Daniel Wabyick wrote: > I am working on an onscreen keyboard for a touchscreen Flex application. > > Building out the UI should be simple, but I am wondering if anyone has > ideas on the best way to 'plug in' to the normal Flash key event > system. I know I can get the current focused object via > focusManager.getFocus(), but I am uncertain as to the best way to > 'simulate' the keyboard. I can create KeyboardEvents, but how do I > dispatch them so that the appropriate components are listening?
First, get the Flex 2.0.1 updater if you haven't already. The new Flex Automation framework source code that's enclosed in it will make all the difference between a couple hours of work versus pulling your hair out in frustration for weeks on end. For components not based on TextField objects, it's trivial--call the dispatchEvent() method on the currently focused component with script-instantiated KeyboardEvent instances. That's how Flex Automation does it. You can see for yourself if you have the Flex 2.0.1 update installed. Just dig framework source directory and check out line 272 of: mx/automation/delegates/core/UIComponentAutomationImpl.as TextFields are trickier. To get correctly emulated behavior, you need to both emulate the original keystroke plus do some text manipulation, since not all of it's behavior is mediated through the script-accessible keyboard events. Aside from dispatching the event, you'll also need to set the selection to the next position and then replace the selected text with the character specified by your virtual keyboard for regular keystrokes, while special characters like enter, delete, backspace and such require some custom handling. Again, the automation classes show you exactly how to do this, see the replayAutomatableEvent method (lines 270-436) of: mx/automation/delegates/TextFieldAutomationHelper.as That should be sufficient for most text entry situations. If you need more even advanced event emulation, you should probably consider using Flex Automation. Having tried and failed to do much of the same thing using ActionScript 2 in the past, I must say that the automation framework is truly a lifesaver when it comes to such skulduggery. While automation is primarily intended for interaction logging and automated replay for testing purposes, it can also be exploited to simulate all manner of user interactions in non-standard ways (such as your virtual on-screen keyboard). While the Mercury QTP plugin is needed for out-of-the-box testing with Mercury, you don't actually need to download the plugin installer (and shell out for a commercial FDS license) to get access to and make use of Flex Automation proper for your own purposes. To hook into Flex Automation yourself, you'll need to write your own custom adapter classes implementing the IAutomationManager and IAutomationObjectHelper interfaces and connect these to whatever floats your boat (perhaps a server back-end, a built-in debugging dialog, or maybe even a future version of John Grden's XRay targeting Flex and ActionScript 3). This shouldn't be too hard for a seasoned Flex developer familiar with the rest of the existing framework--I've managed to make a good bit of headway into writing a few test classes that integrate with the Flex Automation framework after a weekend's worth of hacking. Unfortunately though, there's currently very little in terms of existing examples or documentation to help you find your way around in there. Hopefully, Adobe might remedy this in the near future (hint, hint). Jim Cheng effectiveUI
