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Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <LibCore/Timer.h>
28#include <LibGUI/Painter.h>
29#include <LibGUI/ScrollBar.h>
30#include <LibGfx/CharacterBitmap.h>
31#include <LibGfx/Palette.h>
32#include <LibGfx/StylePainter.h>
33
34namespace GUI {
35
36static const char* s_up_arrow_bitmap_data = {
37 " "
38 " # "
39 " ### "
40 " ##### "
41 " ####### "
42 " ### "
43 " ### "
44 " ### "
45 " "
46};
47
48static const char* s_down_arrow_bitmap_data = {
49 " "
50 " ### "
51 " ### "
52 " ### "
53 " ####### "
54 " ##### "
55 " ### "
56 " # "
57 " "
58};
59
60static const char* s_left_arrow_bitmap_data = {
61 " "
62 " # "
63 " ## "
64 " ###### "
65 " ####### "
66 " ###### "
67 " ## "
68 " # "
69 " "
70};
71
72static const char* s_right_arrow_bitmap_data = {
73 " "
74 " # "
75 " ## "
76 " ###### "
77 " ####### "
78 " ###### "
79 " ## "
80 " # "
81 " "
82};
83
84static Gfx::CharacterBitmap* s_up_arrow_bitmap;
85static Gfx::CharacterBitmap* s_down_arrow_bitmap;
86static Gfx::CharacterBitmap* s_left_arrow_bitmap;
87static Gfx::CharacterBitmap* s_right_arrow_bitmap;
88
89ScrollBar::ScrollBar(Orientation orientation)
90 : m_orientation(orientation)
91{
92 m_automatic_scrolling_timer = add<Core::Timer>();
93 if (!s_up_arrow_bitmap)
94 s_up_arrow_bitmap = &Gfx::CharacterBitmap::create_from_ascii(s_up_arrow_bitmap_data, 9, 9).leak_ref();
95 if (!s_down_arrow_bitmap)
96 s_down_arrow_bitmap = &Gfx::CharacterBitmap::create_from_ascii(s_down_arrow_bitmap_data, 9, 9).leak_ref();
97 if (!s_left_arrow_bitmap)
98 s_left_arrow_bitmap = &Gfx::CharacterBitmap::create_from_ascii(s_left_arrow_bitmap_data, 9, 9).leak_ref();
99 if (!s_right_arrow_bitmap)
100 s_right_arrow_bitmap = &Gfx::CharacterBitmap::create_from_ascii(s_right_arrow_bitmap_data, 9, 9).leak_ref();
101
102 if (m_orientation == Orientation::Vertical) {
103 set_preferred_size(15, 0);
104 } else {
105 set_preferred_size(0, 15);
106 }
107
108 m_automatic_scrolling_timer->set_interval(100);
109 m_automatic_scrolling_timer->on_timeout = [this] {
110 on_automatic_scrolling_timer_fired();
111 };
112}
113
114ScrollBar::~ScrollBar()
115{
116}
117
118void ScrollBar::set_range(int min, int max)
119{
120 ASSERT(min <= max);
121 if (m_min == min && m_max == max)
122 return;
123
124 m_min = min;
125 m_max = max;
126
127 int old_value = m_value;
128 m_value = clamp(m_value, m_min, m_max);
129 if (on_change && m_value != old_value)
130 on_change(m_value);
131
132 update();
133}
134
135void ScrollBar::set_value(int value)
136{
137 value = clamp(value, m_min, m_max);
138 if (value == m_value)
139 return;
140 m_value = value;
141 if (on_change)
142 on_change(value);
143 update();
144}
145
146Gfx::Rect ScrollBar::decrement_button_rect() const
147{
148 return { 0, 0, button_width(), button_height() };
149}
150
151Gfx::Rect ScrollBar::increment_button_rect() const
152{
153 if (orientation() == Orientation::Vertical)
154 return { 0, height() - button_height(), button_width(), button_height() };
155 else
156 return { width() - button_width(), 0, button_width(), button_height() };
157}
158
159Gfx::Rect ScrollBar::decrement_gutter_rect() const
160{
161 if (orientation() == Orientation::Vertical)
162 return { 0, button_height(), button_width(), scrubber_rect().top() - button_height() };
163 else
164 return { button_width(), 0, scrubber_rect().x() - button_width(), button_height() };
165}
166
167Gfx::Rect ScrollBar::increment_gutter_rect() const
168{
169 auto scrubber_rect = this->scrubber_rect();
170 if (orientation() == Orientation::Vertical)
171 return { 0, scrubber_rect.bottom() + 1, button_width(), height() - button_height() - scrubber_rect.bottom() - 1 };
172 else
