ladybird/Libraries/LibGUI/ScrollBar.cpp
Nico Weber 01ff17d374 LibGUI: Do not paint scrollbar button highlight for scrollbars without scrubber
If a scrollbar doesn't have a scrubber (because the view it scrolls is
large enough to display all its contents without scrolling), then
it ignores all clicks. We shouldn't draw a hover highlight that suggests
clickability in that case.
2020-09-09 21:04:15 +02:00

425 lines
14 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <LibCore/Timer.h>
#include <LibGUI/Painter.h>
#include <LibGUI/ScrollBar.h>
#include <LibGfx/CharacterBitmap.h>
#include <LibGfx/Palette.h>
#include <LibGfx/StylePainter.h>
namespace GUI {
static const char* s_up_arrow_bitmap_data = {
" "
" # "
" ### "
" ##### "
" ####### "
" ### "
" ### "
" ### "
" "
};
static const char* s_down_arrow_bitmap_data = {
" "
" ### "
" ### "
" ### "
" ####### "
" ##### "
" ### "
" # "
" "
};
static const char* s_left_arrow_bitmap_data = {
" "
" # "
" ## "
" ###### "
" ####### "
" ###### "
" ## "
" # "
" "
};
static const char* s_right_arrow_bitmap_data = {
" "
" # "
" ## "
" ###### "
" ####### "
" ###### "
" ## "
" # "
" "
};
static Gfx::CharacterBitmap* s_up_arrow_bitmap;
static Gfx::CharacterBitmap* s_down_arrow_bitmap;
static Gfx::CharacterBitmap* s_left_arrow_bitmap;
static Gfx::CharacterBitmap* s_right_arrow_bitmap;
ScrollBar::ScrollBar(Orientation orientation)
: m_orientation(orientation)
{
m_automatic_scrolling_timer = add<Core::Timer>();
if (!s_up_arrow_bitmap)
s_up_arrow_bitmap = &Gfx::CharacterBitmap::create_from_ascii(s_up_arrow_bitmap_data, 9, 9).leak_ref();
if (!s_down_arrow_bitmap)
s_down_arrow_bitmap = &Gfx::CharacterBitmap::create_from_ascii(s_down_arrow_bitmap_data, 9, 9).leak_ref();
if (!s_left_arrow_bitmap)
s_left_arrow_bitmap = &Gfx::CharacterBitmap::create_from_ascii(s_left_arrow_bitmap_data, 9, 9).leak_ref();
if (!s_right_arrow_bitmap)
s_right_arrow_bitmap = &Gfx::CharacterBitmap::create_from_ascii(s_right_arrow_bitmap_data, 9, 9).leak_ref();
if (m_orientation == Orientation::Vertical) {
set_preferred_size(16, 0);
} else {
set_preferred_size(0, 16);
}
m_automatic_scrolling_timer->set_interval(100);
m_automatic_scrolling_timer->on_timeout = [this] {
on_automatic_scrolling_timer_fired();
};
}
ScrollBar::~ScrollBar()
{
}
void ScrollBar::set_range(int min, int max, int page)
{
ASSERT(min <= max);
if (page < 0)
page = 0;
if (m_min == min && m_max == max && m_page == page)
return;
m_min = min;
m_max = max;
m_page = page;
int old_value = m_value;
m_value = clamp(m_value, m_min, m_max);
if (on_change && m_value != old_value)
on_change(m_value);
update();
}
void ScrollBar::set_value(int value)
{
value = clamp(value, m_min, m_max);
if (value == m_value)
return;
m_value = value;
if (on_change)
on_change(value);
update();
}
Gfx::IntRect ScrollBar::decrement_button_rect() const
{
return { 0, 0, button_width(), button_height() };
}
Gfx::IntRect ScrollBar::increment_button_rect() const
{
if (orientation() == Orientation::Vertical)
return { 0, height() - button_height(), button_width(), button_height() };
else
return { width() - button_width(), 0, button_width(), button_height() };
}
Gfx::IntRect ScrollBar::decrement_gutter_rect() const
{
if (orientation() == Orientation::Vertical)
return { 0, button_height(), button_width(), scrubber_rect().top() - button_height() };
else
return { button_width(), 0, scrubber_rect().x() - button_width(), button_height() };
}
Gfx::IntRect ScrollBar::increment_gutter_rect() const
{
auto scrubber_rect = this->scrubber_rect();
if (orientation() == Orientation::Vertical)
return { 0, scrubber_rect.bottom() + 1, button_width(), height() - button_height() - scrubber_rect.bottom() - 1 };
else
return { scrubber_rect.right() + 1, 0, width() - button_width() - scrubber_rect.right() - 1, button_width() };
}
int ScrollBar::scrubbable_range_in_pixels() const
{
if (orientation() == Orientation::Vertical)
return height() - button_height() * 2 - visible_scrubber_size();
