mirror of
https://github.com/MessageKit/MessageKit.git
synced 2026-02-06 19:03:19 +00:00
Steven Deutsch
621 lines
28 KiB
Swift
621 lines
28 KiB
Swift
/*
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MIT License
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Copyright (c) 2017-2018 MessageKit
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in all
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copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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SOFTWARE.
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*/
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import UIKit
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import AVFoundation
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/// The layout object used by `MessagesCollectionView` to determine the size of all
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/// framework provided `MessageCollectionViewCell` subclasses.
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open class MessagesCollectionViewFlowLayout: UICollectionViewFlowLayout {
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open override class var layoutAttributesClass: AnyClass {
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return MessagesCollectionViewLayoutAttributes.self
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}
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/// The width of an item in the `MessagesCollectionView`.
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internal var itemWidth: CGFloat {
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guard let collectionView = collectionView else { return 0 }
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return collectionView.frame.width - sectionInset.left - sectionInset.right
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}
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/// The font to be used by `TextMessageCell` for `MessageData.text(String)` case.
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///
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/// Note: The default value of this property is `UIFont.preferredFont(forTextStyle: .body)`
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open var messageLabelFont: UIFont {
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didSet {
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emojiLabelFont = messageLabelFont.withSize(2 * messageLabelFont.pointSize)
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}
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}
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/// The font to be used by `TextMessageCell` for `MessageData.emoji(String)` case.
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///
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/// Note: The default value of this property is 2x the `messageLabelFont`.
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internal var emojiLabelFont: UIFont
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/// Determines the maximum number of `MessageCollectionViewCell` attributes to cache.
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///
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/// Note: The default value of this property is 500.
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open var attributesCacheMaxSize: Int = 500 {
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didSet {
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layoutContextCache.countLimit = attributesCacheMaxSize
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}
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}
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// MARK: - Layout
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open var incomingAvatarSize = CGSize(width: 30, height: 30)
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open var outgoingAvatarSize = CGSize(width: 30, height: 30)
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open var incomingAvatarPosition = AvatarPosition(vertical: .messageBottom)
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open var outgoingAvatarPosition = AvatarPosition(vertical: .messageBottom)
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open var incomingMessageLabelInsets = UIEdgeInsets(top: 7, left: 18, bottom: 7, right: 14)
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open var outgoingMessageLabelInsets = UIEdgeInsets(top: 7, left: 14, bottom: 7, right: 18)
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open var incomingMessagePadding = UIEdgeInsets(top: 0, left: 4, bottom: 0, right: 30)
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open var outgoingMessagePadding = UIEdgeInsets(top: 0, left: 30, bottom: 0, right: 4)
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typealias MessageID = NSString
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/// The cache for `MessageCellLayoutContext`.
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/// The key is the `messageId` of the `MessageType`.
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fileprivate var layoutContextCache = NSCache<MessageID, MessageCellLayoutContext>()
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/// The `MessageCellLayoutContext` for the current cell.
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internal var currentLayoutContext: MessageCellLayoutContext!
