Android 左飞字幕的实现(带描边)

废话不多说,直接上代码:

public class FiveTextView extends TextView {
    /** 文字长度 */
    private float textLength = 0f;
    /** 滚动条长度 */
    private float viewWidth = 0f;
    /** 文本x轴 的坐标 */
    private float tx = 0f;
    /** 文本Y轴的坐标 */
    private float ty = 0f;
    /** 文本当前长度 */
    private float temp_tx1 = 0.0f;
    /** 文本当前变换的长度 */
    private float temp_tx2 = 0x0f;
    /** 文本滚动开关 */
    private boolean isStarting = false;
    /** 画笔对象 */
    private Paint paint = null;
    /** 显示的文字 */
    private String text = "";
    /** 文本滚动速度 **/
    private float sudu;

    private Paint strokPaint = null;

    private int strokeWidth;

    private int a;

    private int r;

    private int g;

    private int b;

    private int sa;

    private int sr;

    private int sg;

    private int sb;


    public FiveTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    /**
     * 初始化自动滚动条,每次改变文字内容时，都需要重新初始化一次
     *
     *            显示的内容
     * @param
     *
     */

    private void init() {

        strokPaint = new Paint(Paint.ANTI_ALIAS_FLAG);

        //设置抗锯齿
        strokPaint.setAntiAlias(true);

        //设置防抖动
        strokPaint.setDither(true);

        //设置填充方式
        strokPaint.setStyle(Paint.Style.FILL_AND_STROKE);

    }
    public void initScrollTextView(WindowManager windowManager, String text,
                                   float su,int a,int r,int g,int b,int height,String strokewidth,String strokecolor,int textsize) {
        // 得到画笔,获取父类的textPaint
        paint = this.getPaint();
        init();
        if (!"".equals(strokecolor)){
            String substring = strokecolor.substring(strokecolor.indexOf("(")+1, strokecolor.indexOf(")"));
            String trim = substring.replaceAll("\\s+","");
            String[] split1 = trim.split(",");
            this.sa = 255;
            this.sr = Integer.parseInt(split1[0]);
            this.sg = Integer.parseInt(split1[1]);
            this.sb = Integer.parseInt(split1[2]);
        }
        this.a = a;
        this.r = r;
        this.g = g;
        this.b = b;

        if (!"".equals(strokewidth)){
            this.strokeWidth = Integer.parseInt(strokewidth);
        }
        strokPaint.setTextSize(textsize);
        // 得到文字
        this.text = text;
        this.sudu = su;
        textLength = paint.measureText(text);// 获得当前文本字符串长度
        viewWidth = this.getWidth();// 获取宽度return mRight - mLeft;
        if (viewWidth == 0) {
            // 获取当前屏幕的属性
            Display display = windowManager.getDefaultDisplay();
            viewWidth = display.getWidth();// 获取屏幕宽度  viewWidth 是滚动的开始位置，需要修改的
            // 可再此入手
        }
        tx = textLength;
        temp_tx1 = viewWidth + textLength;
        temp_tx2 = viewWidth + new Double(textLength*2.8).intValue();// 自己定义，文字变化多少
        ty = height/2+this.getTextSize()/2;

        starScroll();
    }

    /**
     * 开始滚动
     */
    public void starScroll() {
        // 开始滚动
        isStarting = true;
        this.invalidate();// 刷新屏幕
    }

    /**
     * 停止方法,停止滚动
     */
    public void stopScroll() {
        // 停止滚动
        isStarting = false;
        this.invalidate();// 刷新屏幕
    }

    /** 重写onDraw方法 */
    @Override
    protected void onDraw(Canvas canvas) {

        if (isStarting) {
            strokPaint.setTextAlign(Paint.Align.CENTER);
            strokPaint.setStrokeWidth(strokeWidth);
            strokPaint.setARGB(sa,sr,sg,sb);
            canvas.drawText(text, temp_tx1 - tx, ty, strokPaint);
            // A-Alpha透明度/R-Read红色/g-Green绿色/b-Blue蓝色
            strokPaint.setARGB(a,r,g,b);
            strokPaint.setStrokeWidth(0);
            canvas.drawText(text, temp_tx1 - tx, ty, strokPaint);
            tx += sudu;
            // 当文字滚动到屏幕的最左边
            if (tx > temp_tx2) {
                // 把文字设置到最右边开始
                tx = textLength;
            }
            this.invalidate();// 刷新屏幕
        }
//        super.onDraw(canvas);
    }
} 

在activity中使用:

FiveTextView fiveTextView = new FiveTextView(MainActivity.this, null);
fiveTextView.initScrollTextView(getWindowManager(),"会移动的描边字幕",3,255,98,0,238,350,"2","rgba(255,13,13,1)",30);

mParams.x = 0;
mParams.y = 0;
mParams.width = 1000;
mParams.height =350;
wManager.addView(fiveTextView,mParams);

附加:

windowmanager初始化方法:

private void initWindowManager() {
    wManager = (WindowManager) getApplicationContext().getSystemService(Context.WINDOW_SERVICE);
    mParams = new WindowManager.LayoutParams();
    mParams.gravity = Gravity.TOP | Gravity.LEFT;
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        mParams.type = WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY;
    }else {
        mParams.type = WindowManager.LayoutParams.TYPE_SYSTEM_ALERT;
    }
    mParams.format = PixelFormat.TRANSLUCENT;
    mParams.flags = WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN
            | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE;
}

完事,收工!