On 01/15/2007 12:12 AM, Ron Jensen wrote: > Remapped the G/g keys to control only the gear handle. > controls/gear/gear-down is only controlled by nasal.
That brings to light a problematic situation. There are three properties of interest: 1) gear-handle-down 2) wow (aka squat switch) 3) gear-down There is legacy code wherein the user-interface directly manipulates the gear-down property, via a) the keyboard via keyboard.xml b) buttons on the joystick (e.g. X52.xml) c) possibly others These legacies are bugs, IMHO, because they disregard and bypass any logic associated with squat switches, unserviceable subsystems, et cetera. In particular, fixing bug (a) is a good thing, but does not go far enough, because it leaves bug (b) still on the loose, and presumably other bugs also. Fixing bug (a) is relatively easy, because the RG-aircraft startup code only needs to remap one small feature of the pre-existing UI. Fixing bug (b) is harder, partly because it would require tracking down who-knows-how-many pieces of hardware and fixing their interface definitions. The tricky bit is that fixing (say) X52.xml so that it works properly with the non-naive RG aircraft means that it won't work properly with other aircraft that naively expect the UI to directly set the gear-down property. Remarks: -- gear-down is a low-level property -- as a general principle, the UI should not be messing with low-level properties. There should be at least one layer of indirection. Therefore, a suggestion: There are at least two ways to fix these bugs once and for all: SCHEME 1 (quick and dirty): 1.1) Rampage through all the UI stuff and fix it so that if a property called "gear-handle-down" has been defined, use that; otherwise, for compatibility, (ab)use the gear-down property. SCHEME 2 (nicer, more sophisticated, and better in the long term): 2.1) The fgfs startup code should install a listener attached to gear-handle-down. This default listener should put the gear down/up in response to the gear handle, in the naive, backwards-compatible way. 2.2) After that is done, rampage through all the UI stuff and fix it so that it manipulates the gear handle, not the gear. 3.3) Then revise the default gear-down lister so that if gear-down gets set without gear-handle-down previously being set accordingly, it issues a warning, indicating that that this is improper, and the UI needs to be updated. 3.4) Non-naive aircraft can implement their own functionality by replacing the gear-handle-down listener *without* having to mess with the UI. Note that there is no barrier to doing (1) then (2). Scheme 1 results in added complexity in all UI code, now and in the future. Scheme 2 requires slightly more work now, but yields nicer code in the UI and elsewhere for all time. Comments? Anybody have a better solution? ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
