Tracks the mouse to add
a based on the initial mouse-down or mouse-dragged event
- macOS 10.0+
true if the receiver adds
false if it doesn’t. This method works by sending
true as arguments.
An application typically invokes this method in one of two cases. In the simpler case, the client view can implement
NSRuler to invoke this method when the user presses the mouse button while the cursor is in the NSRulerView’s ruler area. This technique is appropriate when it’s clear what kind of marker will be added by clicking the ruler area. The second, more general, case involves the application providing a palette of different kinds of markers that can be dragged onto the ruler, from the ruler’s accessory view or from some other place. With this technique the palette tracks the cursor until it enters the ruler view, at which time it hands over control to the ruler view by invoking