Merge baa5973128 into b78b97056b

Stop using Sender/Receiver in TerminalInputParser.

This will help removing usage of thread.

At some point, my goal is to have an initialization step when installing
the ScreenInteractive so that we can provide the terminal ID
synchronously without losing some events. This will help with:
https://github.com/ArthurSonzogni/FTXUI/pull/1069

examples/component/button.cpp

@@ -1,9 +1,64 @@
-#include "ftxui/component/component.hpp"
-#include "ftxui/component/screen_interactive.hpp"
+// Copyright 2020 Arthur Sonzogni. All rights reserved.
+// Use of this source code is governed by the MIT license that can be found in
+// the LICENSE file.
+#include <memory>  // for shared_ptr, __shared_ptr_access
+#include <string>  // for operator+, to_string
 
-int main(){
-    auto screen = ftxui::ScreenInteractive::Fullscreen();
-    auto testComponent = ftxui::Renderer([](){return ftxui::text("test Component");});
-    screen.Loop(testComponent);
-    return 0;
+#include "ftxui/component/captured_mouse.hpp"  // for ftxui
+#include "ftxui/component/component.hpp"  // for Button, Horizontal, Renderer
+#include "ftxui/component/component_base.hpp"      // for ComponentBase
+#include "ftxui/component/screen_interactive.hpp"  // for ScreenInteractive
+#include "ftxui/dom/elements.hpp"  // for separator, gauge, text, Element, operator|, vbox, border
+
+using namespace ftxui;
+
+// This is a helper function to create a button with a custom style.
+// The style is defined by a lambda function that takes an EntryState and
+// returns an Element.
+// We are using `center` to center the text inside the button, then `border` to
+// add a border around the button, and finally `flex` to make the button fill
+// the available space.
+ButtonOption Style() {
+  auto option = ButtonOption::Animated();
+  option.transform = [](const EntryState& s) {
+    auto element = text(s.label);
+    if (s.focused) {
+      element |= bold;
+    }
+    return element | center | borderEmpty | flex;
+  };
+  return option;
+}
+
+int main() {
+  int value = 50;
+
+  // clang-format off
+  auto btn_dec_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
+
+  // The tree of components. This defines how to navigate using the keyboard.
+  // The selected `row` is shared to get a grid layout.
+  int row = 0;
+  auto buttons = Container::Vertical({
+      Container::Horizontal({btn_dec_01, btn_inc_01}, &row) | flex,
+      Container::Horizontal({btn_dec_10, btn_inc_10}, &row) | flex,
+  });
+
+  // Modify the way to render them on screen:
+  auto component = Renderer(buttons, [&] {
+    return vbox({
+               text("value = " + std::to_string(value)),
+               separator(),
+               buttons->Render() | flex,
+           }) |
+           flex | border;
+  });
+
+  auto screen = ScreenInteractive::FitComponent();
+  screen.Loop(component);
+  return 0;
 }

include/ftxui/dom/canvas.hpp

@@ -30,7 +30,7 @@ namespace ftxui {
 /// - 2x4 braille characters (1x1 pixel)
 /// - 2x2 block characters (2x2 pixels)
 /// - 2x4 normal characters (2x4 pixels)
-/// 
+///
 /// You need to multiply the x coordinate by 2 and the y coordinate by 4 to
 /// get the correct position in the terminal.
 ///

include/ftxui/dom/flexbox_config.hpp

@@ -12,7 +12,6 @@
 
 namespace ftxui {
 
-
 /// @brief FlexboxConfig is a configuration structure that defines the layout
 /// properties for a flexbox container.
 //

include/ftxui/screen/box.hpp

@@ -11,7 +11,7 @@ namespace ftxui {
 /// It is defined by its minimum and maximum coordinates along the x and y axes.
 /// Note that the coordinates are inclusive, meaning that the box includes both
 /// the minimum and maximum values.
-/// 
+///
 /// @ingroup screen
 struct Box {
   int x_min = 0;

src/ftxui/component/component_fuzzer.cpp

@@ -2,6 +2,7 @@
 // Use of this source code is governed by the MIT license that can be found in
 // the LICENSE file.
 #include <cassert>
+#include <ftxui/component/event.hpp>
 #include <vector>
 #include "ftxui/component/component.hpp"
 #include "ftxui/component/terminal_input_parser.hpp"
@@ -212,16 +213,17 @@ extern "C" int LLVMFuzzerTestOneInput(const char* data, size_t size) {
   auto screen =
       Screen::Create(Dimension::Fixed(width), Dimension::Fixed(height));
 
-  auto event_receiver = MakeReceiver<Task>();
-  {
-    auto parser = TerminalInputParser(event_receiver->MakeSender());
-    for (size_t i = 0; i < size; ++i)
-      parser.Add(data[i]);
+  // Generate some events.
+  std::vector<Event> events;
+  auto parser =
+      TerminalInputParser([&](const Event& event) { events.push_back(event); });
+
+  for (size_t i = 0; i < size; ++i) {
+    parser.Add(data[i]);
   }
 
