java类android.graphics.Region的实例源码

private void drawCurrentPageArea(Canvas canvas, Bitmap bitmap, Path path) {
    mPath0.reset();
    mPath0.moveTo(mBezierStart1.x, mBezierStart1.y);
    mPath0.quadTo(mBezierControl1.x, mBezierControl1.y, mBezierEnd1.x,
            mBezierEnd1.y);
    mPath0.lineTo(mTouch.x, mTouch.y);
    mPath0.lineTo(mBezierEnd2.x, mBezierEnd2.y);
    mPath0.quadTo(mBezierControl2.x, mBezierControl2.y, mBezierStart2.x,
            mBezierStart2.y);
    mPath0.lineTo(mCornerX, mCornerY);
    mPath0.close();

    canvas.save();
    canvas.clipPath(path, Region.Op.XOR);
    canvas.drawBitmap(bitmap, 0, 0, null);
    try {
        canvas.restore();
    } catch (Exception e) {

    }

}

@Override
protected void drawCurrentPageArea(Canvas canvas) {
    mPath0.reset();
    mPath0.moveTo(mBezierStart1.x, mBezierStart1.y);
    mPath0.quadTo(mBezierControl1.x, mBezierControl1.y, mBezierEnd1.x, mBezierEnd1.y);
    mPath0.lineTo(mTouch.x, mTouch.y);
    mPath0.lineTo(mBezierEnd2.x, mBezierEnd2.y);
    mPath0.quadTo(mBezierControl2.x, mBezierControl2.y, mBezierStart2.x, mBezierStart2.y);
    mPath0.lineTo(mCornerX, mCornerY);
    mPath0.close();

    canvas.save();
    canvas.clipPath(mPath0, Region.Op.XOR);
    canvas.drawBitmap(mCurPageBitmap, 0, 0, null);
    try {
        canvas.restore();
    } catch (Exception e) {

    }
}

public void draw(Canvas canvas, Paint paint, float opacity) {
  opacity *= mOpacity;
  if (opacity > MIN_OPACITY_FOR_DRAW) {
    saveAndSetupCanvas(canvas);

    if (mClipping != null) {
      canvas.clipRect(
        mClipping.left * mScale,
        mClipping.top * mScale,
        mClipping.right * mScale,
        mClipping.bottom * mScale,
        Region.Op.REPLACE);
    }

    for (int i = 0; i < getChildCount(); i++) {
      ARTVirtualNode child = (ARTVirtualNode) getChildAt(i);
      child.draw(canvas, paint, opacity);
      child.markUpdateSeen();
    }

    restoreCanvas(canvas);
  }
}

@Override
protected void drawNextPageAreaAndShadow(Canvas canvas) {
    canvas.save();
    if (actiondownX > mScreenWidth >> 1) {
        canvas.clipPath(mPath0);
        canvas.drawBitmap(mNextPageBitmap, 0, 0, null);
    } else {
        canvas.clipPath(mPath0, Region.Op.XOR);
        canvas.drawBitmap(mNextPageBitmap, 0, 0, null);
    }
    try {
        canvas.restore();
    } catch (Exception e) {

    }
}

public CardItemView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    mPaint.setStyle(Paint.Style.FILL);
    TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.Card, defStyleAttr, 0);
    mSize = ta.getDimensionPixelSize(R.styleable.Card_size, 10);
    mPaint.setColor(ta.getColor(R.styleable.Card_bgColor, 0));
    ta.recycle();

    mRegion = new Region();
    mDrawPath = new Path();

    mDrawPath.moveTo(0, mSize / 2);
    mDrawPath.lineTo(mSize / 2, 0);
    mDrawPath.lineTo(mSize, mSize / 2);
    mDrawPath.lineTo(mSize / 2, mSize);
    mDrawPath.close();
}

