Windowing Extension

[davidrg]

Fully implement the Windowing Extension.

At least some work towards this is already done:

• Paging is now supported along with DECPCCM, DECRQDE and DECSNLS
• K95 has supported horzontal scrolling for a long time to work around bugs in the Windows 95 conagent. The support in the GUI version is not fully implemented and/or disabled, but probably not hard to do.

So the main things to finish it off would appear to be:

• Get DECVCCM and DECHCCM implemented
• Support a taller page than the window
• SU/SD should move the top of the window
  • The documentation says this shouldn't affect the data within the logical display. I don't think this is how other terminal emulators (eg, XTERM) implement this.
  • Should check on the VT520 to see how it mixes SU/SD with scrollback:
    • It works as described by the manual: it would be equivalent to operating the scrollbar, except they wouldn't allow scrolling into scrollback.
• Get page scrolling working in K95G.
  • Make SET TERM VIDEO-CHANGE DISABLED actually do something in K95G to allow the window and page sizes to differ
  • Get the horizontal scrollbar working
    • Turns out its working more than I thought it was: on the command screen! If you make the command screen wide, output a bunch of stuff, shrink it, then view the scrollback a horizontal scrollbar appears! And it even works too! So I guess there can't be that much stopping it from working on the terminal screen.
  • With vertical scrolling it would probably be valuable to have a marker (perhaps just draw a line?) to show where the current page ends and scrollback begins.

Questions

• How should this interact with K95Gs Resize Modes:
  • Changes font size: probably would work exactly as it does now
  • Changes Dimensions: Would this just change the dimensions of the window leaving the page size alone? Window size would be entirely decoupled from page size?