FTXUI/doc/mainpage.md

\mainpage

Introduction

Welcome to the FTXUI documentation. Here, you will find the detail of every functions and classes.

@tableofcontents

Short example

main.cpp

#include <ftxui/dom/elements.hpp>
#include <ftxui/screen/screen.hpp>
#include <iostream>

int main(void) {
  using namespace ftxui;

  // Define the document
  Element document =
    hbox({
      text(L"left")   | border,
      text(L"middle") | border | flex,
      text(L"right")  | border,
    });

  auto screen = Screen::Create(
    Dimension::Full(),       // Width
    Dimension::Fit(document) // Height
  );
  Render(screen, document);
  std::cout << screen.ToString() << std::endl;

  return EXIT_SUCCESS;
}

output

┌────┐┌─────────────────────────────────────────────────────────────────┐┌─────┐
│left││middle                                                           ││right│
└────┘└─────────────────────────────────────────────────────────────────┘└─────┘

cmake

cmake_minimum_required (VERSION 3.11)

include(FetchContent)
FetchContent_Declare(ftxui
  GIT_REPOSITORY https://github.com/ArthurSonzogni/ftxui
)
FetchContent_GetProperties(ftxui)
if(NOT ftxui_POPULATED)
  FetchContent_Populate(ftxui)
  add_subdirectory(${ftxui_SOURCE_DIR} ${ftxui_BINARY_DIR} EXCLUDE_FROM_ALL)
endif()

add_executable(main src/main.cpp)
target_link_libraries(main
  PRIVATE ftxui::screen
  PRIVATE ftxui::dom
  PRIVATE ftxui::component # Not needed for this example.
)
set_target_properties(main PROPERTIES CXX_STANDARD 17)

List of modules.

The project is split into 3 modules:

1. ftxui/screen defines a ftxui::Screen, this is a grid of ftxui::Pixel.

2. ftxui/dom is the main module. It defines a hierarchical set of ftxui::Element. An element draws something on the ftxui::Screen. It is responsive to the size of its container.

3. ftxui/component The part is only needed if you need to respond to the User input. It defines a set of ftxui::Component. The use can navigates using the arrow keys and interact with widgets like checkbox/inputbox/... You can make you own components.

screen

It defines a ftxui::Screen. This is a grid of ftxui::Pixel. A Pixel represent a unicode character and its associated style (bold, colors, etc...). The screen can be printed as a string using ftxui::Screen::ToString().

  #include <ftxui/screen/screen.hpp>

  int main(void) {
    using namespace ftxui;
    auto screen = Screen(Dimension::Fixed(32), Dimension::Fixed(10));

    auto& pixel = screen.PixelAt(10,10);
    pixel.character = U'A';
    pixel.bold = true;
    pixel.foreground_color = Color::Blue;

    std::cout << screen.ToString();
    return EXIT_SUCCESS;
  }

dom

This module defines a hierachical set of Element. An element manages layout and can be responsive to the terminal dimensions.

Example:

// Define the document
Element document = vbox({
    text(L"The window") | bold | color(Color::Blue),
    gauge(0.5)
    text(L"The footer")
  });

// Add a border.
document = border(document);

List of elements

You only need one header: ftxui/dom/elements.hpp

\include ftxui/dom/elements.hpp

component

Finally, the ftxui/component directory defines the logic to get interactivity.

Please take a look at ./examples/component

This provides:

1. A main loop.
2. Get events and respond to them.
3. A predefined implementation of "keyboard navigation".
4. A set of predefined widget: CheckBox, RadioBox, Input, Menu, Toggle.

ftxui/dom

Every elements of the dom are declared from:

\include ftxui/dom/elements.hpp

text

The most simple widget. It displays a text.

using namespace ftxui;

text(L"I am a piece of text");

I am a piece of text.

border

Add a border around an element

using namespace ftxui;

border(text(L"The element"))

┌───────────┐
│The element│
└───────────┘

window

A ftxui::window is a ftxui::border, but with some text on top of the border. Add a border around an element

using namespace ftxui;

window(L"The window", text(L"The element"))

┌The window─┐
│The element│
└───────────┘

separator

Display a vertical or horizontal line to visually split the content of a container in two.

border(
  hbox({
    text(L"Left"), 
    separator(),
    text(L"Right")
  })
)

┌────┬─────┐
│left│right│
└────┴─────┘

gauge

A gauge. It can be used to represent a progress bar.

border(gauge(0.5))

┌────────────────────────────────────────────────────────────────────────────┐
│██████████████████████████████████████                                      │
└────────────────────────────────────────────────────────────────────────────┘

graph

@htmlonly

@endhtmlonly

Colors

A terminal console can usually display colored text and colored background.