else
return width() - button_width() * 2 - visible_scrubber_size();
}
bool ScrollBar::has_scrubber() const
{
return m_max != m_min;
}
int ScrollBar::unclamped_scrubber_size() const
{
int pixel_range = length(orientation()) - button_size() * 2;
int value_range = m_max - m_min;
int scrubber_size = 0;
if (value_range > 0) {
// Scrubber size should be proportional to the visible portion
// (page) in relation to the content (value range + page)
scrubber_size = (m_page * pixel_range) / (value_range + m_page);
}
return scrubber_size;
}
int ScrollBar::visible_scrubber_size() const
{
return ::max(unclamped_scrubber_size(), button_size());
}
Gfx::IntRect ScrollBar::scrubber_rect() const
{
if (!has_scrubber() || length(orientation()) <= (button_size() * 2) + visible_scrubber_size())
return {};
float x_or_y;
if (m_value == m_min)
x_or_y = button_size();
else if (m_value == m_max)
x_or_y = (length(orientation()) - button_size() - visible_scrubber_size()) + 1;
else {
float range_size = m_max - m_min;
float available = scrubbable_range_in_pixels();
float step = available / range_size;
x_or_y = (button_size() + (step * m_value));
}
if (orientation() == Orientation::Vertical)
return { 0, (int)x_or_y, button_width(), visible_scrubber_size() };
else
return { (int)x_or_y, 0, visible_scrubber_size(), button_height() };
}
void ScrollBar::paint_event(PaintEvent& event)
{
Painter painter(*this);
painter.add_clip_rect(event.rect());
Component hovered_component_for_painting = m_hovered_component;
if (!has_scrubber() || (m_pressed_component != Component::None && m_hovered_component != m_pressed_component))
hovered_component_for_painting = Component::None;
painter.fill_rect_with_dither_pattern(rect(), palette().button().lightened(1.3f), palette().button());
bool decrement_pressed = m_pressed_component == Component::DecrementButton;
bool increment_pressed = m_pressed_component == Component::IncrementButton;
Gfx::StylePainter::paint_button(painter, decrement_button_rect(), palette(), Gfx::ButtonStyle::Normal, decrement_pressed, hovered_component_for_painting == Component::DecrementButton);
Gfx::StylePainter::paint_button(painter, increment_button_rect(), palette(), Gfx::ButtonStyle::Normal, increment_pressed, hovered_component_for_painting == Component::IncrementButton);
if (length(orientation()) > default_button_size()) {
auto decrement_location = decrement_button_rect().location().translated(3, 3);
if (decrement_pressed)
decrement_location.move_by(1, 1);
painter.draw_bitmap(decrement_location, orientation() == Orientation::Vertical ? *s_up_arrow_bitmap : *s_left_arrow_bitmap, has_scrubber() ? palette().button_text() : palette().threed_shadow1());
auto increment_location = increment_button_rect().location().translated(3, 3);
if (increment_pressed)
increment_location.move_by(1, 1);
painter.draw_bitmap(increment_location, orientation() == Orientation::Vertical ? *s_down_arrow_bitmap : *s_right_arrow_bitmap, has_scrubber() ? palette().button_text() : palette().threed_shadow1());
}
if (has_scrubber())
Gfx::StylePainter::paint_button(painter, scrubber_rect(), palette(), Gfx::ButtonStyle::Normal, false, hovered_component_for_painting == Component::Scrubber || m_pressed_component == Component::Scrubber);
}
void ScrollBar::on_automatic_scrolling_timer_fired()
{
if (m_pressed_component == Component::DecrementButton && component_at_position(m_last_mouse_position) == Component::DecrementButton) {
set_value(value() - m_step);
return;
}
if (m_pressed_component == Component::IncrementButton && component_at_position(m_last_mouse_position) == Component::IncrementButton) {
set_value(value() + m_step);
return;
}
if (m_pressed_component == Component::Gutter && component_at_position(m_last_mouse_position) == Component::Gutter) {
scroll_by_page(m_last_mouse_position);
m_hovered_component = component_at_position(m_last_mouse_position);
return;
}
}
void ScrollBar::mousedown_event(MouseEvent& event)
{
if (event.button() != MouseButton::Left)
