components/MaskedTransition/src/MDCMaskedTransitionController.h

// Copyright 2018-present the Material Components for iOS authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

/**
 MDCMaskedTransitionController implements a custom view controller transition that animates the
 presented view controller using a mask reveal effect from a circular source view.

 The presenting view controller will typically store a reference to an instance of this class and
 assign it to the transitioningDelegate of a view controller prior to presenting it.

 With zero additional configuration, the transition will perform a fullscreen masked reveal
 presentation, with a slide down dismissal.

 It's possible to configure the presented view controller's frame by setting the
 calculateFrameOfPresentedView property. The provided block should return the desired frame of the
 presented view controller. When using calculateFrameOfPresentedView you must also change the
 modalPresentationStyle on the view controller to be presented to `UIModalPresentationCustom`.

 Once the view controller to be presented has been fully configured, you can present the view
 controller using any of the available view controller presentation APIs.
 */
@interface MDCMaskedTransitionController : NSObject <UIViewControllerTransitioningDelegate>

/**
 Initializes the transition controller with a given source view.
 */
- (nonnull instancetype)initWithSourceView:(nullable UIView *)sourceView;

/**
 Initializes the transition controller without a source view.

 Note that if no source view is available at the time of presentation, the transition will fall back
 to the default system presentation.
 */
- (nonnull instancetype)init NS_DESIGNATED_INITIALIZER;

/**
 The view from which the next masked transition should emanate.
 */
@property(nonatomic, strong, nullable, readonly) UIView *sourceView;

/**
 An optional block that may be used to calculate the frame of the presented view controller's view.

 If provided, the block will be invoked once the presentation transition is initiated. The
 returned rect will be assigned to the presented view controller's frame.

 You must set the view controller-to-be-presented's modalPresentationStyle property to
 `UIModalPresentationCustom` in order to use this property.
 */
@property(nonatomic, copy, nullable) CGRect (^calculateFrameOfPresentedView)
    (UIPresentationController *_Nonnull);

@end