DevTools: Remember the last focused widget.

third_party/WebKit/Source/devtools/front_end/ui/UIUtils.js

 /*
  * Copyright (C) 2011 Google Inc.  All rights reserved.
  * Copyright (C) 2006, 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2007 Matt Lilek (pewtermoose@gmail.com).
  * Copyright (C) 2009 Joseph Pecoraro
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
@@ skipping 837 matching lines @@
 {
     if (WebInspector._glassPane && x && !WebInspector._glassPane.element.isAncestor(x))
         return;
     if (x && !x.ownerDocument.isAncestor(x))
         return;
     if (WebInspector._currentFocusElement !== x)
         WebInspector._previousFocusElement = WebInspector._currentFocusElement;
     WebInspector._currentFocusElement = x;
 
     if (x) {
         x.focus();

[luoe, 2016/09/08 20:48:56]

I'm a little confused, if we have this x.focus(), why do we need the extra call
on 873?  Doesn't this focus() trigger the listener?

 
         // Make a caret selection inside the new element if there isn't a range selection and there isn't already a caret selection inside.
         // This is needed (at least) to remove caret from console when focus is moved to some element in the panel.
         // The code below should not be applied to text fields and text areas, hence _isTextEditingElement check.
         var selection = x.getComponentSelection();
         if (!WebInspector._isTextEditingElement(x) && selection.isCollapsed && !x.isInsertionCaretInside()) {
             var selectionRange = x.ownerDocument.createRange();
             selectionRange.setStart(x, 0);
             selectionRange.setEnd(x, 0);
 
             selection.removeAllRanges();
             selection.addRange(selectionRange);
         }
+
+        WebInspector.Widget.focusWidgetForNode(x);

[pfeldman, 2016/09/08 00:53:50]

I'd listen to focus event independently to decouple new nice code from this old
ugly code.

[einbinder, 2016/09/09 01:32:16]

Listening for focus is a bit complicated because of ShadowRoots, but I moved it
to WebInspector._focusChanged instead of setCurrentFocusElement.

     } else if (WebInspector._previousFocusElement)
         WebInspector._previousFocusElement.blur();
 }
 
 WebInspector.restoreFocusFromElement = function(element)
 {
     if (element && element.isSelfOrAncestor(WebInspector.currentFocusElement()))
         WebInspector.setCurrentFocusElement(WebInspector.previousFocusElement());
 }
 
@@ skipping 1129 matching lines @@
  * @param {string} title
  * @return {!Element}
  */
 WebInspector.linkifyDocumentationURLAsNode = function(article, title)
 {
     return WebInspector.linkifyURLAsNode("https://developers.google.com/web/tools/chrome-devtools/" + article, title, undefined, true);
 }
 
 /** @type {!WebInspector.ThemeSupport} */
 WebInspector.themeSupport;