I'm aware of PopUpManager and that custom modal windows can be created.
But let's say I have a simple Canvas(or any component) and when I show it the background needs to be blurred out like how PopUpManager does when a new pop-up is shown.
Is this possible?
I think the blurring has to do with how you set the alpha level on the component.
Not without a lot of work. The PopupManager puts a blur on Application, and then puts the popup in front of the Application, but as a child of the SystemManager, so it's a sibling to the Application in the display list rather than a child. You could take a screen shot of the Application, run a blur filter over it, and place it as the last child of Application, and then place your component on top of that, but if you do that you might as well just use PopupManager in the first place.