1use super::ChartContext;
2use crate::coord::CoordTranslate;
3use crate::drawing::DrawingAreaErrorKind;
4use crate::element::{DynElement, EmptyElement, IntoDynElement, MultiLineText, Rectangle};
5use crate::style::{IntoFont, IntoTextStyle, ShapeStyle, SizeDesc, TextStyle, TRANSPARENT};
6
7use plotters_backend::{BackendCoord, DrawingBackend, DrawingErrorKind};
8
9type SeriesAnnoDrawFn<'a, DB> = dyn Fn(BackendCoord) -> DynElement<'a, DB, BackendCoord> + 'a;
10
11/// The annotations (such as the label of the series, the legend element, etc)
12/// When a series is drawn onto a drawing area, an series annotation object
13/// is created and a mutable reference is returned.
14pub struct SeriesAnno<'a, DB: DrawingBackend> {
15 label: Option<String>,
16 draw_func: Option<Box<SeriesAnnoDrawFn<'a, DB>>>,
17}
18
19impl<'a, DB: DrawingBackend> SeriesAnno<'a, DB> {
20 #[allow(clippy::option_as_ref_deref)]
21 pub(crate) fn get_label(&self) -> &str {
22 // TODO: Change this when we bump the MSRV
23 self.label.as_ref().map(|x| x.as_str()).unwrap_or("")
24 }
25
26 pub(crate) fn get_draw_func(&self) -> Option<&SeriesAnnoDrawFn<'a, DB>> {
27 self.draw_func.as_ref().map(|x| x.as_ref())
28 }
29
30 pub(crate) fn new() -> Self {
31 Self {
32 label: None,
33 draw_func: None,
34 }
35 }
36
37 /**
38 Sets the series label for the current series.
39
40 See [`ChartContext::configure_series_labels()`] for more information and examples.
41 */
42 pub fn label<L: Into<String>>(&mut self, label: L) -> &mut Self {
43 self.label = Some(label.into());
44 self
45 }
46
47 /**
48 Sets the legend element creator function.
49
50 - `func`: The function use to create the element
51
52 # Note
53
54 The creation function uses a shifted pixel-based coordinate system, where the
55 point (0,0) is defined to the mid-right point of the shape.
56
57 # See also
58
59 See [`ChartContext::configure_series_labels()`] for more information and examples.
60 */
61 pub fn legend<E: IntoDynElement<'a, DB, BackendCoord>, T: Fn(BackendCoord) -> E + 'a>(
62 &mut self,
63 func: T,
64 ) -> &mut Self {
65 self.draw_func = Some(Box::new(move |p| func(p).into_dyn()));
66 self
67 }
68}
69
70/**
71Useful to specify the position of the series label.
72
73See [`ChartContext::configure_series_labels()`] for more information and examples.
74*/
75#[derive(Debug, Clone, PartialEq)]
76pub enum SeriesLabelPosition {
77 /// Places the series label at the upper left
78 UpperLeft,
79 /// Places the series label at the middle left
80 MiddleLeft,
81 /// Places the series label at the lower left
82 LowerLeft,
83 /// Places the series label at the upper middle
84 UpperMiddle,
85 /// Places the series label at the middle middle
86 MiddleMiddle,
87 /// Places the series label at the lower middle
88 LowerMiddle,
89 /// Places the series label at the upper right
90 UpperRight,
91 /// Places the series label at the middle right
92 MiddleRight,
93 /// Places the series label at the lower right
94 LowerRight,
95 /// Places the series label at the specific location in backend coordinates
96 Coordinate(i32, i32),
97}
98
99impl SeriesLabelPosition {
100 fn layout_label_area(&self, label_dim: (i32, i32), area_dim: (u32, u32)) -> (i32, i32) {
101 use SeriesLabelPosition::*;
102 (
103 match self {
104 UpperLeft | MiddleLeft | LowerLeft => 5,
105 UpperMiddle | MiddleMiddle | LowerMiddle => (area_dim.0 as i32 - label_dim.0) / 2,
106 UpperRight | MiddleRight | LowerRight => area_dim.0 as i32 - label_dim.0 - 5,
107 Coordinate(x: &i32, _) => *x,
108 },
109 match self {
110 UpperLeft | UpperMiddle | UpperRight => 5,
111 MiddleLeft | MiddleMiddle | MiddleRight => (area_dim.1 as i32 - label_dim.1) / 2,
112 LowerLeft | LowerMiddle | LowerRight => area_dim.1 as i32 - label_dim.1 - 5,
113 Coordinate(_, y: &i32) => *y,
114 },
115 )
116 }
117}
118
119/// The struct to specify the series label of a target chart context
120pub struct SeriesLabelStyle<'a, 'b, DB: DrawingBackend, CT: CoordTranslate> {
121 target: &'b mut ChartContext<'a, DB, CT>,
122 position: SeriesLabelPosition,
123 legend_area_size: u32,
124 border_style: ShapeStyle,
125 background: ShapeStyle,
126 label_font: Option<TextStyle<'b>>,
127 margin: u32,
128}
129
130impl<'a, 'b, DB: DrawingBackend + 'a, CT: CoordTranslate> SeriesLabelStyle<'a, 'b, DB, CT> {