-  Task event;
-  while (event_receiver->Receive(&event)) {
-    component->OnEvent(std::get<Event>(event));
+  for (const auto& event : events) {
+    component->OnEvent(event);
     auto document = component->Render();
     Render(screen, document);
   }

src/ftxui/component/screen_interactive.cpp

@@ -84,7 +84,8 @@ constexpr int timeout_milliseconds = 20;
 
 void EventListener(std::atomic<bool>* quit, Sender<Task> out) {
   auto console = GetStdHandle(STD_INPUT_HANDLE);
-  auto parser = TerminalInputParser(out->Clone());
+  auto parser =
+      TerminalInputParser([&](Event event) { out->Send(std::move(event)); });
   while (!*quit) {
     // Throttle ReadConsoleInput by waiting 250ms, this wait function will
     // return if there is input in the console.
@@ -137,7 +138,8 @@ void EventListener(std::atomic<bool>* quit, Sender<Task> out) {
 
 // Read char from the terminal.
 void EventListener(std::atomic<bool>* quit, Sender<Task> out) {
-  auto parser = TerminalInputParser(std::move(out));
+  auto parser =
+      TerminalInputParser([&](Event event) { out->Send(std::move(event)); });
 
   char c;
   while (!*quit) {
@@ -173,7 +175,8 @@ int CheckStdinReady(int usec_timeout) {
 
 // Read char from the terminal.
 void EventListener(std::atomic<bool>* quit, Sender<Task> out) {
-  auto parser = TerminalInputParser(std::move(out));
+  auto parser =
+      TerminalInputParser([&](Event event) { out->Send(std::move(event)); });
 
   while (!*quit) {
     if (!CheckStdinReady(timeout_microseconds)) {
@@ -381,10 +384,10 @@ ScreenInteractive ScreenInteractive::Fullscreen() {
 ScreenInteractive ScreenInteractive::FullscreenPrimaryScreen() {
   auto terminal = Terminal::Size();
   return {
-    Dimension::Fullscreen,
-    terminal.dimx,
-    terminal.dimy,
-    /*use_alternative_screen=*/false,
+      Dimension::Fullscreen,
+      terminal.dimx,
+      terminal.dimy,
+      /*use_alternative_screen=*/false,
   };
 }
 
@@ -409,7 +412,7 @@ ScreenInteractive ScreenInteractive::TerminalOutput() {
   return {
       Dimension::TerminalOutput,
       terminal.dimx,
-      terminal.dimy, // Best guess.
+      terminal.dimy,  // Best guess.
       /*use_alternative_screen=*/false,
   };
 }
@@ -421,8 +424,8 @@ ScreenInteractive ScreenInteractive::FitComponent() {
   auto terminal = Terminal::Size();
   return {
       Dimension::FitComponent,
-      terminal.dimx, // Best guess.
-      terminal.dimy, // Best guess.
+      terminal.dimx,  // Best guess.
+      terminal.dimy,  // Best guess.
       false,
   };
 }

src/ftxui/component/screen_interactive_test.cpp

@@ -27,9 +27,9 @@ namespace {
 // Capture the standard output (stdout) to a string.
 class StdCapture {
  public:
-  explicit StdCapture(std::string* captured)
-      : captured_(captured) {
-    if (pipe(pipefd_) != 0) return;
+  explicit StdCapture(std::string* captured) : captured_(captured) {
+    if (pipe(pipefd_) != 0)
+      return;
     old_stdout_ = dup(fileno(stdout));
     fflush(stdout);
     dup2(pipefd_[1], fileno(stdout));
@@ -188,9 +188,7 @@ TEST(ScreenInteractive, FixedSizeInitialFrame) {
     auto capture = StdCapture(&output);
 
     auto screen = ScreenInteractive::FixedSize(2, 2);
-    auto component = Renderer([&] {
-      return text("AB");
-    });
+    auto component = Renderer([&] { return text("AB"); });
 
     Loop loop(&screen, component);
     loop.RunOnce();
@@ -241,7 +239,6 @@ TEST(ScreenInteractive, FixedSizeInitialFrame) {
       "\r\n"sv;
   ASSERT_EQ(expected, output);
 #endif
-
 }
 
 }  // namespace ftxui

src/ftxui/component/terminal_input_parser.cpp

@@ -5,7 +5,7 @@
 
 #include <cstdint>                    // for uint32_t
 #include <ftxui/component/mouse.hpp>  // for Mouse, Mouse::Button, Mouse::Motion
-#include <ftxui/component/receiver.hpp>  // for SenderImpl, Sender
+#include <functional>                 // for std::function
 #include <map>
 #include <memory>   // for unique_ptr, allocator
 #include <utility>  // for move
@@ -90,7 +90,7 @@ const std::map<std::string, std::string> g_uniformize = {
     {"\x1B[X", "\x1B[24~"},  // F12
 };
 
