Objective-C Fundamentals

Important protocols
155
Any table view (grouped or standard) may have a
header view. This view can be anything: a single
UIView, UIImageView, or UILabel, for instance, or
a more complex custom UIView subclass. Using the
header view delegate method saves a number of
lines of code required to customize the headers,
and generally is a better practice than attempting
to implement a header yourself. If you have a reason
to add some type of custom view before your
table data is shown, these are the methods you
should implement:
- (CGFloat)tableView:(UITableView *)tableView
heightForFooterInSection:
(NSInteger)section
- (UIView *)tableView:(UITableView
*)tableView
viewForFooterInSection:(NSInteger)section
This set of methods is identical to the header view
methods and likewise must be implemented
together. Once again, this is the best practice
when you need to add some custom content after
your table view section data is presented.
Figure 7.1 Setting an indentation level
for a table view
ACTION METHODS
Most methods that a class conforming to the
can implement are methods
that respond to events that occur in the table view. These methods will inform you
of things like cells being added, cells being removed, cells being modified, cells being
selected, and a few more types of events that can occur:
- (void)tableView:(UITableView *)tableView
accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath
Apple provides some standard-style accessory views for UITableViewCells. Accessory
views are placed on the right-hand side of a UITableViewCell. They’re distinct parts
of a cell that can be hidden or modified when a table view is being edited. UITable-
ViewCellAccessoryTypes come in four default flavors:
■
■
UITableViewCellAccessoryNone
This method leaves the accessory view of the UITableViewCell blank. This is
the default set for UITableViewCells.
UITableViewCellAccessoryDisclosureIndicator
This method leaves the accessory view of the UITableViewCell as a bold
greater-than sign.