Ag-grid uses an internal service called TooltipManager
to display the given tooltips.
For some reason it uses a default delay of 2 seconds:
private readonly MOUSEOVER_SHOW_TOOLTIP_TIMEOUT = 2000;
This value is currently not configurable by any settings interface, making it available is in the backlog.
If you're brave of heart and don't mind breaking changes when updating the library in the future, you can hack it by getting the correct reference from the bean bag.
private onGridReady(params: GridReadyEvent) {
// NB! This is unsupported and may break at any time
try {
(params.api as any).context.beanWrappers.tooltipManager.beanInstance.MOUSEOVER_SHOW_TOOLTIP_TIMEOUT = 0;
} catch (e) {
console.error(e);
}
}
Caveat emptor, but currently this seems to be the only way to remove the built-in delay.