MessageKit/Sources/Controllers/MessagesViewController+State.swift

/*
 MIT License

 Copyright (c) 2017-2022 MessageKit

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */

import Foundation
import UIKit
import Combine
import InputBarAccessoryView

extension MessagesViewController {
    final class State {
        /// Pan gesture for display the date of message by swiping left.
        var panGesture: UIPanGestureRecognizer?
        var maintainPositionOnInputBarHeightChanged: Bool = false
        var scrollsToLastItemOnKeyboardBeginsEditing: Bool = false

        let inputContainerView: MessagesInputContainerView = .init()
        @Published var inputBarType: MessageInputBarKind = .messageInputBar
        let keyboardManager: KeyboardManager = KeyboardManager()
        var disposeBag: Set<AnyCancellable> = .init()
    }

    // MARK: - Getters

    var keyboardManager: KeyboardManager { state.keyboardManager }

    var panGesture: UIPanGestureRecognizer? {
        get { state.panGesture }
        set { state.panGesture = newValue }
    }

    var disposeBag: Set<AnyCancellable> {
        get { state.disposeBag }
        set { state.disposeBag = newValue }
    }
}

public extension MessagesViewController {
    /// Container holding `messageInputBar` view. To change type of input bar, set `inputBarType` to desired kind.
    var inputContainerView: MessagesInputContainerView { state.inputContainerView }

    /// Kind of `messageInputBar` to be added into `inputContainerView`
    var inputBarType: MessageInputBarKind {
        get { state.inputBarType }
        set { state.inputBarType = newValue }
    }

    /// A Boolean value that determines whether the `MessagesCollectionView`
    /// maintains it's current position when the height of the `MessageInputBar` changes.
    ///
    /// The default value of this property is `false`.
    @available(*, deprecated, renamed: "maintainPositionOnInputBarHeightChanged", message: "Please use new property - maintainPositionOnInputBarHeightChanged")
    var maintainPositionOnKeyboardFrameChanged: Bool {
        get { state.maintainPositionOnInputBarHeightChanged }
        set { state.maintainPositionOnInputBarHeightChanged = newValue }
    }

    /// A Boolean value that determines whether the `MessagesCollectionView`
    /// maintains it's current position when the height of the `MessageInputBar` changes.
    ///
    /// The default value of this property is `false` and the `MessagesCollectionView` will scroll to bottom after the
    /// height of the `MessageInputBar` changes.
    var maintainPositionOnInputBarHeightChanged: Bool {
        get { state.maintainPositionOnInputBarHeightChanged }
        set { state.maintainPositionOnInputBarHeightChanged = newValue }
    }

    /// A Boolean value that determines whether the `MessagesCollectionView` scrolls to the
    /// last item whenever the `InputTextView` begins editing.
    ///
    /// The default value of this property is `false`.
    /// NOTE: This is related to `scrollToLastItem` whereas the below flag is related to `scrollToBottom` - check each function for differences
    var scrollsToLastItemOnKeyboardBeginsEditing: Bool {
        get { state.scrollsToLastItemOnKeyboardBeginsEditing }
        set { state.scrollsToLastItemOnKeyboardBeginsEditing = newValue }
    }
}