39 lines
1.2 KiB
Swift
39 lines
1.2 KiB
Swift
//
|
|
// Copyright 2022-2024 New Vector Ltd.
|
|
//
|
|
// SPDX-License-Identifier: AGPL-3.0-only
|
|
// Please see LICENSE in the repository root for full details.
|
|
//
|
|
|
|
import Foundation
|
|
|
|
/// Simple view model that computes the placeholder avatar properties.
|
|
struct PlaceholderAvatarViewModel {
|
|
/// The displayname used to create the `firstCharacterCapitalized`.
|
|
let displayName: String?
|
|
/// The matrix id used as input to create the `stableColorIndex` from.
|
|
let matrixItemId: String
|
|
/// The number of total colors available for the `stableColorIndex`.
|
|
let colorCount: Int
|
|
|
|
/// Get the first character of the display name capitalized or else a space character.
|
|
var firstCharacterCapitalized: Character {
|
|
displayName?.capitalized.first ?? " "
|
|
}
|
|
|
|
/// Provides the same color each time for a specified matrixId
|
|
///
|
|
/// Same algorithm as in AvatarGenerator.
|
|
/// - Parameters:
|
|
/// - matrixItemId: the matrix id used as input to create the stable index.
|
|
/// - Returns: The stable index.
|
|
var stableColorIndex: Int {
|
|
// Sum all characters
|
|
let sum = matrixItemId.utf8
|
|
.map { UInt($0) }
|
|
.reduce(0, +)
|
|
// modulo the color count
|
|
return Int(sum) % colorCount
|
|
}
|
|
}
|