-TerminalInputParser::TerminalInputParser(Sender<Task> out)
+TerminalInputParser::TerminalInputParser(std::function<void(Event)> out)
     : out_(std::move(out)) {}
 
 void TerminalInputParser::Timeout(int time) {
@@ -131,7 +131,7 @@ void TerminalInputParser::Send(TerminalInputParser::Output output) {
       return;
 
     case CHARACTER:
-      out_->Send(Event::Character(std::move(pending_)));
+      out_(Event::Character(std::move(pending_)));
       pending_.clear();
       return;
 
@@ -140,25 +140,25 @@ void TerminalInputParser::Send(TerminalInputParser::Output output) {
       if (it != g_uniformize.end()) {
         pending_ = it->second;
       }
-      out_->Send(Event::Special(std::move(pending_)));
+      out_(Event::Special(std::move(pending_)));
       pending_.clear();
     }
       return;
 
     case MOUSE:
-      out_->Send(Event::Mouse(std::move(pending_), output.mouse));  // NOLINT
+      out_(Event::Mouse(std::move(pending_), output.mouse));  // NOLINT
       pending_.clear();
       return;
 
     case CURSOR_POSITION:
-      out_->Send(Event::CursorPosition(std::move(pending_),  // NOLINT
-                                       output.cursor.x,      // NOLINT
-                                       output.cursor.y));    // NOLINT
+      out_(Event::CursorPosition(std::move(pending_),  // NOLINT
+                                      output.cursor.x,      // NOLINT
+                                      output.cursor.y));    // NOLINT
       pending_.clear();
       return;
 
     case CURSOR_SHAPE:
-      out_->Send(Event::CursorShape(std::move(pending_), output.cursor_shape));
+      out_(Event::CursorShape(std::move(pending_), output.cursor_shape));
       pending_.clear();
       return;
   }

src/ftxui/component/terminal_input_parser.hpp

@@ -4,12 +4,11 @@
 #ifndef FTXUI_COMPONENT_TERMINAL_INPUT_PARSER
 #define FTXUI_COMPONENT_TERMINAL_INPUT_PARSER
 
+#include <functional>
 #include <string>  // for string
 #include <vector>  // for vector
 
-#include "ftxui/component/mouse.hpp"     // for Mouse
-#include "ftxui/component/receiver.hpp"  // for Sender
-#include "ftxui/component/task.hpp"      // for Task
+#include "ftxui/component/mouse.hpp"  // for Mouse
 
 namespace ftxui {
 struct Event;
@@ -17,7 +16,7 @@ struct Event;
 // Parse a sequence of |char| accross |time|. Produces |Event|.
 class TerminalInputParser {
  public:
-  explicit TerminalInputParser(Sender<Task> out);
+  explicit TerminalInputParser(std::function<void(Event)> out);
   void Timeout(int time);
   void Add(char c);
 
@@ -62,7 +61,7 @@ class TerminalInputParser {
   Output ParseMouse(bool altered, bool pressed, std::vector<int> arguments);
   Output ParseCursorPosition(std::vector<int> arguments);
 
-  Sender<Task> out_;
+  std::function<void(Event)> out_;
   int position_ = -1;
   int timeout_ = 0;
   std::string pending_;

src/ftxui/component/terminal_input_parser_test.cpp

@@ -2,12 +2,12 @@
 // Use of this source code is governed by the MIT license that can be found in
 // the LICENSE file.
 #include <ftxui/component/mouse.hpp>  // for Mouse, Mouse::Left, Mouse::Middle, Mouse::Pressed, Mouse::Released, Mouse::Right
-#include <ftxui/component/task.hpp>   // for Task
+#include <functional>                 // for function
 #include <initializer_list>           // for initializer_list
 #include <memory>                     // for allocator, unique_ptr
+#include <vector>                     // for vector
 
 #include "ftxui/component/event.hpp"  // for Event, Event::Return, Event::ArrowDown, Event::ArrowLeft, Event::ArrowRight, Event::ArrowUp, Event::Backspace, Event::End, Event::Home, Event::Custom, Event::Delete, Event::F1, Event::F10, Event::F11, Event::F12, Event::F2, Event::F3, Event::F4, Event::F5, Event::F6, Event::F7, Event::F8, Event::F9, Event::PageDown, Event::PageUp, Event::Tab, Event::TabReverse, Event::Escape
-#include "ftxui/component/receiver.hpp"  // for MakeReceiver, ReceiverImpl
 #include "ftxui/component/terminal_input_parser.hpp"
 #include "gtest/gtest.h"  // for AssertionResult, Test, Message, TestPartResult, EXPECT_EQ, EXPECT_TRUE, TEST, EXPECT_FALSE
 
@@ -22,228 +22,197 @@ TEST(Event, Character) {
   for (char c = 'A'; c <= 'Z'; ++c)
     basic_char.push_back(c);
 
