The spec ( http://www.whatwg.org/specs/web-apps/current-work/#dom-textarea/input-selectiondirection) currently allows for platform-specific differences in selectionDirection that limit its usefulness. Tightening the requirements to be platform-independent will allow selectionDirection to be used for determining the caret location in a selection.
On Windows, selectionDirection indicates which end of the selection the caret should be placed. On Mac, selectionDirection works similarly when the selection is modified using shift+arrow key, but the spec does not require the same functionality when clicking and dragging a selection. This leaves no cross-platform way to determine the correct caret location! It looks like editors using a textarea (such as codemirror) are currently working around this by not drawing a cursor when there is a selection. Are there arguments against making selectionDirection explicitly "forward" or "backward" if the user modifies the selection, regardless of platform? Philip
