FTXUI/src/ftxui/component/dropdown.cpp
2024-04-28 10:40:57 +02:00

122 lines
3.8 KiB
C++

// Copyright 2021 Arthur Sonzogni. All rights reserved.
// Use of this source code is governed by the MIT license that can be found in
// the LICENSE file.
#include <cstddef> // for size_t
#include <functional> // for function
#include <memory> // for __shared_ptr_access, allocator, shared_ptr
#include <string> // for string
#include "ftxui/component/component.hpp" // for Maybe, Checkbox, Make, Radiobox, Vertical, Dropdown
#include "ftxui/component/component_base.hpp" // for Component, ComponentBase
#include "ftxui/component/component_options.hpp" // for CheckboxOption, EntryState
#include "ftxui/dom/elements.hpp" // for operator|, Element, border, filler, operator|=, separator, size, text, vbox, frame, vscroll_indicator, hbox, HEIGHT, LESS_THAN, bold, inverted
#include "ftxui/screen/util.hpp" // for clamp
#include "ftxui/util/ref.hpp" // for ConstStringListRef
namespace ftxui {
/// @brief A dropdown menu.
/// @ingroup component
/// @param entries The list of entries to display.
/// @param selected The index of the selected entry.
Component Dropdown(ConstStringListRef entries, int* selected) {
DropdownOption option;
option.radiobox.entries = entries;
option.radiobox.selected = selected;
return Dropdown(option);
}
/// @brief A dropdown menu.
/// @ingroup component
/// @param option The options for the dropdown.
Component Dropdown(DropdownOption option) {
class Impl : public ComponentBase, public DropdownOption {
public:
explicit Impl(DropdownOption option) : DropdownOption(std::move(option)) {
FillDefault();
checkbox_ = Checkbox(checkbox);
radiobox_ = Radiobox(radiobox);
Add(Container::Vertical({
checkbox_,
Maybe(radiobox_, checkbox.checked),
}));
}
Element Render() override {
radiobox.selected =
util::clamp(radiobox.selected(), 0, int(radiobox.entries.size()) - 1);
checkbox.label =
radiobox.entries[static_cast<size_t>(radiobox.selected())];
return transform(*open_, checkbox_->Render(), radiobox_->Render());
}
// Switch focus in between the checkbox and the radiobox when selecting it.
bool OnEvent(ftxui::Event event) override {
const bool show_old = open_();
const int selected_old = selected_();
const bool handled = ComponentBase::OnEvent(event);
if (!show_old && open_()) {
radiobox_->TakeFocus();
}
if (selected_old != selected_()) {
checkbox_->TakeFocus();
open_ = false;
}
return handled;
}
void FillDefault() {
open_ = checkbox.checked;
selected_ = radiobox.selected;
checkbox.checked = &*open_;
radiobox.selected = &*selected_;
if (!checkbox.transform) {
checkbox.transform = [](const EntryState& s) {
auto prefix = text(s.state ? "" : ""); // NOLINT
auto t = text(s.label);
if (s.active) {
t |= bold;
}
if (s.focused) {
t |= inverted;
}
return hbox({prefix, t});
};
}
if (!transform) {
transform = [](bool is_open, Element checkbox_element,
Element radiobox_element) {
if (is_open) {
const int max_height = 12;
return vbox({
checkbox_element,
separator(),
radiobox_element | vscroll_indicator | frame |
size(HEIGHT, LESS_THAN, max_height),
}) |
border;
}
return vbox({checkbox_element, filler()}) | border;
};
}
}
private:
Ref<bool> open_;
Ref<int> selected_;
Component checkbox_;
Component radiobox_;
};
return Make<Impl>(option);
}
} // namespace ftxui