Nikolay Botev’s Blog

A new split editor prototype that is integrated into the Eclipse workbench API has been available as a patch on the Eclipse Bugzilla for some time now. Unfortunately, I have not able to create an easily deployable plugin that can be installed easily in any Eclipse 3.4 distribution (by copying to the dropins or plugins directories). Even if I did I would probably have to worry about the legal aspects of redistributing Eclipse code, since the plugin will no longer only contain my code.

That said, you can test out the latest split editor by checking out the o.e.ui.workbench project in Eclipse, applying the patch from bugzilla, and debuggin Eclipse from Eclipse. There are no immediately visible changes, but it would be very helpful to have as many people as possible test the split editor in everyday use. I do not expect a lot of users to go through the above procedure, however, and so I will keep trying to get an easily installable package out.

Next time I will talk about the internal integration design of the split editor because I believe this is the most interesting part of all. This will be of particular interest to Eclipse plugin developers who want to know how to enable editor splitting for their custom editors.

There is no new Java split editor yet.

I got overwhelmed by new issues that I discovered while testing last week’s prototype including the fact that most preference changes do not propagate to both editors or cause exceptions.

I am looking into the alternative MultiEditor-based approach and this is leading me to some interesting ideas that I am about to try out… so there should be interesting split-editor-related stuff coming soon.

The first working prototype of a working split editor is here. You can download it and play with it in Eclipse 3.4.

Basic functions like text cursor, current line highlight (these did not work in the first prototype), undo/redo, cut/copy/paste, status bar items (insert mode, line and column numbers) work fine and stay in sync when switching between the top and bottom half of the split editor.

There are also some known issues:

• Ctrl+Left/Right/Home/End keyboard shortcuts always operate on the top part of the split editor, even if the cursor is (blinking) in the bottom half.
• Navigating back and forth using the Alt-Left/Right keys browser-style does not remember the correct editor along with the location and doe not move between the top/bottom half of the editor. I actually have no plans of fixing this. This problem also occurs when opening multiple editor tabs.

Here are some images that demonstrate how to open and use the split editor.

First select the Open With dialog…

Then select the [Split Text Editor] option…

Split the Editor by clicking and dragging on the narrow line that runs all the way across above the first line.

And there you go… long live the split editor!

You can try different commands out and see if they work when you move between the two sides (top and bottom) of the editor…

That’s it for now. Enjoy!

Bonus The plugin now includes source code so you can see the kind of monster that lurks in the background to make editor splitting work.

Up Next Next up is a java code splitter, after I resolve the remaining known issues with basic editing functionality. I will also put up an update site for faster/easier delivery of future updates.