Decorator color(Color);
Decorator bgcolor(Color);

The following colors are available:

• Default

• Black

• GrayDark

• GrayLight

• White

• Blue

• BlueLight

• Cyan

• CyanLight

• Green

• GreenLight

• Magenta

• MagentaLight

• Red

• RedLight

• Yellow

• YellowLight

Example:

text(L"Blue foreground") | color(Color::Blue);
text(L"Blue backgrond") | bgcolor(Color::Blue);
text(L"Black on white") | color(Color::Black) | bgcolor(Color::White);

Style

A terminal console can usually display colored text and colored background. The text can also have different effects: bold, dim, underlined, inverted, blink.

Element bold(Element);
Element dim(Element);
Element inverted(Element);
Element underlined(Element);
Element blink(Element);
Decorator color(Color);
Decorator bgcolor(Color);

Example:

underlined(bold(text(L"This text is bold and underlined")))

Tips: The pipe operator can be used to chain Decorator:

text(L"This text is bold")) | bold | underlined

Layout

These layout are similar to the HTML flexbox:

• vbox (Vertical-box)
• hbox (Horizontal-box)
• dbox (Z-axis-box) They are used to compose all the elements together. Each children are put side by side. If the container is flexible, the extra space available will be shared among the remaining flexible children.

flex(element) can be used to make a non-flexible element flexible. filler() is a flexible empty element. You can use it align children on one side of the container.

An horizontal flow layout is implemented by:

• hflow (Horizontal flow)

Examples

  hbox({
    text(L"left") | border ,
    text(L"middle") | border | flex,
    text(L"right") | border,
    });

┌────┐┌─────────────────────────────────────────────────────────────────┐┌─────┐
│left││middle                                                           ││right│
└────┘└─────────────────────────────────────────────────────────────────┘└─────┘

  hbox({
    text(L"left") | border ,
    text(L"middle") | border | flex,
    text(L"right") | border | flex,
    });

┌────┐┌───────────────────────────────────┐┌───────────────────────────────────┐
│left││middle                             ││right                              │
└────┘└───────────────────────────────────┘└───────────────────────────────────┘

ftxui/component

Element are stateless object. On the other side, components are used when an internal state is needed. Components are used to interact with the user with its keyboard. They handle keyboard navigation, including component focus.

Input

@htmlonly

@endhtmlonly

Menu

@htmlonly

@endhtmlonly

Toggle.

@htmlonly

@endhtmlonly

CheckBox

@htmlonly

@endhtmlonly

RadioBox

@htmlonly

@endhtmlonly

Build

Assuming this example example.cpp file.

main.cpp

#include "ftxui/screen/screen.hpp"
#include "ftxui/dom/elements.hpp"
#include <iostream>

int main(int argc, const char *argv[]) {
  using namespace ftxui;
  auto document =
    hbox({
      text(L"left") | bold | border,
      text(L"middle") | flex | border,
      text(L"right") | border,
    });
  auto screen = Screen::Create(Dimension::Full(), Dimension::Fit(document));
  Render(screen, document);

  std::cout << screen.ToString();

  return 0;
}

Using CMake

CMakeLists.txt

cmake_minimum_required (VERSION 3.11)

# --- Fetch FTXUI --------------------------------------------------------------
include(FetchContent)

set(FETCHCONTENT_UPDATES_DISCONNECTED TRUE)
FetchContent_Declare(ftxui
  GIT_REPOSITORY https://github.com/ArthurSonzogni/ftxui
  # Specify a GIT TAG here.
)

FetchContent_GetProperties(ftxui)
if(NOT ftxui_POPULATED)
  FetchContent_Populate(ftxui)
  add_subdirectory(${ftxui_SOURCE_DIR} ${ftxui_BINARY_DIR} EXCLUDE_FROM_ALL)
endif()

# ------------------------------------------------------------------------------

project(ftxui-starter
  LANGUAGES CXX
  VERSION 1.0.0
)

add_executable(ftxui-starter src/main.cpp)
target_include_directories(ftxui-starter PRIVATE src)

target_link_libraries(ftxui-starter
  PRIVATE ftxui::screen
  PRIVATE ftxui::dom
  PRIVATE ftxui::component # Not needed for this example.
)

# C++17 is used. We requires fold expressions at least.
set_target_properties(ftxui-starter PROPERTIES CXX_STANDARD 17)

Build

mkdir build && cd build
cmake ..
make
./main

Using NXXM

.nxxm/deps

{
  "ArthurSonzogni/FTXUI": {}
}

Build:

nxxm . -t clang-cxx17