coding-style.md

Pixel Wheels coding style

Base

Pixel Wheels is based on the AOSP variant (4 space indents) of Google Java coding style.

Extra rules

if always uses curly braces

Good:

if (something) {
    return;
}

Bad:

if (something) return;

if (something)
    return;

No boolean parameters

Boolean parameters makes callers hard to read. Instead of:

void drawRect(int x, bool y, int width, int height, boolean fill);

// Calling code
drawRect(12, 34, 100, 200, true);

Either use a boolean:

enum FillMode {
    FILLED,
    EMPTY
}

void drawRect(int x, bool y, int width, int height, FillMode fillMode);

drawRect(12, 34, 100, 200, FillMode.FILLED);

Or split the function into two:

void drawFilledRect(int x, bool y, int width, int height);
void drawEmptyRect(int x, bool y, int width, int height);

drawFilledRect(12, 34, 100, 200);

Applying the coding style

You can run tools/apply-codingstyle to apply most of the rules to the code in your checkout. This tool downloads google-java-format in $HOME/.cache and runs it on all the Java files of the project.

The CI checks for coding style conformance.