keystroke and typedText should return boolean

[NSoiffer]

Description

mathlive has two public functions for handling keys:

• MathField.prototype.keystroke
• MathField.prototype.typedText

The functions sometimes handle the key input, and sometimes they pass on handling it. There is currently no way to tell if they did something or not. If they returned a boolean indicating whether they handled character, than it would be possible to call one, and if it didn't handle the key call the other or otherwise process the input.

Implementation Notes:

Making this work for keystroke appears trivial because the function it calls returns a boolean.

For typedText, I'm not sure if this is easy or not. render is always called at the end, so perhaps everything is handled, but I suspect not. Maybe a hook into the selection changing could be used.

[NSoiffer]

Also...
MathField.prototype.keystroke should take as a second arg the event. If not, then _onKeystroke has null for its second param and eventually the code evt.preventDefault(); (etc) could get called, which will generate an error.

[arnog]

I've added a boolean as a return value for keystroke(). Not sure why it wasn't there in the first place.
Also added an optional evt argument. Note that this function was intended to be used in cases where a synthetic event was generated, and therefore no 'real' event object may be available. However, as you pointed out, the internal implementation actually did not handle correctly the missing event. So, this is now fixed, but for good measure, you can also pass an optional event if you have one.

For typedText(), the definition of whether something has been 'handled' or not is more difficult, since really any string could be passed. For example, it would be valid to pass '{}' as a string. Or " ". So, what's the definition of "handled"? Is it whether the formula has been modified? Could you give me an example of some value you would want to pass on to typedText() where you would want it to consider having "not handled" the input?

[NSoiffer]

In playing around with accessibility and the MathField, I tried a version where I was handling all the events. I thought there might be some that weren't handled although, as I noted in the issue, it always called render so maybe it is the case all events are handled. I think that might still be the case that some things are not handled, such as when someone hits just shift or control and not another key. In the end, I abandoned this approach, but it still seemed like there should be return value so I wrote up the issue. <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Virus-free. www.avg.com <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

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On Fri, Feb 23, 2018 at 5:35 PM, Arno Gourdol ***@***.***> wrote: I've added a boolean as a return value for keystroke(). Not sure why it wasn't there in the first place. Also added an optional evt argument. Note that this function was intended to be used in cases where a synthetic event was generated, and therefore no 'real' event object may be available. However, as you pointed out, the internal implementation actually did not handle correctly the missing event. So, this is now fixed, but for good measure, you can also pass an optional event if you have one. For typedText(), the definition of whether something has been 'handled' or not is more difficult, since really any string could be passed. For example, it would be valid to pass '{}' as a string. Or " ". So, what's the definition of "handled"? Is it whether the formula has been modified? Could you give me an example of some value you would want to pass on to typedText() where you would want it to consider having "not handled" the input? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#53 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABeWbAQM_QXqbiiCmPLAddWIlmfSFOXzks5tX2dlgaJpZM4SKBQn> .