Markwon/docs/docs/v4/core/spans-factory.md

Spans Factory

Starting with MarkwonSpansFactory controls what spans are displayed for markdown nodes.

Markwon.builder(context)
        .usePlugin(new AbstractMarkwonPlugin() {
            @Override
            public void configureSpansFactory(@NonNull MarkwonSpansFactory.Builder builder) {
                // passing null as second argument will remove previously added 
                // factory for the Link node
                builder.setFactory(Link.class, null);
            }
        });

SpanFactory

In order to create a generic interface for all possible Nodes, a SpanFactory was added:

builder.setFactory(Link.class, new SpanFactory() {
    @Nullable
    @Override
    public Object getSpans(@NonNull MarkwonConfiguration configuration, @NonNull RenderProps props) {
        return null;
    }
});

All possible arguments are passed via RenderProps:

builder.setFactory(Link.class, new SpanFactory() {
    @Override
    public Object getSpans(@NonNull MarkwonConfiguration configuration, @NonNull RenderProps props) {
        final String href = CoreProps.LINK_DESTINATION.require(props);
        return new LinkSpan(configuration.theme(), href, configuration.linkResolver());
    }
});

SpanFactory allows returning null for a certain span (no span will be applied). Or an array of spans (you can go deeper):

builder.setFactory(Link.class, new SpanFactory() {
    @Override
    public Object getSpans(@NonNull MarkwonConfiguration configuration, @NonNull RenderProps props) {
        return new Object[]{
                new LinkSpan(
                        configuration.theme(),
                        CoreProps.LINK_DESTINATION.require(props),
                        configuration.linkResolver()),
                new ForegroundColorSpan(Color.RED)
        };
    }
});

---

Since you can add multiple SpanFactory for a single node:

final Markwon markwon = Markwon.builder(context)
        .usePlugin(new AbstractMarkwonPlugin() {
            @Override
            public void configureSpansFactory(@NonNull MarkwonSpansFactory.Builder builder) {
                // this factory will be used _along_ with all other factories for specified node
                builder.addFactory(Code.class, new SpanFactory() {
                    @Override
                    public Object getSpans(@NonNull MarkwonConfiguration configuration, @NonNull RenderProps props) {
                        return new ForegroundColorSpan(Color.GREEN);
                    }
                });
            }
        })
        .build();

---

If you wish to inspect existing factory you can use:

• builder#getFactory() -> returns registered factory or null
• builder#requireFactory() -> returns registered factory or throws

final Markwon markwon = Markwon.builder(context)
        .usePlugin(new AbstractMarkwonPlugin() {
            @Override
            public void configureSpansFactory(@NonNull MarkwonSpansFactory.Builder builder) {
                final SpanFactory codeFactory = builder.requireFactory(Code.class);
                final SpanFactory linkFactory = builder.getFactory(Link.class);
                if (linkFactory != null) {
                    {...}
                }
            }
        })
        .build();