Most of the time, the delegate implementation is at the current source file where the delegate and its owning object is created.
But sometimes its not.
For example, say we have a UIView called caliGuestView. We want to set up a popover control in that class.
There is a custom made popover control like so:
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@interface Popover : UIView |
Due to subclassed UIView, we know to drag a UIView component into the xib, then put Popover in its custom class tab. Thus we now have the custom made control in our xib. Once that’s done, we ctrl drag it into our source file and its ready to go.
CaliGuestView.swift
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@IBOutlet weak var aDropDown: Popover! |
CaliGuestView.swift
Initially we think, ok, we get the delegate to point here in the CaliGuestView class. Then we implement the delegate methods in this class.
BUT! what if we have delegate functionality implemented elsewhere (like MyCustomCell.m). How do we get the delegate to point where the implementation is?
1) DO NOT ASSIGN the delegate here (in CailGuestView). Simply initialize it as is.
CaliGuestView.swift
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aDropDown.isUserInteractionEnabled = true let itemsArray = // some array of strings aDropDown.items = itemsArray aDropDown.picker.reloadAllComponents() |
2) make sure MyCustomCell’s delegate implementation is set
MyCustomCell.m
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@interface MyCustomCell : UITableViewCell <DropDownDelegate> ... ... - (void)shouldDisplayPopover:(PopoverDropDown *)popover selectedItemDidChange:(id)item toIndex:(NSUInteger)index { } - (void)shouldHidePopover:(PopoverDropDown *)popover { } - (void)popoverDropView:(PopoverDropDown *)view selectedItemDidChange:(id)item toIndex:(NSUInteger)index{ } |
3) let MyCustomCell’s instance of this class point to self
MyCustomCell owns the CaliGuestView, and thus can simply access its delegate. Then point that delegate to self.
MyCustomCell.m
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if ([item isEqualToString:@"haha"]) { caliGuestView.stateDropDown.delegate = self; } |