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// MARK: - Initializers
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public override init() {
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messageLabelFont = UIFont.preferredFont(forTextStyle: .body)
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emojiLabelFont = messageLabelFont.withSize(2 * messageLabelFont.pointSize)
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super.init()
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sectionInset = UIEdgeInsets(top: 4, left: 8, bottom: 4, right: 8)
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NotificationCenter.default.addObserver(self, selector: #selector(MessagesCollectionViewFlowLayout.handleOrientationChange(_:)), name: .UIDeviceOrientationDidChange, object: nil)
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}
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required public init?(coder aDecoder: NSCoder) {
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fatalError("init(coder:) has not been implemented")
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}
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deinit {
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NotificationCenter.default.removeObserver(self)
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}
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// MARK: - Open
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// MARK: - Attributes
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open override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
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guard let attributesArray = super.layoutAttributesForElements(in: rect) as? [MessagesCollectionViewLayoutAttributes] else { return nil }
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attributesArray.forEach { attributes in
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if attributes.representedElementCategory == UICollectionElementCategory.cell {
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configure(attributes: attributes)
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}
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}
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return attributesArray
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}
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open override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
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guard let attributes = super.layoutAttributesForItem(at: indexPath) as? MessagesCollectionViewLayoutAttributes else { return nil }
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if attributes.representedElementCategory == UICollectionElementCategory.cell {
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configure(attributes: attributes)
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}
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return attributes
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}
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// MARK: - Layout Invalidation
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open override func shouldInvalidateLayout(forBoundsChange newBounds: CGRect) -> Bool {
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if collectionView?.bounds.width != newBounds.width {
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removeAllCachedAttributes()
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return true
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} else {
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return false
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}
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}
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open override func invalidationContext(forBoundsChange newBounds: CGRect) -> UICollectionViewLayoutInvalidationContext {
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let context = super.invalidationContext(forBoundsChange: newBounds)
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guard let flowLayoutContext = context as? UICollectionViewFlowLayoutInvalidationContext else { return context }
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flowLayoutContext.invalidateFlowLayoutDelegateMetrics = shouldInvalidateLayout(forBoundsChange: newBounds)
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return flowLayoutContext
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}
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// MARK: - Avatar Size
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internal func avatarPosition(for message: MessageType, at indexPath: IndexPath) -> AvatarPosition {
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let isFromCurrentSender = messagesDataSource.isFromCurrentSender(message: message)
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var position = isFromCurrentSender ? outgoingAvatarPosition : incomingAvatarPosition
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switch position.horizontal {
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case .cellTrailing, .cellLeading:
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break
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case .natural:
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position.horizontal = messagesDataSource.isFromCurrentSender(message: message) ? .cellTrailing : .cellLeading
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}
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return position
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}
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internal func avatarSize(for message: MessageType, at indexPath: IndexPath) -> CGSize {
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let isFromCurrentSender = messagesDataSource.isFromCurrentSender(message: message)
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return isFromCurrentSender ? outgoingAvatarSize : incomingAvatarSize
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}
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// MARK: - Cell Top Label Size
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/// Returns the `LabelAlignment` of the `MessageCollectionViewCell`'s top label
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/// for the `MessageType` at a given `IndexPath`.
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///
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/// - Parameters:
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/// - message: The `MessageType` for the given `IndexPath`.
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/// - indexPath: The `IndexPath` for the given `MessageType`.
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/// - Note: The default implementation of this method retrieves its value from
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/// `cellTopLabelAlignment(for:at:in)` in `MessagesLayoutDelegate`.
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open func cellTopLabelAlignment(for message: MessageType, at indexPath: IndexPath) -> LabelAlignment {
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return messagesLayoutDelegate.cellTopLabelAlignment(for: message, at: indexPath, in: messagesCollectionView)
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}
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/// Returns the size of the `MessageCollectionViewCell`'s top label
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/// for the `MessageType` at a given `IndexPath`.
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///
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/// - Parameters:
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/// - message: The `MessageType` for the given `IndexPath`.
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/// - indexPath: The `IndexPath` for the given `MessageType`.
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///
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/// - Note: The default implementation of this method sizes the label to fit.
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open func cellTopLabelSize(for message: MessageType, at indexPath: IndexPath) -> CGSize {
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let text = messagesDataSource.cellTopLabelAttributedText(for: message, at: indexPath)
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guard let topLabelText = text else { return .zero }
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let maxWidth = cellTopLabelMaxWidth(for: message, at: indexPath)
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return labelSize(for: topLabelText, considering: maxWidth)
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}
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/// Returns the maximum width of the `MessageCollectionViewCell`'s top label
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/// for the `MessageType` at a given `IndexPath`.
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///
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/// - Parameters:
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/// - message: The `MessageType` for the given `IndexPath`.
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/// - indexPath: The `IndexPath` for the given `MessageType`.
