C H A P T E R 1 5

Controls

Column View Implementation

Column views are available in Interface Builder. To create one using Application Kit programming interfaces, use the NSBrowser class or an NSOutlineView object in column format.

Split Views

A split view groups together two or more other views, such as column or list views, and allows the user to adjust the relative width or height of those views. A split view includes a splitter bar, or splitter, between each of its subviews; for example, a split view with five subviews would have four splitters.

Note: In Mac OS X v10.5 and later, the standard splitter bar is known as a “zero-width” splitter. This splitter is actually 1 pixel wide and, as with wider splitter bars, the pointer changes to one of the move or resize cursors when hovering over it, depending on which direction the splitter can move (see “Standard Cursors” (page 157) for more information on different cursor styles).

A wider splitter bar (9 pixels in width) is also available, but not as frequently used.

Figure 15-82 shows the splitter between the source list and the content view in iCal and the way the pointer looks when hovering over it. (For more information on source lists, see “Source Lists” (page 203).)

Figure 15-82 The pointer changes when it hovers over a splitter

Split View Usage

Use a split view when you want to display two or more different content views that the user can resize. A single split view does not display a combination of vertically and horizontally oriented subviews. However, a single window might contain different split views that each display a different orientation. For an example of how this might look, see the Automator window shown in Figure 15-83.

2008-06-09 | © 1992, 2001-2003, 2008 Apple Inc. All Rights Reserved.

C H A P T E R 1 5

Controls

Figure 15-83 A window can have multiple split views

Users can adjust the relative widths or heights of the subviews in a split view by dragging anywhere on the splitter. The wide splitter bar displays a circular dimple at its midpoint that indicates to the user that it is draggable. For both zero-width and wide splitters, the entire splitter bar is a hot zone. In other words, when the pointer passes over any part of the splitter, the cursor changes to one of the move or resize cursors. For zero-width splitters, the hot zone includes two pixels on both sides of the splitter.

If a user drags a wide splitter bar all the way to the edge of the split view (or to the next splitter bar), the subview should disappear but the splitter bar should not. The splitter bar should remain in view to remind the user where the hidden subview is and to make it easier for the user to uncover it. However, a zero-width splitter bar does not remain visible when the user drags it far enough to hide the subview. For this reason, you can define minimum and maximum sizes for subviews so users can’t lose the splitter. Alternatively, if you want to allow users to completely hide a subview by dragging a zero-width splitter, you should provide a button that re-opens the subview.

Split View Specifications

Control sizes: Split views are available with a horizontal splitter (the views are stacked one above another) or a vertical splitter (the views are side by side), and splitters can be either zero-width (1 pixel wide) or “thick” (9 pixels wide).

2008-06-09 | © 1992, 2001-2003, 2008 Apple Inc. All Rights Reserved.