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#import <Foundation/Foundation.h>
#import "MGLStyleLayer.h"
#import "MGLStyleValue_Private.h"
#include <mbgl/style/layer.hpp>
NS_ASSUME_NONNULL_BEGIN
// A struct to be stored in the `peer` member of mbgl::style::Layer, in order to implement
// object identity. We don't store a MGLStyleLayer pointer directly because that doesn't
// interoperate with ARC. The inner pointer is weak in order to avoid a reference cycle for
// "pending" MGLStyleLayers, which have a strong owning pointer to the mbgl::style::Layer.
struct LayerWrapper {
__weak MGLStyleLayer *layer;
};
/**
Assert that the style layer is valid.
This macro should be used at the beginning of any public-facing instance method
of `MGLStyleLayer` and its subclasses. For private methods, an assertion is more appropriate.
*/
#define MGLAssertStyleLayerIsValid() \
do { \
if (!self.rawLayer) { \
[NSException raise:MGLInvalidStyleLayerException \
format: \
@"-[MGLStyle removeLayer:] has been called " \
@"with this instance but another style layer instance was added with the same identifer. It is an " \
@"error to send any message to this layer since it cannot be recovered after removal due to the " \
@"identifier collision. Use unique identifiers for all layer instances including layers of " \
@"different types."]; \
} \
} while (NO);
@class MGLStyle;
@interface MGLStyleLayer (Private)
/**
Initializes and returns a layer with a raw pointer to the backing store,
associated with a style.
*/
- (instancetype)initWithRawLayer:(mbgl::style::Layer *)rawLayer;
/**
Initializes and returns a layer with an owning pointer to the backing store,
unassociated from a style.
*/
- (instancetype)initWithPendingLayer:(std::unique_ptr<mbgl::style::Layer>)pendingLayer;
@property (nonatomic, readwrite, copy) NSString *identifier;
/**
A raw pointer to the mbgl object, which is always initialized, either to the
value returned by `mbgl::Map getLayer`, or for independently created objects,
to the pointer value held in `pendingLayer`. In the latter case, this raw
pointer value stays even after ownership of the object is transferred via
`mbgl::Map addLayer`.
*/
@property (nonatomic, readonly) mbgl::style::Layer *rawLayer;
/**
Adds the mbgl style layer that this object represents to the mbgl map below the
specified `otherLayer`.
Once a mbgl style layer is added, ownership of the object is transferred to the
`mbgl::Map` and this object no longer has an active unique_ptr reference to the
`mbgl::style::Layer`.
*/
- (void)addToStyle:(MGLStyle *)style belowLayer:(nullable MGLStyleLayer *)otherLayer;
/**
Removes the mbgl style layer that this object represents from the mbgl map.
When a mbgl style layer is removed, ownership of the object is transferred back
to the `MGLStyleLayer` instance and the unique_ptr reference is valid again. It
is safe to add the layer back to the style after it is removed.
*/
- (void)removeFromStyle:(MGLStyle *)style;
@end
namespace mbgl {
class LayerPeerFactory {
public:
virtual ~LayerPeerFactory() = default;
/**
Get the corresponding core layer factory.
*/
virtual LayerFactory* getCoreLayerFactory() = 0;
/**
Creates an MGLStyleLayer instance with a raw pointer to the backing store.
*/
virtual MGLStyleLayer* createPeer(style::Layer*) = 0;
};
} // namespace mbgl
NS_ASSUME_NONNULL_END
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