## Summary of the Pull Request
Operations that erase areas of the screen are typically meant to do so using the current color attributes, but with the rendition attributes reset (what we refer to as meta attributes). This also includes scroll operations that have to clear the area of the screen that has scrolled into view. The only exception is the _Erase Scrollback_ operation, which needs to reset the buffer with the default attributes. This PR updates all of these cases to apply the correct attributes when scrolling and erasing.
## PR Checklist
* [x] Closes#2553
* [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 not really discussed this with core contributors. I'm ready to accept this work might be rejected in favor of a different grand plan.
## Detailed Description of the Pull Request / Additional comments
My initial plan was to use a special case legacy attribute value to indicate the "standard erase attribute" which could safely be passed through the legacy APIs. But this wouldn't cover the cases that required default attributes to be used. And then with the changes in PR #2668 and #2987, it became clear that our requirements could be better achieved with a couple of new private APIs that wouldn't have to depend on legacy attribute hacks at all.
To that end, I've added the `PrivateFillRegion` and `PrivateScrollRegion` APIs to the `ConGetSet` interface. These are just thin wrappers around the existing `SCREEN_INFORMATION::Write` method and the `ScrollRegion` function respectively, but with a simple boolean parameter to choose between filling with default attributes or the standard erase attributes (i.e the current colors but with meta attributes reset).
With those new APIs in place, I could then update most scroll operations to use `PrivateScrollRegion`, and most erase operations to use `PrivateFillRegion`.
The functions affected by scrolling included:
* `DoSrvPrivateReverseLineFeed` (the RI command)
* `DoSrvPrivateModifyLinesImpl` (the IL and DL commands)
* `AdaptDispatch::_InsertDeleteHelper` (the ICH and DCH commands)
* `AdaptDispatch::_ScrollMovement` (the SU and SD commands)
The functions affected by erasing included:
* `AdaptDispatch::_EraseSingleLineHelper` (the EL command, and most ED variants)
* `AdaptDispatch::EraseCharacters` (the ECH command)
While updating these erase methods, I noticed that both of them also required boundary fixes similar to those in PR #2505 (i.e. the horizontal extent of the erase operation should apply to the full width of the buffer, and not just the current viewport width), so I've addressed that at the same time.
In addition to the changes above, there were also a few special cases, the first being the line feed handling, which required updating in a number of places to use the correct erase attributes:
* `SCREEN_INFORMATION::InitializeCursorRowAttributes` - this is used to initialise the rows that pan into view when the viewport is moved down the buffer.
* `TextBuffer::IncrementCircularBuffer` - this occurs when we scroll passed the very end of the buffer, and a recycled row now needs to be reinitialised.
* `AdjustCursorPosition` - when within margin boundaries, this relies on a couple of direct calls to `ScrollRegion` which needed to be passed the correct fill attributes.
The second special case was the full screen erase sequence (`ESC 2 J`), which is handled separately from the other ED sequences. This required updating the `SCREEN_INFORMATION::VtEraseAll` method to use the standard erase attributes, and also required changes to the horizontal extent of the filled area, since it should have been clearing the full buffer width (the same issue as the other erase operations mentioned above).
Finally, there was the `AdaptDispatch::_EraseScrollback` method, which uses both scroll and fill operations, which could now be handled by the new `PrivateScrollRegion` and `PrivateFillRegion` APIs. But in this case we needed to fill with the default attributes rather than the standard erase attributes. And again this implementation needed some changes to make sure the full width of the active area was retained after the erase, similar to the horizontal boundary issues with the other erase operations.
Once all these changes were made, there were a few areas of the code that could then be simplified quite a bit. The `FillConsoleOutputCharacterW`, `FillConsoleOutputAttribute`, and `ScrollConsoleScreenBufferW` were no longer needed in the `ConGetSet` interface, so all of that code could now be removed. The `_EraseSingleLineDistanceHelper` and `_EraseAreaHelper` methods in the `AdaptDispatch` class were also no longer required and could be removed.
Then there were the hacks to handle legacy default colors in the `FillConsoleOutputAttributeImpl` and `ScrollConsoleScreenBufferWImpl` implementations. Since those hacks were only needed for VT operations, and the VT code no longer calls those methods, there was no longer a need to retain that behaviour (in fact there are probably some edge cases where that behaviour might have been considered a bug when reached via the public console APIs).
## Validation Steps Performed
For most of the scrolling operations there were already existing tests in place, and those could easily be extended to check that the meta attributes were correctly reset when filling the revealed lines of the scrolling region.
In the screen buffer tests, I made updates of that sort to the `ScrollOperations` method (handling SU, SD, IL, DL, and RI), the `InsertChars` and `DeleteChars` methods (ICH and DCH), and the `VtNewlinePastViewport` method (LF). I also added a new `VtNewlinePastEndOfBuffer` test to check the case where the line feed causes the viewport to pan past the end of the buffer.
The erase operations, however, were being covered by adapter tests, and those aren't really suited for this kind of functionality (the same sort of issue came up in PR #2505). As a result I've had to reimplement those tests as screen buffer tests.
Most of the erase operations are covered by the `EraseTests` method, except the for the scrollback erase which has a dedicated `EraseScrollbackTests` method. I've also had to replace the `HardReset` adapter test, but that was already mostly covered by the `HardResetBuffer` screen buffer test, which I've now extended slightly (it could do with some more checks, but I think that can wait for a future PR when we're fixing other RIS issues).
EraseInLine calls `FillConsoleOutputCharacterW()`. In filling the row with
chars, we were setting the wrap flag. We need to specifically not do this on
ANY _FILL_ operation. Now a fill operation UNSETS the wrap flag if we fill to
the end of the line.
Originally, we had a boolean `setWrap` that would mean...
- **true**: if writing to the end of the row, SET the wrap value to true
- **false**: if writing to the end of the row, DON'T CHANGE the wrap value
Now we're making this bool a std::optional to allow for a ternary state. This
allows for us to handle the following cases completely. Refer to the table
below:
,- current wrap value
| ,- are we filling the last cell in the row?
| | ,- new wrap value
| | | ,- comments
|-- |-- |-- |
| 0 | 0 | 0 |
| 0 | 1 | 0 |
| 0 | 1 | 1 | THIS CASE WAS HANDLED CORRECTLY
| 1 | 0 | 0 | THIS CASE WAS UNHANDLED
| 1 | 0 | 1 |
| 1 | 1 | 1 |
To handle that special case (1-0-0), we need to UNSET the wrap. So now, we have
~setWrap~ `wrap` mean the following:
- **true**: if writing to the end of the row, SET the wrap value to TRUE
- **false**: if writing to the end of the row, SET the wrap value to FALSE
- **nullopt**: leave the wrap value as it is
Closes#1126
* 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>
