I don’t see a way to display/hide “Grid Control Bar” row based on a condition. I have a page with multiple grids and would like to show “Grid Control bar” for only grid with a selected row. I ended up using DataView of type “Listen to widget” with a container holding action buttons visibility set to “$currentObject != empty”. This has allowed me to hide/display action buttons only when a grid has selected row. Now another problem, here was that if you get rid of control bar then the default behavior (for e.g. opening a page on double click of row) goes away. I had to include control bar for each grid and set it’s Visibility to false inside grid properties window.
With your current approach you can use css to hide the control bar instead of disabling it. This way it will be hidden on the page but your default button behavior will still work.
To get started with styling here is a link to the documentation to get setup with Koala.