pango/layout.rs
1// Take a look at the license at the top of the repository in the LICENSE file.
2
3use glib::translate::*;
4
5use crate::{ffi, LayoutLine, LayoutRun};
6
7// rustdoc-stripper-ignore-next
8/// The result of [`LayoutLine::x_to_index`].
9#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
10pub struct HitPosition {
11 index: i32,
12 trailing: i32,
13 is_inside: bool,
14}
15
16impl HitPosition {
17 // rustdoc-stripper-ignore-next
18 /// The UTF-8 byte offset of the grapheme closest to the position.
19 ///
20 /// This position is relative to the start of the [`Layout`]'s text.
21 ///
22 /// [`Layout`]: crate::Layout
23 pub fn index(self) -> i32 {
24 self.index
25 }
26
27 // rustdoc-stripper-ignore-next
28 /// The codepoint within the grapheme of the position.
29 ///
30 /// This will always be either `0`, or the number of `char`s (*not bytes!*)
31 /// in the grapheme. This represents whether the user clicked near the start
32 /// of the grapheme or near the end; this is important for things like
33 /// resolving cursor positions.
34 pub fn trailing(self) -> i32 {
35 self.trailing
36 }
37
38 // rustdoc-stripper-ignore-next
39 /// Whether or not the position was within the bounds of the line.
40 ///
41 /// If this is `false`, then `index` and `trailing` will always resolve
42 /// to either the very first or the very last position in the line; this
43 /// behaviour is dependent on the line's resolved writing direction.
44 pub fn is_inside(self) -> bool {
45 self.is_inside
46 }
47}
48
49impl LayoutLine {
50 // rustdoc-stripper-ignore-next
51 /// The byte index of the start of this line into the text used to create
52 /// the source [`Layout`].
53 ///
54 /// [`Layout`]: crate::Layout
55 #[cfg(not(feature = "v1_50"))]
56 #[cfg_attr(docsrs, doc(cfg(not(feature = "v1_50"))))]
57 pub fn start_index(&self) -> i32 {
58 unsafe { (*self.as_ptr()).start_index }
59 }
60
61 // rustdoc-stripper-ignore-next
62 /// The length of this line's text, in bytes.
63 #[cfg(not(feature = "v1_50"))]
64 #[cfg_attr(docsrs, doc(cfg(not(feature = "v1_50"))))]
65 pub fn length(&self) -> i32 {
66 unsafe { (*self.as_ptr()).length }
67 }
68
69 #[doc(alias = "pango_layout_line_runs")]
70 pub fn runs(&self) -> Vec<LayoutRun> {
71 unsafe { FromGlibPtrContainer::from_glib_none((*self.as_ptr()).runs) }
72 }
73 /// Converts from x offset to the byte index of the corresponding character
74 /// within the text of the layout.
75 ///
76 /// If @x_pos is outside the line, @index_ and @trailing will point to the very
77 /// first or very last position in the line. This determination is based on the
78 /// resolved direction of the paragraph; for example, if the resolved direction
79 /// is right-to-left, then an X position to the right of the line (after it)
80 /// results in 0 being stored in @index_ and @trailing. An X position to the
81 /// left of the line results in @index_ pointing to the (logical) last grapheme
82 /// in the line and @trailing being set to the number of characters in that
83 /// grapheme. The reverse is true for a left-to-right line.
84 /// ## `x_pos`
85 /// the X offset (in Pango units) from the left edge of the line.
86 ///
87 /// # Returns
88 ///
89 /// [`false`] if @x_pos was outside the line, [`true`] if inside
90 ///
91 /// ## `index_`
92 /// location to store calculated byte index for the grapheme
93 /// in which the user clicked
94 ///
95 /// ## `trailing`
96 /// location to store an integer indicating where in the
97 /// grapheme the user clicked. It will either be zero, or the number of
98 /// characters in the grapheme. 0 represents the leading edge of the grapheme.
99 #[doc(alias = "pango_layout_line_x_to_index")]
100 pub fn x_to_index(&self, x_pos: i32) -> HitPosition {
101 let mut index = 0;
102 let mut trailing = 0;
103
104 let is_inside = unsafe {
105 from_glib(ffi::pango_layout_line_x_to_index(
106 self.to_glib_none().0,
107 x_pos,
108 &mut index,
109 &mut trailing,
110 ))
111 };
112
113 HitPosition {
114 index,
115 trailing,
116 is_inside,
117 }
118 }
119
120 /// Gets a list of visual ranges corresponding to a given logical range.
121 ///
122 /// This list is not necessarily minimal - there may be consecutive
123 /// ranges which are adjacent. The ranges will be sorted from left to
124 /// right. The ranges are with respect to the left edge of the entire
125 /// layout, not with respect to the line.
126 /// ## `start_index`
127 /// Start byte index of the logical range. If this value
128 /// is less than the start index for the line, then the first range
129 /// will extend all the way to the leading edge of the layout. Otherwise,
130 /// it will start at the leading edge of the first character.
131 /// ## `end_index`
132 /// Ending byte index of the logical range. If this value is
133 /// greater than the end index for the line, then the last range will
134 /// extend all the way to the trailing edge of the layout. Otherwise,
135 /// it will end at the trailing edge of the last character.
136 ///
137 /// # Returns
138 ///
139 ///
140 /// ## `ranges`
141 /// location to
142 /// store a pointer to an array of ranges. The array will be of length
143 /// `2*n_ranges`, with each range starting at `(*ranges)[2*n]` and of
144 /// width `(*ranges)[2*n + 1] - (*ranges)[2*n]`. This array must be freed
145 /// with g_free(). The coordinates are relative to the layout and are in
146 /// Pango units.
147 #[doc(alias = "pango_layout_line_get_x_ranges")]
148 #[doc(alias = "get_x_ranges")]
149 pub fn x_ranges(&self, start_index: i32, end_index: i32) -> Vec<i32> {
150 unsafe {
151 let mut ranges = std::ptr::null_mut();
152 let mut n_ranges = std::mem::MaybeUninit::uninit();
153 ffi::pango_layout_line_get_x_ranges(
154 self.to_glib_none().0,
155 start_index,
156 end_index,
157 &mut ranges,
158 n_ranges.as_mut_ptr(),
159 );
160 FromGlibContainer::from_glib_full_num(ranges, 2 * n_ranges.assume_init() as usize)
161 }
162 }
163}