131 pub(super) fn new(target: &'b mut ChartContext<'a, DB, CT>) -> Self {
132 Self {
133 target,
134 position: SeriesLabelPosition::MiddleRight,
135 legend_area_size: 30,
136 border_style: (&TRANSPARENT).into(),
137 background: (&TRANSPARENT).into(),
138 label_font: None,
139 margin: 10,
140 }
141 }
142
143 /**
144 Sets the series label positioning style
145
146 `pos` - The positioning style
147
148 See [`ChartContext::configure_series_labels()`] for more information and examples.
149 */
150 pub fn position(&mut self, pos: SeriesLabelPosition) -> &mut Self {
151 self.position = pos;
152 self
153 }
154
155 /**
156 Sets the margin of the series label drawing area.
157
158 - `value`: The size specification in backend units (pixels)
159
160 See [`ChartContext::configure_series_labels()`] for more information and examples.
161 */
162 pub fn margin<S: SizeDesc>(&mut self, value: S) -> &mut Self {
163 self.margin = value
164 .in_pixels(&self.target.plotting_area().dim_in_pixel())
165 .max(0) as u32;
166 self
167 }
168
169 /**
170 Sets the size of the legend area.
171
172 `size` - The size of legend area in backend units (pixels)
173
174 See [`ChartContext::configure_series_labels()`] for more information and examples.
175 */
176 pub fn legend_area_size<S: SizeDesc>(&mut self, size: S) -> &mut Self {
177 let size = size
178 .in_pixels(&self.target.plotting_area().dim_in_pixel())
179 .max(0) as u32;
180 self.legend_area_size = size;
181 self
182 }
183
184 /**
185 Sets the style of the label series area.
186
187 `style` - The style of the border
188
189 See [`ChartContext::configure_series_labels()`] for more information and examples.
190 */
191 pub fn border_style<S: Into<ShapeStyle>>(&mut self, style: S) -> &mut Self {
192 self.border_style = style.into();
193 self
194 }
195
196 /**
197 Sets the background style of the label series area.
198
199 `style` - The style of the border
200
201 See [`ChartContext::configure_series_labels()`] for more information and examples.
202 */
203 pub fn background_style<S: Into<ShapeStyle>>(&mut self, style: S) -> &mut Self {
204 self.background = style.into();
205 self
206 }
207
208 /**
209 Sets the font for series labels.
210
211 `font` - Desired font
212
213 See [`ChartContext::configure_series_labels()`] for more information and examples.
214 */
215 pub fn label_font<F: IntoTextStyle<'b>>(&mut self, font: F) -> &mut Self {
216 self.label_font = Some(font.into_text_style(&self.target.plotting_area().dim_in_pixel()));
217 self
218 }
219
220 /**
221 Draws the series label area.
222
223 See [`ChartContext::configure_series_labels()`] for more information and examples.
224 */
225 pub fn draw(&mut self) -> Result<(), DrawingAreaErrorKind<DB::ErrorType>> {
226 let drawing_area = self.target.plotting_area().strip_coord_spec();
227
228 // TODO: Issue #68 Currently generic font family doesn't load on OSX, change this after the issue
229 // resolved
230 let default_font = ("sans-serif", 12).into_font();
231 let default_style: TextStyle = default_font.into();
232
233 let font = {
234 let mut temp = None;
235 std::mem::swap(&mut self.label_font, &mut temp);
236 temp.unwrap_or(default_style)
237 };
238
239 let mut label_element = MultiLineText::<_, &str>::new((0, 0), &font);
240 let mut funcs = vec![];
241
242 for anno in self.target.series_anno.iter() {
243 let label_text = anno.get_label();
244 let draw_func = anno.get_draw_func();
245
246 if label_text.is_empty() && draw_func.is_none() {
247 continue;
248 }
249
250 funcs.push(draw_func.unwrap_or(&|p: BackendCoord| EmptyElement::at(p).into_dyn()));
251 label_element.push_line(label_text);
252 }
253
254 let (mut w, mut h) = label_element.estimate_dimension().map_err(|e| {
255 DrawingAreaErrorKind::BackendError(DrawingErrorKind::FontError(Box::new(e)))
256 })?;
257
258 let margin = self.margin as i32;
259
260 w += self.legend_area_size as i32 + margin * 2;
261 h += margin * 2;
262
263 let (area_w, area_h) = drawing_area.dim_in_pixel();
264
265 let (label_x, label_y) = self.position.layout_label_area((w, h), (area_w, area_h));
266
267 label_element.relocate((
268 label_x + self.legend_area_size as i32 + margin,
269 label_y + margin,
270 ));
271
272 drawing_area.draw(&Rectangle::new(
273 [(label_x, label_y), (label_x + w, label_y + h)],
274 self.background.filled(),
275 ))?;
276 drawing_area.draw(&Rectangle::new(
277 [(label_x, label_y), (label_x + w, label_y + h)],
278 self.border_style,
279 ))?;
280 drawing_area.draw(&label_element)?;
281
282 for (((_, y0), (_, y1)), make_elem) in label_element
283 .compute_line_layout()
284 .map_err(|e| {
285 DrawingAreaErrorKind::BackendError(DrawingErrorKind::FontError(Box::new(e)))
286 })?
287 .into_iter()
288 .zip(funcs.into_iter())
289 {
290 let legend_element = make_elem((label_x + margin, (y0 + y1) / 2));
291 drawing_area.draw(&legend_element)?;
292 }
293
294 Ok(())
295 }
296}
297