Sharing the Console

["Darin Wright" <Darin_Wright@xxxxxxx>]

To promote the sharing of the debug console with Ant, and potentially other clients, we intend to open up the console implementation to make it more extensible. The attached document is a high level description of the approach we plan to take. The debug/ant teams have reviewed the plan. If anyone sees any problems with the approach, please let us know. 

The proposal does not include a way to preserve structured output. As of yet, this does not appear to be a concern the community has (noting Jeff's comment yesterday).

Darin

Title: Sharing the Console

Sharing the Console

Author: Darin Wright, October 22, 2002.

This document proposes support for an enhanced debug console.

Background

Currently, the implementation of the console is private. When a launch is registered, a document is created for all associated processes. The document polls the streams associated with the process - standard error and out - appending to the document as the streams are written. As well, input is read from the keyboard and sent to standard in. The user may choose color preferences for the different streams - out, err, in.

Goals

Following are a list of goals motivating an open console API:

• Allow other clients to use the same console as the debugger, with custom/enhanced function
• Allow clients to annotate a console document with hyper links. For example, the Java debugger would annotate stack traces with links to the associated classes. An Ant client would annotate build output with task links, and perhaps create problems/links for errors encountered in a "javac" task.
• Allow clients to color a document in a custom manner, or extend the default coloring policy.

Proposed Implementation

The debug plug-in will provide a default document provider that creates console documents for processes. The default console document will listen to the output streams of its associated process, which will update the document. A default partitioner will be used to partition the document into colored partitions representing standard out, in, and error. The partitions will be implemented as "color partitions" rather than standard in, out, etc., such that other partitioners can easily add more colors to a document. A default implementation of a color partition will be provided.

By default a console document will have an annotation model that understands "hyper link" annotations. Cleints that need to annotate console documents must register as document listeners to the appropriate document. The debug UI will provide notification of console document creation and removal. This will allow clients to register as document listeners where applicable. The console view will render hyper links via underlining, color, or bold (depending on user preference), and the cursor will change to a "hand" when the user moves over a link. As well, the links can be configured to draw dynamically as the user moves the mouse over a valid link, rather than having links drawn all the time which could cause clutter. An implementation of a hyper-link annotation will be provided that opens an editor on a file when followed.

To override the type of document created (and thus, partitioner), clients may specify a custom document provider. Document providers can be registered for launch configuration types via an extension point. Thus, an Ant client could provide a custom document provider that creates a document/partitioner that renders with more colors, and reads its output from an Ant Logger.