signalapp/Signal-iOS
signalapp/Signal-iOS
1
0
Fork 0
Code Issues Pull Requests Actions 1 Packages Projects Releases 4 Wiki Activity

Add TextContext.

Browse Source
This commit is contained in:
Matthew Chen 2021-08-09 11:46:06 -03:00
parent 6940837ced
commit 23ee2bfbcc
1 changed files with 12 additions and 43 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

55
SignalMessaging/Views/ConversationView/CVText.swift
View File

@ -135,8 +135,8 @@ public struct CVLabelConfig {
self.text.apply(label: label)
}
public func measure(maxWidth: CGFloat, textContext: CVText.TextContext) -> CGSize {
let size = CVText.measureLabel(config: self, maxWidth: maxWidth, textContext: textContext)
public func measure(maxWidth: CGFloat) -> CGSize {
let size = CVText.measureLabel(config: self, maxWidth: maxWidth)
if size.width > maxWidth {
owsFailDebug("size.width: \(size.width) > maxWidth: \(maxWidth)")
}
@ -232,36 +232,15 @@ public class CVText {
private static var cacheMeasurements = true
// MARK: - TextContext
// MARK: - ContextState
// We use NSTextStorage to measure text.
// We use NSTextStorage to measure text. During measurement,
// NSTextStorage.processEditing() posts notifications to main thread
// and in doing so blocks on the main thread.
// Therefore it is not safe to simultaneously do measurement on two
// threads if one of them is the main thread unless we use separate
// UnfairLocks or we can hit deadlock. If we use separate UnfairLocks
// we need to use separate caches.
public enum TextContext {
case mainThread
case homeViewAsync
case conversationViewAsync
static var forHomeView: TextContext {
if Thread.isMainThread {
return .mainThread
} else {
return .homeViewAsync
}
}
static var forConversationView: TextContext {
if Thread.isMainThread {
return .mainThread
} else {
return .conversationViewAsync
}
}
}
private class ContextState {
let unfairLock = UnfairLock()
let labelCache: LRUCache<CacheKey, CGSize>
@ -272,18 +251,10 @@ public class CVText {
bodyTextLabelCache = LRUCache<CacheKey, CGSize>(maxSize: cacheSize)
}
}
private static let mainThreadContextState = ContextState(cacheSize: 200)
private static let homeViewAsyncContextState = ContextState(cacheSize: 200)
private static let conversationViewAsyncContextState = ContextState(cacheSize: 500)
private static func contextState(forTextContext textContext: TextContext) -> ContextState {
switch textContext {
case .mainThread:
return Self.mainThreadContextState
case .homeViewAsync:
return Self.homeViewAsyncContextState
case .conversationViewAsync:
return Self.conversationViewAsyncContextState
}
private static let mainThreadContextState = ContextState(cacheSize: 300)
private static let offMainThreadContextState = ContextState(cacheSize: 500)
private static func currentContextState() -> ContextState {
Thread.isMainThread ? mainThreadContextState : offMainThreadContextState
}
// MARK: - UILabel
@ -308,9 +279,8 @@ public class CVText {
public static func measureLabel(mode: MeasurementMode = defaultLabelMeasurementMode,
config: CVLabelConfig,
maxWidth: CGFloat,
textContext: TextContext) -> CGSize {
let contextState = Self.contextState(forTextContext: textContext)
maxWidth: CGFloat) -> CGSize {
let contextState = Self.currentContextState()
return contextState.unfairLock.withLock {
measureLabelLocked(mode: mode, config: config, maxWidth: max(0, maxWidth), contextState: contextState)
}
@ -367,9 +337,8 @@ public class CVText {
// MARK: - CVBodyTextLabel
public static func measureBodyTextLabel(config: CVBodyTextLabel.Config,
maxWidth: CGFloat,
textContext: TextContext) -> CGSize {
let contextState = Self.contextState(forTextContext: textContext)
maxWidth: CGFloat) -> CGSize {
let contextState = Self.currentContextState()
return contextState.unfairLock.withLock {
measureBodyTextLabelLocked(config: config, maxWidth: maxWidth, contextState: contextState)
}