1 | use std::ops::{Add, RangeBounds, Sub}; |
2 | |
3 | use crate::{ |
4 | grid::config::Entity, |
5 | grid::records::{ExactRecords, Records}, |
6 | settings::object::{cell::EntityOnce, Object}, |
7 | }; |
8 | |
9 | use super::util::bounds_to_usize; |
10 | |
11 | /// Column denotes a set of cells on given columns on a [`Table`]. |
12 | /// |
13 | /// [`Table`]: crate::Table |
14 | #[derive (Debug)] |
15 | pub struct Columns<R> { |
16 | range: R, |
17 | } |
18 | |
19 | impl<R> Columns<R> { |
20 | /// Returns a new instance of [`Columns`] for a range of columns. |
21 | /// |
22 | /// If the boundaries are exceeded it may panic. |
23 | pub fn new(range: R) -> Self |
24 | where |
25 | R: RangeBounds<usize>, |
26 | { |
27 | Self { range } |
28 | } |
29 | |
30 | pub(crate) fn get_range(&self) -> &R { |
31 | &self.range |
32 | } |
33 | } |
34 | |
35 | impl Columns<()> { |
36 | /// Returns a new instance of [`Columns`] for a single column. |
37 | /// |
38 | /// If the boundaries are exceeded it may panic. |
39 | pub fn single(index: usize) -> Column { |
40 | Column(index) |
41 | } |
42 | |
43 | /// Returns a new instance of [`Columns`] for a first column. |
44 | /// |
45 | /// If the boundaries are exceeded the object will produce no cells. |
46 | pub fn first() -> FirstColumn { |
47 | FirstColumn |
48 | } |
49 | |
50 | /// Returns a new instance of [`Columns`] for a last column. |
51 | /// |
52 | /// If the boundaries are exceeded the object will produce no cells. |
53 | pub fn last() -> LastColumn { |
54 | LastColumn |
55 | } |
56 | } |
57 | |
58 | impl<I, R> Object<I> for Columns<R> |
59 | where |
60 | R: RangeBounds<usize>, |
61 | I: Records, |
62 | { |
63 | type Iter = ColumnsIter; |
64 | |
65 | fn cells(&self, records: &I) -> Self::Iter { |
66 | let max: usize = records.count_columns(); |
67 | let start: Bound<&usize> = self.range.start_bound(); |
68 | let end: Bound<&usize> = self.range.end_bound(); |
69 | let (x: usize, y: usize) = bounds_to_usize(left:start, right:end, count_elements:max); |
70 | |
71 | ColumnsIter::new(start:x, end:y) |
72 | } |
73 | } |
74 | |
75 | /// `FirstColumn` represents the first column on a grid. |
76 | #[derive (Debug)] |
77 | pub struct FirstColumn; |
78 | |
79 | impl<I> Object<I> for FirstColumn |
80 | where |
81 | I: Records + ExactRecords, |
82 | { |
83 | type Iter = EntityOnce; |
84 | |
85 | fn cells(&self, records: &I) -> Self::Iter { |
86 | if records.count_rows() == 0 || records.count_columns() == 0 { |
87 | return EntityOnce::new(entity:None); |
88 | } |
89 | |
90 | EntityOnce::new(entity:Some(Entity::Column(0))) |
91 | } |
92 | } |
93 | |
94 | impl Add<usize> for FirstColumn { |
95 | type Output = Column; |
96 | |
97 | fn add(self, rhs: usize) -> Self::Output { |
98 | Column(rhs) |
99 | } |
100 | } |
101 | |
102 | /// `LastColumn` represents the last column on a grid. |
103 | #[derive (Debug)] |
104 | pub struct LastColumn; |
105 | |
106 | impl<I> Object<I> for LastColumn |
107 | where |
108 | I: Records + ExactRecords, |
109 | { |
110 | type Iter = EntityOnce; |
111 | |
112 | fn cells(&self, records: &I) -> Self::Iter { |
113 | if records.count_rows() == 0 || records.count_columns() == 0 { |
114 | return EntityOnce::new(entity:None); |
115 | } |
116 | |
117 | let col: usize = records.count_columns().saturating_sub(1); |
118 | EntityOnce::new(entity:Some(Entity::Column(col))) |
119 | } |
120 | } |
121 | |
122 | impl Sub<usize> for LastColumn { |
123 | type Output = LastColumnOffset; |
124 | |
125 | fn sub(self, rhs: usize) -> Self::Output { |
126 | LastColumnOffset { offset: rhs } |
127 | } |
128 | } |
129 | |
130 | /// Column represents a single column on a grid. |
131 | #[derive (Debug, Clone, Copy)] |
132 | pub struct Column(usize); |
133 | |
134 | impl<I> Object<I> for Column { |
135 | type Iter = EntityOnce; |
136 | |
137 | fn cells(&self, _: &I) -> Self::Iter { |
138 | EntityOnce::new(entity:Some(Entity::Column(self.0))) |
139 | } |
140 | } |
141 | |
142 | impl From<usize> for Column { |
143 | fn from(i: usize) -> Self { |
144 | Self(i) |
145 | } |
146 | } |
147 | |
148 | impl From<Column> for usize { |
149 | fn from(val: Column) -> Self { |
150 | val.0 |
151 | } |
152 | } |
153 | |
154 | /// `LastColumnOffset` represents a single column on a grid indexed via offset from the last column. |
155 | #[derive (Debug)] |
156 | pub struct LastColumnOffset { |
157 | offset: usize, |
158 | } |
159 | |
160 | impl<I> Object<I> for LastColumnOffset |
161 | where |
162 | I: Records + ExactRecords, |
163 | { |
164 | type Iter = EntityOnce; |
165 | |
166 | fn cells(&self, records: &I) -> Self::Iter { |
167 | if records.count_rows() == 0 || records.count_columns() == 0 { |
168 | return EntityOnce::new(entity:None); |
169 | } |
170 | |
171 | let col: usize = records.count_columns().saturating_sub(1); |
172 | if self.offset > col { |
173 | return EntityOnce::new(entity:None); |
174 | } |
175 | |
176 | let col: usize = col - self.offset; |
177 | EntityOnce::new(entity:Some(Entity::Column(col))) |
178 | } |
179 | } |
180 | |
181 | /// An [`Iterator`] which goes goes over columns of a [`Table`]. |
182 | /// |
183 | /// [`Table`]: crate::Table |
184 | #[derive (Debug)] |
185 | pub struct ColumnsIter { |
186 | start: usize, |
187 | end: usize, |
188 | } |
189 | |
190 | impl ColumnsIter { |
191 | const fn new(start: usize, end: usize) -> Self { |
192 | Self { start, end } |
193 | } |
194 | } |
195 | |
196 | impl Iterator for ColumnsIter { |
197 | type Item = Entity; |
198 | |
199 | fn next(&mut self) -> Option<Self::Item> { |
200 | if self.start >= self.end { |
201 | return None; |
202 | } |
203 | |
204 | let col: usize = self.start; |
205 | self.start += 1; |
206 | |
207 | Some(Entity::Column(col)) |
208 | } |
209 | } |
210 | |