Addon Development

Addons are written in C# with .NET Core 6 - you don't need any previous experience with C# in order to create addons, but this is not a tutorial for learning C#.

Environment Setup

This assumes you're using Visual Studio with the **.NET/C#** workload installed.

1. Create a new **.NET Core 6 Class Library** type solution, and name it whatever you want.
   
   
   
2. R+Click on your .csproj file and click Properties. In the property pages, change the Target OS to Windows:
   
   Press Ctrl+S to save the project file, then close the tab.
3. In the solution explorer, R+Click on your project and select Manage NuGet Packages for Project
   
   
4. Switch to the Browse tab & install the VolumeControl.SDK package.
   
   

Writing an Addon

Here's an example of an action that opens a file using the default application.

using System.Diagnostics;
using VolumeControl.Core.Attributes;
using VolumeControl.Core.Input;
 
namespace VolumeControl.TestAddon
{
    [HotkeyActionGroup("File", GroupColor = "#F0F")]
    public class FileActions
    {
        [HotkeyAction(Description = "Opens a file with the default application.")]
        [HotkeyActionSetting("Path", typeof(string), Description = "The location of the file to open.")]
        public void OpenFile(object? sender, HotkeyPressedEventArgs e)
        {
            Process.Start(new ProcessStartInfo(e.GetValue<string>("Path"))
            {
                UseShellExecute = true
            })?.Dispose();
        }
    }
}

You can find the full code example here.
Additionally, you can view the source code for Volume Control's built-in actions here.

See the API Documentation for more information on what is available through the Volume Control SDK.

Building Your Addon

Assuming you're using Visual Studio, you can use Publish Profiles to build your addon and place it in an easy-to-access directory.

First, you'll need to create a new publish profile.

1. R+Click your addon project in the solution explorer, and select Publish...
   
2. When asked to choose a target, select Folder.
   
3. Choose an output directory; this should be a relative path that points somewhere within your solution directory / git repository.
   
   
4. Do any additional configuration you want on your new publish profile.
   
   
5. Click the Publish button to build your addon.
   The output files *(and only the output files)* can be found at the location you set in step 3.
   

Loading Your Addon

Tip: In order to see log messages related to the loading of addons, you should enable all of the log filters in the settings tab.

Where to Put Addons

Volume Control will attempt to load addons from a few locations, depending on the version.
Since v6.0.0, Volume Control will *(recursively)* load addons from C:\Users\<USERNAME>\AppData\Local\radj307\VolumeControl\Addons first, if that location exists.
Do not place Volume Control SDK dlls in addon directories, and do not include them when redistributing your addon.

Since v5.1.0, addons may also be located in any directories specified by the CustomAddonDirectories setting, which can be found in the configuration file:
*(until v5.2.0):* ~/AppData/Local/radj307/VolumeControl_Url_<HASH>/<VERSION>/user.config
*(since v5.2.0):* volumecontrol.json located in the same directory as VolumeControl.exe

Assuming you enabled DEBUG log messages, you will see messages in the log confirming that your addon was loaded when launching Volume Control:

Redistributing Addons

Once you've got your shiny new addon, you may want to distribute it to share your work.
To encourage this, I've created an official repository for third-party addons here.
Submit a pull request (or issue) including your addon DLL to add it to the repo! Be sure to include "@radj307" so I get notified.

### Legal Because Volume Control is licensed under the GPLv3, any code that uses the Volume Control SDK must be licensed under the GPLv3 as well; however you are the sole owner of the code that you write.
The only real requirement for you to remain compliant with the GPLv3 license is that you must make the source code for your addon available to users.

Summary:

• Make sure you use the GNU General Public License 3 (GPLv3) license for your addon when uploading it to github or elsewhere.
• Make the source code for your addon available to users.