Tables support in iPhone is thought out well but it seems that due to the complexity of the issue they have dropped out support for alternating rows. I suppose that this is a popular feature so I've written a subclass of UITableViewController that could be used as a drop-in replacement that changes background color of the odd rows.
AltTableViewController.h
#import <UIKit/UIKit.h>
@interface AltTableViewController : UITableViewController {
UIColor *primRowColor, *altRowColor;
}
@property(retain) UIColor *primRowColor, *altRowColor;
- (BOOL)isAltRow:(NSIndexPath *)indexPath;
- (void)updateRowsLook;
@end
AltTableViewController.m
#import "AltTableViewController.h"
@implementation AltTableViewController
@synthesize primRowColor, altRowColor;
+ (UIColor *)defaultAltRowColor {
static UIColor *color;
if (!color) {
color = [UIColor colorWithRed:0 green:0 blue:1 alpha:0.05];
}
return color;
}
- (UIColor *)altRowColor {
return altRowColor ? altRowColor :
[AltTableViewController defaultAltRowColor];
}
- (UIColor *)primRowColor {
return primRowColor ? primRowColor : [UIColor whiteColor];
}
- (void)dealloc {
[altRowColor release];
[primRowColor release];
[super dealloc];
}
- (BOOL)isAltRow:(NSIndexPath *)indexPath {
return indexPath.row == 0 || indexPath.row % 2 == 0;
}
- (void)updateRowsLookLater {
NSArray *indexPaths = [self.tableView indexPathsForVisibleRows];
if (indexPaths) {
for (NSIndexPath *indexPath in indexPaths) {
if ([self isAltRow:indexPath]) {
[self.tableView cellForRowAtIndexPath:indexPath].backgroundColor =
self.altRowColor;
} else {
[self.tableView cellForRowAtIndexPath:indexPath].backgroundColor =
self.primRowColor;
}
}
}
}
- (void)updateRowsLook {
[self performSelector:@selector(updateRowsLookLater)
withObject:nil afterDelay:0.01];
}
- (void)tableView:(UITableView *)tableView
willDisplayCell:(UITableViewCell *)cell
forRowAtIndexPath:(NSIndexPath *)indexPath {
if ([self isAltRow:indexPath]) {
cell.backgroundColor = self.altRowColor;
} else {
cell.backgroundColor = self.primRowColor;
}
}
- (void)tableView:(UITableView *)tableView
commitEditingStyle:(UITableViewCellEditingStyle)editingStyle
forRowAtIndexPath:(NSIndexPath *)indexPath {
[self updateRowsLook];
}
- (void)tableView:(UITableView *)tableView
moveRowAtIndexPath:(NSIndexPath *)fromIndexPath
toIndexPath:(NSIndexPath *)toIndexPath {
[self updateRowsLook];
}
@end
Note that your cells should not contain labels with opaque backgrounds. Background color of the cell should be visible through labels.
I have also implemented methods that are called in response to editing actions since now deletion, insertion and rearrangement of a row impacts other rows. If your table will be editable you should call these methods to update backgrounds of all cells.
