ASM keyhook question

[Mapar007]

Wait... Wasn't the GetKey hook for GetCSC? (oh man, I've misinterpreted that right from the start...)

[FloppusMaximus]

There's been a lot of confusion about both of those hooks in the past. Part of that confusion is the fact that the GetKey hook deals, in part, with keypad scancodes (i.e., "GetCSC" values). But the hook is only called by the GetKey routine, so it can only modify the behavior of programs that use GetKey.

The GetKey hook is called at two points while GetKey is running. First, when GetKey first starts up, or after a key is pressed, but before displaying the cursor, the hook is called with A=1Ah. At that point, if the hook returns with zero set, the value of A is taken as a keycode, and GetKey returns immediately.

Second, after each time GetCSC is called, the hook is called with A=1Bh and B being the value returned by GetCSC (usually either zero or a scancode). If the hook returns with zero set, again, A is taken as a keycode and GetKey returns. Otherwise, A is taken as a scancode which is handled by GetKey as usual.

[account4me2]

Guys, I gave the first post a significant overhaul because it was a bit misleading - I've made things clearer now, and added info I've learned from this thread.

[FloppusMaximus]

Well, I've looked at Notefolio a little bit, and it is incredibly bizarre. You can forget about most of what I just said. :)

The app is actually monitor-driven (I have no idea why) but instead of using cxMain, it receives keypresses using a RawKey hook. Essentially the entire app is driven by calls to that hook; it's a ridiculously complicated way to do something really simple (i.e., GetKey in an infinite loop.) So while it's true that setting a RawKey hook prior to starting Notefolio won't do any good, it's for a rather different reason than I was thinking. :)

Anyway, Notefolio also uses GetKey and font hooks for whatever reason; and it also disables most other hooks while it's running. So if you want to hook your own code in there somewhere, you'll need to be very sneaky. One thing you could do would be to install a localize hook (one of the few hooks Notefolio doesn't disable) that would wait until Notefolio starts up, then replace (say) Notefolio's RawKey hook with your own hook (which, in addition to whatever else it did, would need to call Notefolio's hook.) This is really a horrible kludge, and whatever it is you're trying to do, you may find it easier to replace Notefolio than to try to hack around it like this.

As to what hooks will be called during a *normal* Flash app's execution? Well, lots of apps use GetKey, so the GetKey hook will work a lot of the time, as will the silent link hook. The cursor hook will work if the app uses a cursor; the drawing hook will work if the app uses system drawing routines like IPoint and ILine. Nearly all apps display text at some point, so the font and localize hooks will usually get called at least once. The USB hook will work nearly everywhere. Of course, most of these are not terribly useful; what you really want to know is what hook(s) will be called at the correct time for what you're trying to do (intercept keypresses, display stuff on screen, or whatever.)

I think magicdanw's point was that you could use the app change hook to detect when Notefolio exits (i.e., after the user presses 2nd+Quit); you could regain control at that point and do whatever you want.

[magicdanw]

Yep. Install an app change hook before running Notefolio, and when you quit the app (with the normal keypress, I know you wanted to change it, but that'd be another thing to figure out...) the hook should be called with A=0.

[account4me2]

[FloppusMaximus]

How else would you propose to change the quit key, if not by using a key hook?

[magicdanw]

Maybe if you say what exactly this whole mess is going to be used for, we can recommend another app, or a way to implement functionality into your own program. Basically, what is your goal here?

[account4me2]

[DrDnar]

Oh, well, I'm working on an application that may provide just that. You'll just have to wait until I possibly never finish it. (It may turn out to be slow and require a rewrite.) But I'm hopeful I can have basic editing functionality working by the time my break is over. I already plan on allowing external applications to access the editing functionality via its own callback mechanism. The application would have the responsibility of handling keypresses, and thereby have pretty good control over the edit buffer. For example, if you only wanted to let the user enter a number, you would just not pass any other keys to the editor than numbers.

The editor uses a custom variable width, variable height font routine that can read the font data from both RAM and the archive. It can currently display a string in a box of any size with word wrap and stops when the box is full. The project is currently in an organization and planing stage, as I've found that making an editor with word wrap isn't a trivial task. Here's an old screen shot just because I have it:

[FloppusMaximus]

Great, now you've got that stuck in my head. :P

TI probably would not appreciate you distributing modified versions of the NoteFolio app, so I wouldn't recommend going that route. In any case, if your app is going to depend on NoteFolio, better to depend on the original NoteFolio than some hacked version.

It's a shame there aren't any really good text editors for the TI-83+; I like Evan Hoke's QWERTY, but it's lacking a lot of features, and it has a bit of a learning curve. I'm looking forward to seeing yours, Dr. D'nar, when it gets finished.

[DrDnar]

Hehe!

I liked QWERTY too, though the curvyness of the TI-84+ makes it harder to use. And the fact that my hands have grown since eighth grade, but that's a different matter. It would be possible to add support for QWERTY-style editing easily enough.

The editor is currently taking 0.2 seconds per screen redraw. I may have to drop support for archived fonts and data to speed things up.

Over the weekend I hacked up a mostly functional font editor in Visual Basic Express. All it's currently missing is the ability to save font files, though it can load them.

[FloppusMaximus]

Reading data from the archive shouldn't be a major bottleneck if done properly. If you're using VPutMap or UserPutMap, that's probably a bigger issue; even in textWrite mode, those routines are disgustingly slow. Flashbook gets pretty good frame rates just using LoadPattern and a custom display routine, as well as keeping a table of character widths cached in RAM.

Back on topic (sort of), account4me2, I think if you could explain in more detail what it is you're trying to do with NoteFolio, we might be able to give you better advice.

[account4me2]

[quote name='Dr. D'nar' post='139619' date='Jan 1 2010, 07:12 PM']Oh, well, I'm working on an application that may provide just that.[/quote]
Sounds good. Be sure to post a link here when you've completed it. Btw are you using the GetKey hook in your app?

[magicdanw]

Based on what's been said about how Notefolio uses the monitors, I suspect it would be more difficult than I thought to modify which key quits the app, and what it does from there. I said that when I thought you were talking about a program, not an application.

It still might help if you explain that "irrelevant" function of the other application. You never know!