/10530528