Documentation
¶
Overview ¶
Package objc provides cached Objective-C runtime helpers.
This package wraps purego/objc to provide selector caching for better performance.
Index ¶
- Variables
- func AddMethod(cls Class, sel SEL, impl any, types string) bool
- func AutoreleasePool(fn func())
- func CallWithError(id ID, sel SEL, args ...any) error
- func ConvertSlice[T any](ids []ID, convert func(ID) T) []T
- func ConvertSliceToStrings(ids []ID) []string
- func GoString(cstr *byte) string
- func IDToString(id ID) string
- func MustSend[T any](id ID, sel SEL, args ...any) T
- func NewActionTarget(owner ID, fn func(sender ID)) (target ID, sel SEL)
- func RegisterClassPair(cls Class)
- func RespondsToSelector(id ID, sel SEL) bool
- func SafeSend[T any](id ID, sel SEL, args ...any) (T, error)
- func Send[T any](id ID, sel SEL, args ...any) T
- func SendWithError[T any](id ID, sel SEL, args ...any) (T, error)
- type Block
- type CArrayArg
- type Class
- type FieldDef
- type ID
- type IDGetter
- type MethodDef
- type Protocol
- type SEL
- type UnrecognizedSelectorError
Constants ¶
This section is empty.
Variables ¶
var ErrUnrecognizedSelector = &UnrecognizedSelectorError{}
ErrUnrecognizedSelector is returned when an object does not respond to a selector.
Functions ¶
func AutoreleasePool ¶ added in v0.5.0
func AutoreleasePool(fn func())
AutoreleasePool executes fn within an Objective-C autorelease pool. Any autoreleased objects created during fn are released when fn returns.
func CallWithError ¶
CallWithError calls a void-returning selector and handles the NSError** pattern.
func ConvertSlice ¶
ConvertSlice maps []ID to []T using a converter function.
func ConvertSliceToStrings ¶
ConvertSliceToStrings maps []ID to []string via IDToString.
func GoString ¶
GoString converts a C string (*byte from UTF8String) to a Go string. This is needed because UTF8String returns const char*, not an ObjC object.
func MustSend ¶
MustSend calls a selector and panics with a clear error if the object doesn't respond. Use this when you expect the selector to always exist but want a clearer panic message than the NSInvalidArgumentException.
func NewActionTarget ¶
NewActionTarget creates an Objective-C trampoline object that calls fn when it receives the "invoke:" selector. The trampoline is associated with owner via objc_setAssociatedObject so it is retained for the owner's lifetime and cleaned up automatically when the owner is deallocated or a new action target replaces it.
Returns the trampoline ID and the selector to wire as the action.
func RegisterClassPair ¶
func RegisterClassPair(cls Class)
RegisterClassPair registers a class pair with the runtime.
func RespondsToSelector ¶
RespondsToSelector checks if an object responds to the given selector. This is the safe way to check before calling a method.
func SafeSend ¶
SafeSend calls a selector only if the object responds to it. Returns the zero value and ErrUnrecognizedSelector if the selector is not recognized. This prevents NSInvalidArgumentException crashes from unrecognized selectors.
func Send ¶
Send calls objc_msgSend with the given arguments.
When all arguments are uintptr-sized primitives (ID, SEL, Class, uintptr, bool, or integer types) and T is ID or struct{}, Send uses a pre-registered typed function that avoids reflect.MakeFunc — zero allocations, ~10x faster.
Otherwise Send falls back to purego.Send[T] with full argument processing: IDGetter extraction, nil→ID(0), CArrayArg conversion, and NSArray→[]ID.
Types ¶
type CArrayArg ¶
type CArrayArg struct {
// contains filtered or unexported fields
}
CArrayArg marks a Go slice argument that should be passed to Objective-C as a pointer to contiguous C array storage.
Use CArray at call sites for APIs that take `*T` and a paired `count` parameter.
type Class ¶
Type aliases for convenience
func RegisterClass ¶
func RegisterClass(name string, superClass Class, protocols []*Protocol, ivars []FieldDef, methods []MethodDef) (Class, error)
RegisterClass registers a new Objective-C class with the runtime. The class inherits from superClass and implements the given protocols. ivars defines instance variables, methods defines the class methods.
type ID ¶
Type aliases for convenience
func IDValueAt ¶ added in v0.3.6
IDValueAt loads an Objective-C object ID stored at a symbol address.
Dynamic libraries commonly export Objective-C object constants as pointers to storage containing the real object ID. Dlsym returns the storage address, so callers must load the pointer-sized value stored there.
func NSArrayToSlice ¶
NSArrayToSlice converts an NSArray ID into a []ID by calling count and objectAtIndex:.
type IDGetter ¶
type IDGetter interface {
GetID() ID
}
IDGetter is implemented by types that wrap an Objective-C object ID. This allows objc.Send to automatically extract the ID from wrapper types.
type Protocol ¶
Type aliases for convenience
func GetProtocol ¶
GetProtocol returns the protocol with the given name, or nil if not found.
type SEL ¶
Type aliases for convenience
func RegisterName ¶
RegisterName registers a selector with the Objective-C runtime. This is the same as Sel but without caching - use Sel for repeated calls.
type UnrecognizedSelectorError ¶
type UnrecognizedSelectorError struct {
Selector string
}
UnrecognizedSelectorError indicates an object does not respond to a selector.
func (*UnrecognizedSelectorError) Error ¶
func (e *UnrecognizedSelectorError) Error() string
Source Files