Wiki sections on creating Add-Ins are outdated

[Ed-Silver]

A large amount of the wiki regarding the creation of add-ins is currently wrong, presumably outdated.

For example the section in https://github.com/PintaProject/Pinta/wiki/Writing-a-Configurable-Effect for overriding LaunchConfiguration() needs to be completely ignored in order for an add-in to work correctly on 3.*.

As I've discovered today, this and other misleading snippets makes it much harder to get involved in the community and create plugins for Pinta, although with a bit of source code inspection it's not an insurmountable hurdle.

Sorry if this if issues is the wrong place to report this, as it's not directly code-related; please do send me in another direction.

[Ed-Silver]

(as an aside, I would be open to editing the wiki, but given my new-ness to the community and project, I believe someone else will be better placed to instruct on the intended method of writing add-ins. Whilst I have made a working add-in, whether my implementation is textbook, I'm uncertain! 😂)

[cameronwhite]

thanks for reporting this! It's indeed easy for the documentation to become outdated, so any other issues you ran into would be great to know about

[Ed-Silver]

I've just generated the following summary of the differences between the wiki and how I had to implement my add-in:

Wiki implementation	New implementation
The add-in/effect class has a parameterless constructor	The add-in/effect class constructor receives an IServiceProvider
The constructor only initializes EffectData	The constructor obtains required Pinta services from IServiceProvider and initializes EffectData
public void Initialize() is implemented by the effect class	Initialize() is implemented by a separate IExtension class
Uninitialize() is implemented by the effect class	Uninitialize() is implemented by the separate extension/registration class
LaunchConfiguration() uses the older LaunchSimpleEffectDialog(...) API	LaunchConfiguration() returns Task<bool>
LaunchSimpleEffectDialog(AddinManager.CurrentLocalizer)	Use AddinUtilities.LaunchSimpleEffectDialog(chrome, workspace, this, AddinManager.CurrentLocalizer)
No service dependencies are required by the effect constructor	Configuration-capable effects need IChromeService and IWorkspaceService for the current simple-effect dialog API
[Mono.Addins.Extension] is placed on the effect class	The extension attribute is placed on the separate IExtension registration class
A property does not necessarily need a Caption attribute	[Caption("...")] can be used to explicitly specify the label displayed in the configuration dialog
The old documentation implies the dialog API can be called directly from the effect	The current API uses IChromeService, IWorkspaceService, and AddinUtilities to launch the dialog
A single class is responsible for both the effect and add-in lifecycle	Effect implementation and add-in lifecycle/registration are separate concerns

My functional (but potentially not textbook) add-in implementation can be found at https://github.com/Ed-Silver/pinta-temperature-addon/blob/main/TemperatureAdj.cs and compared with the wiki for more details. Thanks