FlatUI

https://github.com/eluleci/FlatUI

这是我非常喜欢的一个库，现在来一探究竟。

因为项目久远，已经跑不起来了。。。 大致看下 Button。

      // creating normal state drawable
        ShapeDrawable normalFront = new ShapeDrawable(new RoundRectShape(attributes.getOuterRadius(), null, null));
        normalFront.getPaint().setColor(attributes.getColor(2));

        ShapeDrawable normalBack = new ShapeDrawable(new RoundRectShape(attributes.getOuterRadius(), null, null));
        normalBack.getPaint().setColor(attributes.getColor(1));

        normalBack.setPadding(0, 0, 0, bottom);

        Drawable[] d = {normalBack, normalFront};
        LayerDrawable normal = new LayerDrawable(d);

        // creating pressed state drawable
        ShapeDrawable pressedFront = new ShapeDrawable(new RoundRectShape(attributes.getOuterRadius(), null, null));
        pressedFront.getPaint().setColor(attributes.getColor(1));

        ShapeDrawable pressedBack = new ShapeDrawable(new RoundRectShape(attributes.getOuterRadius(), null, null));
        pressedBack.getPaint().setColor(attributes.getColor(0));
        if (bottom != 0) pressedBack.setPadding(0, 0, 0, bottom / 2);

        Drawable[] d2 = {pressedBack, pressedFront};
        LayerDrawable pressed = new LayerDrawable(d2);

就是用 LayerDrawable 实现的图层叠加，貌似是没有动画效果的。