Definition provider

The definition provider will allow users to see and browse to the definition from where they are used.

The definition provider is a class that implements vscode.DefinitionProvider. The provider method will return a vscode.Location when the definition is found.

<<definition provider class>>= 
export class LiterateDefinitionProvider implements vscode.DefinitionProvider
{
    <<definiton provider construction>>
    <<definiton provider implementation>>
}

The constructor for LiterateDefinitionProvider takes a FragmentRepository to access the tools necessary to find the correct fragment definition. We'll do this as a parameter property.

<<definiton provider construction>>= 
constructor(
    private readonly repository : FragmentRepository
) {}

The provider method takes a text document and a position. The cancellation token is unused.

<<definiton provider implementation>>= 
public provideDefinition
    (
        document : vscode.TextDocument,
        position : vscode.Position,
        _ : vscode.CancellationToken
    )
{
    const fragmentLocation = this.repository.getFragmentTagLocation(
        document,
        document.lineAt(position),
        position
    );
    if(fragmentLocation && fragmentLocation.fragment)
    {
        let map = fragmentLocation.fragment.tokens[0].map;
        if(map) {
            let definitionPosition = new vscode.Position(map[0], 0);
            return new vscode.Location(
                fragmentLocation.fragment.env.literateUri,
                definitionPosition
            );
        }
    }
    return null;
}

Registering the definition provider

<<register definiton provider>>= 
context.subscriptions.push(
    vscode.languages.registerDefinitionProvider(
        'markdown',
        new LiterateDefinitionProvider(theOneRepository)
    )
);