Eclipse Plug-in: Content Assist Proposal Info with HTML Format

Question

I'm extending eclipse jdt's content assist,
and I wrote a class that implements IJavaCompletionProposalComputer,
and my code is like the following:

final static String[] fgProposals = { "A", "B" }; 
final static String[] fgInfo = { "<font color='red'>A_info</font>", "B_info" };

@Override
public List<ICompletionProposal>
computeCompletionProposals(ContentAssistInvocationContext context, IProgressMonitor monitor) {
  ICompletionProposal[] result = new ICompletionProposal[fgProposals.length];
  for (int i= 0; i < fgProposals.length; i++) {
    IContextInformation info = new ContextInformation("AA", "BB");
    result[i]= new CompletionProposal(
        fgProposals[i], context.getInvocationOffset(), 0,
        fgProposals[i].length(), null, fgProposals[i],  
        info, fgInfo[i]);   
  }
  return Arrays.asList(result);
}

However,
the additional info (the window at the right of the selected proposal)
ignores html tags and just shows plain text.

My question is the same as this topic:
HTML Formatting in Editor ContentAssit
I've read this,
but I can't understand the explanation they said.

Could anyone tell me how to solve this question with a clearer explanation?
A simple code snippet will help a lot!!
Thanks.

Answer 1

A simple code snippet is not possible because this is not simple!

Instead of your code returning an array of CompletionProposal you must return an array of classes that implement both ICompletionProposal and ICompletionProposalExtension3.

One of the extra methods in ICompletionProposalExtension3 is

public IInformationControlCreator getInformationControlCreator()

This must return an IInformationControlCreator class. This class just has one method:

public IInformationControl createInformationControl(Shell parent)

The returned IInformationControl is the class that displays the proposals and can deal with HTML. There is a abstract class AbstractInformationControl which implements some of the basic requirements but it is down to you to deal with the HTML.

One way to deal with the HTML is to use the SWT Browser widget. There is a BrowserInformationControl which does this but it is in the internal package org.eclipse.jface.internal.text.html so it is not available for use by plugins.