@Override
protected void dispatchDraw(Canvas canvas) {
    // Draw the background below children.
    if (mBackgroundAlpha > 0.0f) {
        // Update the scroll position first to ensure scrim cutout is in the right place.
        mLauncher.getWorkspace().computeScrollWithoutInvalidation();

        int alpha = (int) (mBackgroundAlpha * 255);
        CellLayout currCellLayout = mLauncher.getWorkspace().getCurrentDragOverlappingLayout();
        canvas.save();
        if (currCellLayout != null && currCellLayout != mLauncher.getHotseat().getLayout()) {
            // Cut a hole in the darkening scrim on the page that should be highlighted, if any.
            getDescendantRectRelativeToSelf(currCellLayout, mHighlightRect);
            canvas.clipRect(mHighlightRect, Region.Op.DIFFERENCE);
        }
        canvas.drawColor((alpha << 24) | SCRIM_COLOR);
        canvas.restore();
    }

    mFocusIndicatorHelper.draw(canvas);
    super.dispatchDraw(canvas);
}

private void drawCurrentPageArea(Canvas canvas, Bitmap bitmap, Path path) {
    mPath0.reset();
    mPath0.moveTo(mBezierStart1.x, mBezierStart1.y);
    mPath0.quadTo(mBezierControl1.x, mBezierControl1.y, mBezierEnd1.x,
            mBezierEnd1.y);
    mPath0.lineTo(mTouchX, mTouchY);
    mPath0.lineTo(mBezierEnd2.x, mBezierEnd2.y);
    mPath0.quadTo(mBezierControl2.x, mBezierControl2.y, mBezierStart2.x,
            mBezierStart2.y);
    mPath0.lineTo(mCornerX, mCornerY);
    mPath0.close();

    canvas.save();
    canvas.clipPath(path, Region.Op.XOR);
    canvas.drawBitmap(bitmap, 0, 0, null);
    try {
        canvas.restore();
    } catch (Exception e) {

    }

}

private void drawProgressRectWithClip(Canvas canvas) {
    mPaint.setColor(mProgressBarColor);
    mPaint.setStyle(Paint.Style.FILL);
    //根据进度比率计算出当前的进度值对应的宽度
    int progress = (int) (mValidWidth * (getProgress() * 1.0f / getMax()));
    canvas.save();
    canvas.translate(getPaddingLeft(), getPaddingTop());
    //裁剪圆角矩形路径
    drawRoundRectPath();
    canvas.clipPath(mRoundRectPath);//裁剪之后此时画布就变成了裁剪之后的圆角矩形
    //裁剪进度路径
    drawProgressPath(progress);
    canvas.clipPath(mProgressPath, Region.Op.INTERSECT);
    canvas.drawColor(mProgressBarColor);
    canvas.restore();
}

private void initData() {
    //关闭硬件加速，为了可以设置阴影
    setLayerType(LAYER_TYPE_SOFTWARE, null);

    mOuterPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    mOuterPaint.setStyle(Paint.Style.STROKE);
    mOuterPaint.setStrokeWidth(mOuterWidth);
    mOuterPaint.setColor(mOuterColor);


    mInnerPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    mInnerPaint.setStyle(Paint.Style.FILL_AND_STROKE);
    mInnerPaint.setColor(mInnerColor);


    mRegion = new Region();
    mViewPath = new Path();
}

/**
 * 绘制A区域水平翻页阴影
 * @param canvas
 */
private void drawPathAHorizontalShadow(Canvas canvas, Path pathA){
    canvas.restore();
    canvas.save();
    canvas.clipPath(pathA, Region.Op.INTERSECT);

    int maxShadowWidth = 30;//阴影矩形最大的宽度
    int left = (int) (a.x - Math.min(maxShadowWidth,(rPathAShadowDis/2)));
    int right = (int) (a.x);
    int top = 0;
    int bottom = viewHeight;
    GradientDrawable gradientDrawable = drawableHorizontalLowerRight;
    gradientDrawable.setBounds(left,top,right,bottom);

    float mDegrees = (float) Math.toDegrees(Math.atan2(f.x-a.x,f.y-h.y));
    canvas.rotate(mDegrees, a.x, a.y);
    gradientDrawable.draw(canvas);
}