173 return { scrubber_rect.right() + 1, 0, width() - button_width() - scrubber_rect.right() - 1, button_width() };
174}
175
176int ScrollBar::scrubbable_range_in_pixels() const
177{
178 if (orientation() == Orientation::Vertical)
179 return height() - button_height() * 2 - scrubber_size();
180 else
181 return width() - button_width() * 2 - scrubber_size();
182}
183
184bool ScrollBar::has_scrubber() const
185{
186 return m_max != m_min;
187}
188
189int ScrollBar::scrubber_size() const
190{
191 int pixel_range = length(orientation()) - button_size() * 2;
192 int value_range = m_max - m_min;
193 return ::max(pixel_range - value_range, button_size());
194}
195
196Gfx::Rect ScrollBar::scrubber_rect() const
197{
198 if (!has_scrubber() || length(orientation()) <= (button_size() * 2) + scrubber_size())
199 return {};
200 float x_or_y;
201 if (m_value == m_min)
202 x_or_y = button_size();
203 else if (m_value == m_max)
204 x_or_y = (length(orientation()) - button_size() - scrubber_size()) + 1;
205 else {
206 float range_size = m_max - m_min;
207 float available = scrubbable_range_in_pixels();
208 float step = available / range_size;
209 x_or_y = (button_size() + (step * m_value));
210 }
211
212 if (orientation() == Orientation::Vertical)
213 return { 0, (int)x_or_y, button_width(), scrubber_size() };
214 else
215 return { (int)x_or_y, 0, scrubber_size(), button_height() };
216}
217
218void ScrollBar::paint_event(PaintEvent& event)
219{
220 Painter painter(*this);
221 painter.add_clip_rect(event.rect());
222
223 painter.fill_rect(rect(), palette().button().lightened());
224
225 bool decrement_pressed = m_automatic_scrolling_direction == AutomaticScrollingDirection::Decrement;
226 bool increment_pressed = m_automatic_scrolling_direction == AutomaticScrollingDirection::Increment;
227
228 Gfx::StylePainter::paint_button(painter, decrement_button_rect(), palette(), Gfx::ButtonStyle::Normal, decrement_pressed, m_hovered_component == Component::DecrementButton);
229 Gfx::StylePainter::paint_button(painter, increment_button_rect(), palette(), Gfx::ButtonStyle::Normal, increment_pressed, m_hovered_component == Component::IncrementButton);
230
231 if (length(orientation()) > default_button_size()) {
232 auto decrement_location = decrement_button_rect().location().translated(3, 3);
233 if (decrement_pressed)
234 decrement_location.move_by(1, 1);
235 painter.draw_bitmap(decrement_location, orientation() == Orientation::Vertical ? *s_up_arrow_bitmap : *s_left_arrow_bitmap, has_scrubber() ? palette().button_text() : palette().threed_shadow1());
236
237 auto increment_location = increment_button_rect().location().translated(3, 3);
238 if (increment_pressed)
239 increment_location.move_by(1, 1);
240 painter.draw_bitmap(increment_location, orientation() == Orientation::Vertical ? *s_down_arrow_bitmap : *s_right_arrow_bitmap, has_scrubber() ? palette().button_text() : palette().threed_shadow1());
241 }
242
243 if (has_scrubber())
244 Gfx::StylePainter::paint_button(painter, scrubber_rect(), palette(), Gfx::ButtonStyle::Normal, false, m_hovered_component == Component::Scrubber || m_scrubber_in_use);
245}
246
247void ScrollBar::on_automatic_scrolling_timer_fired()
248{
249 if (m_automatic_scrolling_direction == AutomaticScrollingDirection::Decrement) {
250 set_value(value() - m_step);
251 return;
252 }
253 if (m_automatic_scrolling_direction == AutomaticScrollingDirection::Increment) {
254 set_value(value() + m_step);
255 return;
256 }
257}
258
259void ScrollBar::mousedown_event(MouseEvent& event)
260{
261 if (event.button() != MouseButton::Left)
262 return;
263 if (!has_scrubber())
264 return;
265
266 if (decrement_button_rect().contains(event.position())) {
