Add missing include for std::max (#1124)

The cursor_ variable was being default initialized, which causes
undefined behaviour when accessing properties in
ScreenInteractive::Draw. This caused a crash when running with UBSAN.

```
ftxui/src/ftxui/component/screen_interactive.cpp:852:17: runtime error:
load of value 4195502944, which is not a valid value for type 'Shape'
```

This change causes the shape variable to be explicitly initialized,
similar to the x and y members.

Co-authored-by: Benjamin Gwin <bgwin@google.com>

.github/copilot-instructions.md

@@ -0,0 +1,212 @@
+# FTXUI - Functional Terminal (X) User Interface
+
+FTXUI is a cross-platform C++ library for terminal-based user interfaces with a functional programming approach, inspired by React.
+
+**ALWAYS reference these instructions first and fallback to search or bash commands only when you encounter unexpected information that does not match the information here.**
+
+## Working Effectively
+
+### Build System Setup and Commands
+- Bootstrap and build the repository:
+  ```bash
+  # Basic build (library only) - fast
+  cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
+  cmake --build build --parallel $(nproc)
+  # Build time: ~30 seconds. NEVER CANCEL. Set timeout to 120+ seconds.
+  
+  # Build with examples  
+  cmake -S . -B build -DCMAKE_BUILD_TYPE=Release -DFTXUI_BUILD_EXAMPLES=ON
+  cmake --build build --parallel $(nproc)
+  # Build time: ~70 seconds. NEVER CANCEL. Set timeout to 180+ seconds.
+  
+  # Build with examples and tests
+  cmake -S . -B build -DCMAKE_BUILD_TYPE=Release -DFTXUI_BUILD_EXAMPLES=ON -DFTXUI_BUILD_TESTS=ON
+  cmake --build build --parallel $(nproc)
+  # Build time: ~113 seconds (includes GoogleTest download). NEVER CANCEL. Set timeout to 300+ seconds.
+  ```
+
+- Alternative build with Ninja (faster):
+  ```bash
+  cmake -S . -B build -G Ninja -DCMAKE_BUILD_TYPE=Release -DFTXUI_BUILD_EXAMPLES=ON
+  ninja -C build
+  # Build time: ~62 seconds. NEVER CANCEL. Set timeout to 180+ seconds.
+  ```
+
+- Run unit tests:
+  ```bash
+  # Configure with tests enabled first, then:
+  cd build && ctest --output-on-failure
+  # Test time: ~4 seconds (302 tests). NEVER CANCEL. Set timeout to 60+ seconds.
+  ```
+
+### Bazel Support
+- FTXUI also supports Bazel build system
+- **WARNING**: Bazel may fail due to network connectivity issues in sandboxed environments
+- If Bazel is available:
+  ```bash
+  bazel build //...  # Build everything
+  bazel test //...   # Run tests
+  ```
+
+## Validation
+
+### Manual Testing After Changes
+- **ALWAYS manually validate changes by building and running examples after making code modifications**
+- Run example applications to verify functionality:
+  ```bash
+  # Build an example first
+  cmake --build build --target ftxui_example_border
+  
+  # Run examples (they are interactive, use timeout to terminate)
+  timeout 2s build/examples/dom/ftxui_example_border
+  timeout 2s build/examples/dom/ftxui_example_color_gallery
+  timeout 2s build/examples/component/ftxui_example_button
+  ```
+- Examples should produce visual terminal output with borders, colors, and UI components
+- **CRITICAL**: Always run at least one DOM example and one Component example to verify both modules work
+
+### Code Quality and Formatting
+- Always run formatting before committing:
+  ```bash
+  ./tools/format.sh
+  # Format time: ~7 seconds. NEVER CANCEL. Set timeout to 60+ seconds.
+  ```
+- The format script adds license headers and runs clang-format on all source files
+- **Required**: Run formatting or the CI (.github/workflows/build.yaml) will fail
+
+### Build Validation Requirements
+- ALWAYS build with both `-DFTXUI_BUILD_EXAMPLES=ON` and `-DFTXUI_BUILD_TESTS=ON` when making changes
+- Run the complete test suite with `ctest --output-on-failure`
+- All 302 tests must pass
+- **Scenario Testing**: Run at least these validation scenarios:
+  1. Build library only (basic validation)
+  2. Build with examples and run 2-3 different examples
+  3. Build with tests and run complete test suite
+  4. Run formatting tool to ensure code style compliance
+
+## Project Structure
+
+### Key Directories
+```
+/home/runner/work/FTXUI/FTXUI/
+├── include/ftxui/           # Public header files
+│   ├── component/           # Interactive component headers
+│   ├── dom/                 # DOM element headers  
+│   ├── screen/              # Screen and rendering headers
+│   └── util/                # Utility headers
+├── src/ftxui/               # Implementation files
+│   ├── component/           # Interactive components (buttons, menus, etc.)
