ShadowDrawableWrapper.java 文件源码

private void buildShadowCorners() {
    RectF innerBounds = new RectF(-this.mCornerRadius, -this.mCornerRadius, this.mCornerRadius, this.mCornerRadius);
    RectF outerBounds = new RectF(innerBounds);
    outerBounds.inset(-this.mShadowSize, -this.mShadowSize);
    if (this.mCornerShadowPath == null) {
        this.mCornerShadowPath = new Path();
    } else {
        this.mCornerShadowPath.reset();
    }
    this.mCornerShadowPath.setFillType(FillType.EVEN_ODD);
    this.mCornerShadowPath.moveTo(-this.mCornerRadius, 0.0f);
    this.mCornerShadowPath.rLineTo(-this.mShadowSize, 0.0f);
    this.mCornerShadowPath.arcTo(outerBounds, 180.0f, 90.0f, false);
    this.mCornerShadowPath.arcTo(innerBounds, 270.0f, -90.0f, false);
    this.mCornerShadowPath.close();
    float shadowRadius = -outerBounds.top;
    if (shadowRadius > 0.0f) {
        float startRatio = this.mCornerRadius / shadowRadius;
        float midRatio = startRatio + ((1.0f - startRatio) / 2.0f);
        this.mCornerShadowPaint.setShader(new RadialGradient(0.0f, 0.0f, shadowRadius, new int[]{0, this.mShadowStartColor, this.mShadowMiddleColor, this.mShadowEndColor}, new float[]{0.0f, startRatio, midRatio, 1.0f}, TileMode.CLAMP));
    }
    this.mEdgeShadowPaint.setShader(new LinearGradient(0.0f, innerBounds.top, 0.0f, outerBounds.top, new int[]{this.mShadowStartColor, this.mShadowMiddleColor, this.mShadowEndColor}, new float[]{0.0f, SHADOW_HORIZ_SCALE, 1.0f}, TileMode.CLAMP));
    this.mEdgeShadowPaint.setAntiAlias(false);
}