RCTSurface.h

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */

#import <Foundation/Foundation.h>

#import <React/RCTSurfaceStage.h>

NS_ASSUME_NONNULL_BEGIN

@class RCTBridge;
@class RCTSurfaceView;
@protocol RCTSurfaceDelegate;

/**
 * RCTSurface instance represents React Native-powered piece of a user interface
 * which can be a full-screen app, separate modal view controller,
 * or even small widget.
 * It is called "Surface".
 *
 * The RCTSurface instance is completely thread-safe by design;
 * it can be created on any thread, and any its method can be called from
 * any thread (if the opposite is not mentioned explicitly).
 *
 * The primary goals of the RCTSurface are:
 *  * ability to measure and layout the surface in a thread-safe
 *    and synchronous manner;
 *  * ability to create a UIView instance on demand (later);
 *  * ability to communicate the current stage of the surface granularly.
 */
@interface RCTSurface : NSObject

@property (atomic, readonly) RCTSurfaceStage stage;
@property (atomic, readonly) RCTBridge *bridge;
@property (atomic, readonly) NSString *moduleName;
@property (atomic, readonly) NSNumber *rootViewTag;

@property (atomic, readwrite, weak, nullable) id<RCTSurfaceDelegate> delegate;

@property (atomic, copy, readwrite) NSDictionary *properties;

- (instancetype)initWithBridge:(RCTBridge *)bridge
                    moduleName:(NSString *)moduleName
             initialProperties:(NSDictionary *)initialProperties NS_DESIGNATED_INITIALIZER;

#pragma mark - Dealing with UIView representation, the Main thread only access

/**
 * Creates (if needed) and returns `UIView` instance which represents the Surface.
 * The Surface will cache and *retain* this object.
 * Returning the UIView instance does not mean that the Surface is ready
 * to execute and layout. It can be just a handler which Surface will use later
 * to mount the actual views.
 * RCTSurface does not control (or influence in any way) the size or origin
 * of this view. Some superview (or another owner) must use other methods
 * of this class to setup proper layout and interop interactions with UIKit
 * or another UI framework.
 * This method must be called only from the main queue.
 */
- (RCTSurfaceView *)view;

#pragma mark - Layout: Setting the size constrains

/**
 * Sets `minimumSize` and `maximumSize` layout constraints for the Surface.
 */
- (void)setMinimumSize:(CGSize)minimumSize
           maximumSize:(CGSize)maximumSize;

/**
 * Previously set `minimumSize` layout constraint.
 * Defaults to `{0, 0}`.
 */
@property (atomic, assign, readonly) CGSize minimumSize;

/**
 * Previously set `maximumSize` layout constraint.
 * Defaults to `{INFINITY, INFINITY}`.
 */
@property (atomic, assign, readonly) CGSize maximumSize;


/**
 * Simple shortcut to `-[RCTSurface setMinimumSize:size maximumSize:size]`.
 */
- (void)setSize:(CGSize)size;

#pragma mark - Layout: Measuring

/**
 * Measures the Surface with given constraints.
 * This method does not cause any side effects on the surface object.
 */
- (CGSize)sizeThatFitsMinimumSize:(CGSize)minimumSize
                      maximumSize:(CGSize)maximumSize;

/**
 * Return the current size of the root view based on (but not clamp by) current
 * size constraints.
 */
@property (atomic, assign, readonly) CGSize intrinsicSize;

#pragma mark - Synchronous waiting

/**
 * Synchronously blocks the current thread up to given `timeout` until
 * the Surface will not have given `stage`.
 * Do nothing, if called from the main or `UIManager` queue.
 */
- (BOOL)synchronouslyWaitForStage:(RCTSurfaceStage)stage timeout:(NSTimeInterval)timeout;

@end

NS_ASSUME_NONNULL_END