Another attempt to fix #904 to keep the page from jumping to the focused workspace in IE 11 (#974)

core/inject.js

@@ -65,7 +65,8 @@ Blockly.inject = function(container, opt_options) {
   var workspace = Blockly.createMainWorkspace_(svg, options, blockDragSurface,
       workspaceDragSurface);
   Blockly.init_(workspace);
-  workspace.markFocused();
+  Blockly.mainWorkspace = workspace;
+
   Blockly.svgResize(workspace);
   return workspace;
 };
@@ -212,7 +213,7 @@ Blockly.createMainWorkspace_ = function(svg, options, blockDragSurface, workspac
 
   // A null translation will also apply the correct initial scale.
   mainWorkspace.translate(0, 0);
-  mainWorkspace.markFocused();
+  Blockly.mainWorkspace = mainWorkspace;
 
   if (!options.readOnly && !options.hasScrollbars) {
     var workspaceChanged = function() {

core/workspace_svg.js

@@ -1391,7 +1391,15 @@ Blockly.WorkspaceSvg.prototype.setBrowserFocus = function() {
     // IE and Edge do not support focus on SVG elements. When that fails
     // above, get the injectionDiv (the workspace's parent) and focus that
     // instead.  This doesn't work in Chrome.
-    this.getParentSvg().parentNode.focus();
+    try {
+      // In IE11, use setActive (which is IE only) so the page doesn't scroll
+      // to the workspace gaining focus.
+      this.getParentSvg().parentNode.setActive();
+    } catch (e) {
+      // setActive support was discontinued in Edge so when that fails, call
+      // focus instead.
+      this.getParentSvg().parentNode.focus();
+    }
   }
 };