267 m_automatic_scrolling_direction = AutomaticScrollingDirection::Decrement;
268 set_automatic_scrolling_active(true);
269 update();
270 return;
271 }
272 if (increment_button_rect().contains(event.position())) {
273 m_automatic_scrolling_direction = AutomaticScrollingDirection::Increment;
274 set_automatic_scrolling_active(true);
275 update();
276 return;
277 }
278 if (scrubber_rect().contains(event.position())) {
279 m_scrubber_in_use = true;
280 m_scrubbing = true;
281 m_scrub_start_value = value();
282 m_scrub_origin = event.position();
283 update();
284 return;
285 }
286
287 float range_size = m_max - m_min;
288 float available = scrubbable_range_in_pixels();
289
290 float x = ::max(0, event.position().x() - button_width() - button_width() / 2);
291 float y = ::max(0, event.position().y() - button_height() - button_height() / 2);
292
293 float rel_x = x / available;
294 float rel_y = y / available;
295
296 if (orientation() == Orientation::Vertical)
297 set_value(m_min + rel_y * range_size);
298 else
299 set_value(m_min + rel_x * range_size);
300
301 m_scrubbing = true;
302 m_scrub_start_value = value();
303 m_scrub_origin = event.position();
304}
305
306void ScrollBar::mouseup_event(MouseEvent& event)
307{
308 if (event.button() != MouseButton::Left)
309 return;
310 m_scrubber_in_use = false;
311 m_automatic_scrolling_direction = AutomaticScrollingDirection::None;
312 set_automatic_scrolling_active(false);
313 m_scrubbing = false;
314 update();
315}
316
317void ScrollBar::mousewheel_event(MouseEvent& event)
318{
319 if (!is_scrollable())
320 return;
321 set_value(value() + event.wheel_delta() * m_step);
322 Widget::mousewheel_event(event);
323}
324
325void ScrollBar::set_automatic_scrolling_active(bool active)
326{
327 if (active) {
328 on_automatic_scrolling_timer_fired();
329 m_automatic_scrolling_timer->start();
330 } else {
331 m_automatic_scrolling_timer->stop();
332 }
333}
334
335void ScrollBar::mousemove_event(MouseEvent& event)
336{
337 auto old_hovered_component = m_hovered_component;
338 if (scrubber_rect().contains(event.position()))
339 m_hovered_component = Component::Scrubber;
340 else if (decrement_button_rect().contains(event.position()))
341 m_hovered_component = Component::DecrementButton;
342 else if (increment_button_rect().contains(event.position()))
343 m_hovered_component = Component::IncrementButton;
344 else if (rect().contains(event.position()))
345 m_hovered_component = Component::Gutter;
346 else
347 m_hovered_component = Component::Invalid;
348 if (old_hovered_component != m_hovered_component) {
349 update();
350
351 if (m_automatic_scrolling_direction == AutomaticScrollingDirection::Decrement)
352 set_automatic_scrolling_active(m_hovered_component == Component::DecrementButton);
353 else if (m_automatic_scrolling_direction == AutomaticScrollingDirection::Increment)
354 set_automatic_scrolling_active(m_hovered_component == Component::IncrementButton);
355 }
356 if (!m_scrubbing)
357 return;
358 float delta = orientation() == Orientation::Vertical ? (event.y() - m_scrub_origin.y()) : (event.x() - m_scrub_origin.x());
359 float scrubbable_range = scrubbable_range_in_pixels();
360 float value_steps_per_scrubbed_pixel = (m_max - m_min) / scrubbable_range;
361 float new_value = m_scrub_start_value + (value_steps_per_scrubbed_pixel * delta);
362 set_value(new_value);
363}
364
365void ScrollBar::leave_event(Core::Event&)
366{
367 if (m_hovered_component != Component::Invalid) {
368 m_hovered_component = Component::Invalid;
369 update();
370 }
371}
372
373void ScrollBar::change_event(Event& event)
374{
375 if (event.type() == Event::Type::EnabledChange) {
376 if (!is_enabled())
377 m_scrubbing = false;
378 }
379 return Widget::change_event(event);
380}
381
382}