+│   ├── dom/                 # DOM elements (layout, styling, text)
+│   ├── screen/              # Screen rendering and terminal handling
+│   └── util/                # Utilities
+├── examples/                # Example applications
+│   ├── component/           # Interactive component examples
+│   └── dom/                 # DOM element examples
+├── cmake/                   # CMake configuration files
+├── tools/                   # Development tools (formatting, etc.)
+└── .github/workflows/       # CI/CD configuration
+```
+
+### Core Library Modules
+FTXUI is organized into three main modules that depend on each other:
+```
+┌component──┐  (Interactive UI components)
+│┌dom──────┐│  (Layout and styling elements)  
+││┌screen─┐││  (Terminal rendering and input)
+└┴┴───────┴┴┘
+```
+
+1. **screen**: Low-level terminal handling, colors, pixels, input
+2. **dom**: Layout elements (hbox, vbox, text, borders, etc.)
+3. **component**: Interactive components (buttons, menus, input fields)
+
+### CMake Build Options
+| Option                            | Description                      | Default |
+|-----------------------------------|----------------------------------|---------|
+| FTXUI_BUILD_EXAMPLES              | Build example applications       | OFF     |
+| FTXUI_BUILD_DOCS                  | Build documentation             | OFF     |  
+| FTXUI_BUILD_TESTS                 | Build and enable tests          | OFF     |
+| FTXUI_BUILD_MODULES               | Build C++20 modules             | OFF     |
+| FTXUI_ENABLE_INSTALL              | Generate install targets        | ON      |
+| FTXUI_MICROSOFT_TERMINAL_FALLBACK | Windows terminal compatibility  | ON/OFF  |
+
+## Common Tasks
+
+### Building Examples
+```bash
+# Build specific examples
+cmake --build build --target ftxui_example_border
+cmake --build build --target ftxui_example_button
+cmake --build build --target ftxui_example_menu
+
+# List all available examples
+find build -name "ftxui_example_*" -type f
+```
+
+### Running Tests
+```bash
+# Run all tests
+cd build && ctest
+
+# Run tests with verbose output
+cd build && ctest --verbose
+
+# Run specific test pattern
+cd build && ctest -R "Button" --verbose
+```
+
+### Working with Source Code
+- **Component Development**: Modify files in `src/ftxui/component/` for interactive elements
+- **DOM Development**: Modify files in `src/ftxui/dom/` for layout and styling
+- **Screen Development**: Modify files in `src/ftxui/screen/` for terminal rendering
+- **Adding Examples**: Add new `.cpp` files in `examples/component/` or `examples/dom/`
+- **Header Files**: Public APIs are in `include/ftxui/[module]/`
+
+### Integration Patterns
+When adding FTXUI to a project, use CMake FetchContent (recommended):
+```cmake
+include(FetchContent)
+FetchContent_Declare(ftxui
+  GIT_REPOSITORY https://github.com/ArthurSonzogni/ftxui
+  GIT_TAG v6.1.9
+)
+FetchContent_MakeAvailable(ftxui)
+
+target_link_libraries(your_target PRIVATE
+    ftxui::component  # For interactive components
+    ftxui::dom        # For layout elements  
+    ftxui::screen     # For basic rendering
+)
+```
+
+## Troubleshooting
+
+### Build Issues
+- If CMake configuration fails, ensure C++20 support: `cmake --version` (need 3.12+)
+- If Ninja build fails, fall back to Make: `cmake -S . -B build` (without `-G Ninja`)
+- If tests fail to build, GoogleTest download might have failed - check network connectivity
+- Build artifacts are in `build/` directory - delete with `rm -rf build` to clean
+
+### Example Issues  
+- Examples are interactive terminal applications - use `timeout` to terminate them
+- If examples don't display correctly, terminal might not support colors/Unicode
+- Examples require terminal size of at least 80x24 for proper display
+
+### Formatting Issues
+- Format script requires clang-format to be installed
+- If format script fails, check that source files are not read-only
+- Format script modifies files in-place - commit changes afterwards
+
+## Critical Reminders
+
+- **NEVER CANCEL long-running builds** - they may take 2-3 minutes
+- **ALWAYS run the formatting tool** before committing changes  
+- **ALWAYS build and test examples** when making component/dom changes
+- **SET APPROPRIATE TIMEOUTS**: 300+ seconds for builds, 60+ seconds for tests
+- **BUILD TIMING EXPECTATIONS**:
+  - Basic library: ~30 seconds
+  - With examples: ~70 seconds  
+  - With examples + tests: ~113 seconds (first time, includes GoogleTest download)
+  - Subsequent builds: ~60-70 seconds
+  - Tests execution: ~4 seconds
+  - Formatting: ~7 seconds

