[andy/viking.git] / HACKING

This file is meant to summarize the Viking development policies.

####
#### Also check information in the Wiki:
#### http://sourceforge.net/apps/mediawiki/viking/index.php?title=Main_Page
####

Clean commits
=============

Commits/patches should be as fine-grained as possible (and no finer). Every
distinct change should be in its own commit and every commit should be a
meaningful change on its own.

Preferred Code Contribution Methods
===================================

Since the project uses git for source control, patches that utilize git (especially for patch sets) are preferred in this order:
* Commits pushed to a publically accessible git host (e.g. GitHub, Gitorious, etc...)
   - This enables commits to be easily managed such as pulling, merging or cherry-picking
* Email git diffs to the dev mailing list - use 'git format-patch' method
* Plain diffs can be emailed to the dev mailing list and/or stored in the SourceForge Patch Tracker for Viking.

Coding style
============

Naming:
A "module" is a .c file.

Functions starting with "vik_" operate on an object/structure with the module name (see layer.c for an example).
Functions starting with "a_" do not, these modules may have static variables.
Both are followed by the module name. Unless of course the function is static, in which case it may be called anything.

All (well, practically all) global constants and macros start with "VIK_" and then the module name.

Coding Checks
=============

Code should compile with the minimum number of warnings (ideally none).

Code should pass static analysis with defaults for 'cppcheck' (http://sourceforge.net/projects/cppcheck/) with no errors.

ATM there is one deliberate error in vikgpslayer.c designed to prevent building if the code encounters a GPSD version we don't handle. Something like:
[vikgpslayer.c:1479]: (error) Invalid number of character ({) when these macros are defined: 'GPSD_API_MAJOR_VERSION;VIK_CONFIG_REALTIME_GPS_TRACKING'.
This can be 'hidden' via cppcheck --suppress syntax.

Technical notices
=================

In order to activate reference documentation, you have to specify the following configure command line:
$ ./configure --enable-gtk-doc --enable-gtk-doc-html

Then, cd to doc/reference and launch make command.

---

The layers panel holds all the layers. Layers connect to the layers panel via what I call "interfaces" which are really just a 
structure of function pointers and pointers to other bits such as icons. viklayer.c switches between the layers like 
polymorhpism. Anything specific to the layer should (in theory) be found solely in that layer's source file.

There are some ugly hacks in here, like the layers panel holding the viewport and each layer holding the viewport and a 
GtkTreeIter. Unfortunately it was the only way I could figure out to do some things. It would be _much_ easier with a 
object-oriented language.

---

"xmpp" and "ympp" are really misnomers, as they only represent the Meters Per Pixel in UTM mode. Otherwise they are an artificial
zooming system. In expedia mode it represents the "Alti", in Google mode it represents 2^(scale), e.g. 2^0 = 1, 2^8 = 256.

---
Implementing a MapSource

VikMapSource is the "interface", the really base class of the MapSource tree.
In order to implement a MapSource, you have to prefer to derive from VikMapSourceDefault, a less abstract class, adding a property based implementation for some aspects of the VikMapSource interface.
Then, you have to provide implementation for coord_to_mapcoord, mapcoord_to_center_coord and download methods.
Commit	Line	Data
240d1fc8 GB	1	This file is meant to summarize the Viking development policies.
240d1fc8 GB	2
6c1496fc RN	3	####
	4	#### Also check information in the Wiki:
	5	#### http://sourceforge.net/apps/mediawiki/viking/index.php?title=Main_Page
	6	####
240d1fc8 GB	7
	8	Clean commits
	9	=============
	10
	11	Commits/patches should be as fine-grained as possible (and no finer). Every
	12	distinct change should be in its own commit and every commit should be a
	13	meaningful change on its own.
	14
6c1496fc RN	15	Preferred Code Contribution Methods
	16	===================================
	17
	18	Since the project uses git for source control, patches that utilize git (especially for patch sets) are preferred in this order:
	19	* Commits pushed to a publically accessible git host (e.g. GitHub, Gitorious, etc...)
	20	- This enables commits to be easily managed such as pulling, merging or cherry-picking
	21	* Email git diffs to the dev mailing list - use 'git format-patch' method
	22	* Plain diffs can be emailed to the dev mailing list and/or stored in the SourceForge Patch Tracker for Viking.
	23
240d1fc8 GB	24	Coding style
	25	============
	26
50a14534 EB	27	Naming:
	28	A "module" is a .c file.
	29
	30	Functions starting with "vik_" operate on an object/structure with the module name (see layer.c for an example).
	31	Functions starting with "a_" do not, these modules may have static variables.
	32	Both are followed by the module name. Unless of course the function is static, in which case it may be called anything.
	33
	34	All (well, practically all) global constants and macros start with "VIK_" and then the module name.
	35
6c1496fc RN	36	Coding Checks
	37	=============
	38
	39	Code should compile with the minimum number of warnings (ideally none).
	40
	41	Code should pass static analysis with defaults for 'cppcheck' (http://sourceforge.net/projects/cppcheck/) with no errors.
	42
	43	ATM there is one deliberate error in vikgpslayer.c designed to prevent building if the code encounters a GPSD version we don't handle. Something like:
	44	[vikgpslayer.c:1479]: (error) Invalid number of character ({) when these macros are defined: 'GPSD_API_MAJOR_VERSION;VIK_CONFIG_REALTIME_GPS_TRACKING'.
	45	This can be 'hidden' via cppcheck --suppress syntax.
	46
240d1fc8 GB	47	Technical notices
240d1fc8 GB	48	=================
50a14534	49
e5c58469 GB	50	In order to activate reference documentation, you have to specify the following configure command line:
	51	$ ./configure --enable-gtk-doc --enable-gtk-doc-html
	52
	53	Then, cd to doc/reference and launch make command.
	54
	55	---
	56
50a14534 EB	57	The layers panel holds all the layers. Layers connect to the layers panel via what I call "interfaces" which are really just a
	58	structure of function pointers and pointers to other bits such as icons. viklayer.c switches between the layers like
	59	polymorhpism. Anything specific to the layer should (in theory) be found solely in that layer's source file.
	60
	61	There are some ugly hacks in here, like the layers panel holding the viewport and each layer holding the viewport and a
	62	GtkTreeIter. Unfortunately it was the only way I could figure out to do some things. It would be _much_ easier with a
	63	object-oriented language.
	64
	65	---
	66
	67	"xmpp" and "ympp" are really misnomers, as they only represent the Meters Per Pixel in UTM mode. Otherwise they are an artificial
	68	zooming system. In expedia mode it represents the "Alti", in Google mode it represents 2^(scale), e.g. 2^0 = 1, 2^8 = 256.
2a035b62 GB	69
	70	---
	71	Implementing a MapSource
	72
	73	VikMapSource is the "interface", the really base class of the MapSource tree.
	74	In order to implement a MapSource, you have to prefer to derive from VikMapSourceDefault, a less abstract class, adding a property based implementation for some aspects of the VikMapSource interface.
	75	Then, you have to provide implementation for coord_to_mapcoord, mapcoord_to_center_coord and download methods.