microui-redux 0.6.0

Idiomatic Rust MicroUI (immediate mode GUI) library port
Documentation 
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

//
// Copyright 2022-Present (c) Raja Lehtihet & Wael El Oraiby
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors
// may be used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// -----------------------------------------------------------------------------
// Ported to rust from https://github.com/rxi/microui/ and the original license
//
// Copyright (c) 2020 rxi
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//
use crate::{Recti, Vec2i};

#[derive(Copy, Clone, Debug)]
pub(crate) enum ScrollAxis {
    Vertical,
    Horizontal,
}

pub(crate) fn scrollbar_base(axis: ScrollAxis, body: Recti, scrollbar_size: i32) -> Recti {
    let mut base = body;
    match axis {
        ScrollAxis::Vertical => {
            base.x = body.x + body.width;
            base.width = scrollbar_size;
        }
        ScrollAxis::Horizontal => {
            base.y = body.y + body.height;
            base.height = scrollbar_size;
        }
    }
    base
}

pub(crate) fn scrollbar_max_scroll(content_len: i32, view_len: i32) -> i32 {
    (content_len - view_len).max(0)
}

pub(crate) fn scrollbar_drag_delta(axis: ScrollAxis, delta: Vec2i, content_len: i32, base: Recti) -> i32 {
    let base_len = match axis {
        ScrollAxis::Vertical => base.height,
        ScrollAxis::Horizontal => base.width,
    };
    if base_len <= 0 {
        return 0;
    }
    let axis_delta = match axis {
        ScrollAxis::Vertical => delta.y,
        ScrollAxis::Horizontal => delta.x,
    };
    axis_delta.saturating_mul(content_len) / base_len
}

pub(crate) fn scrollbar_thumb(axis: ScrollAxis, base: Recti, view_len: i32, content_len: i32, scroll: i32, thumb_size: i32) -> Recti {
    let mut thumb = base;
    let base_len = match axis {
        ScrollAxis::Vertical => base.height,
        ScrollAxis::Horizontal => base.width,
    };
    if base_len <= 0 || content_len <= 0 || view_len <= 0 {
        return thumb;
    }

    let mut thumb_len = base_len.saturating_mul(view_len) / content_len;
    if thumb_len < thumb_size {
        thumb_len = thumb_size;
    }
    if thumb_len > base_len {
        thumb_len = base_len;
    }

    match axis {
        ScrollAxis::Vertical => thumb.height = thumb_len,
        ScrollAxis::Horizontal => thumb.width = thumb_len,
    }

    let max_scroll = scrollbar_max_scroll(content_len, view_len);
    if max_scroll > 0 {
        let track_len = base_len - thumb_len;
        if track_len > 0 {
            let offset = scroll.clamp(0, max_scroll) * track_len / max_scroll;
            match axis {
                ScrollAxis::Vertical => thumb.y += offset,
                ScrollAxis::Horizontal => thumb.x += offset,
            }
        }
    }

    thumb
}