The ultimate guide to Android custom views
I've been designing, writing and publishing Android custom views for the past 5 years now. I guess it's about time to sum it up and share the results.
Here you will find the topics related to custom views and a couple of case studies. Code samples will be in Java and Kotlin randomly and the code will be as simple as possible to demonstrate ideas and techniques better. I want this place to be more of a tutorial wiki than a documentation. You can find the documentation on developer.android.com/.
I'll try to add an article or two per week. If there's something missing and you think that I should write about - raise an issue and tell me. If you wish, there's a larger repository with my custom views here.
A progress bar that also has a text. The text should be drawn in one color on the 'done' part of the progress and in another color on the 'remaining' part.
A simple bar chart with color state lists and bar selecting with clicks.
Topics covered: drawing on canvas, state lists, touch events.
See: code.
A more complete version of the view can be found here
A layout that displays its children in rows, side to side and then in another line.
Topics covered: measuring, laying out, custom layout attributes, right to left support.
See: code.
An EditText with support for an invalid state attribute.
Topics covered: custom states.
A very simple toggle with accessibility support.
Topics covered: basic accessibility.
An animated Drawable depicting a landscape with customizable items: trees, clouds, stars, a sun, and fog.
Topics covered: drawing on Canvas, custom drawables.
