Android custom controls create glittering fonts

introduce

In Xiaomi's startup animation and some welcome interfaces, we often see this glittering streamer font. It looks cool. In fact, the implementation principle is quite simple. We just need to write a custom control to inherit textview, then use the renderer gradient to set the color gradient and the setshadowlayer method of paint to set the shadow, and then constantly refresh and change the displacement.

realization

First write a shinetextview class that inherits from textview

In this code, we define two color renderers

LinearGradient is a linear gradient rendering, and the gradient representing the color changes in a linear direction. We can use LinearGradient to achieve the effect in the second figure above

RadialGradient is a circular gradient rendering, and the gradient representing the color changes in a circular ring.

We can use radiogradient to achieve the effect of Xiaomi startup animation in the first picture above.

We make the color change dynamically by controlling the brightness displacement distance of mtranslate.

OnSizeChanged

In the onsizechange method, we mainly complete some initialization operations, such as obtaining the width and height of the control, initializing the color renderer and setting the font shadow effect.

onDraw

In the last step, we only need to draw the effect in the OnDraw method and shift the gradient effect through the matrix matrix.

Source code download: http://xiazai.jb51.net/201701/yuanma/AndroidShineText (jb51.net).rar

The above is the whole content of this article. I hope it will be helpful to your study, and I hope you can support programming tips.