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/*
* Copyright (c) 2022, Mustafa Quraish <mustafa@serenityos.org>
* Copyright (c) 2022, Jelle Raaijmakers <jelle@gmta.nl>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "AbstractZoomPanWidget.h"
namespace GUI {
constexpr float wheel_zoom_factor = 8.0f;
void AbstractZoomPanWidget::set_scale(float new_scale)
{
if (m_original_rect.is_null())
return;
m_scale = clamp(new_scale, m_min_scale, m_max_scale);
m_content_rect.set_size({
m_original_rect.width() * m_scale,
m_original_rect.height() * m_scale,
});
if (on_scale_change)
on_scale_change(m_scale);
relayout();
}
void AbstractZoomPanWidget::scale_by(float delta)
{
float new_scale = m_scale * AK::exp2(delta);
set_scale(new_scale);
}
void AbstractZoomPanWidget::scale_centered(float new_scale, Gfx::IntPoint const& center)
{
if (m_original_rect.is_null())
return;
new_scale = clamp(new_scale, m_min_scale, m_max_scale);
if (new_scale == m_scale)
return;
Gfx::FloatPoint focus_point {
center.x() - width() / 2.0f,
center.y() - height() / 2.0f,
};
m_origin = (m_origin + focus_point) * (new_scale / m_scale) - focus_point;
set_scale(new_scale);
}
void AbstractZoomPanWidget::start_panning(Gfx::IntPoint const& position)
{
m_saved_cursor = override_cursor();
set_override_cursor(Gfx::StandardCursor::Drag);
m_pan_start = m_origin;
m_pan_mouse_pos = position;
m_is_panning = true;
}
void AbstractZoomPanWidget::stop_panning()
{
m_is_panning = false;
set_override_cursor(m_saved_cursor);
}
void AbstractZoomPanWidget::pan_to(Gfx::IntPoint const& position)
{
// NOTE: `position` here (and `m_pan_mouse_pos`) are both in frame coordinates, not
// content coordinates, by design. The derived class should not have to keep track of
// the (zoomed) content coordinates itself, but just pass along the mouse position.
auto delta = position - m_pan_mouse_pos;
m_origin = m_pan_start.translated(-delta.x(), -delta.y());
relayout();
}
Gfx::FloatPoint AbstractZoomPanWidget::frame_to_content_position(Gfx::IntPoint const& frame_position) const
{
return {
(static_cast<float>(frame_position.x()) - m_content_rect.x()) / m_scale,
(static_cast<float>(frame_position.y()) - m_content_rect.y()) / m_scale,
};
}
Gfx::FloatRect AbstractZoomPanWidget::frame_to_content_rect(Gfx::IntRect const& frame_rect) const
{
Gfx::FloatRect content_rect;
content_rect.set_location(frame_to_content_position(frame_rect.location()));
content_rect.set_size({
frame_rect.width() / m_scale,
frame_rect.height() / m_scale,
});
return content_rect;
}
Gfx::FloatPoint AbstractZoomPanWidget::content_to_frame_position(Gfx::IntPoint const& content_position) const
{
return {
m_content_rect.x() + content_position.x() * m_scale,
m_content_rect.y() + content_position.y() * m_scale,
};
}
Gfx::FloatRect AbstractZoomPanWidget::content_to_frame_rect(Gfx::IntRect const& content_rect) const
{
Gfx::FloatRect frame_rect;
frame_rect.set_location(content_to_frame_position(content_rect.location()));
frame_rect.set_size({
content_rect.width() * m_scale,
content_rect.height() * m_scale,
});
return frame_rect;
}
void AbstractZoomPanWidget::mousewheel_event(GUI::MouseEvent& event)
{
float new_scale = scale() / AK::exp2(event.wheel_delta_y() / wheel_zoom_factor);
scale_centered(new_scale, event.position());
}
void AbstractZoomPanWidget::mousedown_event(GUI::MouseEvent& event)
{
if (!m_is_panning && event.button() == GUI::MouseButton::Middle) {
start_panning(event.position());
event.accept();
return;
}
}
void AbstractZoomPanWidget::resize_event(GUI::ResizeEvent& event)
{
relayout();
GUI::Widget::resize_event(event);
}
void AbstractZoomPanWidget::mousemove_event(GUI::MouseEvent& event)
{
if (!m_is_panning)
return;
pan_to(event.position());
event.accept();
}
void AbstractZoomPanWidget::mouseup_event(GUI::MouseEvent& event)
{
if (m_is_panning && event.button() == GUI::MouseButton::Middle) {
stop_panning();
event.accept();
return;
}
}
void AbstractZoomPanWidget::relayout()
{
if (m_original_rect.is_null())
return;
m_content_rect.set_location({
(width() / 2) - (m_content_rect.width() / 2) - m_origin.x(),
(height() / 2) - (m_content_rect.height() / 2) - m_origin.y(),
});
handle_relayout(m_content_rect);
}
void AbstractZoomPanWidget::reset_view()
{
m_origin = { 0, 0 };
set_scale(1.0f);
}
void AbstractZoomPanWidget::set_content_rect(Gfx::IntRect const& content_rect)
{
m_content_rect = enclosing_int_rect(content_to_frame_rect(content_rect));
update();
}
void AbstractZoomPanWidget::set_scale_bounds(float min_scale, float max_scale)
{
m_min_scale = min_scale;
m_max_scale = max_scale;
}
void AbstractZoomPanWidget::fit_content_to_rect(Gfx::IntRect const& viewport_rect, FitType type)
{
const float border_ratio = 0.95f;
auto image_size = m_original_rect.size();
auto height_ratio = floorf(border_ratio * viewport_rect.height()) / image_size.height();
auto width_ratio = floorf(border_ratio * viewport_rect.width()) / image_size.width();
float new_scale = 1.0f;
switch (type) {
case FitType::Width:
new_scale = width_ratio;
break;
case FitType::Height:
new_scale = height_ratio;
break;
case FitType::Both:
new_scale = min(height_ratio, width_ratio);
break;
}
auto const& offset = rect().center() - viewport_rect.center();
set_origin({ offset.x(), offset.y() });
set_scale(new_scale);
}
}
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