View source for Libactivator

{{Infobox Package
|developer=[[User:Rpetrich|Ryan Petrich]]
|version=1.9.0
|package=libactivator
}}

'''libactivator''' is a library that provides a centralized system of activation methods for all of our jailbroken extensions. To accomplish this, the hooks of the activation methods are in one centralized Substrate plugin, which uses small bundles and preference panes to select the activation method for each plugin.

'''libactivator''' works by connecting an event (represented by an <code>LAEvent</code>) to one or multiple actions (represented by <code>LAListener</code>). Developers can create new events or actions to extend the functionality of a device.

== How to use this library ==
Headers are available from [https://github.com/rpetrich/libactivator Activator's GitHub project], and the library can be found at <code>/usr/lib/libactivator.dylib</code> on a device where Activator is installed. If using Theos, place the headers in <code>$THEOS/include/libactivator</code>, the library in <code>$THEOS/lib/</code> and add <code>activator</code> to the <code>XXX_LIBRARIES</code> Makefile variable. See [[#Packaging]] for more usage advice.

= Observing Events (via LAListener) =

There are three steps to follow: describing the action, implementing the code, and allowing users to change activation methods. Optionally, you can also add a method to register your plugin for a certain event on installation, which allows you to implement libactivator without confusing prior users.

== Describing an Action ==

Provide information about your listener to libactivator by specifying the group it belongs to, its name and a short description, along with metadata and an icon.

=== Text ===

Provide all the textual information about your listener. You can do so by using a plist or a tweak-like package.

==== Method One: No Code ====

Create a file in the directory <code>/Library/Activator/Listeners/com.your.packageid/</code> named <code>Info.plist</code> with the following contents:
<source lang="javascript">
{
    group = "My Listener Group";
    title = "My Listener";
    description = "Human Readable Description";
    "compatible-modes" = ("springboard", "lockscreen", "application");
}
</source>

''To do: add a nice table specifying all the valid keys.''

==== Method Two: Some Code ====

The <code>LAListener</code> protocol contains a number of optional methods that are queried by Activator. These can be used if the exact title and description of listeners aren't known until runtime.

<source lang="objc">
- (NSString *)activator:(LAActivator *)activator requiresLocalizedGroupForListenerName:(NSString *)listenerName {
	return @"My Listener Group";
}
- (NSString *)activator:(LAActivator *)activator requiresLocalizedTitleForListenerName:(NSString *)listenerName {
	return @"My Listener";
}
- (NSString *)activator:(LAActivator *)activator requiresLocalizedDescriptionForListenerName:(NSString *)listenerName {
	return @"Human Readable Description";
}
- (NSArray *)activator:(LAActivator *)activator requiresCompatibleEventModesForListenerWithName:(NSString *)listenerName {
	return [NSArray arrayWithObjects:@"springboard", @"lockscreen", @"application", nil];
}
</source>

''To do: add more API methods, and a short commented description about them.''

=== Icon ===

Provide a visual description of your listener. There are two available options to do so: PNG or PDF.

==== Method One: No Code ====

Place your icons in <code>/Library/Activator/Listeners/com.your.packageid/</code>

For the PNG, make a 29x29 pixels image named <code>icon-small.png</code>. Optionally an @2x version, <code>icon-small@2x.png</code>.

For the PDF, make a vector image named <code>glyph.pdf</code>.

==== Method Two: Some Code ====

The <code>LAListener</code> protocol contains a number of optional methods that are queried by Activator. These can be used if the icon images of listeners aren't known until runtime.

<source lang="objc">
//  Fast path that supports scale
- (NSData *)activator:(LAActivator *)activator requiresIconDataForListenerName:(NSString *)listenerName scale:(CGFloat *)scale;
- (NSData *)activator:(LAActivator *)activator requiresSmallIconDataForListenerName:(NSString *)listenerName scale:(CGFloat *)scale;
//  Legacy
- (NSData *)activator:(LAActivator *)activator requiresIconDataForListenerName:(NSString *)listenerName;
- (NSData *)activator:(LAActivator *)activator requiresSmallIconDataForListenerName:(NSString *)listenerName;
//  For cases where PNG data isn't available quickly
- (UIImage *)activator:(LAActivator *)activator requiresIconForListenerName:(NSString *)listenerName scale:(CGFloat)scale;
- (UIImage *)activator:(LAActivator *)activator requiresSmallIconForListenerName:(NSString *)listenerName scale:(CGFloat)scale;

- (id)activator:(LAActivator *)activator requiresGlyphImageDescriptorForListenerName:(NSString *)listenerName;
</source>

''To do: explain image-provider API.''

