Magnify and Overview in GTViewer

GTViewer provides two very useful tools for gaining perspective on your data without constantly zooming in or out. The Magnify and Overview tools are really opposites in what they do, but they can make it very easy to look at your data up close and far away all at the same time without ever modifying your current view.


The Magnify Tool is used to see details around the mouse cursor without having to zoom in or change the view. When the Magnify Tool is activated, a new window is created and the mouse is shown with a box around it. The area in the box is displayed in the Magnify window as a closer zoom level.

The Magnify Window is updated every time the mouse is moved and probably provides a few features that are not commonly known by its users.

• Double-clicking the mouse will match the zoom level of the current view to the Magnify Window. So, if you see something you like in the Magnify window, double-click the mouse and the current view will be set to match.
• If your mouse has a wheel, rolling the wheel up or down will increase or decrease the size of the box around the cursor. This action is a very handy way for getting even more detail once you have found an area of interest. If your mouse does not have a wheel, the Page Up and Page Down keys will perform the same tasks.
• The Magnify Window is movable and resizable. It will also remember the last size and position from one use to the next.

The Overview Tool is somewhat different from the Magnify tools. Instead of providing you with a detailed view of something around the mouse cursor, the Overview Tool creates a new window to show you an overall view of your data with an indicator for the current view location.

The Overview Window is updated every time the view changes and it too probably provides a few features that are not commonly know by its users.

• Clicking the mouse in the Overview Window will set the current view to that location. You can basically drag the view indicator around the Overview Window to get to the location you want.
• The Overview Window is movable and resizable. It will also remember the last size and position from one use to the next.
• The Overview Window’s contents are determined by the Overview Category. All GTViewer datasets must have an Overview category defined and its contents will be used for the Overview Window.
• A special Style Rule called “Overview” can be defined to override the display of all elements in the Overview Window. Sometimes it is useful to remove the weights, linestyles, and color in the Overview window, but leave the element alone when viewing them in a regular view.
  

If you have not used the Magnify or Overview tools before, give them a try. If you have used them before, see if any of the features listed here are new to you.