diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1c72579610aad043ee849100a4351a218e6f6ab9..29a6ae958df76c0068ce6fba10fd36060222cc5f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,10 @@ current (development)
- multiple directions.
- multiple colors.
- various values (value, min, max, increment).
+- Feature: Define `ScreenInteractive::Exit()`.
+- Feature: Add `Loop` to give developers a better control on the main loop. This
+ can be used to integrate FTXUI into another main loop, without taking the full
+ control.
- Feature: `Input` supports CTRL+Left and CTRL+Right
- Improvement: The `Menu` keeps the focus when an entry is selected with the
mouse.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2a884350950942e5c0ab25822f0ce215003aa455..4f885630f41c6c371b6ae1cdc80fd018ddfe7ce0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -93,6 +93,7 @@ add_library(component
include/ftxui/component/component_base.hpp
include/ftxui/component/component_options.hpp
include/ftxui/component/event.hpp
+ include/ftxui/component/loop.hpp
include/ftxui/component/mouse.hpp
include/ftxui/component/receiver.hpp
include/ftxui/component/screen_interactive.hpp
@@ -108,9 +109,10 @@ add_library(component
src/ftxui/component/dropdown.cpp
src/ftxui/component/event.cpp
src/ftxui/component/input.cpp
+ src/ftxui/component/loop.cpp
src/ftxui/component/maybe.cpp
- src/ftxui/component/modal.cpp
src/ftxui/component/menu.cpp
+ src/ftxui/component/modal.cpp
src/ftxui/component/radiobox.cpp
src/ftxui/component/radiobox.cpp
src/ftxui/component/renderer.cpp
diff --git a/examples/component/CMakeLists.txt b/examples/component/CMakeLists.txt
index e89111039690dbcec116ac73c7be52c95db2b52c..4eb971e68cb29e6861355115090540d64c7ac02e 100644
--- a/examples/component/CMakeLists.txt
+++ b/examples/component/CMakeLists.txt
@@ -9,6 +9,7 @@ example(checkbox)
example(checkbox_in_frame)
example(collapsible)
example(composition)
+example(custom_loop)
example(dropdown)
example(flexbox_gallery)
example(focus)
diff --git a/examples/component/custom_loop.cpp b/examples/component/custom_loop.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..50702d038294aa0f4ca4c1bc8a232fc16e37acac
--- /dev/null
+++ b/examples/component/custom_loop.cpp
@@ -0,0 +1,55 @@
+#include <stdlib.h> // for EXIT_SUCCESS
+#include <chrono> // for milliseconds
+#include <ftxui/component/event.hpp> // for Event
+#include <ftxui/dom/elements.hpp> // for text, separator, Element, operator|, vbox, border
+#include <memory> // for shared_ptr
+#include <string> // for operator+, to_string, allocator
+#include <thread> // for sleep_for
+
+#include "ftxui/component/captured_mouse.hpp" // for ftxui
+#include "ftxui/component/component.hpp" // for CatchEvent, Renderer, operator|=
+#include "ftxui/component/loop.hpp" // for Loop
+#include "ftxui/component/screen_interactive.hpp" // for ScreenInteractive
+
+int main(int argc, const char* argv[]) {
+ using namespace ftxui;
+ auto screen = ScreenInteractive::FitComponent();
+
+ // Create a component counting the number of frames drawn and event handled.
+ int custom_loop_count = 0;
+ int frame_count = 0;
+ int event_count = 0;
+ auto component = Renderer([&] {
+ frame_count++;
+ return vbox({
+ text("This demonstrates using a custom ftxui::Loop. It "),
+ text("runs at 100 iterations per seconds. The FTXUI events "),
+ text("are all processed once per iteration and a new frame "),
+ text("is rendered as needed"),
+ separator(),
+ text("ftxui event count: " + std::to_string(event_count)),
+ text("ftxui frame count: " + std::to_string(frame_count)),
+ text("Custom loop count: " + std::to_string(custom_loop_count)),
+ }) |
+ border;
+ });
+
+ component |= CatchEvent([&](Event) -> bool {
+ event_count++;
+ return false;
+ });
+
+ Loop loop(&screen, component);
+
+ while (!loop.HasQuitted()) {
+ custom_loop_count++;
+ loop.RunOnce();
+ std::this_thread::sleep_for(std::chrono::milliseconds(10));
+ }
+
+ return EXIT_SUCCESS;
+}
+
+// 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.