/**
     * 绘制C区域内容
     * @param canvas
     * @param pathA
     */
    private void drawPathCContent(Canvas canvas, Path pathA){
        canvas.save();
        canvas.clipPath(pathA);
        canvas.clipPath(getPathC(), Region.Op.REVERSE_DIFFERENCE);//裁剪出C区域不同于A区域的部分
//        canvas.drawPath(getPathC(),pathCPaint);

        float eh = (float) Math.hypot(f.x - e.x,h.y - f.y);
        float sin0 = (f.x - e.x) / eh;
        float cos0 = (h.y - f.y) / eh;
        //设置翻转和旋转矩阵
        mMatrixArray[0] = -(1-2 * sin0 * sin0);
        mMatrixArray[1] = 2 * sin0 * cos0;
        mMatrixArray[3] = 2 * sin0 * cos0;
        mMatrixArray[4] = 1 - 2 * sin0 * sin0;

        mMatrix.reset();
        mMatrix.setValues(mMatrixArray);//翻转和旋转
        mMatrix.preTranslate(-e.x, -e.y);//沿当前XY轴负方向位移得到 矩形A₃B₃C₃D₃
        mMatrix.postTranslate(e.x, e.y);//沿原XY轴方向位移得到 矩形A4 B4 C4 D4
        canvas.drawBitmap(pathCContentBitmap, mMatrix, null);

        drawPathCShadow(canvas);
        canvas.restore();
    }

@Override
protected void dispatchDraw(Canvas canvas) {

    width = getWidth();
    height = getHeight();
    mClipPath.reset();
    if (position == ElasticDrawer.Position.LEFT) {
        drawLeftMenu();
    } else {
        drawRightMenu();
    }
    canvas.save();
    canvas.drawPath(mClipPath, mPaint);
    canvas.clipPath(mClipPath, Region.Op.REPLACE);
    super.dispatchDraw(canvas);
    canvas.restore();
}

@Override
public void draw(Canvas canvas) {
    int w = getWidth();
    int h = getHeight();
    canvas.clipPath(innerRoundPath(w, h), Region.Op.DIFFERENCE);
    super.draw(canvas);

    degree += speed;
    degree %= 360;
    matrix.setRotate(degree, w / 2, h / 2);
    shader.setLocalMatrix(matrix);
    rectF.left = 0;
    rectF.top = 0;
    rectF.right = w;
    rectF.bottom = h;
    canvas.drawRoundRect(rectF, radius, radius, paint);
    invalidate();

}

private void drawCurrentPageArea(Canvas canvas, Bitmap bitmap, Path path) {
    mPath0.reset();
    mPath0.moveTo(mBezierStart1.x, mBezierStart1.y);
    mPath0.quadTo(mBezierControl1.x, mBezierControl1.y, mBezierEnd1.x,
            mBezierEnd1.y);
    mPath0.lineTo(mTouchX, mTouchY);
    mPath0.lineTo(mBezierEnd2.x, mBezierEnd2.y);
    mPath0.quadTo(mBezierControl2.x, mBezierControl2.y, mBezierStart2.x,
            mBezierStart2.y);
    mPath0.lineTo(mCornerX, mCornerY);
    mPath0.close();

    canvas.save();
    canvas.clipPath(path, Region.Op.XOR);
    canvas.drawBitmap(bitmap, 0, 0, null);
    try {
        canvas.restore();
    } catch (Exception e) {

    }

}

private void drawMinutes(Canvas canvas, Path selectorPath, float alphaMod) {
    final int minutesAlpha = (int) (255f * mHoursToMinutes * alphaMod + 0.5f);
    if (minutesAlpha > 0) {
        // Exclude the selector region, then draw minutes with no
        // activated states.
        canvas.save(Canvas.CLIP_SAVE_FLAG);
        canvas.clipPath(selectorPath, Region.Op.DIFFERENCE);
        drawMinutesClipped(canvas, minutesAlpha, false);
        canvas.restore();

