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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 <AK/Assertions.h>
28#include <AK/StdLibExtras.h>
29#include <LibGUI/Painter.h>
30#include <LibGUI/Slider.h>
31#include <LibGfx/Palette.h>
32#include <LibGfx/StylePainter.h>
33
34namespace GUI {
35
36Slider::Slider(Orientation orientation)
37 : m_orientation(orientation)
38{
39}
40
41Slider::~Slider()
42{
43}
44
45void Slider::set_range(int min, int max)
46{
47 ASSERT(min <= max);
48 if (m_min == min && m_max == max)
49 return;
50 m_min = min;
51 m_max = max;
52 m_value = clamp(m_value, m_min, m_max);
53 update();
54}
55
56void Slider::set_value(int value)
57{
58 value = clamp(value, m_min, m_max);
59 if (m_value == value)
60 return;
61 m_value = value;
62 update();
63
64 if (on_value_changed)
65 on_value_changed(m_value);
66}
67
68void Slider::paint_event(PaintEvent& event)
69{
70 Painter painter(*this);
71 painter.add_clip_rect(event.rect());
72
73 Gfx::Rect track_rect;
74
75 if (orientation() == Orientation::Horizontal) {
76 track_rect = { inner_rect().x(), 0, inner_rect().width(), track_size() };
77 track_rect.center_vertically_within(inner_rect());
78 } else {
79 track_rect = { 0, inner_rect().y(), track_size(), inner_rect().height() };
80 track_rect.center_horizontally_within(inner_rect());
81 }
82
83 Gfx::StylePainter::paint_frame(painter, track_rect, palette(), Gfx::FrameShape::Panel, Gfx::FrameShadow::Sunken, 1);
84 Gfx::StylePainter::paint_button(painter, knob_rect(), palette(), Gfx::ButtonStyle::Normal, false, m_knob_hovered);
85}
86
87Gfx::Rect Slider::knob_rect() const
88{
89 auto inner_rect = this->inner_rect();
90 Gfx::Rect rect;
91 rect.set_secondary_offset_for_orientation(orientation(), 0);
92 rect.set_secondary_size_for_orientation(orientation(), knob_secondary_size());
93
94 if (knob_size_mode() == KnobSizeMode::Fixed) {
95 if (m_max - m_min) {
96 float scale = (float)inner_rect.primary_size_for_orientation(orientation()) / (float)(m_max - m_min);
97 rect.set_primary_offset_for_orientation(orientation(), inner_rect.primary_offset_for_orientation(orientation()) + ((int)(m_value * scale)) - (knob_fixed_primary_size() / 2));
98 } else
99 rect.set_primary_size_for_orientation(orientation(), 0);
100 rect.set_primary_size_for_orientation(orientation(), knob_fixed_primary_size());
101 } else {
102 float scale = (float)inner_rect.primary_size_for_orientation(orientation()) / (float)(m_max - m_min + 1);
103 rect.set_primary_offset_for_orientation(orientation(), inner_rect.primary_offset_for_orientation(orientation()) + ((int)(m_value * scale)));
104 if (m_max - m_min)
105 rect.set_primary_size_for_orientation(orientation(), ::max((int)(scale), knob_fixed_primary_size()));
106 else
107 rect.set_primary_size_for_orientation(orientation(), inner_rect.primary_size_for_orientation(orientation()));
108 }
109 if (orientation() == Orientation::Horizontal)
110 rect.center_vertically_within(inner_rect);
111 else
112 rect.center_horizontally_within(inner_rect);
113 return rect;
114}
115
116void Slider::mousedown_event(MouseEvent& event)
117{
118 if (!is_enabled())
119 return;
120 if (event.button() == MouseButton::Left) {
121 if (knob_rect().contains(event.position())) {
122 m_dragging = true;
123 m_drag_origin = event.position();
124 m_drag_origin_value = m_value;
125 return;
126 } else {
127 if (event.position().primary_offset_for_orientation(orientation()) > knob_rect().last_edge_for_orientation(orientation()))
128 set_value(m_value + 1);
129 else if (event.position().primary_offset_for_orientation(orientation()) < knob_rect().first_edge_for_orientation(orientation()))
130 set_value(m_value - 1);
131 }
132 }
133 return Widget::mousedown_event(event);
134}
135
136void Slider::mousemove_event(MouseEvent& event)
137{
138 if (!is_enabled())
139 return;
140 set_knob_hovered(knob_rect().contains(event.position()));
141 if (m_dragging) {
142 float delta = event.position().primary_offset_for_orientation(orientation()) - m_drag_origin.primary_offset_for_orientation(orientation());
143 float scrubbable_range = inner_rect().primary_size_for_orientation(orientation());
144 float value_steps_per_scrubbed_pixel = (m_max - m_min) / scrubbable_range;
145 float new_value = m_drag_origin_value + (value_steps_per_scrubbed_pixel * delta);
146 set_value((int)new_value);
147 return;
148 }
149 return Widget::mousemove_event(event);
150}
151
152void Slider::mouseup_event(MouseEvent& event)
153{
154 if (!is_enabled())
155 return;
156 if (event.button() == MouseButton::Left) {
157 m_dragging = false;
158 return;
159 }
160
161 return Widget::mouseup_event(event);
162}
163
164void Slider::mousewheel_event(MouseEvent& event)
165{
166 if (!is_enabled())
167 return;
168
169 if (orientation() == Orientation::Horizontal)
170 set_value(value() - event.wheel_delta() * m_step);
171 else
172 set_value(value() + event.wheel_delta() * m_step);
173
174 Widget::mousewheel_event(event);
175}
176
177void Slider::leave_event(Core::Event& event)
178{
179 if (!is_enabled())
180 return;
181 set_knob_hovered(false);
182 Widget::leave_event(event);
183}
184
185void Slider::change_event(Event& event)
186{
187 if (event.type() == Event::Type::EnabledChange) {
188 if (!is_enabled())
189 m_dragging = false;
190 }
191 Widget::change_event(event);
192}
193
194void Slider::set_knob_hovered(bool hovered)
195{
196 if (m_knob_hovered == hovered)
197 return;
198 m_knob_hovered = hovered;
199 update(knob_rect());
200}
201
202}