-  auto event_receiver = MakeReceiver<Task>();
-  {
-    auto parser = TerminalInputParser(event_receiver->MakeSender());
-    for (char c : basic_char)
-      parser.Add(c);
-  }
+  std::vector<Event> received_events;
+  auto parser = TerminalInputParser(
+      [&](Event event) { received_events.push_back(std::move(event)); });
+  for (char c : basic_char)
+    parser.Add(c);
 
-  Task received;
-  for (char c : basic_char) {
-    EXPECT_TRUE(event_receiver->Receive(&received));
-    EXPECT_TRUE(std::get<Event>(received).is_character());
-    EXPECT_EQ(c, std::get<Event>(received).character()[0]);
+  for (size_t i = 0; i < basic_char.size(); ++i) {
+    EXPECT_TRUE(received_events[i].is_character());
+    EXPECT_EQ(basic_char[i], received_events[i].character()[0]);
   }
-  EXPECT_FALSE(event_receiver->Receive(&received));
+  EXPECT_EQ(received_events.size(), basic_char.size());
 }
 
 TEST(Event, EscapeKeyWithoutWaiting) {
-  auto event_receiver = MakeReceiver<Task>();
-  {
-    auto parser = TerminalInputParser(event_receiver->MakeSender());
-    parser.Add('\x1B');
-  }
+  std::vector<Event> received_events;
+  auto parser = TerminalInputParser(
+      [&](Event event) { received_events.push_back(std::move(event)); });
+  parser.Add('');
 
-  Task received;
-  EXPECT_FALSE(event_receiver->Receive(&received));
+  EXPECT_TRUE(received_events.empty());
 }
 
 TEST(Event, EscapeKeyNotEnoughWait) {
-  auto event_receiver = MakeReceiver<Task>();
-  {
-    auto parser = TerminalInputParser(event_receiver->MakeSender());
-    parser.Add('\x1B');
-    parser.Timeout(49);
-  }
+  std::vector<Event> received_events;
+  auto parser = TerminalInputParser(
+      [&](Event event) { received_events.push_back(std::move(event)); });
+  parser.Add('');
+  parser.Timeout(49);
 
-  Task received;
-  EXPECT_FALSE(event_receiver->Receive(&received));
+  EXPECT_TRUE(received_events.empty());
 }
 
 TEST(Event, EscapeKeyEnoughWait) {
-  auto event_receiver = MakeReceiver<Task>();
-  {
-    auto parser = TerminalInputParser(event_receiver->MakeSender());
-    parser.Add('\x1B');
-    parser.Timeout(50);
-  }
+  std::vector<Event> received_events;
+  auto parser = TerminalInputParser(
+      [&](Event event) { received_events.push_back(std::move(event)); });
+  parser.Add('');
+  parser.Timeout(50);
 
-  Task received;
-  EXPECT_TRUE(event_receiver->Receive(&received));
-  EXPECT_EQ(std::get<Event>(received), Event::Escape);
-  EXPECT_FALSE(event_receiver->Receive(&received));
+  EXPECT_EQ(1, received_events.size());
+  EXPECT_EQ(received_events[0], Event::Escape);
 }
 
 TEST(Event, EscapeFast) {
-  auto event_receiver = MakeReceiver<Task>();
-  {
-    auto parser = TerminalInputParser(event_receiver->MakeSender());
-    parser.Add('\x1B');
-    parser.Add('a');
-    parser.Add('\x1B');
-    parser.Add('b');
-    parser.Timeout(49);
-  }
-  Task received;
-  EXPECT_TRUE(event_receiver->Receive(&received));
-  EXPECT_EQ(std::get<Event>(received), Event::AltA);
-  EXPECT_TRUE(event_receiver->Receive(&received));
-  EXPECT_EQ(std::get<Event>(received), Event::AltB);
-  EXPECT_FALSE(event_receiver->Receive(&received));
+  std::vector<Event> received_events;
+  auto parser = TerminalInputParser(
+      [&](Event event) { received_events.push_back(std::move(event)); });
+  parser.Add('');
+  parser.Add('a');
+  parser.Add('');
+  parser.Add('b');
+  parser.Timeout(49);
+
+  EXPECT_EQ(2, received_events.size());
+  EXPECT_EQ(received_events[0], Event::AltA);
+  EXPECT_EQ(received_events[1], Event::AltB);
 }
 
 TEST(Event, MouseLeftClickPressed) {
-  auto event_receiver = MakeReceiver<Task>();
-  {
-    auto parser = TerminalInputParser(event_receiver->MakeSender());
-    parser.Add('\x1B');
-    parser.Add('[');
-    parser.Add('0');
-    parser.Add(';');
-    parser.Add('1');
-    parser.Add('2');
-    parser.Add(';');
-    parser.Add('4');
-    parser.Add('2');
-    parser.Add('M');
-  }
+  std::vector<Event> received_events;
+  auto parser = TerminalInputParser(
+      [&](Event event) { received_events.push_back(std::move(event)); });
+  parser.Add('');
+  parser.Add('[');
+  parser.Add('0');
+  parser.Add(';');
+  parser.Add('1');
+  parser.Add('2');
+  parser.Add(';');
+  parser.Add('4');
+  parser.Add('2');
+  parser.Add('M');
 
