Götterdämmerung

Ben Goetter's unnecessarily apocalyptic weblog.

Thu, 23 Mar 2006

Singing yourself to sleep

Or, how I exercised the hibernation code in the version of pscheme under development:

(load "w32.dll")
(define p (w32:foreign-procedure "coredll.dll" "PostMessageW" '(w32api bool handle dword dword)))
(p w32:*host-hwnd* #x03ff 0 0)

That magic number in the last line is the value of the (poorly named) WM_HIBERNATE message, broadcast by the system in low memory scenarios. I built a thunk to call the PostMessage API, used that thunk to simulate the broadcast of WM_HIBERNATE, then sat back and watched the fireworks.

Zzzzz....

posted at: 15:09 | path: /pscheme | permanent link to this entry

A preliminary 1.3 release

For the brave and the bold, I have finished a preliminary cut at 1.3. To install it, start with an installation of 1.2.2 on a WM 2003, 2003SE, or WM5 device, then unzip this archive into your installation directory thereon.

Again, this version only supports WM 2003, WM 2003 SE, and WM 5.0.

The user interface has changed a fair bit, a result of both my accommodating limitations of the HTML viewer control and my attempting to improve the overall user experience. The changes are mostly obvious upon inspection.

• Separate output and transcript windows.
• Property sheet configuration UI.
• Simpler memory configuration.
• New View→Input, View→Output menus with new commands
• History for the program input window (should help JACAL)

Not yet implemented:

• View→Input→Smart Mode
• Part of Edit→Select S-Expr (presently it works like the awkwardly located 1.2 Edit→Select→Parenthesis)
• Edit→Balance S-Expr
• Context menus
• Script fixes
• Notifications for long-running background tasks
• Legacy hardware (the early-model Pocket PCs)

Not yet exercised:

• Hibernation

Known bugs:

• The transcript of (display 'something)(newline)(read-char) doesn't put echoed input on its own line.
• View→Match Parenthesis doesn't really belong on the View menu. Edit, however, is getting crowded, the toolbar is full, and I don't want to stuff this command on a second level menu.

Known annoyances that 1.3 will have to endure:

• The transcript window quickly flashes the first few items at its top with every update. Correcting this will require either replacing the html viewer control or else logging the transcript in a very different manner.
• The transcript windows slows as the transcript lengthens.
• The edit window moves a little bit when the SIP appears and disappears.

One solution to both the flashing transcript window and the moving edit window involves abandoning the TTY metaphor, i.e., the conceit that your entered expression and the system's response to it appear at the bottom of the screen, scrolling up to make room for new data as necessary. If instead new items appear at the top, with older data scrolling down, then the edit control could be at the top of the screen, where it wouldn't move on SIP state change, and the transcript window below it, not flashing on update because it now starts with the most recent entries. Two problems immediately occur to me, however. First, separating the editable input pane and the command buttons and keys forces the user's eyes to scan greater distances while editing, passing the noise in the transcript pane (though View→Input→Full Screen could help). Second, scrolling down doesn't work so well if the standard program output is interlaced with the transcript. That program output must appear top to bottom and left to right, in the order of the English language.

posted at: 07:50 | path: /pscheme | permanent link to this entry

.