My basic idea was that `WM_CHAR` is just the better `WM_KEYDOWN`.
The latter fails to properly support common dead key sequences like in
#3516.
As such I added some logic to `Terminal::SendKeyEvent` to make it return
false if the pressed key represents a printable character.
This causes us to receive a character event with a (hopefully) correctly
composed code unit, which then gets sent to `Terminal::SendCharEvent`.
`Terminal::SendCharEvent` in turn had to be modified to support
potentially pressed modifier keys, since `Terminal::SendKeyEvent` isn't
doing that for us anymore.
Lastly `TerminalInput` had to be modified heavily to support character
events with modifier key states. In order to do so I merged its
`HandleKey` and `HandleChar` methods into a single one, that now handles
both cases.
Since key events will now contain character data and character events
key codes the decision logic in `TerminalInput::HandleKey` had to be
rewritten.
## PR Checklist
* [x] CLA signed
* [x] Tests added/passed
* [x] I've discussed this with core contributors already.
## Validation Steps Performed
* See #3516.
* I don't have any keyboard that generates surrogate characters. Due to
this I modified `TermControl::_SendPastedTextToConnection` to send the
data to `_terminal->SendCharEvent()` instead. I then pasted the test
string ""𐐌𐐜𐐬" and ensured that the new `TerminalInput::_SendChar`
method still correctly assembles surrogate pairs.
Closes#3516Closes#3554 (obsoleted by this PR)
Potentially impacts #391, which sounds like a duplicate of #3516
## Summary of the Pull Request
Make TerminalControl synthesize mouse events and Terminal send them to
the TerminalInput's MouseInput module.
The implementation here takes significant inspiration from how we handle
KeyEvents.
## References
Closes#545 - VT Mouse Mode (Terminal)
References #376 - VT Mouse Mode (ConPty)
### TerminalControl
- `_TrySendMouseEvent` attempts to send a mouse event via TermInput.
Similar to `_TrySendKeyEvent`
- Use the above function to try and send the mouse event _before_
deciding to modify the selection
### TerminalApi
- Hookup (re)setting the various modes to handle VT Input
- Terminal is _always_ in VT Input mode (important for #4856)
### TerminalDispatch
- Hookup (re)setting the various modes to handle VT Input
### TerminalInput
- Convert the mouse input position from viewport position to buffer
position
- Then send it over to the MouseInput in TerminalInput to actually do it
(#4848)
## Validation Steps Performed
Tests should still pass.
This adds the WPF control to our project, courtesy of the Visual Studio team.
It re-hosts the Terminal Control components inside a reusable WPF adapter so it can be composed onto C# type surfaces like Visual Studio requires.
* Fixed a minor build warning
* Removed an unimplemented method declaration
* Added Microsoft::Terminal::Core::ControlKeyStates
// This class will act as a safe wrapper for the ControlKeyState enum,
// found in the NT console subsystem (<um/wincon.h>).
