OpenTX Code Style Guide - stodev-com-br/opentx GitHub Wiki

We prefer Unix style line ends and will eventually convert all existing source files to Unix line ends.

Use two spaces for indentation.

• the beginning curly brace goes on the next line
• the name of the function (if composed of several words) uses lower case first word and Capital case for other words.
• the parameters and other variables follow the same syntax as function names.
• start the functions on one module with the same keyword if it makes sense. For example all functions dealing with sd card start with sd - e.g. sdOpen(), sdClose()

Example:

int someFunction(const char * firstParameter, uin32_t secondParameter)
{
  // one liner comment, use space before the comment char and first word
  return 4;
}

Either write the call all on a single line, wrap the arguments at the parenthesis,

bool result = someFunction(longlonglonglonglongaFirstParameter,
                          secondParameter, thirdParameter);

or start the arguments on a new line indented by four spaces and continue at that 4 space indent.

bool result = someFunction(
    firstParameter, secondParameter,
    thirdParameter);

The if and else keywords belong on separate lines. There should be a space between the if and the open parenthesis, and between the close parenthesis and the curly brace (if any), but no space between the parentheses and the condition.

if (condition) {  // no spaces inside parentheses
  ...  // 2 space indent.
} 
else if (...) {  // The else goes on the same line as the closing brace.
  ...
} 
else {
  ...
}

In general, curly braces are not required for single-line statements, but they are allowed

if (condition)
  doSomething();  // 2 space indent.

Switch statements may use braces for blocks.

Blocks case in switch statements can have curly braces. If included, curly braces should be placed as in example:

switch (var) {
  case 0: {  // 2 space indent
    ...      // 4 space indent
    break;
  }

  case 1: {
    ...
    break;
  }
}

Braces are optional for single-statement loops.

for (int i = 0; i < n; ++i)
  DoSomething();

Empty loop bodies should use either empty braces or contains continue.

while (condition) {
}

• use Camel Case for class names (all words with first letter capitalized)
• where possible, prefer classes

• use Camel Case for class names (all words with first letter capitalized)
• methods follow the same syntax as normal functions
• try to use the const function attribute where possible

Example:

class SomeClass {
  public:
    SomeClass();

  private:
    int classVariable;
    int classPrivateInlineFunction(int someParam) const
    {
      return someParam * 2;
    }
};

• block statements begin with an opening curly brace on the same line

Example:

  if (foo == bar) {
    // some code (usually multiple lines)
  }
  else if (foo >= bar || bar <= 6) {
    // some code (usually multiple lines)
  }
  else {
    // some code (usually multiple lines)
  }

Enumerators (for both scoped and unscoped enums) should be named like constants: ENUM_NAME.

Example:

enum Analogs {
  STICK,
  TX_VOLTAGE,
};  

They should be avoided when possible. If needed they should be named with all capitals and underscores.

Example:

#define ROUND(x) ...
#define PI_ROUNDED 3.0

The contents of namespaces are not indented.

namespace {

void foo() {  // Correct.  No extra indentation within namespace.
  ...
}

}  // namespace