Added Movement::StartOfDocument; Movement::EndOfDocument.

CHANGELOG.md

@@ -19,6 +19,7 @@ You can find its changes [documented below](#060---2020-06-01).
 - `request_update` in `EventCtx`. ([#1128] by [@raphlinus])
 - `ExtEventSink`s can now be obtained from widget methods. ([#1152] by [@jneem])
 - 'Scope' widget to allow encapsulation of reactive state. ([#1151] by [@rjwittams])
+- `Movement::StartOfDocument`, `Movement::EndOfDocument`. ([#1092] by [@sysint64])
 
 ### Changed
 
@@ -406,6 +407,7 @@ Last release without a changelog :(
 [#1152]: https://github.com/linebender/druid/pull/1152
 [#1157]: https://github.com/linebender/druid/pull/1157
 [#1172]: https://github.com/linebender/druid/pull/1157
+[#1092]: https://github.com/linebender/druid/pull/1092
 
 [Unreleased]: https://github.com/linebender/druid/compare/v0.6.0...master
 [0.6.0]: https://github.com/linebender/druid/compare/v0.5.0...v0.6.0

druid/src/text/editable_text.rs

@@ -58,6 +58,12 @@ pub trait EditableText: Sized {
     /// Get the next codepoint offset from the given offset, if it exists.
     fn next_codepoint_offset(&self, offset: usize) -> Option<usize>;
 
+    /// Get the line beginning offset from the given offset, if it exists.
+    fn left_end_of_line(&self, offset: usize) -> usize;
+
+    /// Get the line ending offset from the given offset, if it exists.
+    fn right_end_of_line(&self, offset: usize) -> usize;
+
     /// Returns `true` if this text has 0 length.
     fn is_empty(&self) -> bool;
 
@@ -156,6 +162,32 @@ impl EditableText for String {
     fn from_str(s: &str) -> Self {
         s.to_string()
     }
+
+    fn left_end_of_line(&self, from: usize) -> usize {
+        let mut offset = from;
+
+        for byte in self.get(0..from).unwrap_or("").bytes().rev() {
+            if byte == 0x0a {
+                return offset;
+            }
+            offset -= 1;
+        }
+
+        0
+    }
+
+    fn right_end_of_line(&self, from: usize) -> usize {
+        let mut offset = from;
+
+        for char in self.get(from..).unwrap_or("").bytes() {
+            if char == 0x0a {
+                return offset;
+            }
+            offset += 1;
+        }
+
+        self.len()
+    }
 }
 
 /// A cursor with convenience functions for moving through EditableText.
@@ -410,4 +442,38 @@ mod tests {
         assert_eq!(Some(35), a.next_word_offset(26));
         assert_eq!(Some(35), a.next_word_offset(35));
     }
+
+    #[test]
+    fn left_end_of_line() {
+        let a = String::from("Technically\na word:\n ৬藏A\u{030a}\n\u{110b}\u{1161}");
+        assert_eq!(0, a.left_end_of_line(0));
+        assert_eq!(0, a.left_end_of_line(11));
+        assert_eq!(12, a.left_end_of_line(12));
+        assert_eq!(12, a.left_end_of_line(13));
+        assert_eq!(20, a.left_end_of_line(21));
+        assert_eq!(31, a.left_end_of_line(31));
+        assert_eq!(31, a.left_end_of_line(34));
+
+        let b = String::from("Technically a word: ৬藏A\u{030a}\u{110b}\u{1161}");
+        assert_eq!(0, b.left_end_of_line(0));
+        assert_eq!(0, b.left_end_of_line(11));
+        assert_eq!(0, b.left_end_of_line(13));
+        assert_eq!(0, b.left_end_of_line(21));
+    }
+
+    #[test]
+    fn right_end_of_line() {
+        let a = String::from("Technically\na word:\n ৬藏A\u{030a}\n\u{110b}\u{1161}");
+        assert_eq!(11, a.right_end_of_line(0));
+        assert_eq!(11, a.right_end_of_line(11));
+        assert_eq!(19, a.right_end_of_line(13));
+        assert_eq!(30, a.right_end_of_line(21));
+        assert_eq!(a.len(), a.right_end_of_line(31));
+
+        let b = String::from("Technically a word: ৬藏A\u{030a}\u{110b}\u{1161}");
+        assert_eq!(b.len(), b.right_end_of_line(0));
+        assert_eq!(b.len(), b.right_end_of_line(11));
+        assert_eq!(b.len(), b.right_end_of_line(13));
+        assert_eq!(b.len(), b.right_end_of_line(19));
+    }
 }

druid/src/text/movement.rs

@@ -31,6 +31,10 @@ pub enum Movement {
     LeftOfLine,
     /// Move to right end of visible line.
     RightOfLine,
+    /// Move to the beginning of the document
+    StartOfDocument,
+    /// Move to the end of the document
+    EndOfDocument,
 }
 
 /// Compute the result of movement on a selection .
@@ -51,8 +55,11 @@ pub fn movement(m: Movement, s: Selection, text: &impl EditableText, modify: boo
             }
         }
 
-        Movement::LeftOfLine => 0,
-        Movement::RightOfLine => text.len(),
+        Movement::LeftOfLine => text.left_end_of_line(s.end),
+        Movement::RightOfLine => text.right_end_of_line(s.end),
+
+        Movement::StartOfDocument => 0,
+        Movement::EndOfDocument => text.len(),
 
         Movement::LeftWord => {
             if s.is_caret() || modify {