ColorPicker.java 文件源码

private void drawColorSquare(Canvas canvas) {
    int pureColor, brightColor, darkColor, transparentColor;

    // pureColor
    mHSV[0] = mColorHSV[0];
    mHSV[1] = 1; mHSV[2] = 1;
    pureColor = Color.HSVToColor(mHSV);
    // brightColor
    mHSV[1] = 0; mHSV[2] = 1;
    brightColor = Color.HSVToColor(mHSV);
    // darkColor
    mHSV[1] = 1; mHSV[2] = 0;
    darkColor = Color.HSVToColor(255, mHSV);
    // alphaColor
    mHSV[1] = 0; mHSV[2] = 0;
    transparentColor = Color.HSVToColor(0, mHSV);

    // drawn without compose shader, but looks worse
    Shader gradient1 = new LinearGradient(mSquareRect.right, mSquareRect.bottom, mSquareRect.right, mSquareRect.top, brightColor, pureColor, TileMode.CLAMP);
    Shader gradient2 = new LinearGradient(mSquareRect.right, mSquareRect.bottom, mSquareRect.left, mSquareRect.bottom, transparentColor, darkColor, TileMode.CLAMP);

    mColorPaint.setShader(gradient1);
    canvas.drawRect(mSquareRect, mColorPaint);
    mColorPaint.setShader(gradient2);
    canvas.drawRect(mSquareRect, mColorPaint);
}