1 files changed, 182 insertions, 0 deletions
diff --git a/packages/svgbob/src/buffer/fragment_buffer/fragment/marker_line.rs b/packages/svgbob/src/buffer/fragment_buffer/fragment/marker_line.rs
new file mode 100644
index 0000000..e52f965
--- /dev/null
+++ b/packages/svgbob/src/buffer/fragment_buffer/fragment/marker_line.rs
@@ -0,0 +1,182 @@
+use crate::{
+    fragment::{marker_line, Bounds, Cell, Fragment, Line, Polygon},
+    Point,
+};
+use sauron::{html::attributes::class, Node};
+use std::fmt;
+
+#[derive(Debug, Clone, PartialEq)]
+pub enum Marker {
+    //   -->
+    Arrow,
+    //  ---|>
+    ClearArrow,
+    //  ----*
+    Circle,
+    // -----#
+    Square,
+    //   \
+    //    \
+    //     #
+    Diamond,
+    // -----o
+    OpenCircle,
+    // -----O
+    BigOpenCircle,
+}
+
+impl Marker {
+    fn is_arrow(&self) -> bool {
+        match self {
+            Marker::Arrow | Marker::ClearArrow => true,
+            _ => false,
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct MarkerLine {
+    pub line: Line,
+    pub start_marker: Option<Marker>,
+    pub end_marker: Option<Marker>,
+}
+
+impl MarkerLine {
+    pub fn new(
+        a: Point,
+        b: Point,
+        is_broken: bool,
+        start_marker: Option<Marker>,
+        end_marker: Option<Marker>,
+    ) -> Self {
+        MarkerLine {
+            line: Line::new_noswap(a, b, is_broken),
+            start_marker,
+            end_marker,
+        }
+    }
+
+    pub fn absolute_position(&self, cell: Cell) -> Self {
+        MarkerLine {
+            line: self.line.absolute_position(cell),
+            start_marker: self.start_marker.clone(),
+            end_marker: self.end_marker.clone(),
+        }
+    }
+
+    pub fn align(&self) -> Self {
+        MarkerLine {
+            line: self.line.align(),
+            start_marker: self.start_marker.clone(),
+            end_marker: self.end_marker.clone(),
+        }
+    }
+
+    pub fn scale(&self, scale: f32) -> Self {
+        MarkerLine {
+            line: self.line.scale(scale),
+            start_marker: self.start_marker.clone(),
+            end_marker: self.end_marker.clone(),
+        }
+    }
+
+    /// merge this marker line to the polygon
+    pub(crate) fn merge_polygon(&self, polygon: &Polygon) -> Option<Fragment> {
+        let poly_center = polygon.center();
+        let distance_end_center = self.line.end.distance(&poly_center);
+        let distance_start_center = self.line.start.distance(&poly_center);
+
+        let line_heading = self.line.heading();
+
+        let threshold_length = line_heading.threshold_length();
+        let is_close_start_point = distance_start_center < threshold_length;
+        let is_close_end_point = distance_end_center < threshold_length;
+
+        let is_same_direction = polygon.matched_direction(line_heading);
+
+        let is_opposite_direction =
+            polygon.matched_direction(line_heading.opposite());
+
+        let can_merge = (is_same_direction || is_opposite_direction)
+            && (is_close_start_point || is_close_end_point);
+
+        if can_merge {
+            let marker = polygon.get_marker();
+
+            let start_marker =
+                if is_close_start_point && self.start_marker.is_none() {
+                    marker.clone()
+                } else {
+                    self.start_marker.clone()
+                };
+            let end_marker = if is_close_end_point && self.end_marker.is_none()
+            {
+                marker
+            } else {
+                self.end_marker.clone()
+            };
+
+            let extended_line = if is_close_start_point {
+                self.line.extend_start(threshold_length / 2.0)
+            } else if is_close_end_point {
+                self.line.extend(threshold_length / 2.0)
+            } else {
+                panic!("There is no endpoint close to the polygon");
+            };
+
+            Some(marker_line(
+                extended_line.start,
+                extended_line.end,
+                extended_line.is_broken,
+                start_marker,
+                end_marker,
+            ))
+        } else {
+            None
+        }
+    }
+}
+
+impl Bounds for MarkerLine {
+    fn bounds(&self) -> (Point, Point) {
+        self.line.bounds()
+    }
+}
+
+impl fmt::Display for Marker {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Marker::Arrow => write!(f, "arrow"),
+            Marker::ClearArrow => write!(f, "clear_arrow"),
+            Marker::Circle => write!(f, "circle"),
+            Marker::Square => write!(f, "square"),
+            Marker::Diamond => write!(f, "diamond"),
+            Marker::OpenCircle => write!(f, "open_circle"),
+            Marker::BigOpenCircle => write!(f, "big_open_circle"),
+        }
+    }
+}
+
+impl fmt::Display for MarkerLine {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "{} {:?} {:?}",
+            self.line, self.start_marker, self.end_marker
+        )
+    }
+}
+
+impl<MSG> Into<Node<MSG>> for MarkerLine {
+    fn into(self) -> Node<MSG> {
+        let node: Node<MSG> = self.line.into();
+        let mut classes = vec![];
+        if let Some(start_marker) = self.start_marker {
+            classes.push(class(format!("start_marked_{}", start_marker)));
+        }
+        if let Some(end_marker) = self.end_marker {
+            classes.push(class(format!("end_marked_{}", end_marker)));
+        }
+        node.add_attributes(classes)
+    }
+}