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open func cellTopLabelMaxWidth(for message: MessageType, at indexPath: IndexPath) -> CGFloat {
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let alignment = cellTopLabelAlignment(for: message, at: indexPath)
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let position = avatarPosition(for: message, at: indexPath)
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let avatarWidth = avatarSize(for: message, at: indexPath).width
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let containerSize = messageContainerSize(for: message, at: indexPath)
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let messagePadding = messageContainerPadding(for: message, at: indexPath)
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let avatarHorizontal = position.horizontal
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let avatarVertical = position.vertical
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switch (alignment, avatarHorizontal) {
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case (.cellLeading, _), (.cellTrailing, _):
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let width = itemWidth - alignment.insets.horizontal
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return avatarVertical != .cellTop ? width : width - avatarWidth
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case (.cellCenter, _):
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let width = itemWidth - alignment.insets.horizontal
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return avatarVertical != .cellTop ? width : width - (avatarWidth * 2)
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case (.messageTrailing, .cellLeading):
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let width = containerSize.width + messagePadding.left - alignment.insets.horizontal
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return avatarVertical == .cellTop ? width : width + avatarWidth
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case (.messageLeading, .cellTrailing):
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let width = containerSize.width + messagePadding.right - alignment.insets.horizontal
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return avatarVertical == .cellTop ? width : width + avatarWidth
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case (.messageLeading, .cellLeading):
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return itemWidth - avatarWidth - messagePadding.left - alignment.insets.horizontal
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case (.messageTrailing, .cellTrailing):
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return itemWidth - avatarWidth - messagePadding.right - alignment.insets.horizontal
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case (_, .natural):
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fatalError(MessageKitError.avatarPositionUnresolved)
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}
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}
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// MARK: - Cell Bottom Label Size
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/// Returns the `LabelAlignment` of the `MessageCollectionViewCell`'s bottom label
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/// for the `MessageType` at a given `IndexPath`.
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///
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/// - Parameters:
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/// - message: The `MessageType` for the given `IndexPath`.
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/// - indexPath: The `IndexPath` for the given `MessageType`.
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/// - Note: The default implementation of this method retrieves its value from
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/// `cellBottomLabelAlignment(for:at:in)` in `MessagesLayoutDelegate`.
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open func cellBottomLabelAlignment(for message: MessageType, at indexPath: IndexPath) -> LabelAlignment {
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return messagesLayoutDelegate.cellBottomLabelAlignment(for: message, at: indexPath, in: messagesCollectionView)
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}
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/// Returns the size of the `MessageCollectionViewCell`'s bottom label
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/// for the `MessageType` at a given `IndexPath`.
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///
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/// - Parameters:
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/// - message: The `MessageType` for the given `IndexPath`.
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/// - indexPath: The `IndexPath` for the given `MessageType`.
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///
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/// - Note: The default implementation of this method sizes the label to fit.
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open func cellBottomLabelSize(for message: MessageType, at indexPath: IndexPath) -> CGSize {
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let text = messagesDataSource.cellBottomLabelAttributedText(for: message, at: indexPath)
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guard let bottomLabelText = text else { return .zero }
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let maxWidth = cellBottomLabelMaxWidth(for: message, at: indexPath)
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return labelSize(for: bottomLabelText, considering: maxWidth)
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}
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/// Returns the maximum width of the `MessageCollectionViewCell`'s bottom label
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/// for the `MessageType` at a given `IndexPath`.
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///
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/// - Parameters:
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/// - message: The `MessageType` for the given `IndexPath`.
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/// - indexPath: The `IndexPath` for the given `MessageType`.
