Article # 268, added by Geoworks, historical record
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What is the difference between focus and target.
Q. I noticed that most controllers have GCI_output = TO_APP_TARGET. What is the difference between focus and target? A. You can set GCI_output to anything you want, but you are right that generally controllers work with the target mechanism. Focus is where input (such as keyboard and mouse) are directed. Focus is set by such actions as placing the mouse pointer over an object and clicking on it or by using the tab key to move the focus from one object to the next. Target in many cases will follow the focus, but only if the object that is gaining the focus has GA_TARGETABLE set. Text objects are good candidates for GA_TARGETABLE; triggers and lists are not (unless you want a controller or something to be able to send a message to the trigger/list). There is a third input flow channel called model, which essentially provides a secondary target hierarchy and is used with documents. These three targeting mechanisms are discussed in the Input chapter of the Concepts book (Concepts\CInput).