Creating an NSTextView Object Programmatically
At times, you may need to assemble the text system programmatically. You can do this in either of two ways: by creating an
NSTextView object and letting it create its network of supporting objects or by building the network of objects yourself. In most cases, you’ll find it sufficient to create an
NSTextView object and let it create the underlying network of text-handling objects, as discussed in this article. If your application has complex text-layout requirements, you’ll have to create the network yourself; see “Creating Text System Objects” in Cocoa Text Architecture Guide for information.
You create an
NSTextView object programmatically in the usual way: by sending the
init... messages. You can also create an
NSTextView object using either of these methods:
The method that takes one argument,
initWithFrame:, is the simplest way to obtain an
NSTextView object—it creates all the other components of the text system for you. If you use the method that takes two arguments,
initWithFrame:textContainer:, you must create the other components yourself.
Listing 1 shows how you can create an
NSTextView object, given an
NSWindow object represented here by
Listing 1 Creating an NSTextView object programmatically
/* determine the size for the NSTextView */
NSRect cFrame =[[aWindow contentView] frame];
/* create the NSTextView and add it to the window */
NSTextView *theTextView = [[NSTextView alloc] initWithFrame:cFrame];
This code determines the size for the text view’s frame rectangle by asking
aWindow for the size of its content view. The
NSTextView is then created and made the content view of
setContentView:. Finally, the
makeFirstResponder: messages display the window and cause the text view to prepare to accept keyboard input.
initWithFrame: method not only initializes the receiving
NSTextView object, it causes the object to create and interconnect the other components of the text system. This is a convenience that frees you from having to create and interconnect them yourself.
© 1997, 2012 Apple Inc. All Rights Reserved. (Last updated: 2012-09-19)