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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibGUI/ScrollableWidget.h>
#include <LibGUI/Scrollbar.h>
namespace GUI {
ScrollableWidget::ScrollableWidget()
{
m_vertical_scrollbar = add<ScrollableWidgetScrollbar>(*this, Orientation::Vertical);
m_vertical_scrollbar->set_step(4);
m_vertical_scrollbar->on_change = [this](int) {
did_scroll();
update();
};
m_horizontal_scrollbar = add<ScrollableWidgetScrollbar>(*this, Orientation::Horizontal);
m_horizontal_scrollbar->set_step(4);
m_horizontal_scrollbar->set_page_step(30);
m_horizontal_scrollbar->on_change = [this](int) {
did_scroll();
update();
};
m_corner_widget = add<Widget>();
m_corner_widget->set_fill_with_background_color(true);
}
ScrollableWidget::~ScrollableWidget()
{
}
void ScrollableWidget::handle_wheel_event(MouseEvent& event, Widget& event_source)
{
if (!m_scrollbars_enabled) {
event.ignore();
return;
}
// FIXME: The wheel delta multiplier should probably come from... somewhere?
if (event.shift() || &event_source == m_horizontal_scrollbar.ptr()) {
horizontal_scrollbar().set_value(horizontal_scrollbar().value() + event.wheel_delta() * 60);
} else {
vertical_scrollbar().set_value(vertical_scrollbar().value() + event.wheel_delta() * 20);
}
}
void ScrollableWidget::mousewheel_event(MouseEvent& event)
{
handle_wheel_event(event, *this);
}
void ScrollableWidget::custom_layout()
{
auto inner_rect = frame_inner_rect_for_size(size());
int height_wanted_by_horizontal_scrollbar = m_horizontal_scrollbar->is_visible() ? m_horizontal_scrollbar->min_height() : 0;
int width_wanted_by_vertical_scrollbar = m_vertical_scrollbar->is_visible() ? m_vertical_scrollbar->min_width() : 0;
m_vertical_scrollbar->set_relative_rect(
inner_rect.right() + 1 - m_vertical_scrollbar->min_width(),
inner_rect.top(),
m_vertical_scrollbar->min_width(),
inner_rect.height() - height_wanted_by_horizontal_scrollbar);
m_horizontal_scrollbar->set_relative_rect(
inner_rect.left(),
inner_rect.bottom() + 1 - m_horizontal_scrollbar->min_height(),
inner_rect.width() - width_wanted_by_vertical_scrollbar,
m_horizontal_scrollbar->min_height());
m_corner_widget->set_visible(m_vertical_scrollbar->is_visible() && m_horizontal_scrollbar->is_visible());
if (m_corner_widget->is_visible()) {
Gfx::IntRect corner_rect { m_horizontal_scrollbar->relative_rect().right() + 1, m_vertical_scrollbar->relative_rect().bottom() + 1, width_occupied_by_vertical_scrollbar(), height_occupied_by_horizontal_scrollbar() };
m_corner_widget->set_relative_rect(corner_rect);
}
}
void ScrollableWidget::resize_event(ResizeEvent& event)
{
Frame::resize_event(event);
update_scrollbar_ranges();
}
Gfx::IntSize ScrollableWidget::available_size() const
{
unsigned available_width = max(frame_inner_rect().width() - m_size_occupied_by_fixed_elements.width() - width_occupied_by_vertical_scrollbar(), 0);
unsigned available_height = max(frame_inner_rect().height() - m_size_occupied_by_fixed_elements.height() - height_occupied_by_horizontal_scrollbar(), 0);
return { available_width, available_height };
}
Gfx::IntSize ScrollableWidget::excess_size() const
{
auto available_size = this->available_size();
int excess_height = max(0, m_content_size.height() - available_size.height());
int excess_width = max(0, m_content_size.width() - available_size.width());
return { excess_width, excess_height };
}
void ScrollableWidget::update_scrollbar_ranges()
{
if (should_hide_unnecessary_scrollbars()) {
if (excess_size().height() - height_occupied_by_horizontal_scrollbar() <= 0 && excess_size().width() - width_occupied_by_vertical_scrollbar() <= 0) {
m_horizontal_scrollbar->set_visible(false);
m_vertical_scrollbar->set_visible(false);
} else {
auto vertical_initial_visibility = m_vertical_scrollbar->is_visible();
auto horizontal_initial_visibility = m_horizontal_scrollbar->is_visible();
m_vertical_scrollbar->set_visible(excess_size().height() > 0);
m_horizontal_scrollbar->set_visible(excess_size().width() > 0);
if (m_vertical_scrollbar->is_visible() != vertical_initial_visibility)
m_horizontal_scrollbar->set_visible(excess_size().width() > 0);
if (m_horizontal_scrollbar->is_visible() != horizontal_initial_visibility)
