Android 可任意拖动的悬浮窗(类似悬浮球）

最近开发项目中，有个在屏幕上任意拖动的悬浮窗功能，其实就是利用 WindowManager的api来完成这个需求，具体的实现的功能如下：
1.自定义view

import android.content.Context;
import android.content.Intent;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.util.TypedValue;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.WindowManager;
import android.widget.LinearLayout;
import com.xinrui.recordscreen.R;

import java.lang.reflect.Field;

/**
 *
 */

public class RecordScreenView extends LinearLayout implements View.OnClickListener{
    private WindowManager mWindowManager;
    private WindowManager.LayoutParams mLayoutParams;
    private long mLastDownTime;
    private float mLastDownX;
    private float mLastDownY;
    private boolean mIsLongTouch;
    private boolean mIsTouching;
    private float mTouchSlop;
    private final static long LONG_CLICK_LIMIT = 20;
    private final static int TIME_COUNT = 0;
    private int mStatusBarHeight;
    private int mCurrentMode,time=0;
    private final static int MODE_NONE = 0x000;
    private final static int MODE_MOVE = 0x001;
    private int mOffsetToParent;
    private int mOffsetToParentY;
    private Context mContext;
    public RecordScreenView(Context context) {
        super(context);
        this.mContext=context;
        mWindowManager = (WindowManager) getContext().getSystemService(Context.WINDOW_SERVICE);
        initView();
    }

    private void initView() {
        View view = inflate(getContext(), R.layout.layout_ball, this)；
        mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();
        mCurrentMode = MODE_NONE;
        recordtime(0);
        mStatusBarHeight = getStatusBarHeight();
        mOffsetToParent = dip2px(25);
        mOffsetToParentY = mStatusBarHeight + mOffsetToParent;

        view.setOnTouchListener(new OnTouchListener() {
            @Override
            public boolean onTouch(View v, final MotionEvent event) {
                switch (event.getAction()) {
                    case MotionEvent.ACTION_DOWN:
                        mIsTouching = true;
                        mLastDownTime = System.currentTimeMillis();
                        mLastDownX = event.getX();
                        mLastDownY = event.getY();
                        postDelayed(new Runnable() {
                            @Override
                            public void run() {
                                if (isLongTouch()) {
                                    mIsLongTouch = true;
                                }
                            }
                        }, LONG_CLICK_LIMIT);
                        break;
                    case MotionEvent.ACTION_MOVE:
                        if (!mIsLongTouch && isTouchSlop(event)) {
                            return true;
                        }
                        if (mIsLongTouch && (mCurrentMode == MODE_NONE || mCurrentMode == MODE_MOVE)) {
                            mLayoutParams.x = (int) (event.getRawX() - mLastDownX);
                            mLayoutParams.y = (int) (event.getRawY() - mLastDownY);
                            mWindowManager.updateViewLayout(RecordScreenView.this, mLayoutParams);//不断刷新悬浮窗的位置
                            mCurrentMode = MODE_MOVE;
                        }
                        break;
                    case MotionEvent.ACTION_CANCEL:
                    case MotionEvent.ACTION_UP:
                        mIsTouching = false;
                        if (mIsLongTouch) {
                            mIsLongTouch = false;
                        }
                        mCurrentMode = MODE_NONE;
                        break;
                }
                return true;
            }
        });
    }

    private boolean isLongTouch() {
        long time = System.currentTimeMillis();
        if (mIsTouching && mCurrentMode == MODE_NONE && (time - mLastDownTime >= LONG_CLICK_LIMIT)) {
            return true;
        }
        return false;
    }

    /**
     * 判断是否是轻微滑动
     *
     * @param event
     * @return
     */
    private boolean isTouchSlop(MotionEvent event) {
        float x = event.getX();
        float y = event.getY();
        if (Math.abs(x - mLastDownX) < mTouchSlop && Math.abs(y - mLastDownY) < mTouchSlop) {
            return true;
        }
        return false;
    }

    public void setLayoutParams(WindowManager.LayoutParams params) {
        mLayoutParams = params;
    }

    /**
     * 获取通知栏高度
     *
     * @return
     */
    private int getStatusBarHeight() {
        int statusBarHeight = 0;
        try {
            Class<?> c = Class.forName("com.android.internal.R$dimen");
            Object o = c.newInstance();
            Field field = c.getField("status_bar_height");
            int x = (Integer) field.get(o);
            statusBarHeight = getResources().getDimensionPixelSize(x);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return statusBarHeight;
    }

    public int dip2px(float dip) {
        return (int) TypedValue.applyDimension(
                TypedValue.COMPLEX_UNIT_DIP, dip, getContext().getResources().getDisplayMetrics()
        );
    }
}

2.添加windowManager添加view

import android.content.Context;
import android.graphics.PixelFormat;
import android.view.Gravity;
import android.view.WindowManager;
import android.view.WindowManager.LayoutParams;

/**
 * Created by wangxiandeng on 2016/11/25.
 */

public class FloatWindowManager {
    private static RecordScreenView mBallView;

    private static WindowManager mWindowManager;


    public static void addBallView(Context context) {
        if (mBallView == null) {
            WindowManager windowManager = getWindowManager(context);
            int screenWidth = windowManager.getDefaultDisplay().getWidth();
            int screenHeight = windowManager.getDefaultDisplay().getHeight();
            mBallView = new RecordScreenView(context);
            LayoutParams params = new LayoutParams();
            params.x = screenWidth/2;
            params.y = screenHeight/2+150;
            params.width = LayoutParams.WRAP_CONTENT;
            params.height = LayoutParams.WRAP_CONTENT;
            params.gravity = Gravity.LEFT | Gravity.TOP;
            params.type = LayoutParams.TYPE_APPLICATION_OVERLAY;
            params.format = PixelFormat.RGBA_8888;
            params.flags = LayoutParams.FLAG_NOT_TOUCH_MODAL
                    | LayoutParams.FLAG_NOT_FOCUSABLE;
            mBallView.setLayoutParams(params);
            windowManager.addView(mBallView, params);
        }
    }

    public static void removeBallView(Context context) {
        if (mBallView != null) {
            WindowManager windowManager = getWindowManager(context);
            windowManager.removeView(mBallView);
            mBallView = null;
        }
    }

    private static WindowManager getWindowManager(Context context) {
        if (mWindowManager == null) {
            mWindowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        }
        return mWindowManager;
    }
}

3.Acitivity中调用

import android.app.Activity;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.provider.Settings;
import android.util.Log;
import android.widget.Toast;

import com.xinrui.recordscreen.view.FloatWindowManager;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (Build.VERSION.SDK_INT >= 23) {
        //设置中请求开启悬浮窗权限
            if (!Settings.canDrawOverlays(this)) {
                Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION);
                intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                startActivity(intent);
                Toast.makeText(this, MainActivity.this.getResources().getString(R.string.open_float), Toast.LENGTH_SHORT).show();
            }else{
                initView();
            }
        }
    }

    private void initView() {
        FloatWindowManager.addBallView(MainActivity.this);
        finish();
    }
}

5.AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.xinrui.recordscreen">
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>//悬浮窗权限
    <application
        android:allowBackup="true"
        android:icon="@drawable/recording_screen_nor"
        android:label="@string/app_name"
        android:supportsRtl="true">
        <activity android:name="com.xinrui.recordscreen.MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
</manifest>