.gitignore

@@ -28,6 +28,7 @@ out/
 # .github directory:
 !.github/**/*.yaml
 !.github/**/*.yml
+!.github/**/*.md
 
 # cmake directory:
 !cmake/**/*.in
@@ -70,3 +71,4 @@ out/
 # tools directory:
 !tools/**/*.sh
 !tools/**/*.cpp
+build/

README.md

@@ -364,6 +364,7 @@ Feel free to add your projects here:
 - [openJuice](https://github.com/mikomikotaishi/openJuice)
 - [SHOOT!](https://github.com/ShingZhanho/ENGG1340-Project-25Spring)
 - [VerifySN (Fast Hash Tool)](https://github.com/d06i/verifySN)
+- [tic-tac-toe](https://github.com/birland/tic-tac-toe)
 
 ### [cpp-best-practices/game_jam](https://github.com/cpp-best-practices/game_jam)
 

doc/installation_conan.md

@@ -1,19 +1,99 @@
 @page installation_conan Conan
+@tableofcontents
 
-Unofficial recipe for FTXUI exists on Conan Center:
+FTXUI can be easily obtained and integrated into your project using the Conan package manager.
-<https://conan.io/center/recipes/ftxui>
+
+## Prerequisites
+
+First, ensure that Conan is installed on your system. If not, you can install it via pip:
+
+```powershell
+pip install conan
+```
+Conan often works in tandem with CMake, so you will need to have CMake installed as well. Once you have confirmed both Conan and CMake are installed, create a project directory, for example, `ftxui-demo`:
+
+```powershell
+mkdir C:\ftxui-demo
+cd C:\ftxui-demo
+```
+
+## Configuration
+
+After ensuring your environment is set up correctly, create a Conan configuration file `conanfile.txt`. This file is used to declare your project's dependencies. The community-maintained package for FTXUI can be found on [Conan Center](https://conan.io/center/recipes/ftxui).
 
 > [!note]
-> This is an unofficial recipe. That means it is not maintained by the FTXUI
+> This is an unofficial build script. This means it is not maintained by the FTXUI
-> team, but by the community. The package maintainers seems to actively update
+> team but by the community. The package maintainer appears to actively update it
-> the package to the latest version. Thanks to the maintainers for their work!
+> to the latest releases. Many thanks to the maintainer for their work!
 
+@todo If you are familiar with the process, please consider adding an "official" build script to Conan Center.
+This could be a GitHub Action that automatically updates Conan Center upon new releases.
 
-@todo Add instructions on how to use the conan recipe.
+```ini
+[requires]
+ftxui/6.0.2
 
