HACKING

This is the coding guideline for Kdenlive.

Committing
    Auto-indent
        Please don't use for existing files. It is very likely to break manual tweaks like:
            const int componentFlags =   (ui->cbY->isChecked() ? 1 : 0) * HistogramGenerator::ComponentY
                                       | (ui->cbS->isChecked() ? 1 : 0) * HistogramGenerator::ComponentSum
                                       | (ui->cbR->isChecked() ? 1 : 0) * HistogramGenerator::ComponentR
                                       | (ui->cbG->isChecked() ? 1 : 0) * HistogramGenerator::ComponentG
                                       | (ui->cbB->isChecked() ? 1 : 0) * HistogramGenerator::ComponentB;
        which are intended to improve readability.

    Changelog
        When adding a new feature, add it to the CHANGELOG file. Features often are not mentioned
        in the bug tracker; adding it to the changelog helps keeping track of them.

    Bug fixes
        Bugs often are in mantis. When fixing a bug, add a link to the bug tracker entry in the commit log
        and close the bug there.
        If the bug is not in mantis, it should be (a) added (and marked as fixed) if it is an important bug,
        or (b) not added otherwise.


Source code comments
    Classes
        Each class should be shortly described in its header file.

    Functions
        Public functions should be documented as well in the header file. Especially regarding side effects!
        (What does a programmer neeed to know in order to use this function without reading the whole source code?)

    Inline comments
        are very helpful for commands (function calls, calculations) that are not obvious. For example, what
        does this function call do?

            davinci.drawLine(0, y, scopeRect().size().width()-RGBParadeGenerator::distRight, y);

        A short comment makes it obvious (also helps locating bugs when something needs to be fixed):

            // Draw a horizontal line through the current mouse position
            davinci.drawLine(0, y, scopeRect().size().width()-RGBParadeGenerator::distRight, y);


API documentation
    The docs can be generated by using doxygen (doxygen DoxyConfig in the main directory).
    See [1] for an overview of doxygen commands.
    Often used: \brief, \param, \return


Coding style
    This part is based on Krita's HACKING file[2].

    Indentation, Braces etc.
        4 Spaces for indentation. Always braces.
        This is, according to the Qt4 coding style, which is documented here:
        http://techbase.kde.org/Policies/Kdelibs_Coding_Style

    Includes
        Avoid as much as possible #includes in header files; use forward declarations
        of classes.

    Initializers
        Avoid as much as possible initializers in the body of the constructor. Use
        initializer lists instead.

    Scope prefixes
        Use only m_ for class-level variables. No other scope prefixes; no g_, l_,
        no 'p' for pointer variables.

    Shared pointers
        Use shared pointers wherever possible.

    Getter/setter
        Getter/setters are named x() for getters and setX(int x) for setters. If you
        come across violations of this rule, change the code.

    Function naming
        Functions should be named in camelBackedFashion, to conform to Qt's standards.
        If you encounter functions in c_style_like_this, feel free to rename. Also:
        verbNoun -- i.e., rotateLayer, not layer_rotate. The latter is a true c-ism,
        introduced by a language that needs to prefix the 'class' name to every function
        in order to have something that not quite OO.

    Variable/Parameter names
        Variable/parameter names start with an undercast letter. A name composed of different
        words is done in camelBackedStyle.

    Files and classes
        It's preferred (and strongly preferred) to have only one class per .h/.cpp file.
        (Which is logical, because otherwise you won't be able to keep to the naming scheme.)

    Spaces
        Keep the source airy and open. In particular, there should be empty lines between function
        declarations and definitions.

    Slots and signals
        Prefix slots with slot and signals with signal: slotUpdateSelection, signalSelectionUpdated.

    Boolean operators
        Use the standard !, !=, ==, && etc style, not the "not", "and" etc. style. Keep kdenlive code
        using one, easily recognizable, C++ style.


    Exceptions
        These rules are merely guidelines for making the code consistent and more readable. In some cases
        it makes sense to not follow some of the points mentioned above.


[1] http://www.stack.nl/~dimitri/doxygen/commands.html
[2] http://quickgit.kde.org/?p=calligra.git&a=blob_plain&h=3e8fcab9dd3588c0228498af2795d3b714b73d42&f=krita/HACKING