Update doc

.gitignore

@@ -44,6 +44,7 @@ out/
 !doc/**/*.html
 !doc/**/*.xml
 !doc/**/*.md
+!doc/*.md
 
 # examples directory:
 !examples/**/*.cpp

README.md

@@ -378,21 +378,7 @@ Several games using the FTXUI have been made during the Game Jam:
 - [smoothlife](https://github.com/cpp-best-practices/game_jam/blob/main/Jam1_April_2022/smoothlife.md)
 - [Consu](https://github.com/cpp-best-practices/game_jam/blob/main/Jam1_April_2022/consu.md)
 
-## Advanced Usage
 
-### Piped Input Support
-
-If your application reads from stdin (piped data) and also needs interactive keyboard input:
-
-```cpp
-auto screen = ScreenInteractive::Fullscreen();
-screen.HandlePipedInput(true);  // Enable before Loop()
-screen.Loop(component);
-```
-
-This allows commands like `cat data.txt | your_app` to work with full keyboard interaction.
-
-**Note:** This feature is only available on POSIX systems (Linux/macOS). On Windows, the method call is a no-op.
 
 ## Build using CMake
 

doc/posix_pipe.md

@@ -0,0 +1,55 @@
+# POSIX Piped Input in FTXUI
+
+## What is a POSIX Pipe?
+
+A POSIX pipe is a way for two separate programs to communicate. One program sends its output directly as input to another program. Think of it like a one-way tube for data.
+
+**Example:**
+
+Imagine you want to list files and then filter them interactively.
+
+- `ls`: Lists files.
+- `interactive_grep`: An FTXUI application that filters text and lets you type.
+
+You can connect them with a pipe (`|`):
+
+```bash
+ls -l | interactive_grep
+```
+
+Here's what happens:
+1. `ls -l` lists files with details.
+2. The `|` sends this list directly to `interactive_grep`.
+3. `interactive_grep` receives the list and displays it. Because it's an FTXUI app, you can then type to filter the list, even though it received initial data from `ls`.
+
+## How FTXUI Handles Piped Input
+
+Now that you understand what a POSIX pipe is, let's look at how FTXUI uses them.
+
+FTXUI lets your application read data from other programs (like from a pipe) while still allowing you to use your keyboard for interaction. This is useful for interactive command-line tools that process data.
+
+Normally, FTXUI applications receive all input from `stdin`. However, when FTXUI detects that `stdin` is connected to the output of a pipe (meaning data is being piped into your application), it automatically switches to reading interactive keyboard input from `/dev/tty`. This ensures that your application can still receive user input even while processing piped data.
+
+This feature is **turned on by default**.
+
+If your FTXUI application needs to read piped data and also respond to keyboard input, you typically don't need to do anything special:
+
+```cpp
+auto screen = ScreenInteractive::Fullscreen();
+// screen.HandlePipedInput(true); // This is enabled by default
+screen.Loop(component);
+```
+
+**Note:** This feature works only on Linux and macOS. It does nothing on Windows.
+
+## Turning Off Piped Input
+
+If you don't need this feature, or if it conflicts with your custom input handling, you can turn it off.
+
+To disable it, call `HandlePipedInput(false)` before starting your application's main loop:
+
+```cpp
+auto screen = ScreenInteractive::Fullscreen();
+screen.HandlePipedInput(false); // Turn off piped input handling
+screen.Loop(component);
+```

include/ftxui/component/screen_interactive.hpp

@@ -144,7 +144,7 @@ class ScreenInteractive : public Screen {
 
 #if !defined(_WIN32) && !defined(__EMSCRIPTEN__)
   // Piped input handling state (POSIX only)
-  bool handle_piped_input_ = false;
+  bool handle_piped_input_ = true;
   bool stdin_was_redirected_ = false;
   int original_stdin_fd_ = -1;
 #endif

src/ftxui/component/screen_interactive.cpp

@@ -376,9 +376,9 @@ void ScreenInteractive::TrackMouse(bool enable) {
 /// When enabled, FTXUI will detect piped input and redirect stdin to /dev/tty
 /// for keyboard input, allowing applications to read piped data while still
 /// receiving interactive keyboard events.
-/// @param enable Whether to enable piped input handling
+/// @param enable Whether to enable piped input handling. Default is true.
 /// @note This must be called before Loop().
-/// @note This feature is disabled by default for backward compatibility.
+/// @note This feature is enabled by default.
 /// @note This feature is only available on POSIX systems (Linux/macOS).
 #if !defined(_WIN32) && !defined(__EMSCRIPTEN__)
 void ScreenInteractive::HandlePipedInput(bool enable) {

src/ftxui/component/screen_interactive_piped_input_test.cpp

@@ -63,19 +63,23 @@ class PipedInputTest : public ::testing::Test {
   bool piped_stdin_setup_ = false;
 };
 
-TEST_F(PipedInputTest, DefaultBehaviorNoChange) {
+TEST_F(PipedInputTest, DefaultBehaviorEnabled) {
-  // Test that HandlePipedInput is disabled by default
+  // Test that HandlePipedInput is enabled by default
+  if (!IsTtyAvailable()) {
+    GTEST_SKIP() << "/dev/tty not available in this environment";
+  }
+
   auto screen = ScreenInteractive::TerminalOutput();
   auto component = Renderer([] { return text("test"); });
 
   SetupPipedStdin();
   WriteToPipedStdin("test data\n");
 
-  // Install should not redirect stdin since HandlePipedInput not called
+  // Install should redirect stdin since HandlePipedInput is on by default
   screen.Install();
 
-  // Stdin should still be the pipe (isatty should return false)
+  // Stdin should be the tty
-  EXPECT_FALSE(isatty(STDIN_FILENO));
+  EXPECT_TRUE(isatty(STDIN_FILENO));
 
   screen.Uninstall();
 }
@@ -97,7 +101,7 @@ TEST_F(PipedInputTest, ExplicitlyDisabled) {
   screen.Uninstall();
 }
 
-TEST_F(PipedInputTest, PipedInputDetectionAndRedirection) {
+TEST_F(PipedInputTest, ExplicitlyEnabled) {
   if (!IsTtyAvailable()) {
     GTEST_SKIP() << "/dev/tty not available in this environment";
   }
@@ -127,7 +131,6 @@ TEST_F(PipedInputTest, PipedInputDetectionAndRedirection) {
 TEST_F(PipedInputTest, NormalStdinUnchanged) {
   // Test that normal stdin (not piped) is not affected
   auto screen = ScreenInteractive::TerminalOutput();
-  screen.HandlePipedInput(true);
   auto component = Renderer([] { return text("test"); });
 
   // Don't setup piped stdin - use normal stdin
@@ -150,7 +153,6 @@ TEST_F(PipedInputTest, MultipleInstallUninstallCycles) {
   }
 
   auto screen = ScreenInteractive::TerminalOutput();
-  screen.HandlePipedInput(true);
   auto component = Renderer([] { return text("test"); });
 
   SetupPipedStdin();
@@ -192,7 +194,6 @@ TEST_F(PipedInputTest, HandlePipedInputMethodBehavior) {
 // This test simulates environments like containers where /dev/tty might not exist
 TEST_F(PipedInputTest, GracefulFallbackWhenTtyUnavailable) {
   auto screen = ScreenInteractive::TerminalOutput();
-  screen.HandlePipedInput(true);
   auto component = Renderer([] { return text("test"); });
 
   SetupPipedStdin();