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open func cellBottomLabelMaxWidth(for message: MessageType, at indexPath: IndexPath) -> CGFloat {
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let alignment = cellBottomLabelAlignment(for: message, at: indexPath)
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let avatarWidth = avatarSize(for: message, at: indexPath).width
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let containerSize = messageContainerSize(for: message, at: indexPath)
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let messagePadding = messageContainerPadding(for: message, at: indexPath)
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let position = avatarPosition(for: message, at: indexPath)
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let avatarHorizontal = position.horizontal
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let avatarVertical = position.vertical
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switch (alignment, avatarHorizontal) {
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case (.cellLeading, _), (.cellTrailing, _):
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let width = itemWidth - alignment.insets.horizontal
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return avatarVertical != .cellBottom ? width : width - avatarWidth
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case (.cellCenter, _):
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let width = itemWidth - alignment.insets.horizontal
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return avatarVertical != .cellBottom ? width : width - (avatarWidth * 2)
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case (.messageTrailing, .cellLeading):
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let width = containerSize.width + messagePadding.left - alignment.insets.horizontal
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return avatarVertical == .cellBottom ? width : width + avatarWidth
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case (.messageLeading, .cellTrailing):
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let width = containerSize.width + messagePadding.right - alignment.insets.horizontal
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return avatarVertical == .cellBottom ? width : width + avatarWidth
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case (.messageLeading, .cellLeading):
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return itemWidth - avatarWidth - messagePadding.left - alignment.insets.horizontal
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case (.messageTrailing, .cellTrailing):
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return itemWidth - avatarWidth - messagePadding.right - alignment.insets.horizontal
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case (_, .natural):
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fatalError(MessageKitError.avatarPositionUnresolved)
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}
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}
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// MARK: - Message Container Size
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internal func messageLabelInsets(for message: MessageType, at indexPath: IndexPath) -> UIEdgeInsets {
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let isFromCurrentSender = messagesDataSource.isFromCurrentSender(message: message)
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return isFromCurrentSender ? outgoingMessageLabelInsets : incomingMessageLabelInsets
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}
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internal func messageContainerPadding(for message: MessageType, at indexPath: IndexPath) -> UIEdgeInsets {
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let isFromCurrentSender = messagesDataSource.isFromCurrentSender(message: message)
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return isFromCurrentSender ? outgoingMessagePadding : incomingMessagePadding
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}
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/// Returns the maximum width of the `MessageContainerView` in a `MessageCollectionViewCell`
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/// for the `MessageType` at a given `IndexPath`.
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///
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/// - Parameters:
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/// - message: The `MessageType` for the given `IndexPath`.
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/// - indexPath: The `IndexPath` for the given `MessageType`.
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open func messageContainerMaxWidth(for message: MessageType, at indexPath: IndexPath) -> CGFloat {
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let avatarWidth = avatarSize(for: message, at: indexPath).width
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let messagePadding = messageContainerPadding(for: message, at: indexPath)
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switch message.data {
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case .text, .attributedText:
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let messageInsets = messageLabelInsets(for: message, at: indexPath)
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return itemWidth - avatarWidth - messagePadding.horizontal - messageInsets.horizontal
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default:
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return itemWidth - avatarWidth - messagePadding.horizontal
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}
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}
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/// Returns the size of the `MessageContainerView` in a `MessageCollectionViewCell`
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/// for the `MessageType` at a given `IndexPath`.
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///
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/// - Parameters:
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/// - message: The `MessageType` for the given `IndexPath`.
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/// - indexPath: The `IndexPath` for the given `MessageType`.
