Add option for Toggle.

include/ftxui/component/button.hpp

@@ -23,7 +23,7 @@ class ButtonBase : public ComponentBase {
   // Constructor.
   ButtonBase(ConstStringRef label,
              std::function<void()> on_click,
-             ConstRef<ButtonOption> option);
+             ConstRef<ButtonOption> option = {});
   ~ButtonBase() override = default;
 
   // Component implementation.

include/ftxui/component/component.hpp

@@ -39,7 +39,9 @@ Component Menu(const std::vector<std::wstring>* entries,
 Component Radiobox(const std::vector<std::wstring>* entries,
                    int* selected_,
                    ConstRef<RadioboxOption> option = {});
-Component Toggle(const std::vector<std::wstring>* entries, int* selected);
+Component Toggle(const std::vector<std::wstring>* entries,
+                 int* selected,
+                 ConstRef<ToggleOption> option = {});
 template <class T>  // T = {int, float, long}
 Component Slider(StringRef label, T* value, T min, T max, T increment);
 Component Renderer(Component child, std::function<Element()>);

include/ftxui/component/component_options.hpp

@@ -46,6 +46,17 @@ struct RadioboxOption {
   std::function<void()> on_change = []() {};
 };
 
+struct ToggleOption {
+  Decorator normal_style = dim;
+  Decorator focused_style = inverted;
+  Decorator selected_style = bold;
+  Decorator selected_focused_style = focused_style | selected_style;
+
+  // Callback.
+  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/radiobox.hpp

@@ -24,7 +24,7 @@ class RadioboxBase : public ComponentBase {
   // Constructor.
   RadioboxBase(const std::vector<std::wstring>* entries,
                int* selected,
-               ConstRef<RadioboxOption> option);
+               ConstRef<RadioboxOption> option = {});
   ~RadioboxBase() override = default;
 
   int focused = 0;

include/ftxui/component/toggle.hpp

@@ -21,21 +21,14 @@ class ToggleBase : public ComponentBase {
   static ToggleBase* From(Component component);
 
   // Constructor.
-  ToggleBase(const std::vector<std::wstring>* entries, int* selected);
+  ToggleBase(const std::vector<std::wstring>* entries,
+             int* selected,
+             ConstRef<ToggleOption> option = {});
   ~ToggleBase() override = default;
 
   // State.
   int focused = 0;
 
-  Decorator normal_style = dim;
-  Decorator focused_style = inverted;
-  Decorator selected_style = bold;
-  Decorator selected_focused_style = focused_style | selected_style;
-
-  // Callback.
-  std::function<void()> on_change = []() {};
-  std::function<void()> on_enter = []() {};
-
   // Component implementation.
   Element Render() override;
   bool OnEvent(Event) override;
@@ -46,6 +39,7 @@ class ToggleBase : public ComponentBase {
 
   bool OnMouseEvent(Event event);
   std::vector<Box> boxes_;
+  ConstRef<ToggleOption> option_;
 };
 
 }  // namespace ftxui

src/ftxui/component/toggle.cpp

@@ -10,8 +10,10 @@
 
 namespace ftxui {
 
-Component Toggle(const std::vector<std::wstring>* entries, int* selected) {
+Component Toggle(const std::vector<std::wstring>* entries,
-  return Make<ToggleBase>(entries, selected);
+                 int* selected,
+                 ConstRef<ToggleOption> option) {
+  return Make<ToggleBase>(entries, selected, std::move(option));
 }
 
 // static
@@ -19,8 +21,10 @@ ToggleBase* ToggleBase::From(Component component) {
   return static_cast<ToggleBase*>(component.get());
 }
 
-ToggleBase::ToggleBase(const std::vector<std::wstring>* entries, int* selected)
+ToggleBase::ToggleBase(const std::vector<std::wstring>* entries,
-    : entries_(entries), selected_(selected) {}
+                       int* selected,
+                       ConstRef<ToggleOption> option)
+    : entries_(entries), selected_(selected), option_(std::move(option)) {}
 
 Element ToggleBase::Render() {
   Elements children;
@@ -34,9 +38,10 @@ Element ToggleBase::Render() {
     bool is_focused = (focused == int(i)) && is_toggle_focused;
     bool is_selected = (*selected_ == int(i));
 
-    auto style = is_selected
+    auto style = is_selected ? (is_focused ? option_->selected_focused_style
-                     ? (is_focused ? selected_focused_style : selected_style)
+                                           : option_->selected_style)
-                     : (is_focused ? focused_style : normal_style);
+                             : (is_focused ? option_->focused_style
+                                           : option_->normal_style);
     auto focus_management = !is_selected        ? nothing
                             : is_toggle_focused ? focus
                                                 : select;
@@ -64,12 +69,12 @@ bool ToggleBase::OnEvent(Event event) {
 
   if (old_selected != *selected_) {
     focused = *selected_;
-    on_change();
+    option_->on_change();
     return true;
   }
 
   if (event == Event::Return) {
-    on_enter();
+    option_->on_enter();
     return true;
   }
 
@@ -90,7 +95,7 @@ bool ToggleBase::OnMouseEvent(Event event) {
       TakeFocus();
       if (*selected_ != i) {
         *selected_ = i;
-        on_change();
+        option_->on_change();
       }
       return true;
     }

src/ftxui/component/toggle_test.cpp

@@ -83,10 +83,11 @@ TEST(ToggleTest, Tab) {
 TEST(ToggleTest, OnChange) {
   std::vector<std::wstring> entries = {L"1", L"2", L"3"};
   int selected = 0;
-  auto toggle = Toggle(&entries, &selected);
-
   int counter = 0;
-  ToggleBase::From(toggle)->on_change = [&] { counter++; };
+  auto option = ToggleOption();
+  option.on_change = [&] { counter++; };
+
+  auto toggle = Toggle(&entries, &selected, &option);
 
   EXPECT_FALSE(toggle->OnEvent(Event::ArrowLeft));  // Reached far left.
   EXPECT_EQ(counter, 0);
@@ -111,10 +112,11 @@ TEST(ToggleTest, OnChange) {
 TEST(ToggleTest, OnEnter) {
   std::vector<std::wstring> entries = {L"1", L"2", L"3"};
   int selected = 0;
-  auto toggle = Toggle(&entries, &selected);
-
   int counter = 0;
-  ToggleBase::From(toggle)->on_enter = [&] { counter++; };
+
+  auto option = ToggleOption();
+  option.on_enter = [&] { counter++; };
+  auto toggle = Toggle(&entries, &selected, &option);
 
   EXPECT_FALSE(toggle->OnEvent(Event::ArrowLeft));  // Reached far left.
   EXPECT_TRUE(toggle->OnEvent(Event::Return));