summaryrefslogtreecommitdiff
path: root/Libraries/LibGUI/GScrollableWidget.cpp
blob: e1d78aa98a916fe9c1524ca529a62fa538d08dcc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
#include <LibGUI/GScrollBar.h>
#include <LibGUI/GScrollableWidget.h>

GScrollableWidget::GScrollableWidget(GWidget* parent)
    : GFrame(parent)
{
    m_vertical_scrollbar = GScrollBar::construct(Orientation::Vertical, this);
    m_vertical_scrollbar->set_step(4);
    m_vertical_scrollbar->on_change = [this](int) {
        did_scroll();
        update();
    };

    m_horizontal_scrollbar = GScrollBar::construct(Orientation::Horizontal, this);
    m_horizontal_scrollbar->set_step(4);
    m_horizontal_scrollbar->set_big_step(30);
    m_horizontal_scrollbar->on_change = [this](int) {
        did_scroll();
        update();
    };

    m_corner_widget = GWidget::construct(this);
    m_corner_widget->set_fill_with_background_color(true);
}

GScrollableWidget::~GScrollableWidget()
{
}

void GScrollableWidget::mousewheel_event(GMouseEvent& event)
{
    // FIXME: The wheel delta multiplier should probably come from... somewhere?
    vertical_scrollbar().set_value(vertical_scrollbar().value() + event.wheel_delta() * 20);
}

void GScrollableWidget::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->preferred_size().height() : 0;
    int width_wanted_by_vertical_scrollbar = m_vertical_scrollbar->is_visible() ? m_vertical_scrollbar->preferred_size().width() : 0;

    m_vertical_scrollbar->set_relative_rect(
        inner_rect.right() + 1 - m_vertical_scrollbar->preferred_size().width(),
        inner_rect.top(),
        m_vertical_scrollbar->preferred_size().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->preferred_size().height(),
        inner_rect.width() - width_wanted_by_vertical_scrollbar,
        m_horizontal_scrollbar->preferred_size().height());

    m_corner_widget->set_visible(m_vertical_scrollbar->is_visible() && m_horizontal_scrollbar->is_visible());
    if (m_corner_widget->is_visible()) {
        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() };
        m_corner_widget->set_relative_rect(corner_rect);
    }
}

void GScrollableWidget::resize_event(GResizeEvent& event)
{
    GFrame::resize_event(event);
    update_scrollbar_ranges();
}

Size GScrollableWidget::available_size() const
{
    int available_width = frame_inner_rect().width() - m_size_occupied_by_fixed_elements.width() - width_occupied_by_vertical_scrollbar();
    int available_height = frame_inner_rect().height() - m_size_occupied_by_fixed_elements.height() - height_occupied_by_horizontal_scrollbar();
    return { available_width, available_height };
}

void GScrollableWidget::update_scrollbar_ranges()
{
    auto available_size = this->available_size();

    int excess_height = max(0, m_content_size.height() - available_size.height());
    m_vertical_scrollbar->set_range(0, excess_height);

    if (should_hide_unnecessary_scrollbars())
        m_vertical_scrollbar->set_visible(excess_height > 0);

    int excess_width = max(0, m_content_size.width() - available_size.width());
    m_horizontal_scrollbar->set_range(0, excess_width);

    if (should_hide_unnecessary_scrollbars())
        m_horizontal_scrollbar->set_visible(excess_width > 0);

    m_vertical_scrollbar->set_big_step(visible_content_rect().height() - m_vertical_scrollbar->step());
}

void GScrollableWidget::set_content_size(const Size& size)
{
    if (m_content_size == size)
        return;
    m_content_size = size;
    update_scrollbar_ranges();
}

void GScrollableWidget::set_size_occupied_by_fixed_elements(const Size& size)
{
    if (m_size_occupied_by_fixed_elements == size)
        return;
    m_size_occupied_by_fixed_elements = size;
    update_scrollbar_ranges();
}

int GScrollableWidget::height_occupied_by_horizontal_scrollbar() const
{
    return m_horizontal_scrollbar->is_visible() ? m_horizontal_scrollbar->height() : 0;
}

int GScrollableWidget::width_occupied_by_vertical_scrollbar() const
{
    return m_vertical_scrollbar->is_visible() ? m_vertical_scrollbar->width() : 0;
}

Rect GScrollableWidget::visible_content_rect() const
{
    return {
        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())
    };
}

void GScrollableWidget::scroll_into_view(const Rect& rect, Orientation orientation)
{
    if (orientation == Orientation::Vertical)
        return scroll_into_view(rect, false, true);
    return scroll_into_view(rect, true, false);
}

void GScrollableWidget::scroll_into_view(const Rect& 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.bottom() > visible_content_rect.bottom())
            m_vertical_scrollbar->set_value(rect.bottom() - visible_content_rect.height());
    }
    if (scroll_horizontally) {
        if (rect.left() < visible_content_rect.left())
            m_horizontal_scrollbar->set_value(rect.left());
        else if (rect.right() > visible_content_rect.right())
            m_horizontal_scrollbar->set_value(rect.right() - visible_content_rect.width());
    }
}

void GScrollableWidget::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 GScrollableWidget::scroll_to_top()
{
    scroll_into_view({ 0, 0, 1, 1 }, Orientation::Vertical);
}

void GScrollableWidget::scroll_to_bottom()
{
    scroll_into_view({ 0, content_height(), 1, 1 }, Orientation::Vertical);
}

Rect GScrollableWidget::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;
}

Point GScrollableWidget::to_content_position(const Point& 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;
}

Point GScrollableWidget::to_widget_position(const Point& 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;
}