components/TextFields/src/MDCMultilineTextField.h

// Copyright 2017-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 <UIKit/UIKit.h>

#import "MDCTextInput.h"

@class MDCIntrinsicHeightTextView;

@protocol MDCMultilineTextInputDelegate;
@protocol MDCMultilineTextInputLayoutDelegate;

/**
  Material Design themed mutiline text field (multiline text input).
  https://www.google.com/design/spec/components/text-fields.html#text-fields-multi-line-text-field
 */
@interface MDCMultilineTextField : UIView <MDCTextInput, MDCMultilineTextInput>

/** A mirror of the same property that already exists on UITextField, UITextView, and UILabel. */
@property(nonatomic, assign) BOOL adjustsFontForContentSizeCategory;

/**
 Should the text field grow vertically as new lines are added.

 Default is YES.

 Note: Inherited from MDCMultilineTextInput protocol. Added here to declare Interface Builder
 support (IBInspectable).
 */
@property(nonatomic, assign) IBInspectable BOOL expandsOnOverflow;

/**
 The delegate for changes to preferred content size.

 If using auto layout, it is not necessary to have a layout delegate.
 */
@property(nonatomic, nullable, weak) IBOutlet id<MDCMultilineTextInputLayoutDelegate>
    layoutDelegate;

/** An optional delegate for useful methods not included in UITextViewDelegate.*/
@property(nonatomic, nullable, weak) IBOutlet id<MDCMultilineTextInputDelegate> multilineDelegate;

/**
 The text string of the placeholder label.
 Bringing convenience api found in UITextField to all MDCTextInputs. Maps to the .text of the
 placeholder label.

 Note: Inherited from MDCTextInput protocol. Added here to declare Interface Builder support
 (IBInspectable).
 */
@property(nonatomic, nullable, copy) IBInspectable NSString *placeholder;

/** Insets used to calculate the spacing of subviews. */
@property(nonatomic, assign, readonly) UIEdgeInsets textInsets;

/**
 Embedded textView. Can be set from storyboard or will be auto-created during initialization.
 */
@property(nonatomic, nullable, strong) IBOutlet MDCIntrinsicHeightTextView *textView;

@end

/** Delegate for MDCTextInput size changes. */
@protocol MDCMultilineTextInputLayoutDelegate <NSObject>

@optional
/**
 Notifies the delegate that the text field's content size changed, requiring the size provided for
 best display.

 If using auto layout, this method is unnecessary; this is a way for views not implementing auto
 layout to know when to grow and shrink height to accomodate changes in content.

 @param multilineTextField  The text field for which the content size changed.
 @param size                The size required by the text view to fit all of its content.
 */
- (void)multilineTextField:(id<MDCMultilineTextInput> _Nonnull)multilineTextField
      didChangeContentSize:(CGSize)size;

@end