        // Intersect the selector region, then draw minutes with only
        // activated states.
        canvas.save(Canvas.CLIP_SAVE_FLAG);
        canvas.clipPath(selectorPath, Region.Op.INTERSECT);
        drawMinutesClipped(canvas, minutesAlpha, true);
        canvas.restore();
    }
}

@Override protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    super.onSizeChanged(w, h, oldw, oldh);
    mLayer = new RectF(0, 0, w, h);
    RectF areas = new RectF();
    areas.left = getPaddingLeft();
    areas.top = getPaddingTop();
    areas.right = w - getPaddingRight();
    areas.bottom = h - getPaddingBottom();
    mClipPath.reset();
    if (mRoundAsCircle) {
        float d = areas.width() >= areas.height() ? areas.height() : areas.width();
        float r = d / 2;
        PointF center = new PointF(w / 2, h / 2);
        mClipPath.addCircle(center.x, center.y, r, Path.Direction.CW);
        mClipPath.moveTo(-mEdgeFix, -mEdgeFix);  // 通过空操作让Path区域占满画布
        mClipPath.moveTo(w + mEdgeFix, h + mEdgeFix);
    } else {
        mClipPath.addRoundRect(areas, radii, Path.Direction.CW);
    }
    Region clip = new Region((int) areas.left, (int) areas.top,
                             (int) areas.right, (int) areas.bottom);
    mAreaRegion.setPath(mClipPath, clip);
}

/**
 * 绘制外发光阴影
 * 
 * @param canvas
 */
private void onDrawShadow(Canvas canvas)
{
    if (mShadowWidth > 0)
    {
        canvas.save();
        // 裁剪处理(使阴影矩形框内变为透明)
        if (mRoundRadius > 0)
        {
            canvas.clipRect(0, 0, getWidth(), getHeight());
            mTempRectF.set(mFrameRectF);
            mTempRectF.inset(mRoundRadius / 2f, mRoundRadius / 2f);
            canvas.clipRect(mTempRectF, Region.Op.DIFFERENCE);
        }
        // 绘制外发光阴影效果
        canvas.drawRoundRect(mFrameRectF, mRoundRadius, mRoundRadius, mShadowPaint);
        canvas.restore();
    }
}

@Override
protected void drawCurrentPageArea(Canvas canvas) {
    mPath0.reset();
    mPath0.moveTo(mBezierStart1.x, mBezierStart1.y);
    mPath0.quadTo(mBezierControl1.x, mBezierControl1.y, mBezierEnd1.x, mBezierEnd1.y);
    mPath0.lineTo(mTouch.x, mTouch.y);
    mPath0.lineTo(mBezierEnd2.x, mBezierEnd2.y);
    mPath0.quadTo(mBezierControl2.x, mBezierControl2.y, mBezierStart2.x, mBezierStart2.y);
    mPath0.lineTo(mCornerX, mCornerY);
    mPath0.close();

    canvas.save();
    canvas.clipPath(mPath0, Region.Op.XOR);
    canvas.drawBitmap(mCurPageBitmap, 0, 0, null);
    try {
        canvas.restore();
    } catch (Exception e) {

    }
}

@Override
protected void drawNextPageAreaAndShadow(Canvas canvas) {
    canvas.save();
    if (actiondownX > mScreenWidth >> 1) {
        canvas.clipPath(mPath0);
        canvas.drawBitmap(mNextPageBitmap, 0, 0, null);
    } else {
        canvas.clipPath(mPath0, Region.Op.XOR);
        canvas.drawBitmap(mNextPageBitmap, 0, 0, null);
    }
    try {
        canvas.restore();
    } catch (Exception e) {