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open func messageContainerSize(for message: MessageType, at indexPath: IndexPath) -> CGSize {
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let maxWidth = messageContainerMaxWidth(for: message, at: indexPath)
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var messageContainerSize: CGSize = .zero
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switch message.data {
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case .text(let text):
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let messageInsets = messageLabelInsets(for: message, at: indexPath)
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messageContainerSize = labelSize(for: text, considering: maxWidth, and: messageLabelFont)
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messageContainerSize.width += messageInsets.horizontal
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messageContainerSize.height += messageInsets.vertical
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case .attributedText(let text):
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let messageInsets = messageLabelInsets(for: message, at: indexPath)
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messageContainerSize = labelSize(for: text, considering: maxWidth)
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messageContainerSize.width += messageInsets.horizontal
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messageContainerSize.height += messageInsets.vertical
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case .emoji(let text):
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let messageInsets = messageLabelInsets(for: message, at: indexPath)
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messageContainerSize = labelSize(for: text, considering: maxWidth, and: emojiLabelFont)
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messageContainerSize.width += messageInsets.horizontal
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messageContainerSize.height += messageInsets.vertical
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case .photo, .video:
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let width = messagesLayoutDelegate.widthForMedia(message: message, at: indexPath, with: maxWidth, in: messagesCollectionView)
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let height = messagesLayoutDelegate.heightForMedia(message: message, at: indexPath, with: maxWidth, in: messagesCollectionView)
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messageContainerSize = CGSize(width: width, height: height)
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case .location:
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let width = messagesLayoutDelegate.widthForLocation(message: message, at: indexPath, with: maxWidth, in: messagesCollectionView)
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let height = messagesLayoutDelegate.heightForLocation(message: message, at: indexPath, with: maxWidth, in: messagesCollectionView)
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messageContainerSize = CGSize(width: width, height: height)
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case .custom:
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fatalError(MessageKitError.customDataUnresolvedSize)
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}
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return messageContainerSize
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}
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// MARK: - Cell Size
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/// Returns the height of a `MessageCollectionViewCell`'s content at a given `IndexPath`
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///
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/// - Parameters:
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/// - message: The `MessageType` for the given `IndexPath`.
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/// - indexPath: The `IndexPath` for the given `MessageType`.
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open func cellContentHeight(for message: MessageType, at indexPath: IndexPath) -> CGFloat {
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let avatarVerticalPosition = avatarPosition(for: message, at: indexPath).vertical
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let avatarHeight = avatarSize(for: message, at: indexPath).height
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let messageContainerHeight = messageContainerSize(for: message, at: indexPath).height
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let bottomLabelHeight = cellBottomLabelSize(for: message, at: indexPath).height
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let topLabelHeight = cellTopLabelSize(for: message, at: indexPath).height
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let messageVerticalPadding = messageContainerPadding(for: message, at: indexPath).vertical
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var cellHeight: CGFloat = 0
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switch avatarVerticalPosition {
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case .cellTop:
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cellHeight += max(avatarHeight, topLabelHeight)
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cellHeight += bottomLabelHeight
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cellHeight += messageContainerHeight
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cellHeight += messageVerticalPadding
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case .cellBottom:
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cellHeight += max(avatarHeight, bottomLabelHeight)
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cellHeight += topLabelHeight
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cellHeight += messageContainerHeight
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cellHeight += messageVerticalPadding
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case .messageTop, .messageCenter, .messageBottom:
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cellHeight += max(avatarHeight, messageContainerHeight)
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cellHeight += messageVerticalPadding
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cellHeight += topLabelHeight
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cellHeight += bottomLabelHeight
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}
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return cellHeight
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}
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/// Returns the size for the `MessageCollectionViewCell` at a given `IndexPath`
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/// considering all of the cell's content.
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///
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/// - Parameters:
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/// - indexPath: The `IndexPath` of the cell.
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open func sizeForItem(at indexPath: IndexPath) -> CGSize {
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let message = messagesDataSource.messageForItem(at: indexPath, in: messagesCollectionView)
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let context = cellLayoutContext(for: message, at: indexPath)
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guard let itemHeight = context.itemHeight else {
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fatalError("Unexpectedly received a nil itemHeight")
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}
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return CGSize(width: itemWidth, height: itemHeight)
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}
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}
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// MARK: - Cache Invalidation
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extension MessagesCollectionViewFlowLayout {
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/// Removes the cached layout information for a given `MessageType`.
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///
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/// - Parameters:
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/// - message: The `MessageType` whose cached layout information is to be removed.
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public func removeCachedAttributes(for message: MessageType) {
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removeCachedAttributes(for: message.messageId)
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}
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/// Removes the cached layout information for a `MessageType` with a given `messageId`.
