Change accessibility notifier creation so we do not create one when we're in PTY mode. (Guard all call sites to skip math/event work when the notifier is null.) MSAA events are legacy events that are registered for globally and used by some screen readers to find content in the conhost window. The PTY mode is not responsible for hosting the display content or input window, so it makes sense for it to not broadcast these events and delegate the accessibility requirement to the connected terminal.
## References
- #10537
## PR Checklist
* [x] Closes#10568
* [x] I work here
* [x] Manual test launches passed.
This PR adds support for the VT line rendition attributes, which allow
for double-width and double-height line renditions. These renditions are
enabled with the `DECDWL` (double-width line) and `DECDHL`
(double-height line) escape sequences. Both reset to the default
rendition with the `DECSWL` (single-width line) escape sequence. For now
this functionality is only supported by the GDI renderer in conhost.
There are a lot of changes, so this is just a general overview of the
main areas affected.
Previously it was safe to assume that the screen had a fixed width, at
least for a given point in time. But now we need to deal with the
possibility of different lines have different widths, so all the
functions that are constrained by the right border (text wrapping,
cursor movement operations, and sequences like `EL` and `ICH`) now need
to lookup the width of the active line in order to behave correctly.
Similarly it used to be safe to assume that buffer and screen
coordinates were the same thing, but that is no longer true. Lots of
places now need to translate back and forth between coordinate systems
dependent on the line rendition. This includes clipboard handling, the
conhost color selection and search, accessibility location tracking and
screen reading, IME editor positioning, "snapping" the viewport, and of
course all the rendering calculations.
For the rendering itself, I've had to introduce a new
`PrepareLineTransform` method that the render engines can use to setup
the necessary transform matrix for a given line rendition. This is also
now used to handle the horizontal viewport offset, since that could no
longer be achieved just by changing the target coordinates (on a double
width line, the viewport offset may be halfway through a character).
I've also had to change the renderer's existing `InvalidateCursor`
method to take a `SMALL_RECT` rather than a `COORD`, to allow for the
cursor being a variable width. Technically this was already a problem,
because the cursor could occupy two screen cells when over a
double-width character, but now it can be anything between one and four
screen cells (e.g. a double-width character on the double-width line).
In terms of architectural changes, there is now a new `lineRendition`
field in the `ROW` class that keeps track of the line rendition for each
row, and several new methods in the `ROW` and `TextBuffer` classes for
manipulating that state. This includes a few helper methods for handling
the various issues discussed above, e.g. position clamping and
translating between coordinate systems.
## Validation Steps Performed
I've manually confirmed all the double-width and double-height tests in
_Vttest_ are now working as expected, and the _VT100 Torture Test_ now
renders correctly (at least the line rendition aspects). I've also got
my own test scripts that check many of the line rendition boundary cases
and have confirmed that those are now passing.
I've manually tested as many areas of the conhost UI that I could think
of, that might be affected by line rendition, including things like
searching, selection, copying, and color highlighting. For
accessibility, I've confirmed that the _Magnifier_ and _Narrator_
correctly handle double-width lines. And I've also tested the Japanese
IME, which while not perfect, is at least useable.
Closes#7865
This PR adds support for the _blink_ graphic rendition attribute. When a
character is output with this attribute set, it "blinks" at a regular
interval, by cycling its color between the normal rendition and a dimmer
shade of that color.
The majority of the blinking mechanism is encapsulated in a new
`BlinkingState` class, which is shared between the Terminal and Conhost
implementations. This class keeps track of the position in the blinking
cycle, which determines whether characters are rendered as normal or
faint.
In Windows Terminal, the state is stored in the `Terminal` class, and in
Conhost it's stored in the `CONSOLE_INFORMATION` class. In both cases,
the `IsBlinkingFaint` method is used to determine the current blinking
rendition, and that is passed on as a parameter to the
`TextAttribute::CalculateRgbColors` method when these classes are
looking up attribute colors.
Prior to calculating the colors, the current attribute is also passed to
the `RecordBlinkingUsage` method, which keeps track of whether there are
actually any blink attributes in use. This is used to determine whether
the screen needs to be refreshed when the blinking cycle toggles between
the normal and faint renditions.
The refresh itself is handled by the `ToggleBlinkingRendition` method,
which is triggered by a timer. In Conhost this is just piggybacking on
the existing cursor blink timer, but in Windows Terminal it needs to
have its own separate timer, since the cursor timer is reset whenever a
key is pressed, which is not something we want for attribute blinking.
Although the `ToggleBlinkingRendition` is called at the same rate as the
cursor blinking, we actually only want the cells to blink at half that
frequency. We thus have a counter that cycles through four phases, and
blinking is rendered as faint for two of those four. Then every two
cycles - when the state changes - a redraw is triggered, but only if
there are actually blinking attributes in use (as previously recorded).
As mentioned earlier, the blinking frequency is based on the cursor
blink rate, so that means it'll automatically be disabled if a user has
set their cursor blink rate to none. It can also be disabled by turning
off the _Show animations in Windows_ option. In Conhost these settings
take effect immediately, but in Windows Terminal they only apply when a
new tab is opened.
This PR also adds partial support for the `SGR 6` _rapid blink_
attribute. This is not used by DEC terminals, but was defined in the
ECMA/ANSI standards. It's not widely supported, but many terminals just
it implement it as an alias for the regular `SGR 5` blink attribute, so
that's what I've done here too.
## Validation Steps Performed
I've checked the _Graphic rendition test pattern_ in Vttest, and
compared our representation of the blink attribute to that of an actual
DEC VT220 terminal as seen on [YouTube]. With the right color scheme
it's a reasonably close match.
[YouTube]: https://www.youtube.com/watch?v=03Pz5AmxbE4&t=1m55sCloses#7388
<!-- Enter a brief description/summary of your PR here. What does it fix/what does it change/how was it tested (even manually, if necessary)? -->
## Summary of the Pull Request
Many places in this codebase has an equality comparison to the boolean FALSE. This adds unneeded complexity as C and C++ has a NOT operand for use of these in if statements. This makes the code more readable in those areas.
<!-- Other than the issue solved, is this relevant to any other issues/existing PRs? -->
## References
<!-- Please review the items on the PR checklist before submitting-->
## PR Checklist
* [X] CLA signed. If not, go over [here](https://cla.opensource.microsoft.com/microsoft/Terminal) and sign the CLA
* [X] Tests added/passed
* [ ] Requires documentation to be updated
* [ ] I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx
<!-- Provide a more detailed description of the PR, other things fixed or any additional comments/features here -->
## Detailed Description of the Pull Request / Additional comments
One boolean being compared to FALSE was only used once, with the boolean name being "b", so it is better off not existing at all.
<!-- Describe how you validated the behavior. Add automated tests wherever possible, but list manual validation steps taken as well -->
## Validation Steps Performed
Unit Testing passed, compiler refactoring
* Removed using namespace directive from header files and put these in cpp files where they are used
* Fixed tabbing issues by replacing them with spaces.
Also regrouped the using directives.
* Update src/host/exemain.cpp
Co-Authored-By: Mike Griese <migrie@microsoft.com>
* Update src/interactivity/win32/find.cpp
Co-Authored-By: Mike Griese <migrie@microsoft.com>
