Inherits NSObject.
Instance Methods | |
| (void) | - registerNeedByObject: |
| (void) | - unregisterNeedByObject: |
| (void) | - requestPickerForObject:withScanSettings:successBlock: |
| (void) | - releasePickerForObject: |
| (void) | - freezePickerForObject: |
| (void) | - unfreezePickerForObject: |
Class Methods | |
| (nonnull instancetype) | + manager |
Properties | |
| NSTimeInterval | timeToDeallocAfterNoNeed |
| NSTimeInterval | timeToDeallocAfterAction |
Detailed Description
Manages a barcode picker instance, allocating and releasing it dependent on need.
Alternatively to directly allocating a SBSBarcodePicker you can use an SBSBarcodePickerManager to get a SBSBarcodePicker instance. By using the manager it is possible to allocate a picker when the app knows that it will likely need to scan a barcode soon such that when the app actually displays the picker the camera is already running and there is no delay for the user.
There are three important concepts for understanding the functionality of the manager:
- Registering/unregistering need: An object can register need for the picker which will cause the manager to keep a running instance of the picker available for future use (by any object not just the registered one).
- Requesting/releasing picker: An object can request the picker to use it. The object does not have to register need before requesting the picker directly. As only one object can ever use the picker at the same time this call is asynchronous.
- Freeze/unfreeze picker:
Important: Be aware that the manager caches the running camera to be able to eliminate the delay that would be needed to start the camera this will lead to increased battery usage.
Method Documentation
| + (nonnull instancetype) manager |
| - (void) registerNeedByObject: | (nonnull id) | anObject |
Registers need for the specified object in case the picker will be used in the near future.
To unregister call unregisterNeedByObject: with the same object that this function was called with. Unless unregisterNeedByObject: is called with every object that registerNeedByObject: was called with, the picker will stay cached (unless no functions are called on the manager and timeToDeallocAfterAction time passes).
- Parameters
-
anObject The object for which need is registered.
| - (void) unregisterNeedByObject: | (nonnull id) | anObject |
Unregisters need for the specified object when the picker will likely not be used in the near future.
Unless unregisterNeedByObject: is called with every object that registerNeedByObject: was called with, the picker will stay cached (unless no functions are called on the manager and timeToDeallocAfterAction time passes). Calling this multiple times with the same object or with an object for which registerNeedByObject: was never called has no effect.
- Parameters
-
anObject The object for which need is unregistered.
| - (void) requestPickerForObject: | (nonnull id) | anObject | |
| withScanSettings: | (nonnull SBSScanSettings *) | settings | |
| successBlock: | (nullable void(^)(SBSBarcodePicker *_Nonnull picker)) | requestBlock | |
Requests the picker for the specified object to display it and start scanning.
As the picker might still be used by a different object it is returned asynchronously through a block when it is no longer in use (possibly instantly).
To release call releasePickerForObject: with the same object that this function was called with. Unless releasePickerForObject: is called for the same object the picker will stay locked and future calls to this function will never invoke the requestBlock.
- Parameters
-
anObject The object for which the picker is requested. settings The settings to be applied to the picker. requestBlock The block that is called when the picker is available.
| - (void) releasePickerForObject: | (nonnull id) | anObject |
Releases the picker for the specified object when it no longer needs to be displayed.
Unless releasePickerForObject: is called for the same object the picker will stay locked and future calls to this function will never invoke the requestBlock. Calling this multiple times with the same object or with an object for which requestPickerForObject:withScanSettings:successBlock: was never called has no effect.
Make sure that before you release the picker it is entirely removed from the view and view controller hierarchy.
- Parameters
-
anObject The object for which the picker is released.
| - (void) freezePickerForObject: | (nonnull id) | anObject |
Freezes the picker's camera to allow other camera objects to be opened.
Use this to allow another camera instance to be opened like a UIImagePickerController.
To unfreeze call unfreezePickerForObject: with the same object that this function was called with. Unless unfreezePickerForObject: is called with every object that freezePickerForObject: was called with, the picker will stay frozen.
- Parameters
-
anObject The object for which the picker is frozen.
| - (void) unfreezePickerForObject: | (nonnull id) | anObject |
Unfreezes the picker's camera after other camera objects have been closed.
Unless unfreezePickerForObject: is called with every object that freezePickerForObject: was called with, the picker will stay frozen. Calling this multiple times with the same object or with an object for which freezePickerForObject: was never called has no effect.
- Parameters
-
anObject The object for which the picker is unfrozen.
Property Documentation
|
readwritenonatomicassign |
The time in seconds until the picker is deallocated after the last object that has registered need unregistered and there are no more objects with registered need for the picker. If no need is registered but the picker was requested and is currently in use it will never be deallocated.
It is generally not a good idea to set this to 0 seconds as there may be times (for example when animating between view controllers) where there is no need for a split second.
By default this is set to 3.
|
readwritenonatomicassign |
The time in seconds until the picker is deallocated after the last function call on the manager. This comes mostly into play if the app registers need for the picker but then does not actually use the picker for a prolonged time. In this case it is economical to deallocate the picker as we expect it to not be requested in the near future.
If the picker was requested and is in use it will never be deallocated no matter how much time has passed.
By default this is set to 30. Setting it to 0 causes the manager to never deallocate the picker while an object has registered need.
The documentation for this class was generated from the following file: