docs(guide/directive): fix myDraggable for zoomed page

If you have zoomed into the page in your browser then the screen coordinate system no longer
matches the page coordinate system.  To ensure that dragged elements work correctly when zoomed
we should use pageX/pageY rather than screenX/screenY.

Closes #4687

1 files changed, 4 insertions, 4 deletions

diff --git a/docs/content/guide/directive.ngdoc b/docs/content/guide/directive.ngdoc
index 03da25d1..d45cacd3 100644
--- a/docs/content/guide/directive.ngdoc
+++ b/docs/content/guide/directive.ngdoc
@@ -748,15 +748,15 @@ element?
           element.on('mousedown', function(event) {
             // Prevent default dragging of selected content
             event.preventDefault();
-            startX = event.screenX - x;
-            startY = event.screenY - y;
+            startX = event.pageX - x;
+            startY = event.pageY - y;
             $document.on('mousemove', mousemove);
             $document.on('mouseup', mouseup);
           });
 
           function mousemove(event) {
-            y = event.screenY - startY;
-            x = event.screenX - startX;
+            y = event.pageY - startY;
+            x = event.pageX - startX;
             element.css({
               top: y + 'px',
               left:  x + 'px'