Dev:SBIconListView

SBIconListView is a UIView subclass that contains list of icons (SBIconView objects). Each page on the home screen is a different instance of SBIconListView.

It is available in iOS 4-6, replacing SBIconList; this article is based on iOS 6. If you're developing a tweak that modifies icon layouts, make sure to use IconSupport.

Notable subclasses

 * SBDockIconListView is used for the dock.
 * SBFolderIconListView is used for folders

Description
SBIconListView is backed by a SBIconModel for the icons, and a SBIconViewMap, which handles the recycling of icon views, accessory updates, and some basic folder handling (nodes).

SBIconListView handles the rotation of lists, animations for app launching, transforms, icon additions, layouts, etc.

All the views of this class on the home screen are managed by the SBIconController singleton. Since it is just a subclass of UIView, it fits into the "View" of the "Model-View-Controller" paradigm. Thus, any changes made to the visible icons by this class are not saved. For modifying or adding icons, look at SBIconModel.

Edit mode and icon moving
Icon moving in edit/wiggle mode is not, contrary to expectations, related at all to where icons are located onscreen. If you have a 4x4 home screen but you play with the values returned by originForIconAtX:Y: (iOS 6) or originForIconAtCoordinate: (iOS 7) for each of these icons, you will notice that moving icons (by altering their origin, for instance) around will be exactly the same as it was before you changed their origins. Two methods, columnAtPoint: and rowAtPoint: estimate which column and row you are in according to the point passed in. Anyone wanting to make icon moving more natural for a modified layout would have to hook these methods accordingly.

Icon coordinates
All the icons in this view are backed by an index -- a NSUInteger. The indexes start from 0 for the icon at the top-left, to +[SBIconListView maxIcons] - 1. You can find icons' locations in the view by using -[SBIconListView originForIcon:], -originForIconAtIndex, or -originForIconAtX:Y:.
 * In iOS 7, these methods no longer accept separate arguments for the X and Y coordinate of an icon. Instead, it has been replaced by SBIconCoordinate:

There is also -iconAtPoint:, which gives the icon for a CGPoint that is inside the list view's bounds.
 * Methods that return the origin for an icon are not constrained to the list view's bounds, and are calculated via simple math.
 * An important difference between iOS 6 and 7 to watch out for is that while SBIconCoordinate begins from {row: 1, col:1}, the list view in iOS 6 beginning its icons' coordinates from {Y: 0, X: 0}. "However, rowAtPoint:, columnAtPoint:, rowForIcon:, columnForIcon: are still 0-indexed on iOS 7, which may cause some confusion."

Modifying icon locations
Hooking into the methods mentioned above is the best way to modify the position of an icon on the home screen, rather than explicitly modifying its frame with a bunch of hacks to detect changes.

Reference

 * Headers:

https://github.com/caughtinflux/iOS-6-SpringBoard-Headers/blob/master/SBIconListView.h (iOS 6) https://github.com/caughtinflux/include/blob/master/SpringBoard/SBIconListView.h (iOS 7)