--- /dev/null
+//
+// ImageModifier.swift
+// Kingfisher
+//
+// Created by Ethan Gill on 2017/11/28.
+//
+// Copyright (c) 2018 Ethan Gill <ethan.gill@me.com>
+//
+// 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
+
+/// An `ImageModifier` can be used to change properties on an Image in between
+/// cache serialization and use of the image.
+public protocol ImageModifier {
+ /// Modify an input `Image`.
+ ///
+ /// - parameter image: Image which will be modified by `self`
+ ///
+ /// - returns: The modified image.
+ ///
+ /// - Note: The return value will be unmodified if modifying is not possible on
+ /// the current platform.
+ /// - Note: Most modifiers support UIImage or NSImage, but not CGImage.
+ func modify(_ image: Image) -> Image
+}
+
+extension ImageModifier {
+ func modify(_ image: Image?) -> Image? {
+ guard let image = image else {
+ return nil
+ }
+ return modify(image)
+ }
+}
+
+typealias ModifierImp = ((Image) -> Image)
+
+fileprivate struct GeneralModifier: ImageModifier {
+ let identifier: String
+ let m: ModifierImp
+ func modify(_ image: Image) -> Image {
+ return m(image)
+ }
+}
+
+/// The default modifier.
+/// Does nothing and returns the image it was given
+public struct DefaultImageModifier: ImageModifier {
+
+ /// A default `DefaultImageModifier` which can be used everywhere.
+ public static let `default` = DefaultImageModifier()
+
+ /// Initialize a `DefaultImageModifier`
+ private init() {}
+
+ /// Modify an input `Image`.
+ ///
+ /// - parameter image: Image which will be modified by `self`
+ ///
+ /// - returns: The modified image.
+ ///
+ /// - Note: See documentation of `ImageModifier` protocol for more.
+ public func modify(_ image: Image) -> Image {
+ return image
+ }
+}
+
+/// A custom modifier.
+/// Can be initialized with a block to modify images in a custom way
+public struct AnyImageModifier: ImageModifier {
+
+ /// A block which modifies images, or returns the original image
+ /// if modification cannot be performed.
+ let block: (Image) -> Image
+
+ /// Initialize an `AnyImageModifier`
+ public init(modify: @escaping (Image) -> Image) {
+ block = modify
+ }
+
+ /// Modifies an input `Image` using this `AnyImageModifier`'s `block`.
+ ///
+ /// - parameter image: Image which will be modified by `self`
+ ///
+ /// - returns: The modified image.
+ ///
+ /// - Note: See documentation of `ImageModifier` protocol for more.
+ public func modify(_ image: Image) -> Image {
+ return block(image)
+ }
+}
+
+#if os(iOS) || os(tvOS) || os(watchOS)
+import UIKit
+
+/// Modifier for setting the rendering mode of images.
+/// Only UI-based images are supported; if a non-UI image is passed in, the
+/// modifier will do nothing.
+public struct RenderingModeImageModifier: ImageModifier {
+
+ /// The rendering mode to apply to the image.
+ public let renderingMode: UIImageRenderingMode
+
+ /// Initialize a `RenderingModeImageModifier`
+ ///
+ /// - parameter renderingMode: The rendering mode to apply to the image.
+ /// Default is .automatic
+ public init(renderingMode: UIImageRenderingMode = .automatic) {
+ self.renderingMode = renderingMode
+ }
+
+ /// Modify an input `Image`.
+ ///
+ /// - parameter image: Image which will be modified by `self`
+ ///
+ /// - returns: The modified image.
+ ///
+ /// - Note: See documentation of `ImageModifier` protocol for more.
+ public func modify(_ image: Image) -> Image {
+ return image.withRenderingMode(renderingMode)
+ }
+}
+
+/// Modifier for setting the `flipsForRightToLeftLayoutDirection` property of images.
+/// Only UI-based images are supported; if a non-UI image is passed in, the
+/// modifier will do nothing.
+public struct FlipsForRightToLeftLayoutDirectionImageModifier: ImageModifier {
+ /// Initialize a `FlipsForRightToLeftLayoutDirectionImageModifier`
+ ///
+ /// - Note: On versions of iOS lower than 9.0, the image will be returned
+ /// unmodified.
+ public init() {}
+
+ /// Modify an input `Image`.
+ ///
+ /// - parameter image: Image which will be modified by `self`
+ ///
+ /// - returns: The modified image.
+ ///
+ /// - Note: See documentation of `ImageModifier` protocol for more.
+ public func modify(_ image: Image) -> Image {
+ if #available(iOS 9.0, *) {
+ return image.imageFlippedForRightToLeftLayoutDirection()
+ } else {
+ return image
+ }
+ }
+}
+
+/// Modifier for setting the `alignmentRectInsets` property of images.
+/// Only UI-based images are supported; if a non-UI image is passed in, the
+/// modifier will do nothing.
+public struct AlignmentRectInsetsImageModifier: ImageModifier {
+
+ /// The alignment insets to apply to the image
+ public let alignmentInsets: UIEdgeInsets
+
+ /// Initialize a `AlignmentRectInsetsImageModifier`
+ public init(alignmentInsets: UIEdgeInsets) {
+ self.alignmentInsets = alignmentInsets
+ }
+
+ /// Modify an input `Image`.
+ ///
+ /// - parameter image: Image which will be modified by `self`
+ ///
+ /// - returns: The modified image.
+ ///
+ /// - Note: See documentation of `ImageModifier` protocol for more.
+ public func modify(_ image: Image) -> Image {
+ return image.withAlignmentRectInsets(alignmentInsets)
+ }
+}
+#endif
fnp / wl-app.git / blobdiff