== Implementing the Code ==

Implementing the code can be done in two different methods, depending on your plugin. If you have an object that is always in memory, you can use method one, otherwise, use method two.

=== Method One: Add the Code ===

First, <code>#import <libactivator/libactivator.h></code> and have your class implement the LAListener protocol.

To register for events, you must add a piece of code to your init method, replacing the parts as needed:
<source lang="objc">
[LASharedActivator registerListener:YOUR_SHARED_OBJECT forName:@"com.your.packageid"];
</source>

Then, you must also implement two simple delegate methods:

<source lang="objc">
- (void)activator:(LAActivator *)activator receiveEvent:(LAEvent *)event;
- (void)activator:(LAActivator *)activator abortEvent:(LAEvent *)event;
</source>

In the first method, you should first check if your plugin is already active. If it is active, you should deactivate your plugin and return. Otherwise, just activate your plugin. In addition, in the activator:recieveEvent: method, you must call [event setHandled:YES] if you wish to disable the default OS action for that activation event. If you do not set handled then receive event may be called twice for the same event. In the second method you should simply deactivate your plugin. 

The implementation of these methods is left completely up to the programmer. The LAEvent objects can be used to discover more information about the event, such as the type, if you wish to perform a different action based on the type of event. Use the event's <code>userInfo</code> dictionary to get extra information. Do not use that information to disable certain types of events for your plugin!

=== Method Two: New Object ===

The second method of implementing '''libactivator''' is to insert a new class in your code, one instance of which is always initialized, and informs your main classes when an activation event has occurred (so your main plugin can activate). A sample class is provided below with placeholder comments where additional code would be needed:

<source lang="objc">
#import <libactivator/libactivator.h>
#import <UIKit/UIKit.h>

@interface LAExample : NSObject <LAListener>
@end

@implementation LAExample

- (void)activator:(LAActivator *)activator receiveEvent:(LAEvent *)event {
	if (/* your plugin is activated */) {
		// Dismiss your plugin
		return;
	}
	
	// Activate your plugin

	[event setHandled:YES]; // To prevent the default OS implementation
}

- (void)activator:(LAActivator *)activator abortEvent:(LAEvent *)event {
	// Dismiss your plugin
}

+ (void)load {
	if ([LASharedActivator isRunningInsideSpringBoard]) {
		[LASharedActivator registerListener:[self new] forName:@"com.your.packageid"];
	}
}

@end
</source>

=== Default Activation Methods ===

To implement default activation methods, call <code>assignEvent:toListenerWithName:</code> before registering your listener:

<source lang="objc">
if (![LASharedActivator hasSeenListenerWithName:@"com.your.packageid"]) {
	[LASharedActivator assignEvent:[LAEvent eventWithName:@"libactivator.motion.shake"] toListenerWithName:@"com.your.packageid"];
}
</source>

== Allowing Activator Assignment from a Settings Pane ==

{{main|PreferenceLoader}}

''Modern versions of Activator (1.1 and later) support assigning actions from the settings pane provided via Activator. This section provided for packages that wish to provide integration with their existing settings panes or apps.''

=== Simple Method ===

The simplest method to allow users to change activation methods is if you use [[PreferenceLoader]] and a simple plist format. Then, you can just paste in this code to create a cell that when tapped will allow users to select an activation method (again replacing the package id with the correct one):
<source lang="xml">
<dict>
	<key>cell</key>
	<string>PSLinkCell</string>
	<key>label</key>
	<string>Activation Methods</string>
	<key>isController</key>
	<true/>
	<key>bundle</key>
	<string>LibActivator</string>
	<key>activatorListener</key>
	<string>com.your.packageid</string>
</dict>
</source>

If you are assigning a [[flipswitch]], it will be: <code>switch-flip.com.your.packageid</code>

=== Advanced Method ===

A more complex method is to integrate the settings pane directly into your application's navigation controller:

<source lang="objc">
LAListenerSettingsViewController *vc = [[LAListenerSettingsViewController new] autorelease];
vc.listenerName = @"com.your.packageid";
[myNavigationController pushViewController:vc animated:YES];
</source>

= Sending Events (via LAEvent) =
There are 2 steps to follow: dispatching event and providing metadata.


== Dispatching Events ==
Custom events can be sent to assigned listeners by constructing an <code>LAEvent</code> object and passing it to the <code>sendEventToListener:</code> method. Activator will take care of looking up which listeners are assigned and delivering the event to them.

