php短视频源码Android手绘电子签名

 /**
     * 清空签名
     */
    public void clear() {
        if (mCanvas != null) {
            isTouched = false;
            mPaint.setColor(mPenColor);
            mCanvas.drawColor(mBackColor, PorterDuff.Mode.CLEAR);
            mPaint.setColor(mPenColor);
            invalidate();
        }
    }
 
    /**
     * 保存图片
     * @param path 保存的地址
     * @param clearBlank 是否清除空白区域
     * @param blank 空白区域留空距离
     */
    public void save(String path, boolean clearBlank, int blank) throws IOException {
        if (TextUtils.isEmpty(path)) {
            return;
        }
        mSavePath = path;
        Bitmap bitmap = cacheBitmap;
        if (clearBlank) {
            bitmap = clearBlank(bitmap, blank);
        }
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.PNG, 100, bos);
        byte[] buffer = bos.toByteArray();
        if (buffer != null) {
            File file = new File(path);
            if (file.exists()) {
                file.delete();
            }
            OutputStream os = new FileOutputStream(file);
            os.write(buffer);
            os.close();
            bos.close();
        }
    }
 
    /**
     * 获取Bitmap缓存
     */
    public Bitmap getBitmap() {
        setDrawingCacheEnabled(true);
        buildDrawingCache();
        Bitmap bitmap = getDrawingCache();
        setDrawingCacheEnabled(false);
        return bitmap;
    }
 
    /**
     * 获取保存路径
     */
    public String getSavePath() {
        return mSavePath;
    }
 
    /**
     * 逐行扫描，清除边界空白
     */
    private Bitmap clearBlank(Bitmap bmp, int blank) {
        int height = bmp.getHeight();
        int width = bmp.getWidth();
        int top = 0, left = 0, right = 0, bottom = 0;
        int[] pixs = new int[width];
        boolean isStop;
        //扫描上边距不等于背景颜色的第一个点
        for (int i = 0; i < height; i++) {
            bmp.getPixels(pixs, 0, width, 0, i, width, 1);
            isStop = false;
            for (int pix :
                pixs) {
                if (pix != mBackColor) {
                    top = i;
                    isStop = true;
                    break;
                }
            }
            if (isStop) {
                break;
            }
        }
        //扫描下边距不等于背景颜色的第一个点
        for (int i = height - 1; i >= 0; i--) {
            bmp.getPixels(pixs, 0, width, 0, i, width, 1);
            isStop = false;
            for (int pix :
                pixs) {
                if (pix != mBackColor) {
                    bottom = i;
                    isStop = true;
                    break;
                }
            }
            if (isStop) {
                break;
            }
        }
        pixs = new int[height];
        //扫描左边距不等于背景颜色的第一个点
        for (int x = 0; x < width; x++) {
            bmp.getPixels(pixs, 0, 1, x, 0, 1, height);
            isStop = false;
            for (int pix : pixs) {
                if (pix != mBackColor) {
                    left = x;
                    isStop = true;
                    break;
                }
            }
            if (isStop) {
                break;
            }
        }
        //扫描右边距不等于背景颜色的第一个点
        for (int x = width - 1; x > 0; x--) {
            bmp.getPixels(pixs, 0, 1, x, 0, 1, height);
            isStop = false;
            for (int pix : pixs) {
                if (pix != mBackColor) {
                    right = x;
                    isStop = true;
                    break;
                }
            }
            if (isStop) {
                break;
            }
        }
        if (blank < 0) {
            blank = 0;
        }
        //计算加上保留空白距离之后的图像大小
        left = left - blank > 0 ? left - blank : 0;
        top = top - blank > 0 ? top - blank : 0;
        right = right + blank > width - 1 ? width - 1 : right + blank;
        bottom = bottom + blank > height - 1 ? height - 1 : bottom + blank;
        return Bitmap.createBitmap(bmp, left, top, right - left, bottom - top);
    }
 
    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        cacheBitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);
        mCanvas = new Canvas(cacheBitmap);
        mCanvas.drawColor(mBackColor);
        isTouched = false;
    }
 
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        canvas.drawBitmap(cacheBitmap, 0, 0, mPaint);
        canvas.drawPath(mPath, mPaint);
    }
 
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mPenX = event.getX();
                mPenY = event.getY();
                mPath.moveTo(mPenX, mPenY);
                return true;
            case MotionEvent.ACTION_MOVE:
                isTouched = true;
                float x = event.getX();
                float y = event.getY();
                float preX = mPenX;
                float preY = mPenY;
                float dx = Math.abs(x - preX);
                float dy = Math.abs(y - preY);
                if (dx >= 3 || dy >= 3) {
                    float cx = (x + preX) / 2;
                    float cy = (y + preY) / 2;
                    mPath.quadTo(preX, preY, cx, cy);
                    mPenX = x;
                    mPenY = y;
                }
                invalidate();
                break;
            case MotionEvent.ACTION_UP:
                mCanvas.drawPath(mPath, mPaint);
                mPath.reset();
                break;
            default:
                break;
        }
 
        return super.onTouchEvent(event);
    }