Mosaic has been designed with both the casual and the professional user in mind. Basic Layouts offer a simple and fast way to define layouts that are applicable on any screen size whilst achieving the same results. Advanced Layouts are intended to provide power users greater flexibility when required for configuring the precise size and location of a window. Below is a description of each type of Layout to give an indication of the intended usage:
A basic layout is defined by dividing a screen into grid squares, and specifying which squares a window should occupy. The grid is relative to the size of the screen, which means it doesn't matter what resolution your screen is, a layout which is 1/3 the width of the screen for example will be 1/3 the width of any screen. The grid is configurable to allow you to divide the screen up in a way that works for you. Basic layouts are flexible in multiple screen situations and provide the simplest way to specify where a window should be on the screen.
Basic Layouts also provide a gutter option, which allows windows to be positioned with some empty space around them which many people find to be more visually pleasing than having windows that touch. A more detailed article describing gutters can be found in the FAQ.
An advanced layout gives greater flexibility using a constraint style system which allows you to specify sizes and positions relative to screen edges in either pixels or as a percentage of the screen size. A powerful set of features let you specify positions relative to any edge of the screen, or to have the layout centred on the screen. Each constraint can be independently set to % of screen or pixels for ultimate flexibility.
Advanced layouts are particularly useful for uses such as screen casting, where you wish to record a particular section of the screen and require your window to fit exactly. For example, you may wish to create a window exactly 640x480 pixels and position it at the screen origin. You can do this with ease using advanced layouts.