Polyfill caretRangeFromPoint()

Gecko did not implment the older caretRangeFromPoint() and instead
implemented the newer caretPositionFromPoint()

1 files changed, 13 insertions, 0 deletions

diff --git a/ext/fg/js/range.js b/ext/fg/js/range.js
index 182e242c..0befe279 100644
--- a/ext/fg/js/range.js
+++ b/ext/fg/js/range.js
@@ -16,6 +16,19 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+// Polyfill caretRangeFromPoint() using the newer caretPositionFromPoint()
+if (!document.caretRangeFromPoint){
+    document.caretRangeFromPoint = function polyfillcaretRangeFromPoint(x,y){
+        let range = document.createRange();
+        let position = document.caretPositionFromPoint(x,y);
+        if (!position) {
+            return null;
+        }
+        range.setStart(position.offsetNode, position.offset);
+        range.setEnd(position.offsetNode, position.offset);
+        return range;
+    };
+}
 
 class Range {
     constructor(range) {