[royale-asjs] 01/03: Workaround for an issue with text measurement requested in content that is not yet in the DOM. Needs review.

[gregdove]

This is an automated email from the ASF dual-hosted git repository.

gregdove pushed a commit to branch develop
in repository https://gitbox.apache.org/repos/asf/royale-asjs.git

commit 2b6cf7ebe24d93c76e7417fcfced301c9c7562d5
Author: greg-dove <greg.d...@gmail.com>
AuthorDate: Fri May 22 21:41:28 2020 +1200

    Workaround for an issue with text measurement requested in content that is 
not yet in the DOM. Needs review.
---
 .../src/main/royale/mx/core/UITextFormat.as        | 47 ++++++++++++++--------
 1 file changed, 31 insertions(+), 16 deletions(-)

diff --git 
a/frameworks/projects/MXRoyale/src/main/royale/mx/core/UITextFormat.as 
b/frameworks/projects/MXRoyale/src/main/royale/mx/core/UITextFormat.as
index 1ce581a..1b2d696 100644
--- a/frameworks/projects/MXRoyale/src/main/royale/mx/core/UITextFormat.as
+++ b/frameworks/projects/MXRoyale/src/main/royale/mx/core/UITextFormat.as
@@ -558,7 +558,10 @@ public class UITextFormat extends TextFormat
         
         return lineMetrics;
     }
-    
+
+    COMPILE::JS
+    private static var measuringElementRef:HTMLSpanElement
+
     /**
      * @royaleignorecoercion mx.managers.SystemManager;
      * @royaleignorecoercion HTMLSpanElement; 
@@ -566,25 +569,37 @@ public class UITextFormat extends TextFormat
     COMPILE::JS
     private function measure(s:String, html:Boolean, 
roundUp:Boolean):TextLineMetrics
     {
-        var sm:SystemManager = systemManager as SystemManager;
-        if (sm.measuringElement == null)
-        {
-            sm.measuringElement = document.createElement("span") as 
HTMLSpanElement;
-            //everything else is absolute position so should be above this 
element
-            //sm.measuringElement.style.position = "float"; // to try to keep 
it from affecting position of other elements
-            // offsetWidth/Height not computed for display: none
-            //sm.measuringElement.style.display = "none"; // to try to keep it 
hidden
-            sm.measuringElement.style.opacity = 0;
-            sm.measuringElement.style["pointer-events"] = "none";
-            sm.element.appendChild(sm.measuringElement);
+        //sometimes this can be requested in some code that does not pass a 
reference to systemManager, so use
+        //a cached reference to the measuringElement - needs review
+        var measuringElement:HTMLSpanElement = measuringElementRef;
+
+        if (!measuringElement) {
+            measuringElementRef = (systemManager as 
SystemManager).measuringElement;
+            measuringElement = measuringElementRef;
+            if (!measuringElement) {
+                var sm:SystemManager = systemManager as SystemManager;
+                if (sm.measuringElement == null)
+                {
+                    measuringElement = document.createElement("span") as 
HTMLSpanElement;
+                    //everything else is absolute position so should be above 
this element
+                    //sm.measuringElement.style.position = "float"; // to try 
to keep it from affecting position of other elements
+                    // offsetWidth/Height not computed for display: none
+                    //sm.measuringElement.style.display = "none"; // to try to 
keep it hidden
+                    measuringElement.style.opacity = 0;
+                    measuringElement.style["pointer-events"] = "none";
+                    sm.element.appendChild(measuringElement);
+                    sm.measuringElement = measuringElement;
+                }
+            }
         }
+
         if (s.indexOf("&nbsp;") >= 0)
-            sm.measuringElement.innerHTML = s;
+            measuringElement.innerHTML = s;
         else
-            sm.measuringElement.textContent = s;
+            measuringElement.textContent = s;
         var tlm:TextLineMetrics = new TextLineMetrics();
-        tlm.width = sm.measuringElement.offsetWidth;
-        tlm.height = sm.measuringElement.offsetHeight;
+        tlm.width = measuringElement.offsetWidth;
+        tlm.height = measuringElement.offsetHeight;
         return tlm;
     }