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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 <LibGUI/ScrollBar.h>
28#include <LibGUI/ScrollableWidget.h>
29
30namespace GUI {
31
32ScrollableWidget::ScrollableWidget()
33{
34 m_vertical_scrollbar = add<ScrollBar>(Orientation::Vertical);
35 m_vertical_scrollbar->set_step(4);
36 m_vertical_scrollbar->on_change = [this](int) {
37 did_scroll();
38 update();
39 };
40
41 m_horizontal_scrollbar = add<ScrollBar>(Orientation::Horizontal);
42 m_horizontal_scrollbar->set_step(4);
43 m_horizontal_scrollbar->set_big_step(30);
44 m_horizontal_scrollbar->on_change = [this](int) {
45 did_scroll();
46 update();
47 };
48
49 m_corner_widget = add<Widget>();
50 m_corner_widget->set_fill_with_background_color(true);
51}
52
53ScrollableWidget::~ScrollableWidget()
54{
55}
56
57void ScrollableWidget::mousewheel_event(MouseEvent& event)
58{
59 if (!m_scrollbars_enabled) {
60 event.ignore();
61 return;
62 }
63 // FIXME: The wheel delta multiplier should probably come from... somewhere?
64 vertical_scrollbar().set_value(vertical_scrollbar().value() + event.wheel_delta() * 20);
65}
66
67void ScrollableWidget::custom_layout()
68{
69 auto inner_rect = frame_inner_rect_for_size(size());
70 int height_wanted_by_horizontal_scrollbar = m_horizontal_scrollbar->is_visible() ? m_horizontal_scrollbar->preferred_size().height() : 0;
71 int width_wanted_by_vertical_scrollbar = m_vertical_scrollbar->is_visible() ? m_vertical_scrollbar->preferred_size().width() : 0;
72
73 m_vertical_scrollbar->set_relative_rect(
74 inner_rect.right() + 1 - m_vertical_scrollbar->preferred_size().width(),
75 inner_rect.top(),
76 m_vertical_scrollbar->preferred_size().width(),
77 inner_rect.height() - height_wanted_by_horizontal_scrollbar);
78
79 m_horizontal_scrollbar->set_relative_rect(
80 inner_rect.left(),
81 inner_rect.bottom() + 1 - m_horizontal_scrollbar->preferred_size().height(),
82 inner_rect.width() - width_wanted_by_vertical_scrollbar,
83 m_horizontal_scrollbar->preferred_size().height());
84
85 m_corner_widget->set_visible(m_vertical_scrollbar->is_visible() && m_horizontal_scrollbar->is_visible());
86 if (m_corner_widget->is_visible()) {
87 Gfx::Rect 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() };
88 m_corner_widget->set_relative_rect(corner_rect);
89 }
90}
91
92void ScrollableWidget::resize_event(ResizeEvent& event)
93{
94 Frame::resize_event(event);
95 update_scrollbar_ranges();
96}
97
98Gfx::Size ScrollableWidget::available_size() const
99{
100 int available_width = frame_inner_rect().width() - m_size_occupied_by_fixed_elements.width() - width_occupied_by_vertical_scrollbar();
101 int available_height = frame_inner_rect().height() - m_size_occupied_by_fixed_elements.height() - height_occupied_by_horizontal_scrollbar();
102 return { available_width, available_height };
103}
104
105void ScrollableWidget::update_scrollbar_ranges()
106{
107 auto available_size = this->available_size();
108
109 int excess_height = max(0, m_content_size.height() - available_size.height());
110 m_vertical_scrollbar->set_range(0, excess_height);
111
112 if (should_hide_unnecessary_scrollbars())
113 m_vertical_scrollbar->set_visible(excess_height > 0);
114
115 int excess_width = max(0, m_content_size.width() - available_size.width());
116 m_horizontal_scrollbar->set_range(0, excess_width);
117
118 if (should_hide_unnecessary_scrollbars())
119 m_horizontal_scrollbar->set_visible(excess_width > 0);
120
121 m_vertical_scrollbar->set_big_step(visible_content_rect().height() - m_vertical_scrollbar->step());
122}
123
124void ScrollableWidget::set_content_size(const Gfx::Size& size)
125{
126 if (m_content_size == size)
127 return;
128 m_content_size = size;
