Using the inspectors
Use the Inspectors menu to show or hide the inspectors of your choice.
If you drag an inspector window near another or near the edge of the screen, it snaps to the edges for easy and neat positioning. You can collapse or expand an inspector window by clicking its title bar once or by typing the key combination for one of its sections.
Each of the three inspector windows contains several different inspectors you can view; just click one of the icons across the top of the window to switch to that inspector, then click the icon again to hide the inspector. If you want to view more than one inspector in the same window, just hold Command while you click their icons, or drag across several icons.
Dragging the top inspector window in a stack of attached ones moves them all, and clicking its close button closes all attached inspector windows as well.
In all of the inspectors, you can click in a text field that contains a number, then press the up or down arrow keys to increment or decrement the number. Also, once you click a circular rotation control, you can keep the mouse button held down while moving the pointer away from the control to gain more rotational precision.
Any color well can have its color dragged to an object on the canvas or to another color well. When you drag to an object, you can drop the color on the object's stroke, fill, or text.
In places where you can enter measurements, such as in the Properties: Geometry inspector, values are shown in the current ruler units, or, if there is no ruler scale, in the canvas units. You can, however, enter values in any units that are available in the ruler. As soon as you finish entering the value, OmniGraffle automatically converts it to the correct units.
You can also perform simple arithmetic and mix units. Add (+), subtract (-), multiply (*), or divide (/) numbers right in the input fields.