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///
|
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/// - Parameters:
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/// - messageId: The id for the `MessageType` whose cached layout information is to be removed.
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public func removeCachedAttributes(for messageId: String) {
|
|
layoutContextCache.removeObject(forKey: messageId as NSString)
|
|
}
|
|
|
|
/// Removes the cached layout information for all `MessageType`s.
|
|
public func removeAllCachedAttributes() {
|
|
layoutContextCache.removeAllObjects()
|
|
}
|
|
|
|
@objc
|
|
private func handleOrientationChange(_ notification: Notification) {
|
|
removeAllCachedAttributes()
|
|
invalidateLayout()
|
|
}
|
|
}
|
|
|
|
// MARK: - MessagesCollectionViewLayoutAttributes
|
|
|
|
extension MessagesCollectionViewFlowLayout {
|
|
|
|
private func configure(attributes: MessagesCollectionViewLayoutAttributes) {
|
|
|
|
let indexPath = attributes.indexPath
|
|
let message = messagesDataSource.messageForItem(at: indexPath, in: messagesCollectionView)
|
|
let context = cellLayoutContext(for: message, at: indexPath)
|
|
|
|
attributes.avatarSize = context.avatarSize!
|
|
attributes.avatarPosition = context.avatarPosition!
|
|
|
|
attributes.messageContainerPadding = context.messageContainerPadding!
|
|
attributes.messageContainerSize = context.messageContainerSize!
|
|
attributes.messageLabelInsets = context.messageLabelInsets!
|
|
|
|
attributes.topLabelAlignment = context.topLabelAlignment!
|
|
attributes.topLabelSize = context.topLabelSize!
|
|
|
|
attributes.bottomLabelAlignment = context.bottomLabelAlignment!
|
|
attributes.bottomLabelSize = context.bottomLabelSize!
|
|
|
|
switch message.data {
|
|
case .emoji:
|
|
attributes.messageLabelFont = emojiLabelFont
|
|
case .text:
|
|
attributes.messageLabelFont = messageLabelFont
|
|
case .attributedText(let text):
|
|
guard !text.string.isEmpty else { return }
|
|
guard let font = text.attribute(.font, at: 0, effectiveRange: nil) as? UIFont else { return }
|
|
attributes.messageLabelFont = font
|
|
default:
|
|
break
|
|
}
|
|
}
|
|
}
|
|
|
|
// MARK: - MessageCellLayoutContext
|
|
|
|
extension MessagesCollectionViewFlowLayout {
|
|
|
|
internal func cellLayoutContext(for message: MessageType, at indexPath: IndexPath) -> MessageCellLayoutContext {
|
|
guard let cachedContext = layoutContextCache.object(forKey: message.messageId as NSString) else {
|
|
let newContext = newCellLayoutContext(for: message, at: indexPath)
|
|
|
|
if messagesLayoutDelegate.shouldCacheLayoutAttributes(for: message) {
|
|
layoutContextCache.setObject(newContext, forKey: message.messageId as NSString)
|
|
}
|
|
return newContext
|
|
}
|
|
return cachedContext
|
|
}
|
|
|
|
internal func newCellLayoutContext(for message: MessageType, at indexPath: IndexPath) -> MessageCellLayoutContext {
|
|
currentLayoutContext = MessageCellLayoutContext()
|
|
currentLayoutContext.avatarPosition = avatarPosition(for: message, at: indexPath)
|
|
currentLayoutContext.avatarSize = avatarSize(for: message, at: indexPath)
|
|
currentLayoutContext.messageContainerPadding = messageContainerPadding(for: message, at: indexPath)
|
|
currentLayoutContext.messageLabelInsets = messageLabelInsets(for: message, at: indexPath)
|
|
currentLayoutContext.messageContainerMaxWidth = messageContainerMaxWidth(for: message, at: indexPath)
|
|
currentLayoutContext.messageContainerSize = messageContainerSize(for: message, at: indexPath)
|
|
currentLayoutContext.topLabelAlignment = cellTopLabelAlignment(for: message, at: indexPath)
|
|
currentLayoutContext.topLabelMaxWidth = cellTopLabelMaxWidth(for: message, at: indexPath)
|
|
currentLayoutContext.topLabelSize = cellTopLabelSize(for: message, at: indexPath)
|
|
currentLayoutContext.bottomLabelAlignment = cellBottomLabelAlignment(for: message, at: indexPath)
|
|
currentLayoutContext.bottomLabelMaxWidth = cellBottomLabelMaxWidth(for: message, at: indexPath)
|
|
currentLayoutContext.bottomLabelSize = cellBottomLabelSize(for: message, at: indexPath)
|
|
currentLayoutContext.itemHeight = cellContentHeight(for: message, at: indexPath)
|
|
return currentLayoutContext
|
|
}
|
|
}
|
|
|
|
// MARK: - Helpers
|
|
|
|
extension MessagesCollectionViewFlowLayout {
|
|
|
|
/// Returns the size required fit a NSAttributedString considering a constrained max width.
