Files
Terminal.Gui/Terminal.Gui
Copilot aab90e1fbc Fixes #4463 - Adds LineCanvas.GetRegion() - 10x performance regression in RenderLineCanvas (#4464)
* Initial plan

* Revert xunit maxParallelThreads to default to fix performance issue

Co-authored-by: tig <585482+tig@users.noreply.github.com>

* Fix 10x performance regression in RenderLineCanvas

Found via binary search of 51 commits that commit 027018368 introduced
the slowdown by calling context.AddDrawnRectangle() for every cell in
the LineCanvas (thousands of times per frame).

Fixed by reporting the entire LineCanvas.Bounds once instead of per-cell.

Test results:
- Before: 1m 33s (10x slower than v2_release)
- After: 9s (same as v2_release)

Fixes the performance issue in AllViews_Draw_Does_Not_Layout test.

Co-authored-by: tig <585482+tig@users.noreply.github.com>

* Add comment clarifying LineCanvas coordinate system

Addresses code review feedback about coordinate system conversion.
LineCanvas.Bounds is already in screen-relative coordinates since
cells are stored with screen positions (used with Driver.Move).

Co-authored-by: tig <585482+tig@users.noreply.github.com>

* Build non-rectangular Region from LineCanvas cells efficiently

Instead of reporting entire LineCanvas.Bounds (which includes empty space),
efficiently build a Region that encompasses only the actual line cells.

Algorithm groups contiguous horizontal cells into spans per row, avoiding
per-cell overhead while accurately representing the non-rectangular shape.

Performance maintained: 10s (same as v2_release)
All tests pass: 5695 drawing tests, 200 LineCanvas tests, 33 transparency tests

Co-authored-by: tig <585482+tig@users.noreply.github.com>

* Address code review feedback - improve robustness

- Remove redundant empty check (caller already verifies)
- Add safety check for empty row groups to prevent IndexOutOfRangeException
- Update documentation to clarify precondition

Tests still pass with 9s performance.

Co-authored-by: tig <585482+tig@users.noreply.github.com>

* Optimize BuildRegionFromLineCells - eliminate redundant sort

Remove redundant OrderBy since X values are already sorted from the
initial OrderBy().ThenBy() operation. Also remove unreachable empty
check since GroupBy guarantees non-empty groups.

Performance maintained at 9s.

Co-authored-by: tig <585482+tig@users.noreply.github.com>

* Final code review fixes - improve comments and add defensive check

- Clarify comment about sorting behavior
- Add defensive empty check for edge cases
- Performance maintained at 10s

Co-authored-by: tig <585482+tig@users.noreply.github.com>

* Move BuildRegionFromCells to LineCanvas class

Moved the BuildRegionFromCells method from View.Drawing.cs to LineCanvas
where it logically belongs as a public static method.

Updated View.Drawing.cs to call Drawing.LineCanvas.BuildRegionFromCells.

Performance maintained at 9s. All tests pass.

Co-authored-by: tig <585482+tig@users.noreply.github.com>

* Update documentation for BuildRegionFromCells

- Clarify that method handles empty cellMap gracefully
- Improve comment explaining the defensive empty check
- Performance maintained at 10s

Co-authored-by: tig <585482+tig@users.noreply.github.com>

* Rename BuildRegionFromCells to GetRegion

Renamed the method as requested to have a more concise name.

Performance maintained at 10s. All tests pass.

Co-authored-by: tig <585482+tig@users.noreply.github.com>

* Add GetCellMapWithRegion optimization for single-pass iteration

Implemented optimized method that builds both cell map and Region in a
single pass through the canvas bounds, eliminating the need for separate
GetCellMap() and GetRegion() calls.

Benefits:
- Reduces from 2 iterations to 1 (GetCellMap then GetRegion -> single pass)
- Eliminates sorting overhead (O(n log n) -> O(n))
- X values already sorted due to inner loop order
- Builds Region incrementally per row as cells are discovered

Performance maintained at 10s. All tests pass:
- AllViews_Draw_Does_Not_Layout: 10s
- 5695 drawing tests passed
- 200 LineCanvas tests passed
- 33 transparency tests passed

Co-authored-by: tig <585482+tig@users.noreply.github.com>

* Add comprehensive unit tests for GetRegion and GetCellMapWithRegion

Added 15 new unit tests covering:

GetRegion tests:
- Empty cell map handling
- Single cell regions
- Horizontal and vertical lines
- L-shaped regions
- Discontiguous cells creating separate spans
- Intersecting lines

GetCellMapWithRegion tests:
- Empty canvas handling
- Single horizontal/vertical lines
- Intersecting lines with proper intersection handling
- Complex shapes (boxes)
- Consistency with separate GetCellMap + GetRegion calls
- Negative coordinate handling
- Exclusion region support

All 215 LineCanvas tests pass. Performance maintained at 9s.

