magnifier: Apply scale factor to crosshair length

On hidpi displays the length is double as advertised, make it match
the advertised length.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/984

diff --git a/js/ui/magnifier.js b/js/ui/magnifier.js
index d7d3506a57cbcb8cb250c03abfd55c8a418dcccc..af6c2567d665fd31f87e5ec790404afe7196f9ec 100644 (file)
--- a/js/ui/magnifier.js
+++ b/js/ui/magnifier.js
@@ -430,8 +430,10 @@ var Magnifier = class Magnifier {
      *     lines making up the crosshairs.
      */
     setCrosshairsLength(length) {
-        if (this._crossHairs)
-            this._crossHairs.setLength(length);
+        if (this._crossHairs) {
+            let scaleFactor = St.ThemeContext.get_for_stage(global.stage).scale_factor;
+            this._crossHairs.setLength(length / scaleFactor);
+        }
     }
 
     /**