    }
}

private void drawCurrentPageArea(Canvas canvas, Bitmap bitmap) {
    mPath1.reset();
    mPath1.moveTo(mBzStart1.x, mBzStart1.y);
    mPath1.quadTo(mBzControl1.x, mBzControl1.y, mBzEnd1.x,
            mBzEnd1.y);
    mPath1.lineTo(mTouch.x, mTouch.y);
    mPath1.lineTo(mBzEnd2.x, mBzEnd2.y);
    mPath1.quadTo(mBzControl2.x, mBzControl2.y, mBzStart2.x,
            mBzStart2.y);
    mPath1.lineTo(mCornerX, mCornerY);
    mPath1.close();

    canvas.save();
    canvas.clipPath(mPath1, Region.Op.XOR);
    canvas.drawBitmap(bitmap, 0, 0, null);
    canvas.restore();
}

@Override
public void draw(Canvas canvas) {
    int height = getBounds().height();
    int width = getBounds().width();

    // allow drawing out of bounds vertically
    Rect clipBounds = canvas.getClipBounds();
    clipBounds.inset(-12, -12);
    canvas.clipRect(clipBounds, Region.Op.REPLACE);

    RectF rect = new RectF(0.0f, 0.0f, width, height);

    // background
    canvas.drawRoundRect(rect, mRadius, mRadius, mPaintBg);

    // border
    canvas.drawRoundRect(rect, mRadius, mRadius, mPaintBorder);
}

private void drawTimeColumnAndAxes(Canvas canvas) {
    // Draw the background color for the header column.
    canvas.drawRect(0, mHeaderTextHeight + mHeaderRowPadding * 2, mHeaderColumnWidth, getHeight(), mHeaderColumnBackgroundPaint);

    // Clip to paint in left column only.
    canvas.clipRect(0, mHeaderTextHeight + mHeaderRowPadding * 2, mHeaderColumnWidth, getHeight(), Region.Op.REPLACE);

    for (int i = 0; i < 24; i++) {
        float top = mHeaderTextHeight + mHeaderRowPadding * 2 + mCurrentOrigin.y + mHourHeight * i + mHeaderMarginBottom;

        // Draw the text if its y position is not outside of the visible area. The pivot point of the text is the point at the bottom-right corner.
        String time = getDateTimeInterpreter().interpretTime(i);
        if (time == null)
            throw new IllegalStateException("A DateTimeInterpreter must not return null time");
        if (top < getHeight()) canvas.drawText(time, mTimeTextWidth + mHeaderColumnPadding, top + mTimeTextHeight, mTimeTextPaint);
    }
}

@Override
protected void dispatchDraw(Canvas canvas) {
    // Draw the background below children.
    if (mBackgroundAlpha > 0.0f) {
        // Update the scroll position first to ensure scrim cutout is in the right place.
        mLauncher.getWorkspace().computeScrollWithoutInvalidation();

        int alpha = (int) (mBackgroundAlpha * 255);
        CellLayout currCellLayout = mLauncher.getWorkspace().getCurrentDragOverlappingLayout();
        canvas.save();
        if (currCellLayout != null && currCellLayout != mLauncher.getHotseat().getLayout()) {
            // Cut a hole in the darkening scrim on the page that should be highlighted, if any.
            getDescendantRectRelativeToSelf(currCellLayout, mHighlightRect);
            canvas.clipRect(mHighlightRect, Region.Op.DIFFERENCE);
        }
        canvas.drawColor((alpha << 24) | SCRIM_COLOR);
        canvas.restore();
    }

    mFocusIndicatorHelper.draw(canvas);
    super.dispatchDraw(canvas);
}

@Override
    protected boolean drawChild(Canvas canvas, View child, long drawingTime) {
        Integer index = (Integer) child.getTag();
        VoronoiRegion region = mRegions.get(index);

        // firstly clip and draw children
        canvas.clipPath(region.path, Region.Op.REPLACE);
        boolean result = super.drawChild(canvas, child, drawingTime);

        // then draw borders
        if (mBorderEnabled)
            canvas.drawPath(region.path, p);

