Once the ToolTip is ready, I'll begin working on this.

Summarizing what appear to be agreed-upon changes to be made (keeping original numbering for reference):

1. Avoid expanding large output accidentally / too easily. Current suggestions are expanding part of the output with a "more..." button, and a confirmation dialog e.g. "Are you sure? This could bring IDLE to a halt! Consider other methods of viewing the output."

2. Avoid using the middle button. Either use a more commonly accessible mouse-click combo, make it a context-menu option, or make it user-configurable.

3. Make the "preview" functionality use our tkTextView (will need testing to make sure it performs reasonably).

4. Increase default minimum # lines for auto-squeezing. 50? 100?

7. Change implementation method from an extension to an integrated part of IDLE.