Example event dispatch using the <code>_awayControllerUnlocked:</code> method of <code>SBIconController</code>
<source lang="objc">
%hook SBIconController

- (void)_awayControllerUnlocked:(id)unlocked {
        LAEvent *event = [LAEvent eventWithName:@"com.your.packageid.springboard.unlocked" mode:[LASharedActivator currentEventMode]];
        [LASharedActivator sendEventToListener:event];
        if (event.handled) {
                NSLog(@"Event was handled by an assignment in Activator!");
        }
        %orig();
}

%end
</source>

If the device is locked and one of the assigned listeners does not support receiving events at the lock screen, Activator will attempt to unlock the device. If a passcode is set, the user will be prompted to enter it.

== Providing Event Metadata ==
Activator requires metadata on which events are possible to allow assignment through the settings pane.

The simplest way to provide event metadata is to create a subfolder in <code>/Library/Activator/Events</code> with the name of your event, and describe it using an <code>Info.plist</code>:

<code>/Library/Activator/Events/com.your.packageid.springboard.unlocked/Info.plist</code>:
<source lang="javascript">
{
	title = "Unlock Succeeded";
	group = "Unlocking";
	description = "Device unlock succeeded";
}
</source>

Alternatively, event metadata can be setup by passing an object conforming to <code>LAEventDataSource</code> to <code>LAActivator</code>'s <code>registerEventDataSource:forEventName:</code> method. This allows for adding and removing events based on runtime conditions.

Equivalent example, performed in code:
<source lang="objc">
@interface SomeDataSource: NSObject <LAEventDataSource>
@end

@implementation SomeDataSource

static SomeDataSource *myDataSource;

+ (void)load
{
        @autoreleasepool {
                myDataSource = [[SomeDataSource alloc] init];
        }
}

- (id)init {
        if ((self = [super init])) {
                [LASharedActivator registerEventDataSource:self forEventName:@"com.your.packageid.springboard.unlocked"];
        }
        return self;
}

- (void)dealloc {
        [LASharedActivator unregisterEventDataSourceWithEventName:@"com.your.packageid.springboard.unlocked"];
        [super dealloc];
}

- (NSString *)localizedTitleForEventName:(NSString *)eventName {
        return @"Unlock Succeeded";
}

- (NSString *)localizedGroupForEventName:(NSString *)eventName {
        return @"Unlocking";
}

- (NSString *)localizedDescriptionForEventName:(NSString *)eventName {
        return @"Device unlock succeeded";
}

@end
</source>

Registering <code>LAEventDataSource</code>s must be performed from within SpringBoard.

= Packaging =

Packages that provide Activator actions or events (especially if this is their primary purpose) should set up a dependency on the earliest version of Activator they support, as part of their package's control file:

<source lang="javascript">
Depends: libactivator (>= 1.8.3), mobilesubstrate
</source>

Packages that work without Activator installed but still provide some level of Activator integration should conflict with older versions of Activator that they are untested with:

<source lang="javascript">
Depends: mobilesubstrate
Conflicts: libactivator (<< 1.8.3)
</source>

== Runtime access to Activator ==

If you do not want to depend on libactivator being installed, you can use the following snippet as a starting line, to access Activator APIs:

<source lang="c">
...
dlopen("/usr/lib/libactivator.dylib", RTLD_LAZY);
Class la = objc_getClass("LAActivator");
if (la) { //libactivator is installed
	...
} else {  //libactivator is not installed
	...
}
...
</source>

= References =

=== Examples of LAListeners ===

{| class="wikitable"
|-
! Project
! Author
|-
| [https://github.com/hbang/BrightVol BrightVol]
| [https://github.com/hbang HASHBANG]
|-
| [https://github.com/nickfrey/NowNow NowNow]
| [https://github.com/nickfrey Nick Frey]
|-
| [https://github.com/twodayslate/slideback slideback]
| [https://github.com/twodayslate twodayslate]
|-
| [https://github.com/c-ryan747/SpeakTime SpeakTime]
| [https://github.com/c-ryan747 Callum Ryan]
|-
| [https://github.com/Sassoty/theos-examples/tree/master/activatorlistener ActivatorPopup]
| [https://github.com/Sassoty Sassoty]
|}

=== Examples of LAEvents ===

{| class="wikitable"
|-
! Project
! Author
|-
| [https://github.com/uroboro/UnlockEvents UnlockEvents]
| [https://github.com/uroboro uroboro]
|-
| [https://github.com/r-plus/GeoEvent-for-Activator GeoEvent for Activator]
| [https://github.com/r-plus/ r_plus]
|-
| [https://github.com/MiloSovoy/Dropped Dropped]
| [https://github.com/MiloSovoy/ James-Isaac-Neutron]
|}

== External links ==
* [http://github.com/rpetrich/libactivator/tree/master/ libactivator GitHub]
* [http://github.com/rpetrich/libactivator/blob/master/libactivator.h libactivator.h]

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