2 files changed, 18 insertions, 0 deletions
diff --git a/components/script/dom/htmltextareaelement.rs b/components/script/dom/htmltextareaelement.rs
index d802760a308..2ef5a24775d 100644
--- a/components/script/dom/htmltextareaelement.rs
+++ b/components/script/dom/htmltextareaelement.rs
@@ -46,6 +46,8 @@ pub struct HTMLTextAreaElement {
 pub trait LayoutHTMLTextAreaElementHelpers {
     #[allow(unsafe_code)]
     unsafe fn get_value_for_layout(self) -> String;
+    #[allow(unsafe_code)]
+    unsafe fn get_absolute_insertion_point_for_layout(self) -> usize;
 }
 
 pub trait RawLayoutHTMLTextAreaElementHelpers {
@@ -61,6 +63,12 @@ impl LayoutHTMLTextAreaElementHelpers for LayoutJS<HTMLTextAreaElement> {
     unsafe fn get_value_for_layout(self) -> String {
         (*self.unsafe_get()).textinput.borrow_for_layout().get_content()
     }
+
+    #[allow(unrooted_must_root)]
+    #[allow(unsafe_code)]
+    unsafe fn get_absolute_insertion_point_for_layout(self) -> usize {
+        (*self.unsafe_get()).textinput.borrow_for_layout().get_absolute_insertion_point()
+    }
 }
 
 impl<'a> RawLayoutHTMLTextAreaElementHelpers for &'a HTMLTextAreaElement {
diff --git a/components/script/textinput.rs b/components/script/textinput.rs
index 627ecf29a5f..c75d246d3ba 100644
--- a/components/script/textinput.rs
+++ b/components/script/textinput.rs
@@ -455,4 +455,14 @@ impl<T: ClipboardProvider> TextInput<T> {
         self.edit_point.line = min(self.edit_point.line, self.lines.len() - 1);
         self.edit_point.index = min(self.edit_point.index, self.current_line_length());
     }
+
+    pub fn get_absolute_insertion_point(&self) -> usize {
+        self.lines.iter().enumerate().fold(0, |acc, (i, val)| {
+            if i < self.edit_point.line {
+                acc + val.len() + 1 // +1 for the \n
+            } else {
+                acc
+            }
+        }) + self.edit_point.index
+    }
 }