|
|
///
|
|
/// - Parameters:
|
|
/// - attributedText: The `NSAttributedString` used to calculate a size that fits.
|
|
/// - maxWidth: The max width available for the label.
|
|
internal func labelSize(for attributedText: NSAttributedString, considering maxWidth: CGFloat) -> CGSize {
|
|
|
|
let estimatedHeight = attributedText.height(considering: maxWidth)
|
|
let estimatedWidth = attributedText.width(considering: estimatedHeight)
|
|
|
|
let finalHeight = estimatedHeight.rounded(.up)
|
|
let finalWidth = estimatedWidth > maxWidth ? maxWidth : estimatedWidth.rounded(.up)
|
|
|
|
return CGSize(width: finalWidth, height: finalHeight)
|
|
}
|
|
|
|
/// Returns the size required to fit a String considering a constrained max width.
|
|
///
|
|
/// - Parameters:
|
|
/// - text: The `String` used to calculate a size that fits.
|
|
/// - maxWidth: The max width available for the label.
|
|
internal func labelSize(for text: String, considering maxWidth: CGFloat, and font: UIFont) -> CGSize {
|
|
|
|
let estimatedHeight = text.height(considering: maxWidth, and: font)
|
|
let estimatedWidth = text.width(considering: estimatedHeight, and: font)
|
|
|
|
let finalHeight = estimatedHeight.rounded(.up)
|
|
let finalWidth = estimatedWidth > maxWidth ? maxWidth : estimatedWidth.rounded(.up)
|
|
|
|
return CGSize(width: finalWidth, height: finalHeight)
|
|
}
|
|
|
|
/// Convenience property for accessing the layout object's `MessagesCollectionView`.
|
|
internal var messagesCollectionView: MessagesCollectionView {
|
|
guard let messagesCollectionView = collectionView as? MessagesCollectionView else {
|
|
fatalError(MessageKitError.layoutUsedOnForeignType)
|
|
}
|
|
return messagesCollectionView
|
|
}
|
|
|
|
/// Convenience property for unwrapping the `MessagesCollectionView`'s `MessagesDataSource`.
|
|
internal var messagesDataSource: MessagesDataSource {
|
|
guard let messagesDataSource = messagesCollectionView.messagesDataSource else {
|
|
fatalError(MessageKitError.nilMessagesDataSource)
|
|
}
|
|
return messagesDataSource
|
|
}
|
|
|
|
/// Convenience property for unwrapping the `MessagesCollectionView`'s `MessagesLayoutDelegate`.
|
|
internal var messagesLayoutDelegate: MessagesLayoutDelegate {
|
|
guard let messagesLayoutDelegate = messagesCollectionView.messagesLayoutDelegate else {
|
|
fatalError(MessageKitError.nilMessagesLayoutDelegate)
|
|
}
|
|
return messagesLayoutDelegate
|
|
}
|
|
}
|