Add more documentation.

src/ftxui/component/component.cpp

@@ -5,28 +5,44 @@
 #include <algorithm>
 
 namespace ftxui {
-void Component::Detach() {
-  if (!parent_)
-    return;
-  auto it = std::find(std::begin(parent_->children_),
-                      std::end(parent_->children_), this);
-  parent_->children_.erase(it);
-}
-
-void Component::Attach(Component* parent) {
-  Detach();
-  parent_ = parent;
-  parent_->children_.push_back(this);
-}
-
-void Component::Add(Component* child) {
-  child->Attach(this);
-}
 
 Component::~Component() {
   Detach();
 }
 
+/// @brief Return the parent Component, or nul if any.
+/// @see Attach
+/// @see Detach
+/// @see Parent 
+/// @ingroup component
+Component* Component::Parent() {
+  return parent_;
+}
+
+/// @brief Add a children.
+/// @@param child The child to be attached.
+/// @ingroup component
+void Component::Add(Component* child) {
+  child->Attach(this);
+}
+
+/// @brief Draw the component.
+/// Build a ftxui::Element to be drawn on the ftxi::Screen representing this
+/// ftxui::Component.
+/// @ingroup component
+Element Component::Render() {
+  if (children_.size() == 1)
+    return children_.front()->Render();
+
+  return text(L"Not implemented component");
+}
+
+/// @brief Called in response to an event.
+/// @param event The event.
+/// @return True when the event has been handled.
+/// The default implementation called OnEvent on every child until one return
+/// true. If none returns true, return false.
+/// @ingroup component
 bool Component::OnEvent(Event event) {
   for (Component* child : children_) {
     if (child->OnEvent(event))
@@ -35,17 +51,16 @@ bool Component::OnEvent(Event event) {
   return false;
 }
 
+/// @brief Return the currently Active child.
+/// @return the currently Active child.
+/// @ingroup component
 Component* Component::ActiveChild() {
   return children_.empty() ? nullptr : children_.front();
 }
 
-Element Component::Render() {
-  if (children_.size() == 1)
-    return children_.front()->Render();
-
-  return text(L"Not implemented component");
-}
-
+/// @brief Returns if the elements if focused by the user.
+/// True when the Component is focused by the user. An element is Focused when
+/// it is with all its ancestors the ActiveChild() of their parents.
 bool Component::Focused() {
   Component* current = this;
   for (;;) {
@@ -58,6 +73,31 @@ bool Component::Focused() {
   }
 }
 
+/// @brief Detach this children from its parent.
+/// @see Attach
+/// @see Detach
+/// @see Parent 
+/// @ingroup component
+void Component::Detach() {
+  if (!parent_)
+    return;
+  auto it = std::find(std::begin(parent_->children_),
+                      std::end(parent_->children_), this);
+  parent_->children_.erase(it);
+}
+
+/// @brief Attach this element to its parent.
+/// @see Attach
+/// @see Detach
+/// @see Parent 
+/// @ingroup component
+void Component::Attach(Component* parent) {
+  Detach();
+  parent_ = parent;
+  parent_->children_.push_back(this);
+}
+
+
 }  // namespace ftxui
 
 // Copyright 2020 Arthur Sonzogni. All rights reserved.