Hi Boris,

On 22.05.2017 12:07, Boris Mulder wrote:

I'm trying to compile the new toolchain using tool/tool_chain x86. However, it gives the following error:

does the attached patch help?

It might be necessary to delete the tool chain build directory before running the tool_chain script again.

Christian

Hi,

we want to create a virtual keyboard for touch screen devices. This shall be done by letting the keyboard provide an input service. The problem here is that Nitpicker only provides input to the currently active client. Since the keyboard needs to receive input events from the touch screen, with this policy it would also receive its own sent keys. We need a way to send these keys to another client while still receiving further touch input. How can this be done without compromising current security mechanism or creating unnecessary large pieces of trusted code?

Regards JK

Hi Norman,

thanks for your answer!

I guess that you are already using the input filter to feed the virtual keyboard's events back to nitpicker?

We have not yet implemented the input service as we're yet thinking about the overall architecture but that would have been our approach.

Nitpicker's focus policy can be configured depending on the client's label. Usually, the "click" policy is in effect, which means that a click event implicitly changes the focus to the clicked-on client. However, this policy is not always desired, like in your case or when implementing a global menu. In the latter case, one wants to let the menu handle a click yet retain the original focus. To accommodate such scenarios, nitpicker supports the so-called "transient" focus policy (documentation at [1]). If such a client is clicked-on, it receives the press event and all subsequent events until all buttons/keys are released.

[1] https://github.com/genodelabs/genode/blob/staging/repos/os/src/server/nitpic...

I think that the transient focus policy is the right tool for your use case if your virtual keyboards delivers its artificial events after the release event (otherwise, nitpicker would send the artificial event to the virtual keyboard which still has the transient focus).

For a practical example for configuring the transient focus feature, please have a look at the gems/run/launcher.run script.

I'd be very interested in how this approach works for you. We previously discussed on the list [2] that nitpicker's focus handling is still somewhat limited. So your experience may give me valuable input for possibly refining it.

[2] https://sourceforge.net/p/genode/mailman/genode-main/thread/1a5cd577-1e4c-ba...

Thanks for these sources. The transient policy sounds right for what we want to do. Sending input events after release might be necessary anyways if we want to handle longer presses. I will give feedback when we are in progress with the implementation.

Regards, JK