-  Task received;
-  EXPECT_TRUE(event_receiver->Receive(&received));
-  EXPECT_TRUE(std::get<Event>(received).is_mouse());
-  EXPECT_EQ(Mouse::Left, std::get<Event>(received).mouse().button);
-  EXPECT_EQ(12, std::get<Event>(received).mouse().x);
-  EXPECT_EQ(42, std::get<Event>(received).mouse().y);
-  EXPECT_EQ(std::get<Event>(received).mouse().motion, Mouse::Pressed);
-  EXPECT_FALSE(event_receiver->Receive(&received));
+  EXPECT_EQ(1, received_events.size());
+  EXPECT_TRUE(received_events[0].is_mouse());
+  EXPECT_EQ(Mouse::Left, received_events[0].mouse().button);
+  EXPECT_EQ(12, received_events[0].mouse().x);
+  EXPECT_EQ(42, received_events[0].mouse().y);
+  EXPECT_EQ(received_events[0].mouse().motion, Mouse::Pressed);
 }
 
 TEST(Event, MouseLeftMoved) {
-  auto event_receiver = MakeReceiver<Task>();
-  {
-    auto parser = TerminalInputParser(event_receiver->MakeSender());
-    parser.Add('\x1B');
-    parser.Add('[');
-    parser.Add('3');
-    parser.Add('2');
-    parser.Add(';');
-    parser.Add('1');
-    parser.Add('2');
-    parser.Add(';');
-    parser.Add('4');
-    parser.Add('2');
-    parser.Add('M');
-  }
+  std::vector<Event> received_events;
+  auto parser = TerminalInputParser(
+      [&](Event event) { received_events.push_back(std::move(event)); });
+  parser.Add('');
+  parser.Add('[');
+  parser.Add('3');
+  parser.Add('2');
+  parser.Add(';');
+  parser.Add('1');
+  parser.Add('2');
+  parser.Add(';');
+  parser.Add('4');
+  parser.Add('2');
+  parser.Add('M');
 
-  Task received;
-  EXPECT_TRUE(event_receiver->Receive(&received));
-  EXPECT_TRUE(std::get<Event>(received).is_mouse());
-  EXPECT_EQ(Mouse::Left, std::get<Event>(received).mouse().button);
-  EXPECT_EQ(12, std::get<Event>(received).mouse().x);
-  EXPECT_EQ(42, std::get<Event>(received).mouse().y);
-  EXPECT_EQ(std::get<Event>(received).mouse().motion, Mouse::Moved);
-  EXPECT_FALSE(event_receiver->Receive(&received));
+  EXPECT_EQ(1, received_events.size());
+  EXPECT_TRUE(received_events[0].is_mouse());
+  EXPECT_EQ(Mouse::Left, received_events[0].mouse().button);
+  EXPECT_EQ(12, received_events[0].mouse().x);
+  EXPECT_EQ(42, received_events[0].mouse().y);
+  EXPECT_EQ(received_events[0].mouse().motion, Mouse::Moved);
 }
 
 TEST(Event, MouseLeftClickReleased) {
-  auto event_receiver = MakeReceiver<Task>();
-  {
-    auto parser = TerminalInputParser(event_receiver->MakeSender());
-    parser.Add('\x1B');
-    parser.Add('[');
-    parser.Add('0');
-    parser.Add(';');
-    parser.Add('1');
-    parser.Add('2');
-    parser.Add(';');
-    parser.Add('4');
-    parser.Add('2');
-    parser.Add('m');
-  }
+  std::vector<Event> received_events;
+  auto parser = TerminalInputParser(
+      [&](Event event) { received_events.push_back(std::move(event)); });
+  parser.Add('');
+  parser.Add('[');
+  parser.Add('0');
+  parser.Add(';');
+  parser.Add('1');
+  parser.Add('2');
+  parser.Add(';');
+  parser.Add('4');
+  parser.Add('2');
+  parser.Add('m');
 
-  Task received;
-  EXPECT_TRUE(event_receiver->Receive(&received));
-  EXPECT_TRUE(std::get<Event>(received).is_mouse());
-  EXPECT_EQ(Mouse::Left, std::get<Event>(received).mouse().button);
-  EXPECT_EQ(12, std::get<Event>(received).mouse().x);
-  EXPECT_EQ(42, std::get<Event>(received).mouse().y);
-  EXPECT_EQ(std::get<Event>(received).mouse().motion, Mouse::Released);
-  EXPECT_FALSE(event_receiver->Receive(&received));
+  EXPECT_EQ(1, received_events.size());
+  EXPECT_TRUE(received_events[0].is_mouse());
+  EXPECT_EQ(Mouse::Left, received_events[0].mouse().button);
+  EXPECT_EQ(12, received_events[0].mouse().x);
+  EXPECT_EQ(42, received_events[0].mouse().y);
+  EXPECT_EQ(received_events[0].mouse().motion, Mouse::Released);
 }
 