        // draw site
//        canvas.drawCircle((float)region.site.x, (float)region.site.y, 10, p);

        return result;
    }

private Bitmap clippedRotatedOval(Bitmap bitmap) {
    Bitmap bmp;
    float width = bitmap.getWidth();
    float height = bitmap.getHeight();

    bmp = Bitmap.createBitmap((int) width, (int) height, Bitmap.Config.ARGB_8888);
    BitmapShader shader = new BitmapShader(bitmap, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP);

    Canvas canvas = new Canvas(bmp);
    Paint paint = new Paint();
    paint.setAntiAlias(true);
    paint.setShader(shader);

    Path oval = new Path();
    Matrix matrix = new Matrix();
    Region region = new Region();
    RectF ovalRect = new RectF(width / OVAL_FACTOR, 0, width - (width / OVAL_FACTOR), height);

    oval.addOval(ovalRect, Path.Direction.CW);
    matrix.postRotate(ROTATION, width / 2, height / 2);
    oval.transform(matrix, oval);
    region.setPath(oval, new Region((int) width / 2, 0, (int) width, (int) height));
    canvas.drawPath(region.getBoundaryPath(), paint);

    return bmp;
}

public void draw(Canvas canvas, Paint paint, float opacity) {
  opacity *= mOpacity;
  if (opacity > MIN_OPACITY_FOR_DRAW) {
    saveAndSetupCanvas(canvas);

    if (mClipping != null) {
      canvas.clipRect(
        mClipping.left * mScale,
        mClipping.top * mScale,
        mClipping.right * mScale,
        mClipping.bottom * mScale,
        Region.Op.REPLACE);
    }

    for (int i = 0; i < getChildCount(); i++) {
      ARTVirtualNode child = (ARTVirtualNode) getChildAt(i);
      child.draw(canvas, paint, opacity);
      child.markUpdateSeen();
    }

    restoreCanvas(canvas);
  }
}

@Override
protected void draw(Canvas canvas, Rect bounds) {
    int saveCount = canvas.save();
    RectF arcBounds = mTempBounds;
    arcBounds.set(bounds);

    mPaint.setColor(mColor);

    //calculate fish clip bounds
    //clip the width of the fish need to increase mPathDottedLineSize * 1.2f
    RectF fishRectF = new RectF(mFishHeadPos[0] - mFishWidth / 2.0f - mPathDottedLineSize * 1.2f, mFishHeadPos[1] - mFishHeight / 2.0f,
            mFishHeadPos[0] + mFishWidth / 2.0f + mPathDottedLineSize * 1.2f, mFishHeadPos[1] + mFishHeight / 2.0f);
    Matrix matrix = new Matrix();
    matrix.postRotate(mFishRotateDegrees, fishRectF.centerX(), fishRectF.centerY());
    matrix.mapRect(fishRectF);

    //draw river
    int riverSaveCount = canvas.save();
    mPaint.setStyle(Paint.Style.STROKE);
    canvas.clipRect(fishRectF, Region.Op.DIFFERENCE);
    canvas.drawPath(createRiverPath(arcBounds), mPaint);
    canvas.restoreToCount(riverSaveCount);

    //draw fish
    int fishSaveCount = canvas.save();
    mPaint.setStyle(Paint.Style.FILL);
    canvas.rotate(mFishRotateDegrees, mFishHeadPos[0], mFishHeadPos[1]);
    canvas.clipPath(createFishEyePath(mFishHeadPos[0], mFishHeadPos[1] - mFishHeight * 0.06f), Region.Op.DIFFERENCE);
    canvas.drawPath(createFishPath(mFishHeadPos[0], mFishHeadPos[1]), mPaint);
    canvas.restoreToCount(fishSaveCount);

