Struct GKBehavior

Source

pub struct GKBehavior { /* private fields */ }

Available on crate feature GKBehavior only.

Expand description

A collection of GKGoals or GKBehaviors with weights that can be applied to a GKAgent The sub-goals or sub-behaviors are summed to produce a total force to be applied to an agent

Implementations§

Source §

impl GKBehavior

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pub unsafe fn goalCount(&self) -> NSInteger

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pub unsafe fn behaviorWithGoal_weight( goal: &GKGoal, weight: c_float, ) -> Retained<Self>

Available on crate feature GKGoal only.

Creates a behavior with a single goal and weight

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pub unsafe fn behaviorWithGoals(goals: &NSArray<GKGoal>) -> Retained<Self>

Available on crate feature GKGoal only.

Creates a behavior with an array of goals. All weights are set to 1.0f

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pub unsafe fn behaviorWithGoals_andWeights( goals: &NSArray<GKGoal>, weights: &NSArray<NSNumber>, ) -> Retained<Self>

Available on crate feature GKGoal only.

Creates a behavior with two associated arrays of goals and weights

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pub unsafe fn behaviorWithWeightedGoals( weighted_goals: &NSDictionary<GKGoal, NSNumber>, ) -> Retained<Self>

Available on crate feature GKGoal only.

Creates a behavior with a dictionary of goal/weight pairs

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pub unsafe fn setWeight_forGoal(&self, weight: c_float, goal: &GKGoal)

Available on crate feature GKGoal only.

Adds a new goal or changes the weight of the existing goal in this behavior. If the goal does not exist in this behavior, it is added.

Parameter weight: the weight for this goal

Parameter goal: the goal who’s weight to change

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pub unsafe fn weightForGoal(&self, goal: &GKGoal) -> c_float

Available on crate feature GKGoal only.

Gets the current weight for a given goal.

Returns: the weight of the goal, or 0 if there is no such goal on this behavior

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pub unsafe fn removeGoal(&self, goal: &GKGoal)

Available on crate feature GKGoal only.

Remove the indicated goal from this behavior.

Parameter goal: the goal to be removed

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pub unsafe fn removeAllGoals(&self)

Removes all the goals on the behavior.

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pub unsafe fn objectAtIndexedSubscript( &self, idx: NSUInteger, ) -> Retained<GKGoal>

Available on crate feature GKGoal only.

Supports getting goals via a [int] subscript.

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pub unsafe fn setObject_forKeyedSubscript( &self, weight: &NSNumber, goal: &GKGoal, )

Available on crate feature GKGoal only.

Supports setting a weight via a [goal] subscript.

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pub unsafe fn objectForKeyedSubscript( &self, goal: &GKGoal, ) -> Option<Retained<NSNumber>>

Available on crate feature GKGoal only.

Supports getting a weight via a [goal] subscript.

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impl GKBehavior

Methods declared on superclass NSObject.

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pub unsafe fn init(this: Allocated<Self>) -> Retained<Self>

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pub unsafe fn new() -> Retained<Self>

Methods from Deref<Target = NSObject>§

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pub fn doesNotRecognizeSelector(&self, sel: Sel) -> !

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>§

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pub fn class(&self) -> &'static AnyClass

Dynamically find the class of this object.

§Panics

May panic if the object is invalid (which may be the case for objects returned from unavailable init/new methods).

§Example

Check that an instance of NSObject has the precise class NSObject.

use objc2::ClassType;
use objc2::runtime::NSObject;

let obj = NSObject::new();
assert_eq!(obj.class(), NSObject::class());

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pub unsafe fn get_ivar<T>(&self, name: &str) -> &T
where T: Encode,

👎Deprecated: this is difficult to use correctly, use Ivar::load instead.

Use Ivar::load instead.

§Safety

The object must have an instance variable with the given name, and it must be of type T.

See Ivar::load_ptr for details surrounding this.

Source

pub fn downcast_ref<T>(&self) -> Option<&T>
where T: DowncastTarget,

Attempt to downcast the object to a class of type T.

This is the reference-variant. Use Retained::downcast if you want to convert a retained object to another type.

§Mutable classes

Some classes have immutable and mutable variants, such as NSString and NSMutableString.

When some Objective-C API signature says it gives you an immutable class, it generally expects you to not mutate that, even though it may technically be mutable “under the hood”.

So using this method to convert a NSString to a NSMutableString, while not unsound, is generally frowned upon unless you created the string yourself, or the API explicitly documents the string to be mutable.

See Apple’s documentation on mutability and on isKindOfClass: for more details.

§Generic classes

Objective-C generics are called “lightweight generics”, and that’s because they aren’t exposed in the runtime. This makes it impossible to safely downcast to generic collections, so this is disallowed by this method.

You can, however, safely downcast to generic collections where all the type-parameters are AnyObject.

§Panics

This works internally by calling isKindOfClass:. That means that the object must have the instance method of that name, and an exception will be thrown (if CoreFoundation is linked) or the process will abort if that is not the case. In the vast majority of cases, you don’t need to worry about this, since both root objects NSObject and NSProxy implement this method.

§Examples

Cast an NSString back and forth from NSObject.

use objc2::rc::Retained;
use objc2_foundation::{NSObject, NSString};

let obj: Retained<NSObject> = NSString::new().into_super();
let string = obj.downcast_ref::<NSString>().unwrap();
// Or with `downcast`, if we do not need the object afterwards
let string = obj.downcast::<NSString>().unwrap();

Try (and fail) to cast an NSObject to an NSString.

use objc2_foundation::{NSObject, NSString};

let obj = NSObject::new();
assert!(obj.downcast_ref::<NSString>().is_none());

Try to cast to an array of strings.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);
// This is invalid and doesn't type check.
let arr = arr.downcast_ref::<NSArray<NSString>>();

This fails to compile, since it would require enumerating over the array to ensure that each element is of the desired type, which is a performance pitfall.

Downcast when processing each element instead.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);

for elem in arr {
    if let Some(data) = elem.downcast_ref::<NSString>() {
        // handle `data`
    }
}