diff --git a/include/ftxui/component/loop.hpp b/include/ftxui/component/loop.hpp
new file mode 100644
index 0000000000000000000000000000000000000000..63200bed599ea12137b3caabebb6e5b3a1737747
--- /dev/null
+++ b/include/ftxui/component/loop.hpp
@@ -0,0 +1,39 @@
+#ifndef FTXUI_COMPONENT_LOOP_HPP
+#define FTXUI_COMPONENT_LOOP_HPP
+
+#include <memory> // for shared_ptr
+
+#include "ftxui/component/component_base.hpp" // for ComponentBase
+
+namespace ftxui {
+class ComponentBase;
+
+using Component = std::shared_ptr<ComponentBase>;
+class ScreenInteractive;
+
+class Loop {
+ public:
+ Loop(ScreenInteractive* screen, Component component);
+ ~Loop();
+
+ bool HasQuitted();
+ void RunOnce();
+ void RunOnceBlocking();
+ void Run();
+
+ private:
+ // This class is non copyable.
+ Loop(const ScreenInteractive&) = delete;
+ Loop& operator=(const Loop&) = delete;
+
+ ScreenInteractive* screen_;
+ Component component_;
+};
+
+} // namespace ftxui
+
+#endif // FTXUI_COMPONENT_LOOP_HPP
+
+// Copyright 2022 Arthur Sonzogni. All rights reserved.
+// Use of this source code is governed by the MIT license that can be found in
+// the LICENSE file.
diff --git a/include/ftxui/component/receiver.hpp b/include/ftxui/component/receiver.hpp
index d2579889d1f93a23cf966a712bff907db6f3d2fd..1d487644f7d96fa4879339395de9a5e87e708634 100644
--- a/include/ftxui/component/receiver.hpp
+++ b/include/ftxui/component/receiver.hpp
@@ -86,11 +86,25 @@ class ReceiverImpl {
return false;
}
+ bool ReceiveNonBlocking(T* t) {
+ std::unique_lock<std::mutex> lock(mutex_);
+ if (queue_.empty())
+ return false;
+ *t = queue_.front();
+ queue_.pop();
+ return true;
+ }
+
bool HasPending() {
std::unique_lock<std::mutex> lock(mutex_);
return !queue_.empty();
}
+ bool HasQuitted() {
+ std::unique_lock<std::mutex> lock(mutex_);
+ return queue_.empty() && !senders_;
+ }
+
private:
friend class SenderImpl<T>;
diff --git a/include/ftxui/component/screen_interactive.hpp b/include/ftxui/component/screen_interactive.hpp
index ab3420741a98b826500e37f19ebef69bd19eef88..9aed718f78aa452cdf9d67aefdd61d8a3eda59d1 100644
--- a/include/ftxui/component/screen_interactive.hpp
+++ b/include/ftxui/component/screen_interactive.hpp
@@ -12,11 +12,12 @@
#include "ftxui/component/animation.hpp" // for TimePoint
#include "ftxui/component/captured_mouse.hpp" // for CapturedMouse
#include "ftxui/component/event.hpp" // for Event
-#include "ftxui/component/task.hpp" // for Closure, Task
+#include "ftxui/component/task.hpp" // for Task, Closure
#include "ftxui/screen/screen.hpp" // for Screen
namespace ftxui {
class ComponentBase;
+class Loop;
struct Event;
using Component = std::shared_ptr<ComponentBase>;
@@ -33,9 +34,12 @@ class ScreenInteractive : public Screen {
// Return the currently active screen, nullptr if none.
static ScreenInteractive* Active();
+ // Start/Stop the main loop.
void Loop(Component);
+ void Exit();
Closure ExitLoopClosure();
+ // Post tasks to be executed by the loop.
