====== Operations with grids: Check all, Uncheck all, Invert, Check selected, Uncheck selected. ======

//Introduction://
Some grids that have checkboxes for selection allow you to do complex operations.
{{ :selectgrig.jpg?nolink&600 |}}
**Check all:**
Right-click in the grid area and select the "Check All" menu item

__Expected Result:__
All rows will have checkmarks in the "Selected" column

**Uncheck all:**
Right-click in the grid area and select the "Uncheck All" menu item

__Expected Result:__
No row will be checked in the "Selected" column

**Invert:**
Right-click in the grid area and select the "Invert" menu item

__Expected Result:__
Those lines that had marks will be unchecked, and those that have been marked will no longer have a mark in the "Selected" column

**Check selected:**
Right-click in the grid area and select the "Check selected" menu item

__Expected Result:__
Those lines, which were selected, will have marks in the "Selected" column. No other line will change its state.

**Uncheck selected:**
Right-click in the grid area and select the "Uncheck selected" menu item

__Expected Result:__
Those lines that have been selected will not have a mark in the "Selected" column. No other line will change its state.