m_vertical_scrollbar->set_visible(excess_size().height() > 0);
}
}
m_horizontal_scrollbar->set_range(0, excess_size().width());
m_horizontal_scrollbar->set_page_step(visible_content_rect().width() - m_horizontal_scrollbar->step());
m_vertical_scrollbar->set_range(0, excess_size().height());
m_vertical_scrollbar->set_page_step(visible_content_rect().height() - m_vertical_scrollbar->step());
}
void ScrollableWidget::set_content_size(const Gfx::IntSize& size)
{
if (m_content_size == size)
return;
m_content_size = size;
update_scrollbar_ranges();
}
void ScrollableWidget::set_size_occupied_by_fixed_elements(const Gfx::IntSize& size)
{
if (m_size_occupied_by_fixed_elements == size)
return;
m_size_occupied_by_fixed_elements = size;
update_scrollbar_ranges();
}
int ScrollableWidget::height_occupied_by_horizontal_scrollbar() const
{
return m_horizontal_scrollbar->is_visible() ? m_horizontal_scrollbar->height() : 0;
}
int ScrollableWidget::width_occupied_by_vertical_scrollbar() const
{
return m_vertical_scrollbar->is_visible() ? m_vertical_scrollbar->width() : 0;
}
Gfx::IntRect ScrollableWidget::visible_content_rect() const
{
Gfx::IntRect rect {
m_horizontal_scrollbar->value(),
m_vertical_scrollbar->value(),
min(m_content_size.width(), frame_inner_rect().width() - width_occupied_by_vertical_scrollbar() - m_size_occupied_by_fixed_elements.width()),
min(m_content_size.height(), frame_inner_rect().height() - height_occupied_by_horizontal_scrollbar() - m_size_occupied_by_fixed_elements.height())
};
if (rect.is_empty())
return {};
return rect;
}
void ScrollableWidget::scroll_into_view(const Gfx::IntRect& rect, Orientation orientation)
{
if (orientation == Orientation::Vertical)
return scroll_into_view(rect, false, true);
return scroll_into_view(rect, true, false);
}
void ScrollableWidget::scroll_into_view(const Gfx::IntRect& rect, bool scroll_horizontally, bool scroll_vertically)
{
auto visible_content_rect = this->visible_content_rect();
if (visible_content_rect.contains(rect))
return;
if (scroll_vertically) {
if (rect.top() < visible_content_rect.top()) {
m_vertical_scrollbar->set_value(rect.top());
} else if (rect.top() > visible_content_rect.top() && rect.bottom() > visible_content_rect.bottom()) {
m_vertical_scrollbar->set_value(rect.bottom() - visible_content_rect.height() + 1);
}
}
if (scroll_horizontally) {
if (rect.left() < visible_content_rect.left()) {
m_horizontal_scrollbar->set_value(rect.left());
} else if (rect.left() > visible_content_rect.left() && rect.right() > visible_content_rect.right()) {
m_horizontal_scrollbar->set_value(rect.right() - visible_content_rect.width() + 1);
}
}
}
void ScrollableWidget::set_scrollbars_enabled(bool scrollbars_enabled)
{
if (m_scrollbars_enabled == scrollbars_enabled)
return;
m_scrollbars_enabled = scrollbars_enabled;
m_vertical_scrollbar->set_visible(m_scrollbars_enabled);
m_horizontal_scrollbar->set_visible(m_scrollbars_enabled);
m_corner_widget->set_visible(m_scrollbars_enabled);
}
void ScrollableWidget::scroll_to_top()
{
scroll_into_view({}, Orientation::Vertical);
}
void ScrollableWidget::scroll_to_bottom()
{
scroll_into_view({ 0, content_height(), 0, 0 }, Orientation::Vertical);
}
Gfx::IntRect ScrollableWidget::widget_inner_rect() const
{
auto rect = frame_inner_rect();
rect.set_width(rect.width() - width_occupied_by_vertical_scrollbar());
rect.set_height(rect.height() - height_occupied_by_horizontal_scrollbar());
return rect;
}
Gfx::IntPoint ScrollableWidget::to_content_position(const Gfx::IntPoint& widget_position) const
{
auto content_position = widget_position;
content_position.move_by(horizontal_scrollbar().value(), vertical_scrollbar().value());
content_position.move_by(-frame_thickness(), -frame_thickness());
return content_position;
}
Gfx::IntPoint ScrollableWidget::to_widget_position(const Gfx::IntPoint& content_position) const
{
auto widget_position = content_position;
widget_position.move_by(-horizontal_scrollbar().value(), -vertical_scrollbar().value());
widget_position.move_by(frame_thickness(), frame_thickness());
return widget_position;
}
}
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