force preview update after clear selection pressed
Review Request #130017 - Created March 16, 2017 and submitted
A small fix for a small bug. When user selects some area in preview widget and then clicks on Clear Selection button below it the highlighted area isn't redrawn till he moves mouse pointer over preview widget again. This affects clear button and not clear command from context menu as the cursor is always over preview widget in second case. It could confuse user in some cases.