 TEST(Event, MouseReporting) {
-  auto event_receiver = MakeReceiver<Task>();
-  {
-    auto parser = TerminalInputParser(event_receiver->MakeSender());
-    parser.Add('\x1B');
-    parser.Add('[');
-    parser.Add('1');
-    parser.Add('2');
-    parser.Add(';');
-    parser.Add('4');
-    parser.Add('2');
-    parser.Add('R');
-  }
+  std::vector<Event> received_events;
+  auto parser = TerminalInputParser(
+      [&](Event event) { received_events.push_back(std::move(event)); });
+  parser.Add('');
+  parser.Add('[');
+  parser.Add('1');
+  parser.Add('2');
+  parser.Add(';');
+  parser.Add('4');
+  parser.Add('2');
+  parser.Add('R');
 
-  Task received;
-  EXPECT_TRUE(event_receiver->Receive(&received));
-  EXPECT_TRUE(std::get<Event>(received).is_cursor_position());
-  EXPECT_EQ(42, std::get<Event>(received).cursor_x());
-  EXPECT_EQ(12, std::get<Event>(received).cursor_y());
-  EXPECT_FALSE(event_receiver->Receive(&received));
+  EXPECT_EQ(1, received_events.size());
+  EXPECT_TRUE(received_events[0].is_cursor_position());
+  EXPECT_EQ(42, received_events[0].cursor_x());
+  EXPECT_EQ(12, received_events[0].cursor_y());
 }
 
 TEST(Event, MouseMiddleClick) {
-  auto event_receiver = MakeReceiver<Task>();
-  {
-    auto parser = TerminalInputParser(event_receiver->MakeSender());
-    parser.Add('\x1B');
-    parser.Add('[');
-    parser.Add('3');
-    parser.Add('3');
-    parser.Add(';');
-    parser.Add('1');
-    parser.Add('2');
-    parser.Add(';');
-    parser.Add('4');
-    parser.Add('2');
-    parser.Add('M');
-  }
+  std::vector<Event> received_events;
+  auto parser = TerminalInputParser(
+      [&](Event event) { received_events.push_back(std::move(event)); });
+  parser.Add('');
+  parser.Add('[');
+  parser.Add('3');
+  parser.Add('3');
+  parser.Add(';');
+  parser.Add('1');
+  parser.Add('2');
+  parser.Add(';');
+  parser.Add('4');
+  parser.Add('2');
+  parser.Add('M');
 
-  Task received;
-  EXPECT_TRUE(event_receiver->Receive(&received));
-  EXPECT_TRUE(std::get<Event>(received).is_mouse());
-  EXPECT_EQ(Mouse::Middle, std::get<Event>(received).mouse().button);
-  EXPECT_EQ(12, std::get<Event>(received).mouse().x);
-  EXPECT_EQ(42, std::get<Event>(received).mouse().y);
-  EXPECT_FALSE(event_receiver->Receive(&received));
+  EXPECT_EQ(1, received_events.size());
+  EXPECT_TRUE(received_events[0].is_mouse());
+  EXPECT_EQ(Mouse::Middle, received_events[0].mouse().button);
+  EXPECT_EQ(12, received_events[0].mouse().x);
+  EXPECT_EQ(42, received_events[0].mouse().y);
 }
 
 TEST(Event, MouseRightClick) {
-  auto event_receiver = MakeReceiver<Task>();
-  {
-    auto parser = TerminalInputParser(event_receiver->MakeSender());
-    parser.Add('\x1B');
-    parser.Add('[');
-    parser.Add('3');
-    parser.Add('4');
-    parser.Add(';');
-    parser.Add('1');
-    parser.Add('2');
-    parser.Add(';');
-    parser.Add('4');
-    parser.Add('2');
-    parser.Add('M');
-  }
+  std::vector<Event> received_events;
+  auto parser = TerminalInputParser(
+      [&](Event event) { received_events.push_back(std::move(event)); });
+  parser.Add('');
+  parser.Add('[');
+  parser.Add('3');
+  parser.Add('4');
+  parser.Add(';');
+  parser.Add('1');
+  parser.Add('2');
+  parser.Add(';');
+  parser.Add('4');
+  parser.Add('2');
+  parser.Add('M');
 
