Add option for input.

examples/component/homescreen.cpp

@@ -156,13 +156,19 @@ int main(int argc, const char* argv[]) {
       false,
       false,
   };
-  std::wstring input_add_content;
-  Component input_add = Input(&input_add_content, "input files");
 
   std::vector<std::wstring> input_entries;
   int input_selected = 0;
   Component input = Menu(&input_entries, &input_selected);
 
+  auto input_option = InputOption();
+  std::wstring input_add_content;
+  input_option.on_enter = [&] {
+    input_entries.push_back(input_add_content);
+    input_add_content = L"";
+  };
+  Component input_add = Input(&input_add_content, "input files", input_option);
+
   std::wstring executable_content_ = L"";
   Component executable_ = Input(&executable_content_, "executable");
 
@@ -185,11 +191,6 @@ int main(int argc, const char* argv[]) {
       }),
   });
 
-  InputBase::From(input_add)->on_enter = [&] {
-    input_entries.push_back(input_add_content);
-    input_add_content = L"";
-  };
-
   auto render_command = [&] {
     Elements line;
     // Compiler

include/ftxui/component/component.hpp

@@ -30,7 +30,9 @@ Component Button(ConstStringRef label,
 Component Checkbox(ConstStringRef label,
                    bool* checked,
                    ConstRef<CheckboxOption> option = {});
-Component Input(StringRef content, ConstStringRef placeholder);
+Component Input(StringRef content,
+                ConstStringRef placeholder,
+                ConstRef<InputOption> option = {});
 Component Menu(const std::vector<std::wstring>* entries,
                int* selected_,
                ConstRef<MenuOption> = {});

include/ftxui/component/component_options.hpp

@@ -31,6 +31,11 @@ struct CheckboxOption {
   std::function<void()> on_change = []() {};
 };
 
+struct InputOption {
+  std::function<void()> on_change = [] {};
+  std::function<void()> on_enter = [] {};
+};
+
 };  // namespace ftxui
 
 #endif /* end of include guard: FTXUI_COMPONENT_COMPONENT_OPTIONS_HPP */

include/ftxui/component/input.hpp

@@ -21,16 +21,14 @@ class InputBase : public ComponentBase {
   static InputBase* From(Component component);
 
   // Constructor.
-  InputBase(StringRef content, ConstStringRef placeholder);
+  InputBase(StringRef content,
+            ConstStringRef placeholder,
+            ConstRef<InputOption> option = {});
   ~InputBase() override = default;
 
   // State.
   int cursor_position = 0;
 
-  // State update callback.
-  std::function<void()> on_change = [] {};
-  std::function<void()> on_enter = [] {};
-
   // Component implementation.
   Element Render() override;
   bool OnEvent(Event) override;
@@ -42,6 +40,7 @@ class InputBase : public ComponentBase {
   bool OnMouseEvent(Event);
   Box input_box_;
   Box cursor_box_;
+  ConstRef<InputOption> option_;
 };
 
 }  // namespace ftxui

src/ftxui/component/input.cpp

@@ -31,8 +31,10 @@ namespace ftxui {
 /// ```bash
 /// placeholder
 /// ```
-Component Input(StringRef content, ConstStringRef placeholder) {
+Component Input(StringRef content,
-  return Make<InputBase>(content, placeholder);
+                ConstStringRef placeholder,
+                ConstRef<InputOption> option) {
+  return Make<InputBase>(content, placeholder, std::move(option));
 }
 
 // static
@@ -40,8 +42,10 @@ InputBase* InputBase::From(Component component) {
   return static_cast<InputBase*>(component.get());
 }
 
-InputBase::InputBase(StringRef content, ConstStringRef placeholder)
+InputBase::InputBase(StringRef content,
-    : content_(content), placeholder_(placeholder) {}
+                     ConstStringRef placeholder,
+                     ConstRef<InputOption> option)
+    : content_(content), placeholder_(placeholder), option_(option) {}
 
 // Component implementation.
 Element InputBase::Render() {
@@ -97,7 +101,7 @@ bool InputBase::OnEvent(Event event) {
       return false;
     content_->erase(cursor_position - 1, 1);
     cursor_position--;
-    on_change();
+    option_->on_change();
     return true;
   }
 
@@ -106,13 +110,13 @@ bool InputBase::OnEvent(Event event) {
     if (cursor_position == int(content_->size()))
       return false;
     content_->erase(cursor_position, 1);
-    on_change();
+    option_->on_change();
     return true;
   }
 
   // Enter.
   if (event == Event::Return) {
-    on_enter();
+    option_->on_enter();
     return true;
   }
 
@@ -144,7 +148,7 @@ bool InputBase::OnEvent(Event event) {
   if (event.is_character()) {
     content_->insert(cursor_position, 1, event.character());
     cursor_position++;
-    on_change();
+    option_->on_change();
     return true;
   }
   return false;
@@ -166,7 +170,7 @@ bool InputBase::OnMouseEvent(Event event) {
         std::max(0, std::min<int>(content_->size(), new_cursor_position));
     if (cursor_position != new_cursor_position) {
       cursor_position = new_cursor_position;
-      on_change();
+      option_->on_change();
     }
   }
   return true;