Enhancement
(User-visible)
Grid can now do multiple selection with Ctrl-Click and Shift-Click(#23468). Unfortunately you can't deselect an already selected row with Ctrl-Click (Toggle). But this is useful if you want to make a complex selection "All from ... to ... except ...".
Implementation
In the function 'writeColumn' in DefaultTableRenderer the 'onclick' method was added to a row only if it is selectable (isSelectable) and not already selected (isSelected). Now, regardless of the current selection state (isSelected) of the row, the 'onclick' method is written if the row is selectable.
Test
In a 'Grid' that allows multiple selections, select rows and deselect them with CTRL-click. Do this in 'EditMode' and 'ViewMode' to check the correct creation and deletion of 'FormFields'.