tui_scrollview/
state.rs

1use ratatui::layout::{Position, Size};
2
3#[derive(Debug, Default, Clone, Copy, Eq, PartialEq, Hash)]
4pub struct ScrollViewState {
5    /// The offset is the number of rows and columns to shift the scroll view by.
6    pub(crate) offset: Position,
7    /// The size of the scroll view. Not set until the first render call.
8    pub(crate) size: Option<Size>,
9    /// The size of a page of the scroll view. Not set until the first render call.
10    pub(crate) page_size: Option<Size>,
11}
12
13impl ScrollViewState {
14    /// Create a new scroll view state with an offset of (0, 0)
15    pub fn new() -> Self {
16        Self::default()
17    }
18
19    /// Create a new scroll view state with the given offset
20    pub fn with_offset(offset: Position) -> Self {
21        Self {
22            offset,
23            ..Default::default()
24        }
25    }
26
27    /// Set the offset of the scroll view state
28    pub const fn set_offset(&mut self, offset: Position) {
29        self.offset = offset;
30    }
31
32    /// Get the offset of the scroll view state
33    pub const fn offset(&self) -> Position {
34        self.offset
35    }
36
37    /// Move the scroll view state up by one row
38    pub const fn scroll_up(&mut self) {
39        self.offset.y = self.offset.y.saturating_sub(1);
40    }
41
42    /// Move the scroll view state down by one row
43    pub const fn scroll_down(&mut self) {
44        self.offset.y = self.offset.y.saturating_add(1);
45    }
46
47    /// Move the scroll view state down by one page
48    pub fn scroll_page_down(&mut self) {
49        let page_size = self.page_size.map_or(1, |size| size.height);
50        // we subtract 1 to ensure that there is a one row overlap between pages
51        self.offset.y = self.offset.y.saturating_add(page_size).saturating_sub(1);
52    }
53
54    /// Move the scroll view state up by one page
55    pub fn scroll_page_up(&mut self) {
56        let page_size = self.page_size.map_or(1, |size| size.height);
57        // we add 1 to ensure that there is a one row overlap between pages
58        self.offset.y = self.offset.y.saturating_add(1).saturating_sub(page_size);
59    }
60
61    /// Move the scroll view state left by one column
62    pub const fn scroll_left(&mut self) {
63        self.offset.x = self.offset.x.saturating_sub(1);
64    }
65
66    /// Move the scroll view state right by one column
67    pub const fn scroll_right(&mut self) {
68        self.offset.x = self.offset.x.saturating_add(1);
69    }
70
71    /// Move the scroll view state to the top of the buffer
72    pub const fn scroll_to_top(&mut self) {
73        self.offset = Position::ORIGIN;
74    }
75
76    /// Move the scroll view state to the bottom of the buffer
77    pub fn scroll_to_bottom(&mut self) {
78        // the render call will adjust the offset to ensure that we don't scroll past the end of
79        // the buffer, so we can set the offset to the maximum value here
80        let bottom = self
81            .size
82            .map_or(u16::MAX, |size| size.height.saturating_sub(1));
83        self.offset.y = bottom;
84    }
85}
tui_scrollview/state.rs

tui_scrollview/
state.rs
