LibLine: Handle Ctrl-C and Ctrl-D in a way similar to other line editors

Makes C-c print "^C" and continue prompting on a new line.
Also fixes a problem where an interrupted get_line() would need more
read()'s than required to update the display.

Libraries/LibLine/Editor.cpp

@@ -407,6 +407,55 @@ void Editor::initialize()
  m_initialized = true;
 }
 
+void Editor::interrupted()
+{
+ if (!m_is_editing)
+ return;
+
+ m_was_interrupted = true;
+ handle_interrupt_event();
+ if (!m_finish)
+ return;
+
+ m_finish = false;
+ reposition_cursor(true);
+ if (m_suggestion_display->cleanup())
+ reposition_cursor();
+ cleanup();
+ fprintf(stderr, "\n");
+ fflush(stderr);
+ m_buffer.clear();
+ m_is_editing = false;
+ restore();
+ m_notifier->set_event_mask(Core::Notifier::None);
+ deferred_invoke([this](auto&) {
+ remove_child(*m_notifier);
+ m_notifier = nullptr;
+ Core::EventLoop::current().quit(Retry);
+ });
+}
+
+void Editor::really_quit_event_loop()
+{
+ m_finish = false;
+ reposition_cursor(true);
+ fprintf(stderr, "\n");
+ fflush(stderr);
+ auto string = line();
+ m_buffer.clear();
+ m_is_editing = false;
+ restore();
+
+ m_returned_line = string;
+
+ m_notifier->set_event_mask(Core::Notifier::None);
+ deferred_invoke([this](auto&) {
+ remove_child(*m_notifier);
+ m_notifier = nullptr;
+ Core::EventLoop::current().quit(Exit);
+ });
+}
+
 auto Editor::get_line(const String& prompt) -> Result<String, Editor::Error>
 {
  initialize();
@@ -454,8 +503,9 @@ auto Editor::get_line(const String& prompt) -> Result<String, Editor::Error>
  add_child(*m_notifier);
 
  m_notifier->on_ready_to_read = [&] {
- if (m_was_interrupted)
+ if (m_was_interrupted) {
  handle_interrupt_event();
+ }
 
  handle_read_event();
 
@@ -464,28 +514,12 @@ auto Editor::get_line(const String& prompt) -> Result<String, Editor::Error>
 
  refresh_display();
 
- if (m_finish) {
- m_finish = false;
- reposition_cursor(true);
- fprintf(stderr, "\n");
- fflush(stderr);
- auto string = line();
- m_buffer.clear();
- m_is_editing = false;
- restore();
-
- m_returned_line = string;
-
- m_notifier->set_event_mask(Core::Notifier::None);
- deferred_invoke([this](auto&) {
- remove_child(*m_notifier);
- m_notifier = nullptr;
- Core::EventLoop::current().quit(0);
- });
- }
+ if (m_finish)
+ really_quit_event_loop();
  };
 
- loop.exec();
+ if (loop.exec() == Retry)
+ return get_line(prompt);
 
  return m_input_error.has_value() ? Result<String, Editor::Error> { m_input_error.value() } : Result<String, Editor::Error> { m_returned_line };
 }
@@ -512,17 +546,29 @@ void Editor::handle_interrupt_event()
 {
  m_was_interrupted = false;
 
- if (!m_buffer.is_empty())
- fprintf(stderr, "^C");
+ auto cb = m_key_callbacks.get(ctrl('C'));
+ if (cb.has_value()) {
+ if (!cb.value()->callback(*this)) {
+ // Oh well.
+ return;
+ }
+ }
 
- m_buffer.clear();
- m_cursor = 0;
+ if (!m_buffer.is_empty()) {
+ fprintf(stderr, "^C");
+ fflush(stderr);
+ }
 
  if (on_interrupt_handled)
  on_interrupt_handled();
 
- m_refresh_needed = true;
- refresh_display();
+ if (m_buffer.is_empty())
+ return;
+
+ m_buffer.clear();
+ m_cursor = 0;
+
+ finish();
 }
 
 void Editor::handle_read_event()

Libraries/LibLine/Editor.h

@@ -196,13 +196,7 @@ class Editor : public Core::Object {
 
  // FIXME: we will have to kindly ask our instantiators to set our signal handlers,
  // since we can not do this cleanly ourselves. (signal() limitation: cannot give member functions)
- void interrupted()
- {
- if (m_is_editing) {
- m_was_interrupted = true;
- handle_interrupt_event();
- }
- }
+ void interrupted();
  void resized()
  {
  m_was_resized = true;
@@ -277,6 +271,11 @@ class Editor : public Core::Object {
 
  static VTState actual_rendered_string_length_step(StringMetrics&, size_t& length, u32, u32, VTState);
 
+ enum LoopExitCode {
+ Exit = 0,
+ Retry
+ };
+
  // ^Core::Object
  virtual void save_to(JsonObject&) override;
 
@@ -336,6 +335,7 @@ class Editor : public Core::Object {
 
  void refresh_display();
  void cleanup();
+ void really_quit_event_loop();
 
  void restore()
  {

Libraries/LibLine/InternalFunctions.cpp

@@ -168,6 +168,7 @@ void Editor::finish_edit()
  if (!m_always_refresh) {
  m_input_error = Error::Eof;
  finish();
+ really_quit_event_loop();
  }
 }
 

Shell/main.cpp

@@ -238,10 +238,6 @@ int main(int argc, char** argv)
  return 1;
  }
 
- editor->on_interrupt_handled = [&] {
- editor->finish();
- };
-
  shell->add_child(*editor);
 
  Core::EventLoop::current().post_event(*shell, make<Core::CustomEvent>(Shell::ShellEventType::ReadLine));