On every object , on the layout tab there is a show/conditional expression that will hide the object unless the condition is met.
There is no way to figure out if a selection is made in chart per se, but you can capture if a selection is made in a field (and trigger a variable change that would hide an object) and you can count the number of selections that have been made in a field (using getselectedcount(FieldName)) which could also cause an object to hide.
Challenge is to figure out if you want it hidden when any selection on the field is made, just one value etc.. etc...
Let us assume that you are displaying Dimension1 and Dimension2 in your straight table.
Now in Bar chart try like this to hide if any selections are made in Straight table
Bar Chart Properties -> Layout -> Show Conditional and give below expression
=Len(GetFieldSelections(Dimension1) = 0 AND Len(GetFieldSelections(Dimension2) = 0
Now whenever you select any values in this dimensions the chart will hide.
Note : Qlikview dont have OnClick event of a Chart object, so to overcome this we are using GetFieldSelections(), whenever you select any values in a Dimension this function will return the selected values.
Hope this helps you.