Layered Pages

Layering of pages has been added in Aria 4.0 and each page is now by default layered. Layering provides for multiple transparent containers within the page space. Layers can be shown, hidden, locked and moved in z-order both at design time and in the finished application.

In the simplest approach layers make it possible to work with overlapping components or with closely aligned components. In more complex applications layers may be manipulated at runtime to enable or disable functionality or modes as a whole, rather than having to manipulate individual components. Layers might also be used to introduce simple visual effects by manipulating background layers so as to change the appearance of the application.

The individual layers work as any other container and components can be added and deleted in the usual fashion. Layers are just like any other container so the layering of pages has no other effect other than would be achieved by adding components to say a panel. However the layout of the layers is controlled by the page and cannot be changed.

Design Time

At design time a new Layer Palette is added and this provides a facility for adding new layers or changing the order of layers. The background layers is added by default and is treated as a special layer in that it cannot be deleted or repositioned.

At design time layers can also be locked so that they are unaffected by the mouse or keyboard input, in effect they cannot be manipulated while locked.

To see the layers in action click on the image above for a video or install and run the NetBeans editor plugin.