T-DeckLoader/lib/AceButton/CONTRIBUTING.md

How to Contribute

Thank you for your interest in this library. I do appreciate any constructive comments or suggestions about this library. If you would like to contribute code, please do the following for non-trivial changes:

1. Create an issue or send me an email so that I have some advance warning on what you would like to change.
2. Please rebase your branch off the 'develop' branch, and preferably squash all your changes into a single commit so that it's easier to review.

Coding Style

I use the following style for this library. New code should follow the same style for consistency and ease of diffing.

• formatting
  • 80 column lines
    • rationale: I often use vertically split, side-by-side editing on my small laptop screen.
  • 2 space indents, no tabs
  • 4 space indents for continuation lines
  • no trailing white spaces
• spacing
  • consistent and generous spaces around operators and symbols
    • e.g. for (int i = 0; i < 10; i++) {
    • e.g. a = (flag) ? 3 : -1;
    • rationale: Helps readability.
  • space after language keywords: e.g. for, while, if, etc
  • no space after function names
• pointer declaration * attached to the class, not the variable
  • e.g. AceButton* button, not AceButton *button
  • rationale: I know the latter could be argued to be technically more correct under the C/C++ syntax, but I think the former is more intuitive for many people. I've personally gone back and forth, and I decided to just pick a style.
• only one variable declaration per line
  • e.g. int i, j; not allowed, use 2 lines
  • rationale: Helps readability, and avoids the confusion of AceButton* b1, *b2; caused by the previous rule.
• open brace on the same line as the function name (Java style)
• naming conventions
  • class names: CamelCase
    • e.g. MyClass, YourClass
  • methods: camelCase
    • e.g. doSomething(), isCondition(), etc
    • rationale: Seems like the Arduino convention. Helps readability.
  • class static constants: 'k' followed by CamelCase
    • e.g. kSomeConstant
    • rationale: Prevents conflicts with #define macros which use the ALL_CAPS_MACRO pattern. Since AceButton is a library, I cannot predict which other libraries may be used by the end-user. If there is a macro conflict, I have no way to fix the problem.
    • in user-land codes, ALL_CAPS for constants would be ok because if there's a conflict, you can change it
  • member variables: 'm' followed by CamelCase
    • e.g. mSomeVariable
    • rationale: Many symbols beginning with a single or double underscore __ are reserved by the C language, C++ language, or their standard libraries. So I avoid them completely. One alternative is to append an underscore after the variable name. But this makes the -> and the . operators hard to read. The 'm' prefix seems consistent with the 'k' prefix for constants, and it's easy on the eyes.
  • global variables
    • there ought to be no global variables in this library
    • if there were any, the naming convention would be 'gCamelCase'
• doxygen comments for all public and protected methods and constants
  • comments are recommended for private methods and variables as well, since private methods sometimes become protected or public

Unit Tests

Any non-trivial change should have a unit test. Even a seemingly trivial change can often use a unit test to prevent typos.

Make sure that all the unit tests under the tests directory pass. I had to split the unit tests into multiple *.ino files because they became too big to fit into the 32KB flash memory space of an Arduino board.

Authorship and License

I will assume that your code is licensed under the same MIT License as the rest of the library.