129 update_scrollbar_ranges();
130}
131
132void ScrollableWidget::set_size_occupied_by_fixed_elements(const Gfx::Size& size)
133{
134 if (m_size_occupied_by_fixed_elements == size)
135 return;
136 m_size_occupied_by_fixed_elements = size;
137 update_scrollbar_ranges();
138}
139
140int ScrollableWidget::height_occupied_by_horizontal_scrollbar() const
141{
142 return m_horizontal_scrollbar->is_visible() ? m_horizontal_scrollbar->height() : 0;
143}
144
145int ScrollableWidget::width_occupied_by_vertical_scrollbar() const
146{
147 return m_vertical_scrollbar->is_visible() ? m_vertical_scrollbar->width() : 0;
148}
149
150Gfx::Rect ScrollableWidget::visible_content_rect() const
151{
152 return {
153 m_horizontal_scrollbar->value(),
154 m_vertical_scrollbar->value(),
155 min(m_content_size.width(), frame_inner_rect().width() - width_occupied_by_vertical_scrollbar() - m_size_occupied_by_fixed_elements.width()),
156 min(m_content_size.height(), frame_inner_rect().height() - height_occupied_by_horizontal_scrollbar() - m_size_occupied_by_fixed_elements.height())
157 };
158}
159
160void ScrollableWidget::scroll_into_view(const Gfx::Rect& rect, Orientation orientation)
161{
162 if (orientation == Orientation::Vertical)
163 return scroll_into_view(rect, false, true);
164 return scroll_into_view(rect, true, false);
165}
166
167void ScrollableWidget::scroll_into_view(const Gfx::Rect& rect, bool scroll_horizontally, bool scroll_vertically)
168{
169 auto visible_content_rect = this->visible_content_rect();
170 if (visible_content_rect.contains(rect))
171 return;
172
173 if (scroll_vertically) {
174 if (rect.top() < visible_content_rect.top())
175 m_vertical_scrollbar->set_value(rect.top());
176 else if (rect.bottom() > visible_content_rect.bottom())
177 m_vertical_scrollbar->set_value(rect.bottom() - visible_content_rect.height());
178 }
179 if (scroll_horizontally) {
180 if (rect.left() < visible_content_rect.left())
181 m_horizontal_scrollbar->set_value(rect.left());
182 else if (rect.right() > visible_content_rect.right())
183 m_horizontal_scrollbar->set_value(rect.right() - visible_content_rect.width());
184 }
185}
186
187void ScrollableWidget::set_scrollbars_enabled(bool scrollbars_enabled)
188{
189 if (m_scrollbars_enabled == scrollbars_enabled)
190 return;
191 m_scrollbars_enabled = scrollbars_enabled;
192 m_vertical_scrollbar->set_visible(m_scrollbars_enabled);
193 m_horizontal_scrollbar->set_visible(m_scrollbars_enabled);
194 m_corner_widget->set_visible(m_scrollbars_enabled);
195}
196
197void ScrollableWidget::scroll_to_top()
198{
199 scroll_into_view({ 0, 0, 1, 1 }, Orientation::Vertical);
200}
201
202void ScrollableWidget::scroll_to_bottom()
203{
204 scroll_into_view({ 0, content_height(), 1, 1 }, Orientation::Vertical);
205}
206
207Gfx::Rect ScrollableWidget::widget_inner_rect() const
208{
209 auto rect = frame_inner_rect();
210 rect.set_width(rect.width() - width_occupied_by_vertical_scrollbar());
211 rect.set_height(rect.height() - height_occupied_by_horizontal_scrollbar());
212 return rect;
213}
214
215Gfx::Point ScrollableWidget::to_content_position(const Gfx::Point& widget_position) const
216{
217 auto content_position = widget_position;
218 content_position.move_by(horizontal_scrollbar().value(), vertical_scrollbar().value());
219 content_position.move_by(-frame_thickness(), -frame_thickness());
220 return content_position;
221}
222
223Gfx::Point ScrollableWidget::to_widget_position(const Gfx::Point& content_position) const
224{
225 auto widget_position = content_position;
226 widget_position.move_by(-horizontal_scrollbar().value(), -vertical_scrollbar().value());
227 widget_position.move_by(frame_thickness(), frame_thickness());
228 return widget_position;
229}
230
231}