portapack-mayhem/firmware/common/ui_focus.cpp
2016-05-09 21:05:11 +02:00

183 lines
4.4 KiB
C++

/*
* Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
*
* This file is part of PortaPack.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include "ui_focus.hpp"
#include "ui_widget.hpp"
#include <cstdint>
#include <algorithm>
#include <functional>
#include <utility>
#include <vector>
namespace ui {
Widget* FocusManager::focus_widget() const {
return focus_widget_;
}
void FocusManager::set_focus_widget(Widget* const new_focus_widget) {
// Widget already has focus.
if( new_focus_widget == focus_widget() ) {
return;
}
if( new_focus_widget ) {
// if( !new_focus_widget->visible() ) {
// if( new_focus_widget->hidden() ) {
// // New widget is not visible. Do nothing.
// // TODO: Should this be a debug assertion?
// return;
// }
if( !new_focus_widget->focusable() ) {
return;
}
}
// Blur old widget.
if( focus_widget() ) {
focus_widget()->on_blur();
focus_widget()->set_dirty();
}
focus_widget_ = new_focus_widget;
if( focus_widget() ) {
focus_widget()->on_focus();
focus_widget()->set_dirty();
}
}
using test_result_t = std::pair<Widget* const, const uint32_t>;
using test_fn = std::function<test_result_t(Widget* const)>;
using test_collection_t = std::vector<test_result_t>;
/* Walk all visible widgets in hierarchy, collecting those that pass test */
template<typename TestFn>
static void widget_collect_visible(Widget* const w, TestFn test, test_collection_t& collection) {
for(auto child : w->children()) {
if( !child->hidden() ) {
const auto result = test(child);
if( result.first ) {
collection.push_back(result);
}
widget_collect_visible(child, test, collection);
}
}
}
static int32_t rect_distances(
const KeyEvent direction,
const Rect& rect_start,
const Rect& rect_end
) {
Coord on_axis_max, on_axis_min;
switch(direction) {
case KeyEvent::Right:
on_axis_max = rect_end.left();
on_axis_min = rect_start.right();
break;
case KeyEvent::Left:
on_axis_max = rect_start.left();
on_axis_min = rect_end.right();
break;
case KeyEvent::Down:
on_axis_max = rect_end.top();
on_axis_min = rect_start.bottom();
break;
case KeyEvent::Up:
on_axis_max = rect_start.top();
on_axis_min = rect_end.bottom();
break;
default:
return -1;
}
Coord on_axis_distance = on_axis_max - on_axis_min;
if( on_axis_distance < 0 ) {
return -1;
}
Coord perpendicular_axis_start, perpendicular_axis_end;
switch(direction) {
case KeyEvent::Right:
case KeyEvent::Left:
perpendicular_axis_start = rect_start.center().y;
perpendicular_axis_end = rect_end.center().y;
break;
case KeyEvent::Up:
case KeyEvent::Down:
perpendicular_axis_start = rect_start.center().x;
perpendicular_axis_end = rect_end.center().x;
break;
default:
return -1;
}
return (std::abs(perpendicular_axis_end - perpendicular_axis_start) + 1) * (on_axis_distance + 1);
}
void FocusManager::update(
Widget* const top_widget,
const KeyEvent event
) {
if( focus_widget() ) {
const auto focus_screen_rect = focus_widget()->screen_rect();
const auto test_fn = [&focus_screen_rect, event](ui::Widget* const w) -> test_result_t {
// if( w->visible() && w->focusable() ) {
if( w->focusable() ) {
const auto distance = rect_distances(event, focus_screen_rect, w->screen_rect());
if( distance >= 0 ) {
return { w, distance };
}
}
return { nullptr, 0 };
};
test_collection_t collection;
widget_collect_visible(top_widget, test_fn, collection);
const auto compare_fn = [](const test_result_t& a, const test_result_t& b) {
return a.second < b.second;
};
const auto nearest = std::min_element(collection.cbegin(), collection.cend(), compare_fn);
if( nearest != collection.cend() ) {
//focus->blur();
const auto new_focus = (*nearest).first;
set_focus_widget(new_focus);
}
}
}
} /* namespace ui */