Using TAB key event.

A key event that makes use of TAB key to cycle the elements.

Co-authored-by: Trim Bresilla <trim.bresilla@gmail.com>"
Co-authored-by: ArthurSonzogni <sonzogniarthur@gmail.com>

include/ftxui/component/event.hpp

@@ -33,6 +33,8 @@ struct Event {
   static Event Delete;
   static Event Return;
   static Event Escape;
+  static Event Tab;
+  static Event TabReverse;
   static Event F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12;
 
   // --- Custom ---

src/ftxui/component/container.cpp

@@ -44,45 +44,33 @@ Component* Container::ActiveChild() {
 }
 
 bool Container::VerticalEvent(Event event) {
-  selected_ %= children_.size();
-  // Left pressed ?
-  if (event == Event::ArrowUp || event == Event::Character('k')) {
-    if (selected_ != 0) {
-      selected_--;
-      return true;
-    }
-  }
+  int old_selected = selected_;
+  if (event == Event::ArrowUp || event == Event::Character('k'))
+    selected_--;
+  if (event == Event::ArrowDown || event == Event::Character('j'))
+    selected_++;
+  if (event == Event::Tab && children_.size())
+    selected_ = (selected_ + 1) % children_.size();
+  if (event == Event::TabReverse && children_.size())
+    selected_ = (selected_ + children_.size() - 1) % children_.size();
 
-  // Left pressed ?
-  if (event == Event::ArrowDown || event == Event::Character('j')) {
-    if (selected_ != int(children_.size()) - 1) {
-      selected_++;
-      return true;
-    }
-  }
-
-  return false;
+  selected_ = std::max(0, std::min(int(children_.size()) - 1, selected_));
+  return old_selected != selected_;
 }
 
 bool Container::HorizontalEvent(Event event) {
-  selected_ %= children_.size();
-  // Left pressed ?
-  if (event == Event::ArrowLeft || event == Event::Character('h')) {
-    if (selected_ != 0) {
-      selected_--;
-      return true;
-    }
-  }
+  int old_selected = selected_;
+  if (event == Event::ArrowLeft || event == Event::Character('h'))
+    selected_--;
+  if (event == Event::ArrowRight || event == Event::Character('l'))
+    selected_++;
+  if (event == Event::Tab && children_.size())
+    selected_ = (selected_ + 1) % children_.size();
+  if (event == Event::TabReverse && children_.size())
+    selected_ = (selected_ + children_.size() - 1) % children_.size();
 
-  // Left pressed ?
-  if (event == Event::ArrowRight || event == Event::Character('l')) {
-    if (selected_ != int(children_.size()) - 1) {
-      selected_++;
-      return true;
-    }
-  }
-
-  return false;
+  selected_ = std::max(0, std::min(int(children_.size()) - 1, selected_));
+  return old_selected != selected_;
 }
 
 Element Container::Render() {
@@ -91,7 +79,7 @@ Element Container::Render() {
 
 Element Container::VerticalRender() {
   Elements elements;
-  for(auto& it : children_)
+  for (auto& it : children_)
     elements.push_back(it->Render());
   if (elements.size() == 0)
     return text(L"Empty container");
@@ -100,7 +88,7 @@ Element Container::VerticalRender() {
 
 Element Container::HorizontalRender() {
   Elements elements;
-  for(auto& it : children_)
+  for (auto& it : children_)
     elements.push_back(it->Render());
   if (elements.size() == 0)
     return text(L"Empty container");

src/ftxui/component/event.cpp

@@ -137,6 +137,8 @@ Event Event::Backspace = Event::Special({127});
 Event Event::Delete = Event::Special("\e[3~");
 Event Event::Escape = Event::Special("\e");
 Event Event::Return = Event::Special({10});
+Event Event::Tab = Event::Special({9});
+Event Event::TabReverse = Event::Special({27, 91, 90});
 Event Event::F1 = Event::Special("\e[OP");
 Event Event::F2 = Event::Special("\e[OQ");
 Event Event::F3 = Event::Special("\e[OR");

src/ftxui/component/menu.cpp

@@ -22,15 +22,19 @@ bool Menu::OnEvent(Event event) {
   if (!Focused())
     return false;
 
-  int new_selected = selected;
+  int old_selected = selected;
   if (event == Event::ArrowUp || event == Event::Character('k'))
-    new_selected--;
+    selected--;
   if (event == Event::ArrowDown || event == Event::Character('j'))
-    new_selected++;
-  new_selected = std::max(0, std::min(int(entries.size()) - 1, new_selected));
+    selected++;
+  if (event == Event::Tab && entries.size())
+    selected = (selected + 1) % entries.size();
+  if (event == Event::TabReverse && entries.size())
+    selected = (selected + entries.size() - 1) % entries.size();
 
-  if (selected != new_selected) {
-    selected = new_selected;
+  selected = std::max(0, std::min(int(entries.size()) - 1, selected));
+
+  if (selected != old_selected) {
     on_change();
     return true;
   }

src/ftxui/component/radiobox.cpp

@@ -28,7 +28,13 @@ bool RadioBox::OnEvent(Event event) {
     new_focused--;
   if (event == Event::ArrowDown || event == Event::Character('j'))
     new_focused++;
+  if (event == Event::Tab && entries.size())
+    new_focused = (new_focused + 1) % entries.size();
+  if (event == Event::TabReverse && entries.size())
+    new_focused = (new_focused + entries.size() - 1) % entries.size();
+
   new_focused = std::max(0, std::min(int(entries.size()) - 1, new_focused));
+
   if (focused != new_focused) {
     focused = new_focused;
     return true;

src/ftxui/component/toggle.cpp

@@ -6,7 +6,7 @@ Element Toggle::Render() {
   bool is_focused = Focused();
 
   Elements children;
-  for(size_t i = 0; i<entries.size(); ++i) {
+  for (size_t i = 0; i < entries.size(); ++i) {
     // Separator.
     if (i != 0)
       children.push_back(separator());
@@ -22,21 +22,18 @@ Element Toggle::Render() {
 }
 
 bool Toggle::OnEvent(Event event) {
-  if (selected > 0 &&
-      (event == Event::ArrowLeft || event == Event::Character('h'))) {
+  int old_selected = selected;
+  if (event == Event::ArrowLeft || event == Event::Character('h'))
     selected--;
-    on_change();
-    return true;
-  }
-
-  if (selected < int(entries.size()) - 1 &&
-      (event == Event::ArrowRight || event == Event::Character('l'))) {
+  if (event == Event::ArrowRight || event == Event::Character('l'))
     selected++;
-    on_change();
-    return true;
-  }
+  if (event == Event::Tab && entries.size())
+    selected = (selected + 1) % entries.size();
+  if (event == Event::TabReverse && entries.size())
+    selected = (selected + entries.size() - 1) % entries.size();
 
-  return false;
+  selected = std::max(0, std::min(int(entries.size()) - 1, selected));
+  return old_selected != selected;
 }
 
 }  // namespace ftxui