Struct GKGraphNode2D

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pub struct GKGraphNode2D { /* private fields */ }

Available on crate feature GKGraphNode only.

Expand description

GKGraphNode coupled with a 2D position

Implementations§

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impl GKGraphNode2D

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 = GKGraphNode>§

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pub unsafe fn connectedNodes(&self) -> Retained<NSArray<GKGraphNode>>

List of other graph nodes that this node has an edge leading to.

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pub unsafe fn addConnectionsToNodes_bidirectional( &self, nodes: &NSArray<GKGraphNode>, bidirectional: bool, )

Add a connection to a group of other nodes indicating those nodes can be reached from this node. A new connection is not created if it already exists.

Parameter nodes: The array of nodes that are end points for their respective connections

Parameter bidirectional: should a connection also be added connecting the destination node back to this node?

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pub unsafe fn removeConnectionsToNodes_bidirectional( &self, nodes: &NSArray<GKGraphNode>, bidirectional: bool, )

Removes connections to a group of other nodes indicating those nodes can no longer be reached from this node. Nothing happens if a particular connection does not exist.

Parameter nodes: The array of nodes that are end points of the edges to be removed

Parameter bidirectional: should the connection also be added the destination node back to this node also be removed if it exists?

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pub unsafe fn estimatedCostToNode(&self, node: &GKGraphNode) -> c_float

Returns the estimated heuristic cost to reach the indicated node from this node

Parameter node: The end point of the edge who’s cost is to be estimated

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pub unsafe fn costToNode(&self, node: &GKGraphNode) -> c_float

Returns the actual cost to reach the indicated node from this node

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pub unsafe fn findPathToNode( &self, goal_node: &GKGraphNode, ) -> Retained<NSArray<GKGraphNode>>

Attempts to find the optimal path between this node and the indicated goal node. If such a path exists, it is returned in start to end order. If it doesn’t exist, the array returned will be empty.

Parameter goalNode: the goal node of the pathfinding attempt

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pub unsafe fn findPathFromNode( &self, start_node: &GKGraphNode, ) -> Retained<NSArray<GKGraphNode>>

As with findPathToNode: except this node is the goal node and a startNode is specified

Parameter startNode: the start node of the pathfinding attempt

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.

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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`
    }
}