    canvas.restoreToCount(saveCount);
}

@Override
protected void drawNextPageAreaAndShadow(Canvas canvas) {
    mPath1.reset();
    mPath1.moveTo(mBezierStart1.x, mBezierStart1.y);
    mPath1.lineTo(mBeziervertex1.x, mBeziervertex1.y);
    mPath1.lineTo(mBeziervertex2.x, mBeziervertex2.y);
    mPath1.lineTo(mBezierStart2.x, mBezierStart2.y);
    mPath1.lineTo(mCornerX, mCornerY);
    mPath1.close();

    mDegrees = (float) Math.toDegrees(Math.atan2(mBezierControl1.x - mCornerX, mBezierControl2.y - mCornerY));
    int leftx;
    int rightx;
    GradientDrawable mBackShadowDrawable;
    if (mIsRTandLB) {  //左下及右上
        leftx = (int) (mBezierStart1.x);
        rightx = (int) (mBezierStart1.x + mTouchToCornerDis / 4);
        mBackShadowDrawable = mBackShadowDrawableLR;
    } else {
        leftx = (int) (mBezierStart1.x - mTouchToCornerDis / 4);
        rightx = (int) mBezierStart1.x;
        mBackShadowDrawable = mBackShadowDrawableRL;
    }
    canvas.save();
    try {
        canvas.clipPath(mPath0);
        canvas.clipPath(mPath1, Region.Op.INTERSECT);
    } catch (Exception e) {
    }


    canvas.drawBitmap(mNextPageBitmap, 0, 0, null);
    canvas.rotate(mDegrees, mBezierStart1.x, mBezierStart1.y);
    mBackShadowDrawable.setBounds(leftx, (int) mBezierStart1.y,
            rightx, (int) (mMaxLength + mBezierStart1.y));//左上及右下角的xy坐标值,构成一个矩形
    mBackShadowDrawable.draw(canvas);
    canvas.restore();
}

private boolean isEventInPath(MotionEvent event) {
    RectF bounds = new RectF();
    mDrawPath.computeBounds(bounds, true);
    mRegion.setPath(mDrawPath, new Region((int)bounds.left,
            (int)bounds.top, (int)bounds.right, (int)bounds.bottom));
    return mRegion.contains((int) event.getX(), (int) event.getY());
}

private void drawNextPageAreaAndShadow(Canvas canvas, Bitmap bitmap) {
    mPath1.reset();
    mPath1.moveTo(mBezierStart1.x, mBezierStart1.y);
    mPath1.lineTo(mBeziervertex1.x, mBeziervertex1.y);
    mPath1.lineTo(mBeziervertex2.x, mBeziervertex2.y);
    mPath1.lineTo(mBezierStart2.x, mBezierStart2.y);
    mPath1.lineTo(mCornerX, mCornerY);
    mPath1.close();

    mDegrees = (float) Math.toDegrees(Math.atan2(mBezierControl1.x
            - mCornerX, mBezierControl2.y - mCornerY));
    int leftx;
    int rightx;
    GradientDrawable mBackShadowDrawable;
    if (mIsRTandLB) {  //左下及右上
        leftx = (int) (mBezierStart1.x);
        rightx = (int) (mBezierStart1.x + mTouchToCornerDis / 4);
        mBackShadowDrawable = mBackShadowDrawableLR;
    } else {
        leftx = (int) (mBezierStart1.x - mTouchToCornerDis / 4);
        rightx = (int) mBezierStart1.x;
        mBackShadowDrawable = mBackShadowDrawableRL;
    }
    canvas.save();
    try {
        canvas.clipPath(mPath0);
        canvas.clipPath(mPath1, Region.Op.INTERSECT);
    } catch (Exception e) {
    }


    canvas.drawBitmap(bitmap, 0, 0, null);
    canvas.rotate(mDegrees, mBezierStart1.x, mBezierStart1.y);
    mBackShadowDrawable.setBounds(leftx, (int) mBezierStart1.y, rightx,
            (int) (mMaxLength + mBezierStart1.y));//左上及右下角的xy坐标值,构成一个矩形
    mBackShadowDrawable.draw(canvas);
    canvas.restore();
}