summaryrefslogtreecommitdiff
path: root/LibGUI/GScrollableWidget.cpp
blob: d0ec6a12ccd74f43986567f797813b595e82e8b1 (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
#include <LibGUI/GScrollableWidget.h>
#include <LibGUI/GScrollBar.h>

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

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

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

GScrollableWidget::~GScrollableWidget()
{
}

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

    int height_wanted_by_horizontal_scrollbar = m_horizontal_scrollbar->is_visible() ? m_horizontal_scrollbar->height() : 0;
    int width_wanted_by_vertical_scrollbar = m_vertical_scrollbar->is_visible() ? m_vertical_scrollbar->width() : 0;

    m_vertical_scrollbar->set_relative_rect(event.size().width() - m_vertical_scrollbar->preferred_size().width(), 0, m_vertical_scrollbar->preferred_size().width(), event.size().height() - height_wanted_by_horizontal_scrollbar);
    m_horizontal_scrollbar->set_relative_rect(0, event.size().height() - m_horizontal_scrollbar->preferred_size().height(), event.size().width() - m_vertical_scrollbar->preferred_size().width(), width_wanted_by_vertical_scrollbar);

    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->rect().right() + 1, m_vertical_scrollbar->rect().bottom() + 1, height_occupied_by_horizontal_scrollbar(), width_occupied_by_vertical_scrollbar() };
        m_corner_widget->set_relative_rect(corner_rect);
    }
}

Size GScrollableWidget::available_size() const
{
    int available_width = width() - m_size_occupied_by_fixed_elements.width() - width_occupied_by_vertical_scrollbar();
    int available_height = 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);

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

    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(),
        width() - width_occupied_by_vertical_scrollbar() - m_size_occupied_by_fixed_elements.width(),
        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);
}