InputCommon: Add hotkey support to input expressions.

[jordan-woyak]

I've added support for hotkeys in our input expressions.

Fixes issue: https://bugs.dolphin-emu.org/issues/9320

Demonstration:
https://giant.gfycat.com/RapidScientificArgali.webm

Note the following improvements:

• Button combos are now detected and do not require use of the "advanced" dialog.
  • Simultaneous and successive presses also produce & and | operator usages.
• Hotkeys suppress other references to the same input.
  • Ugly !Alt & Return mappings are no longer required to prevent regular press activation.
• Hotkeys require pressing of modifers first.
  • e.g. Ctrl+O does not work unless you press Ctrl first.

The current syntax is of the form @(Ctrl+Shift+R) but I am open to suggestions.

Any input can be used as a "modifier". It is not limited to the typical ctrl, shift, alt.
This will make mapping button combinations on gamepads easier for users.

There is a disadvantage.. but I do not think it is horrendous.
@(Ctrl+O) Does not know Shift is a modifer unless a @(Shift+O) hotkey also exists.
In other words.. pressing Ctrl+Shift+O will present the "open file" dialog.
If you map something else to Shift+O, however, then it will not.

[iwubcode]

Very nice @jordan-woyak ! No real concerns with the code on an initial pass.

I did a bit of testing. Seems like a massive step up. For button combos, the hotkey vs "|" seems to give me what I expect part of the time. I need to increase my dexterity :)

I plan on coming back and testing the hotkey suppression + giving the code another once over before the final review.

[iwubcode]

This is fine but I was surprised Dolphin doesn't already have a scoped-lambda type thing, always found the unique_ptr approach to be too terse for my liking

[iwubcode]

Code LGTM

[JMC47]

Well, I needed something big for the GUI section anyway and hotkeys are fun.

[i30817]

I'm not sure i should ask this here, but since i don't have a account in the real bug report page a merged issue that touches this recently is the best i can do.

Anyway: would it be possible to make a way to 'lift a finger' automatically recenter the wii pointer?

I'm doing something where the touchpad is the wii pointer and a modifer(right touchpad button)+the touchpad is the tilt.

This works fine, but when i stop using the tilt shortcuts, the wii cursor shortcut activate and jump the mouse to where the 'cursor' is, while i'd prefer it was kept in the same position as it was move the tilt movement.

Part of the problem is that the cursor is not recentered after i release the modifier.

I wonder if it's possible to add a controller 'hotkey' to the motion simulation screen which is not part of the 'gestures of the controller' and just triggers some 'function' when a button is pressed or released and calls functions like 'recenter wii cursor' that have nothing to do with a predefined gesture the controller functions.

Then i could have the tilt and when releasing the modifier call a 'recenter cursor' function. That function would have to exist ofc. I'm not sure how it would work in practice and if i would have to lift up the finger touching the touchpad before releasing the modifier (because the cursor moves anyway to the projected absolute touchpad coordinates on the screen), but it seems something like this could be useful to minimize cursor drift on 2d simulations of 3d movements.

[jordan-woyak]

@i30817 Ask on the forums. Also I can't figure out what you're asking for.

[i30817]

You're right, i probably should make sure it's actually a important issue in a game before i ask for this. I thought of it because the tilt is often used to control the camera and using the tilt and the pointer at the same time could be important to games that use a simulation of archery for example, but on second thought it's kind of unlikely though maybe it happens with the nunchuck accessory.