WIP: Start on pushing selection management down into Buffer

2021-04-12 16:01:41 +02:00
parent 472ff1621f
commit 551c86f87a
3 changed files with 336 additions and 347 deletions
@@ -0,0 +1,75 @@
+use crate::{
+    editor::{
+        buffer::{Anchor, Buffer, Point, ToPoint},
+        display_map::DisplayMap,
+        DisplayPoint,
+    },
+    time,
+};
+use gpui::AppContext;
+use std::{cmp::Ordering, mem, ops::Range};
+
+pub type SelectionSetId = time::Lamport;
+pub type SelectionsVersion = usize;
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Selection {
+    pub start: Anchor,
+    pub end: Anchor,
+    pub reversed: bool,
+    pub goal_column: Option<u32>,
+}
+
+impl Selection {
+    pub fn head(&self) -> &Anchor {
+        if self.reversed {
+            &self.start
+        } else {
+            &self.end
+        }
+    }
+
+    pub fn set_head(&mut self, buffer: &Buffer, cursor: Anchor) {
+        if cursor.cmp(self.tail(), buffer).unwrap() < Ordering::Equal {
+            if !self.reversed {
+                mem::swap(&mut self.start, &mut self.end);
+                self.reversed = true;
+            }
+            self.start = cursor;
+        } else {
+            if self.reversed {
+                mem::swap(&mut self.start, &mut self.end);
+                self.reversed = false;
+            }
+            self.end = cursor;
+        }
+    }
+
+    pub fn tail(&self) -> &Anchor {
+        if self.reversed {
+            &self.end
+        } else {
+            &self.start
+        }
+    }
+
+    pub fn range(&self, buffer: &Buffer) -> Range<Point> {
+        let start = self.start.to_point(buffer).unwrap();
+        let end = self.end.to_point(buffer).unwrap();
+        if self.reversed {
+            end..start
+        } else {
+            start..end
+        }
+    }
+
+    pub fn display_range(&self, map: &DisplayMap, app: &AppContext) -> Range<DisplayPoint> {
+        let start = self.start.to_display_point(map, app).unwrap();
+        let end = self.end.to_display_point(map, app).unwrap();
+        if self.reversed {
+            end..start
+        } else {
+            start..end
+        }
+    }
+}