Coding Style

Coding Style

This page is under construction. Check here for the discussion.

See https://wiki.qt.io/Qt_Coding_Style for general code style guidelines.

item	convention	example
Directory	All lowercase with - for word separator if necessary.	src/subdirectory/directory-of-doom/
File	All lowercase, follow Qts conventions.	src/subdirectory/directory-of-doom/adatabase.h
Class	PascalCase, follow Qt convention but change Q to A	class ADataBase
Methods	camelCase	methodOfClass
Member variable	camelCase	importantVariable
Free Function	camelCase with an extra a	aConquerTheWorld()
Static Function	Without a and snake_case to emphasise limited scope	void utility_function_one()
Limited scope variables	snake_case	temporary_variable
constants	All capital snake_case	const auto IMPORTANT_CONSTANT = ASecretOfUniverse(42);
Type Alias	follow Qt Convention	using NewType = QMap<QString, int>

Boolean Expressions

Consider the following:

if(!selected) { ... }

In this case what does selected mean? Selected or not, so bool? or the selected pointer is null? or perhaps selected is a numerical so 0? In order to avoid confusion and make the code more readable, be explicit when using boolean expressions to compare numerical values, enums and pointers.

• Numeric

  if(i == 0) ...  // Good
  if(!i) ...      // Bad

• Enum

  if(e == Enum::someValue) // Good
  if(e == 7)               // Bad

• Pointers

  if(p == nullptr) // Good
  if(!p)           // Bad

• For bool variables, the abbreviated notation is acceptable:

  if(!b)         // This is fine
  if(b == false) // This is also fine

Strings in openPilotLog

Aim to construct and use strings in the most efficient way.

• For all user-facing strings use tr(), so that the app is translatable.

• Use QStringLiteral where possible, except when using a function that has a char * overload.

• For string comparisons using the == operator, use QLatin1String

• For concatenations, openPilotLog uses QStringBuilder globally, so the + operator can be used.

• (Debug etc. can be char *, QString or anything else)

Examples

const auto IMPORTANT_CONSTANT = ASecretOfUniverse(42);

APilotEntry(int throwaway_variable)
    : importantMemberVariable(throwaway_variable)
{}

- AFooBar           - an important custom class.
- FooBar            - alias of important type.
- aFooBar()         - an important free function
- foo_bar()         - a static "utility" function
- niceVariable      - an important variable
- nice_variable     - a "consumable", limited scope variable.

class Foo {
    int rowId;
    Foo(int row_id) : rowId(row_id) {}
    void set(int parameter);
}

void Foo::set(int parameter)
{
   auto calc_flag = false;
   // complex calculations
   if(!calc_flag)
       return;
   ...
}