void Post(Task task);
void PostEvent(Event event);
void RequestAnimationFrame();
@@ -51,9 +55,16 @@ class ScreenInteractive : public Screen {
void Install();
void Uninstall();
- void Main(Component component);
+ void PreMain();
+ void PostMain();
+ bool HasQuitted();
+ void RunOnce(Component component);
+ void RunOnceBlocking(Component component);
+
+ void HandleTask(Component component, Task& task);
void Draw(Component component);
+
void SigStop();
ScreenInteractive* suspended_screen_ = nullptr;
@@ -80,7 +91,7 @@ class ScreenInteractive : public Screen {
std::thread event_listener_;
std::thread animation_listener_;
bool animation_requested_ = false;
- animation::TimePoint previous_animation_time;
+ animation::TimePoint previous_animation_time_;
int cursor_x_ = 1;
int cursor_y_ = 1;
@@ -88,6 +99,10 @@ class ScreenInteractive : public Screen {
bool mouse_captured = false;
bool previous_frame_resized_ = false;
+ bool frame_valid_ = false;
+
+ friend class Loop;
+
public:
class Private {
public:
diff --git a/src/ftxui/component/loop.cpp b/src/ftxui/component/loop.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..264642880ffe4c6da96ed58d958dee07e4793223
--- /dev/null
+++ b/src/ftxui/component/loop.cpp
@@ -0,0 +1,44 @@
+#include "ftxui/component/loop.hpp"
+#include "ftxui/component/screen_interactive.hpp"
+
+namespace ftxui {
+
+Loop::Loop(ScreenInteractive* screen, Component component)
+ : screen_(screen), component_(component) {
+ screen_->PreMain();
+}
+
+Loop::~Loop() {
+ screen_->PostMain();
+}
+
+bool Loop::HasQuitted() {
+ return screen_->HasQuitted();
+}
+
+/// @brief Execute the loop. Make the `component` to process every pending
+/// tasks/events. A new frame might be drawn if the previous was invalidated.
+/// Return true until the loop hasn't completed.
+void Loop::RunOnce() {
+ screen_->RunOnce(component_);
+}
+
+/// @brief Wait for at least one event to be handled and execute
+/// `Loop::RunOnce()`.
+void Loop::RunOnceBlocking() {
+ screen_->RunOnceBlocking(component_);
+}
+
+/// Execute the loop, blocking the current thread, up until the loop has
+/// quitted.
+void Loop::Run() {
+ while (!HasQuitted()) {
+ RunOnceBlocking();
+ }
+}
+
+} // namespace ftxui
+
+// Copyright 2022 Arthur Sonzogni. All rights reserved.
+// Use of this source code is governed by the MIT license that can be found in
+// the LICENSE file.
diff --git a/src/ftxui/component/screen_interactive.cpp b/src/ftxui/component/screen_interactive.cpp
index 32d7aabc034021202a391433c10e3596ba2418fb..278c53cd3906756d2b9cbc2d8a1bc905edb84576 100644
--- a/src/ftxui/component/screen_interactive.cpp
+++ b/src/ftxui/component/screen_interactive.cpp
@@ -20,6 +20,7 @@
#include "ftxui/component/captured_mouse.hpp" // for CapturedMouse, CapturedMouseInterface
#include "ftxui/component/component_base.hpp" // for ComponentBase
#include "ftxui/component/event.hpp" // for Event
+#include "ftxui/component/loop.hpp" // for Loop
#include "ftxui/component/receiver.hpp" // for Sender, ReceiverImpl, MakeReceiver, SenderImpl, Receiver
#include "ftxui/component/screen_interactive.hpp"
#include "ftxui/component/terminal_input_parser.hpp" // for TerminalInputParser
@@ -350,8 +351,8 @@ void ScreenInteractive::RequestAnimationFrame() {
animation_requested_ = true;
auto now = animation::Clock::now();
const auto time_histeresis = std::chrono::milliseconds(33);
- if (now - previous_animation_time >= time_histeresis) {
- previous_animation_time = now;
+ if (now - previous_animation_time_ >= time_histeresis) {
+ previous_animation_time_ = now;
}
}
@@ -365,6 +366,15 @@ CapturedMouse ScreenInteractive::CaptureMouse() {
}
void ScreenInteractive::Loop(Component component) { // NOLINT
+ class Loop loop(this, component);
+ loop.Run();
+}
+
+bool ScreenInteractive::HasQuitted() {
+ return task_receiver_->HasQuitted();
+}
+
+void ScreenInteractive::PreMain() {
// Suspend previously active screen:
if (g_active_screen) {