-@todo Please consider adding an "official" recipe to Conan Center if know how.
+[generators]
-It could be a github action that will automatically update the conan center
+CMakeDeps
-when a new release is made.
+CMakeToolchain
+
+[layout]
+cmake_layout
+```
+
+## Install Dependencies and Build
+
+Once configured, run the following command to install FTXUI and its dependencies:
+
+```powershell
+conan install . --output-folder=build --build=missing
+```
+
+This will download and install `ftxui/6.0.2` along with all its dependencies from Conan's remote repositories.
+
+After the installation completes, you can test it by creating a `demo.cpp` file in your project directory:
+
+```cpp
+#include <ftxui/screen/screen.hpp>
+#include <ftxui/dom/elements.hpp>
+#include <iostream>
+
+int main() {
+    using namespace ftxui;
+    auto document = hbox({
+        text(" Hello "),
+        text("FTXUI ") | bold | color(Color::Red),
+        text(" world! ")
+    });
+    auto screen = Screen::Create(Dimension::Full(), Dimension::Fit(document));
+    Render(screen, document);
+    std::cout << screen.ToString() << std::endl;
+    return 0;
+}
+```
+
+If the test is successful, you can then create a `CMakeLists.txt` file in the project directory:
+
+```cmake
+cmake_minimum_required(VERSION 3.20)
+project(ftxui-demo)
+
+# Set the C++ standard
+set(CMAKE_CXX_STANDARD 20)
+
+# Find the FTXUI package installed via Conan
+find_package(ftxui CONFIG REQUIRED)
+
+# Create the executable
+add_executable(demo demo.cpp)
+
+# Link the executable to the FTXUI library
+target_link_libraries(demo PRIVATE ftxui::component)
+```
+
+@todo 考虑到中国多数地区使用Conan很有可能遇到各种网络问题，我想做一个定制的版本说明，但是我对conan的了解有限再加上没有找到合适的资料，因此这个计划短暂的被搁置了，如果您知道方法，欢迎在[中文版本](xiaoditx.girhub.io/public/docs/ftxui%E4%B8%AD%E6%96%87%E7%BF%BB%E8%AF%91/installation/conan/)的下方留下评论以提醒我
+
+---
 
 <div class="section_buttons">
 

examples/component/button.cpp

@@ -34,8 +34,8 @@ int main() {
   int value = 50;
 
   // clang-format off
-  auto btn_dec_01 = Button("-1", [&] { value += 1; }, Style());
+  auto btn_dec_01 = Button("-1", [&] { value -= 1; }, Style());
-  auto btn_inc_01 = Button("+1", [&] { value -= 1; }, Style());
+  auto btn_inc_01 = Button("+1", [&] { value += 1; }, Style());
   auto btn_dec_10 = Button("-10", [&] { value -= 10; }, Style());
   auto btn_inc_10 = Button("+10", [&] { value += 10; }, Style());
   // clang-format on

include/ftxui/component/receiver.hpp

@@ -4,10 +4,10 @@
 #ifndef FTXUI_COMPONENT_RECEIVER_HPP_
 #define FTXUI_COMPONENT_RECEIVER_HPP_
 
-#include <ftxui/util/warn_windows_macro.hpp>
 #include <algorithm>           // for copy, max
 #include <atomic>              // for atomic, __atomic_base
 #include <condition_variable>  // for condition_variable
+#include <ftxui/util/warn_windows_macro.hpp>
 #include <memory>   // for unique_ptr, make_unique
 #include <mutex>    // for mutex, unique_lock
 #include <queue>    // for queue

include/ftxui/screen/screen.hpp

@@ -60,7 +60,7 @@ class Screen : public Image {
       BarBlinking = 5,
       Bar = 6,
     };
-    Shape shape;
+    Shape shape = Hidden;
   };
 
   Cursor cursor() const { return cursor_; }

src/ftxui/component/resizable_split.cpp

@@ -4,6 +4,7 @@
 #include <ftxui/component/component_options.hpp>  // for ResizableSplitOption
 #include <ftxui/dom/direction.hpp>  // for Direction, Direction::Down, Direction::Left, Direction::Right, Direction::Up
 #include <ftxui/util/ref.hpp>       // for Ref
+#include <algorithm>                // for max
 #include <functional>               // for function
 #include <utility>                  // for move
 

src/ftxui/component/task_runner.hpp

@@ -21,8 +21,8 @@ class TaskRunner {
   auto PostTask(Task task) -> void;
 
   /// Schedules a task to be executed after a certain duration.
-  auto PostDelayedTask(Task task, std::chrono::steady_clock::duration duration)
+  auto PostDelayedTask(Task task,
-      -> void;
+                       std::chrono::steady_clock::duration duration) -> void;
 
   /// Runs the tasks in the queue, return the delay until the next delayed task
   /// can be executed.

src/ftxui/dom/size.cpp

@@ -81,7 +81,7 @@ class Size : public Node {
 }  // namespace
 
 /// @brief Apply a constraint on the size of an element.
-/// @param direction Whether the WIDTH of the HEIGHT of the element must be
+/// @param direction Whether the WIDTH or the HEIGHT of the element must be
 ///                  constrained.
 /// @param constraint The type of constaint.
 /// @param value The value.