-  Task received;
-  EXPECT_TRUE(event_receiver->Receive(&received));
-  EXPECT_TRUE(std::get<Event>(received).is_mouse());
-  EXPECT_EQ(Mouse::Right, std::get<Event>(received).mouse().button);
-  EXPECT_EQ(12, std::get<Event>(received).mouse().x);
-  EXPECT_EQ(42, std::get<Event>(received).mouse().y);
-  EXPECT_FALSE(event_receiver->Receive(&received));
+  EXPECT_EQ(1, received_events.size());
+  EXPECT_TRUE(received_events[0].is_mouse());
+  EXPECT_EQ(Mouse::Right, received_events[0].mouse().button);
+  EXPECT_EQ(12, received_events[0].mouse().x);
+  EXPECT_EQ(42, received_events[0].mouse().y);
 }
 
 TEST(Event, UTF8) {
@@ -313,31 +282,29 @@ TEST(Event, UTF8) {
 
   };
   for (auto test : kTestCase) {
-    auto event_receiver = MakeReceiver<Task>();
-    {
-      auto parser = TerminalInputParser(event_receiver->MakeSender());
-      for (auto input : test.input)
-        parser.Add(input);
-    }
-    Task received;
+    std::vector<Event> received_events;
+    auto parser = TerminalInputParser(
+        [&](Event event) { received_events.push_back(std::move(event)); });
+    for (auto input : test.input)
+      parser.Add(input);
+
     if (test.valid) {
-      EXPECT_TRUE(event_receiver->Receive(&received));
-      EXPECT_TRUE(std::get<Event>(received).is_character());
+      EXPECT_EQ(1, received_events.size());
+      EXPECT_TRUE(received_events[0].is_character());
+    } else {
+      EXPECT_TRUE(received_events.empty());
     }
-    EXPECT_FALSE(event_receiver->Receive(&received));
   }
 }
 
 TEST(Event, NewLine) {
   for (char newline : {'\r', '\n'}) {
-    auto event_receiver = MakeReceiver<Task>();
-    {
-      auto parser = TerminalInputParser(event_receiver->MakeSender());
-      parser.Add(newline);
-    }
-    Task received;
-    EXPECT_TRUE(event_receiver->Receive(&received));
-    EXPECT_TRUE(std::get<Event>(received) == Event::Return);
+    std::vector<Event> received_events;
+    auto parser = TerminalInputParser(
+        [&](Event event) { received_events.push_back(std::move(event)); });
+    parser.Add(newline);
+    EXPECT_EQ(1, received_events.size());
+    EXPECT_TRUE(received_events[0] == Event::Return);
   }
 }
 
@@ -357,17 +324,16 @@ TEST(Event, Control) {
   cases.push_back({char(127), false});
 
   for (auto test : cases) {
-    auto event_receiver = MakeReceiver<Task>();
-    {
-      auto parser = TerminalInputParser(event_receiver->MakeSender());
-      parser.Add(test.input);
-    }
-    Task received;
+    std::vector<Event> received_events;
+    auto parser = TerminalInputParser(
+        [&](Event event) { received_events.push_back(std::move(event)); });
+    parser.Add(test.input);
+
     if (test.cancel) {
-      EXPECT_FALSE(event_receiver->Receive(&received));
+      EXPECT_TRUE(received_events.empty());
     } else {
-      EXPECT_TRUE(event_receiver->Receive(&received));
-      EXPECT_EQ(std::get<Event>(received), Event::Special({test.input}));
+      EXPECT_EQ(1, received_events.size());
+      EXPECT_EQ(received_events[0], Event::Special({test.input}));
     }
   }
 }
@@ -385,10 +351,9 @@ TEST(Event, Special) {
     Event expected;
   } kTestCase[] = {
       // Arrow (default cursor mode)
-      {str("\x1B[A"), Event::ArrowUp},    {str("\x1B[B"), Event::ArrowDown},
-      {str("\x1B[C"), Event::ArrowRight}, {str("\x1B[D"), Event::ArrowLeft},
-      {str("\x1B[H"), Event::Home},       {str("\x1B[F"), Event::End},
-      /*
+      {str(""), Event::ArrowUp},    {str(""), Event::ArrowDown},
+      {str(""), Event::ArrowRight}, {str(""), Event::ArrowLeft},
+      {str(""), Event::Home},       {str(""), Event::End},
 
       // Arrow (application cursor mode)
       {str("\x1BOA"), Event::ArrowUp},
@@ -469,45 +434,38 @@ TEST(Event, Special) {
 
       // Custom:
       {{0}, Event::Custom},
-      */
   };
 
   for (auto test : kTestCase) {
-    auto event_receiver = MakeReceiver<Task>();
-    {
-      auto parser = TerminalInputParser(event_receiver->MakeSender());
-      for (auto input : test.input) {
-        parser.Add(input);
-      }
+    std::vector<Event> received_events;
+    auto parser = TerminalInputParser(
+        [&](Event event) { received_events.push_back(std::move(event)); });
+    for (auto input : test.input) {
+      parser.Add(input);
     }
-    Task received;
-    EXPECT_TRUE(event_receiver->Receive(&received));
-    EXPECT_EQ(std::get<Event>(received), test.expected);
-    EXPECT_FALSE(event_receiver->Receive(&received));
+    EXPECT_EQ(1, received_events.size());
+    EXPECT_EQ(received_events[0], test.expected);
   }
 }
 