return;
if (!has_scrubber())
return;
m_last_mouse_position = event.position();
m_pressed_component = component_at_position(m_last_mouse_position);
if (m_pressed_component == Component::DecrementButton) {
set_automatic_scrolling_active(true, Component::DecrementButton);
update();
return;
}
if (m_pressed_component == Component::IncrementButton) {
set_automatic_scrolling_active(true, Component::IncrementButton);
update();
return;
}
if (event.shift()) {
scroll_to_position(event.position());
m_pressed_component = component_at_position(event.position());
ASSERT(m_pressed_component == Component::Scrubber);
}
if (m_pressed_component == Component::Scrubber) {
m_scrub_start_value = value();
m_scrub_origin = event.position();
update();
return;
}
ASSERT(!event.shift());
ASSERT(m_pressed_component == Component::Gutter);
set_automatic_scrolling_active(true, Component::Gutter);
update();
}
void ScrollBar::mouseup_event(MouseEvent& event)
{
if (event.button() != MouseButton::Left)
return;
set_automatic_scrolling_active(false, Component::None);
update();
}
void ScrollBar::mousewheel_event(MouseEvent& event)
{
if (!is_scrollable())
return;
set_value(value() + event.wheel_delta() * m_step);
Widget::mousewheel_event(event);
}
void ScrollBar::set_automatic_scrolling_active(bool active, Component pressed_component)
{
m_pressed_component = pressed_component;
if (m_pressed_component == Component::Gutter)
m_automatic_scrolling_timer->set_interval(200);
else
m_automatic_scrolling_timer->set_interval(100);
if (active) {
on_automatic_scrolling_timer_fired();
m_automatic_scrolling_timer->start();
} else {
m_automatic_scrolling_timer->stop();
}
}
void ScrollBar::scroll_by_page(const Gfx::IntPoint& click_position)
{
float range_size = m_max - m_min;
float available = scrubbable_range_in_pixels();
float rel_scrubber_size = unclamped_scrubber_size() / available;
float page_increment = range_size * rel_scrubber_size;
if (click_position.primary_offset_for_orientation(orientation()) < scrubber_rect().primary_offset_for_orientation(orientation()))
set_value(value() - page_increment);
else
set_value(value() + page_increment);
}
void ScrollBar::scroll_to_position(const Gfx::IntPoint& click_position)
{
float range_size = m_max - m_min;
float available = scrubbable_range_in_pixels();
float x_or_y = ::max(0, click_position.primary_offset_for_orientation(orientation()) - button_width() - button_width() / 2);
float rel_x_or_y = x_or_y / available;
set_value(m_min + rel_x_or_y * range_size);
}
ScrollBar::Component ScrollBar::component_at_position(const Gfx::IntPoint& position)
{
if (scrubber_rect().contains(position))
return Component::Scrubber;
if (decrement_button_rect().contains(position))
return Component::DecrementButton;
if (increment_button_rect().contains(position))
return Component::IncrementButton;
if (rect().contains(position))
return Component::Gutter;
return Component::None;
}
void ScrollBar::mousemove_event(MouseEvent& event)
{
m_last_mouse_position = event.position();
auto old_hovered_component = m_hovered_component;
m_hovered_component = component_at_position(m_last_mouse_position);
if (old_hovered_component != m_hovered_component) {
update();
}
if (m_pressed_component != Component::Scrubber)
return;
float delta = orientation() == Orientation::Vertical ? (event.y() - m_scrub_origin.y()) : (event.x() - m_scrub_origin.x());
float scrubbable_range = scrubbable_range_in_pixels();
float value_steps_per_scrubbed_pixel = (m_max - m_min) / scrubbable_range;
float new_value = m_scrub_start_value + (value_steps_per_scrubbed_pixel * delta);
set_value(new_value);
}
void ScrollBar::leave_event(Core::Event&)
{
if (m_hovered_component != Component::None) {
m_hovered_component = Component::None;
update();
}
}
void ScrollBar::change_event(Event& event)
{
if (event.type() == Event::Type::EnabledChange) {
if (!is_enabled())
set_automatic_scrolling_active(false, Component::None);
}
return Widget::change_event(event);
}
}