std::swap(suspended_screen_, g_active_screen);
@@ -378,7 +388,11 @@ void ScreenInteractive::Loop(Component component) { // NOLINT
// This screen is now active:
g_active_screen = this;
g_active_screen->Install();
- g_active_screen->Main(std::move(component));
+
+ previous_animation_time_ = animation::Clock::now();
+}
+
+void ScreenInteractive::PostMain() {
g_active_screen->Uninstall();
g_active_screen = nullptr;
@@ -531,81 +545,78 @@ void ScreenInteractive::Uninstall() {
}
// NOLINTNEXTLINE
-void ScreenInteractive::Main(Component component) {
- previous_animation_time = animation::Clock::now();
+void ScreenInteractive::RunOnceBlocking(Component component) {
+ Task task;
+ if (task_receiver_->Receive(&task)) {
+ HandleTask(component, task);
+ }
- auto draw = [&] {
- Draw(component);
- std::cout << ToString() << set_cursor_position;
- Flush();
- Clear();
- };
+ RunOnce(component);
+}
- bool attempt_draw = true;
- while (!quit_) {
- if (attempt_draw && !task_receiver_->HasPending()) {
- draw();
- attempt_draw = false;
- }
+void ScreenInteractive::RunOnce(Component component) {
+ Task task;
+ while (task_receiver_->ReceiveNonBlocking(&task)) {
+ HandleTask(component, task);
+ }
+ Draw(component);
+}
- Task task;
- if (!task_receiver_->Receive(&task)) {
- break;
- }
+void ScreenInteractive::HandleTask(Component component, Task& task) {
+ // clang-format off
+ std::visit([&](auto&& arg) {
+ using T = std::decay_t<decltype(arg)>;
- // clang-format off
- std::visit([&](auto&& arg) {
- using T = std::decay_t<decltype(arg)>;
-
- // Handle Event.
- if constexpr (std::is_same_v<T, Event>) {
- if (arg.is_cursor_reporting()) {
- cursor_x_ = arg.cursor_x();
- cursor_y_ = arg.cursor_y();
- return;
- }
-
- if (arg.is_mouse()) {
- arg.mouse().x -= cursor_x_;
- arg.mouse().y -= cursor_y_;
- }
-
- arg.screen_ = this;
- component->OnEvent(arg);
- attempt_draw = true;
+ // Handle Event.
+ if constexpr (std::is_same_v<T, Event>) {
+ if (arg.is_cursor_reporting()) {
+ cursor_x_ = arg.cursor_x();
+ cursor_y_ = arg.cursor_y();
return;
}
- // Handle callback
- if constexpr (std::is_same_v<T, Closure>) {
- arg();
- return;
+ if (arg.is_mouse()) {
+ arg.mouse().x -= cursor_x_;
+ arg.mouse().y -= cursor_y_;
}
- // Handle Animation
- if constexpr (std::is_same_v<T, AnimationTask>) {
- if (!animation_requested_) {
- return;
- }
+ arg.screen_ = this;
+ component->OnEvent(arg);
+ frame_valid_ = false;
+ return;
+ }
- animation_requested_ = false;
- animation::TimePoint now = animation::Clock::now();
- animation::Duration delta = now - previous_animation_time;
- previous_animation_time = now;
+ // Handle callback
+ if constexpr (std::is_same_v<T, Closure>) {
+ arg();
+ return;
+ }
- animation::Params params(delta);
- component->OnAnimation(params);
- attempt_draw = true;
+ // Handle Animation
+ if constexpr (std::is_same_v<T, AnimationTask>) {
+ if (!animation_requested_) {
return;
}
- },
- task);
- // clang-format on
- }
+
+ animation_requested_ = false;
+ animation::TimePoint now = animation::Clock::now();
+ animation::Duration delta = now - previous_animation_time_;
+ previous_animation_time_ = now;
+
+ animation::Params params(delta);
+ component->OnAnimation(params);
+ frame_valid_ = false;
+ return;
+ }
+ },
+ task);
+ // clang-format on
}
// NOLINTNEXTLINE
void ScreenInteractive::Draw(Component component) {
+ if (frame_valid_)
+ return;
auto document = component->Render();
int dimx = 0;
int dimy = 0;
@@ -685,13 +696,22 @@ void ScreenInteractive::Draw(Component component) {
set_cursor_position += "\x1B[" + std::to_string(dy) + "A";
reset_cursor_position += "\x1B[" + std::to_string(dy) + "B";
}
+
+ std::cout << ToString() << set_cursor_position;
+ Flush();
+ Clear();
+ frame_valid_ = true;
}
Closure ScreenInteractive::ExitLoopClosure() {
- return [this] {
+ return [this] { Exit(); };
+}
+
+void ScreenInteractive::Exit() {
+ Post([this] {
quit_ = true;
task_sender_.reset();
- };
+ });
}
void ScreenInteractive::SigStop() {