 TEST(Event, DeviceControlString) {
-  auto event_receiver = MakeReceiver<Task>();
-  {
-    auto parser = TerminalInputParser(event_receiver->MakeSender());
-    parser.Add(27);   // ESC
-    parser.Add(80);   // P
-    parser.Add(49);   // 1
-    parser.Add(36);   // $
-    parser.Add(114);  // r
-    parser.Add(49);   // 1
-    parser.Add(32);   // SP
-    parser.Add(113);  // q
-    parser.Add(27);   // ESC
-    parser.Add(92);   // (backslash)
-  }
+  std::vector<Event> received_events;
+  auto parser = TerminalInputParser(
+      [&](Event event) { received_events.push_back(std::move(event)); });
+  parser.Add(27);   // ESC
+  parser.Add(80);   // P
+  parser.Add(49);   // 1
+  parser.Add(36);   // $
+  parser.Add(114);  // r
+  parser.Add(49);   // 1
+  parser.Add(32);   // SP
+  parser.Add(113);  // q
+  parser.Add(27);   // ESC
+  parser.Add(92);   // (backslash)
 
-  Task received;
-  EXPECT_TRUE(event_receiver->Receive(&received));
-  EXPECT_TRUE(std::get<Event>(received).is_cursor_shape());
-  EXPECT_EQ(1, std::get<Event>(received).cursor_shape());
-  EXPECT_FALSE(event_receiver->Receive(&received));
+  EXPECT_EQ(1, received_events.size());
+  EXPECT_TRUE(received_events[0].is_cursor_shape());
+  EXPECT_EQ(1, received_events[0].cursor_shape());
 }
 
 }  // namespace ftxui

src/ftxui/component/terminal_input_parser_test_fuzzer.cpp

@@ -1,21 +1,16 @@
 // Copyright 2021 Arthur Sonzogni. All rights reserved.
 // Use of this source code is governed by the MIT license that can be found in
 // the LICENSE file.
+#include <cstddef>
+#include <ftxui/component/event.hpp>
 #include "ftxui/component/terminal_input_parser.hpp"
 
 extern "C" int LLVMFuzzerTestOneInput(const char* data, size_t size) {
   using namespace ftxui;
-  auto event_receiver = MakeReceiver<Task>();
-  {
-    auto parser = TerminalInputParser(event_receiver->MakeSender());
-    for (size_t i = 0; i < size; ++i) {
-      parser.Add(data[i]);
-    }
+  auto parser = TerminalInputParser([&](Event) {});
+  for (size_t i = 0; i < size; ++i) {
+    parser.Add(data[i]);
   }
 
-  Task received;
-  while (event_receiver->Receive(&received)) {
-    // Do nothing.
-  }
   return 0;  // Non-zero return values are reserved for future use.
 }

src/ftxui/screen/terminal.cpp

@@ -48,25 +48,38 @@ Dimensions& FallbackSize() {
   return g_fallback_size;
 }
 
-const char* Safe(const char* c) {
-  return (c != nullptr) ? c : "";
-}
-
 bool Contains(const std::string& s, const char* key) {
   return s.find(key) != std::string::npos;
 }
 
+// https://github.com/gabime/spdlog/blob/885b5473e291833b148eeac3b7ce227e582cd88b/include/spdlog/details/os-inl.h#L566
+std::string getenv_safe(const char *field) {
+#if defined(_MSC_VER)
+#if defined(__cplusplus_winrt)
+  return std::string{};  // not supported under uwp
+#else
+  size_t len = 0;
+  char buf[1024];
+  bool ok = ::getenv_s(&len, buf, sizeof(buf), field) == 0;
+  return ok ? buf : std::string{};
+#endif
+#else  // revert to getenv
+  char *buf = ::getenv(field); // NOLINT(*-mt-unsafe)
+  return buf ? buf : std::string{};
+#endif
+}
+
 Terminal::Color ComputeColorSupport() {
 #if defined(__EMSCRIPTEN__)
   return Terminal::Color::TrueColor;
 #endif
 
-  std::string COLORTERM = Safe(std::getenv("COLORTERM"));  // NOLINT
+  std::string COLORTERM = getenv_safe("COLORTERM");
   if (Contains(COLORTERM, "24bit") || Contains(COLORTERM, "truecolor")) {
     return Terminal::Color::TrueColor;
   }
 
-  std::string TERM = Safe(std::getenv("TERM"));  // NOLINT
+  std::string TERM = getenv_safe("TERM");
   if (Contains(COLORTERM, "256") || Contains(TERM, "256")) {
     return Terminal::Color::Palette256;
   }