NetNewsWire/Mac/MainWindow/Timeline/Cell/SingleLineTextFieldSizer.swift

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//
// SingleLineTextFieldSizer.swift
2018-08-29 07:18:24 +02:00
// NetNewsWire
//
// Created by Brent Simmons on 2/19/18.
// Copyright © 2018 Ranchero Software. All rights reserved.
//
import AppKit
// Get the size of an NSTextField configured with a specific font with a specific size.
// Uses a cache.
// Main thready only.
final class SingleLineTextFieldSizer {
let font: NSFont
private let textField: NSTextField
private var cache = [String: NSSize]()
/// Get the NSTextField size for text, given a font.
static func size(for text: String, font: NSFont) -> NSSize {
return sizer(for: font).size(for: text)
}
init(font: NSFont) {
self.textField = NSTextField(labelWithString: "")
self.textField.font = font
self.font = font
}
func size(for text: String) -> NSSize {
if let cachedSize = cache[text] {
return cachedSize
}
textField.stringValue = text
var calculatedSize = textField.fittingSize
calculatedSize.height = ceil(calculatedSize.height)
calculatedSize.width = ceil(calculatedSize.width)
cache[text] = calculatedSize
return calculatedSize
}
static private var sizers = [SingleLineTextFieldSizer]()
static private func sizer(for font: NSFont) -> SingleLineTextFieldSizer {
// We used to use an [NSFont: SingleLineTextFieldSizer] dictionary
// until, in 10.14.5, we started getting crashes with the message:
// Fatal error: Duplicate keys of type 'NSFont' were found in a Dictionary.
// This usually means either that the type violates Hashable's requirements, or
// that members of such a dictionary were mutated after insertion.
// We use just an array of sizers now which is totally fine,
// because theres only going to be like three of them.
if let cachedSizer = sizers.firstElementPassingTest({ $0.font == font }) {
return cachedSizer
}
let newSizer = SingleLineTextFieldSizer(font: font)
sizers.append(newSizer)
return newSizer
}
}