Co-authored-by: tig <585482+tig@users.noreply.github.com>

* Fix code style violations per CONTRIBUTING.md

- Replace var with explicit types (Dictionary<Point, Cell?>, LineCanvas, Region, etc.)
- Replace new TypeName() with target-typed new () where type is declared
- Fix foreach loop to use explicit IGrouping<int, Point> type
- Use StraightLine instead of var in foreach

All style violations fixed per CONTRIBUTING.md coding conventions.
Tests still pass: 215 LineCanvas tests, 9s performance maintained.

Co-authored-by: tig <585482+tig@users.noreply.github.com>

* Code cleanup.

* Upgrades Transparent Scenario to demonstrate LineCanvas transparency. "dotnet" is drawn using LineCanvas.

* Comment out debug assertions in View drawing logic

The debug assertions in the `View` class, which validated the relationships between `Margin`, `Border`, `Padding`, and their parent objects, as well as their `SubViewNeedsDraw` and `NeedsDraw` states, have been commented out. These assertions were conditionally executed when the current object and its `SuperView` were not of type `Adornment`.

The code has been retained as comments for potential future reference or debugging purposes, but the assertions are no longer active in the current implementation.

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: tig <585482+tig@users.noreply.github.com>
Co-authored-by: Tig <tig@users.noreply.github.com>
2025-12-08 17:13:58 -07:00
..

Terminal.Gui Project

Terminal.Gui is a cross-platform UI toolkit for creating console-based graphical user interfaces in .NET. This repository contains all files required to build the Terminal.Gui library and NuGet package, enabling developers to create rich terminal applications with ease.

Project Overview

Terminal.Gui provides a comprehensive framework for building interactive console applications with support for keyboard and mouse input, customizable views, and a robust event system. It is designed to work across Windows, macOS, and Linux, leveraging platform-specific console capabilities where available.

Project Folder Structure

This directory contains the core Terminal.Gui library source code. For a detailed repository structure, see CONTRIBUTING.md - Repository Structure.

Getting Started

For instructions on how to start using Terminal.Gui, refer to the Getting Started Guide in our documentation.

Documentation

Comprehensive documentation is available at gui-cs.github.io/Terminal.Gui.

For information on generating and updating the API documentation locally, refer to the DocFX README.

Versioning

Version information for Terminal.Gui is managed by gitversion. To install gitversion:

dotnet tool install --global GitVersion.Tool
dotnet-gitversion

The project version (used in the NuGet package and Terminal.Gui.dll) is determined from the latest git tag. The format of version numbers is major.minor.patch.build.height and follows Semantic Versioning rules.

To define a new version, tag a commit using git tag:

git tag v2.1.0-beta.1 -a -m "Release v2.1.0 Beta 1"
dotnet-gitversion /updateprojectfiles
dotnet build -c Release

DO NOT COMMIT AFTER USING /updateprojectfiles! Doing so will update the .csproj files in your branch with version info, which we do not want.

Publishing a Release of Terminal.Gui

To release a new version, follow these steps based on Semantic Versioning rules:

  • MAJOR version for incompatible API changes.
  • MINOR version for backwards-compatible functionality additions.
  • PATCH version for backwards-compatible bug fixes.

Steps for Release:

  1. Verify the v2_develop branch is ready for release:

    • Ensure all changes are committed and pushed to the v2_develop branch.
    • Ensure your local v2_develop branch is up-to-date with upstream/v2_develop.
  2. Create a pull request for the release in the v2_develop branch:

    • Title the PR as "Release vX.Y.Z".
    git checkout v2_develop
    git pull upstream v2_develop
    git checkout -b vX_Y_Z
    git add .
    git commit -m "Release vX.Y.Z"
    git push
    
    • Go to the link printed by git push and fill out the Pull Request.
  3. On github.com, verify the build action worked on your fork, then merge the PR.

  4. Pull the merged v2_develop from upstream:

    git checkout v2_develop
    git pull upstream v2_develop
    
  5. Merge v2_develop into v2_release:

    git checkout v2_release
    git pull upstream v2_release
    git merge v2_develop
    
    • Fix any merge errors.
  6. Create a new annotated tag for the release on v2_release:

    git tag vX.Y.Z -a -m "Release vX.Y.Z"
    
  7. Push the new tag to v2_release on upstream:

    git push --atomic upstream v2_release vX.Y.Z
    
  8. Monitor Github Actions to ensure the NuGet publishing worked:

  9. Check NuGet to see the new package version (wait a few minutes):

  10. Add a new Release in Github:

    • Go to GitHub Releases and generate release notes with the list of PRs since the last release.
  11. Update the v2_develop branch with the new version:

    git checkout v2_develop
    git pull upstream v2_develop
    git merge v2_release
    git push upstream v2_develop
    

NuGet

The official NuGet package for Terminal.Gui is available at https://www.nuget.org/packages/Terminal.Gui. When a new version tag is defined and merged into v2_release, a NuGet package is automatically generated by a GitHub Action. Pre-release versions (e.g., 2.0.0-beta.5) are tagged as pre-release on NuGet.

Contributing

We welcome contributions from the community. For complete contribution guidelines, including:

  • Build and test instructions
  • Coding conventions and style rules
  • Testing requirements and patterns
  • Pull request guidelines
  • CI/CD workflows

Please refer to CONTRIBUTING.md in the repository root.