FTXUI/include/ftxui/component/component_base.hpp
Tushar Maheshwari 7f95d59954
Deduplicate logic in ComponentBase members (#162)
- Invoke DetachAllChildren from ~ComponentBase
- Define Focused using Active
- Compact TakeFocus loop code
- const-correctness for Parent, Active and Focused
2021-07-21 00:37:44 +02:00

82 lines
2.2 KiB
C++

#ifndef FTXUI_COMPONENT_BASE_HPP
#define FTXUI_COMPONENT_BASE_HPP
#include <memory> // for unique_ptr
#include <vector> // for vector
#include "ftxui/component/captured_mouse.hpp" // for CaptureMouse
#include "ftxui/dom/elements.hpp" // for Element
namespace ftxui {
class Delegate;
class Focus;
struct Event;
class ComponentBase;
using Component = std::shared_ptr<ComponentBase>;
using Components = std::vector<Component>;
/// @brief It implement rendering itself as ftxui::Element. It implement
/// keyboard navigation by responding to ftxui::Event.
/// @ingroup component
class ComponentBase {
public:
// virtual Destructor.
virtual ~ComponentBase();
// Component hierarchy:
ComponentBase* Parent() const;
Component& ChildAt(size_t i);
size_t ChildCount() const;
void Add(Component children);
void Detach();
void DetachAllChildren();
// Renders the component.
virtual Element Render();
// Handles an event.
// By default, reduce on children with a lazy OR.
//
// Returns whether the event was handled or not.
virtual bool OnEvent(Event);
// Focus management ----------------------------------------------------------
//
// If this component contains children, this indicates which one is active,
// nullptr if none is active.
//
// We say an element has the focus if the chain of ActiveChild() from the
// root component contains this object.
virtual Component ActiveChild();
// Whether this is the active child of its parent.
bool Active() const;
// Whether all the ancestors are active.
bool Focused() const;
// Make the |child| to be the "active" one.
virtual void SetActiveChild(ComponentBase* child);
void SetActiveChild(Component child);
// Configure all the ancestors to give focus to this component.
void TakeFocus();
protected:
CapturedMouse CaptureMouse(const Event& event);
Components children_;
private:
ComponentBase* parent_ = nullptr;
};
} // namespace ftxui
#endif /* end of include guard: FTXUI_COMPONENT_BASE_HPP */
// Copyright 2020 Arthur Sonzogni. All rights reserved.
// Use of this source code is governed by the MIT license that can be found in
// the LICENSE file.