From 11ade8e54b98a58b3e1c70ce41c2b6f22bdf43c3 Mon Sep 17 00:00:00 2001
From: Riley Testut <riley@rileytestut.com>
Date: Wed, 24 May 2023 16:19:58 -0500
Subject: [PATCH] Fixes AppViewController scrolling performance for apps with
 several privacy permissions

---
 AltStore/Components/CollapsingTextView.swift | 54 +++++++++++++-------
 1 file changed, 35 insertions(+), 19 deletions(-)

diff --git a/AltStore/Components/CollapsingTextView.swift b/AltStore/Components/CollapsingTextView.swift
index 8ffef7a3..fb995221 100644
--- a/AltStore/Components/CollapsingTextView.swift
+++ b/AltStore/Components/CollapsingTextView.swift
@@ -12,18 +12,23 @@ class CollapsingTextView: UITextView
 {
     var isCollapsed = true {
         didSet {
+            guard self.isCollapsed != oldValue else { return }
+            self.shouldResetLayout = true
             self.setNeedsLayout()
         }
     }
     
     var maximumNumberOfLines = 2 {
         didSet {
+            self.shouldResetLayout = true
             self.setNeedsLayout()
         }
     }
     
     var lineSpacing: Double = 2 {
         didSet {
+            self.shouldResetLayout = true
+            
             if #available(iOS 16, *)
             {
                 self.updateText()
@@ -37,6 +42,8 @@ class CollapsingTextView: UITextView
     
     override var text: String! {
         didSet {
+            self.shouldResetLayout = true
+            
             guard #available(iOS 16, *) else { return }
             self.updateText()
         }
@@ -44,6 +51,9 @@ class CollapsingTextView: UITextView
     
     let moreButton = UIButton(type: .system)
     
+    private var shouldResetLayout: Bool = false
+    private var previousSize: CGSize?
+    
     override init(frame: CGRect, textContainer: NSTextContainer?)
     {
         super.init(frame: frame, textContainer: textContainer)
@@ -105,38 +115,44 @@ class CollapsingTextView: UITextView
                                      height: font.lineHeight)
         self.moreButton.frame = moreButtonFrame
         
-        if self.isCollapsed
+        if self.shouldResetLayout || self.previousSize != self.bounds.size
         {
-            self.textContainer.maximumNumberOfLines = self.maximumNumberOfLines
-            
-            let boundingSize = self.attributedText.boundingRect(with: CGSize(width: self.textContainer.size.width, height: .infinity), options: [.usesLineFragmentOrigin, .usesFontLeading], context: nil)
-            let maximumCollapsedHeight = font.lineHeight * Double(self.maximumNumberOfLines)
-            
-            if boundingSize.height.rounded() > maximumCollapsedHeight.rounded()
+            if self.isCollapsed
             {
-                var exclusionFrame = moreButtonFrame
-                exclusionFrame.origin.y += self.moreButton.bounds.midY
-                exclusionFrame.size.width = self.bounds.width // Extra wide to make sure it wraps to next line.
-                self.textContainer.exclusionPaths = [UIBezierPath(rect: exclusionFrame)]
+                self.textContainer.maximumNumberOfLines = self.maximumNumberOfLines
                 
-                self.moreButton.isHidden = false
+                let boundingSize = self.attributedText.boundingRect(with: CGSize(width: self.textContainer.size.width, height: .infinity), options: [.usesLineFragmentOrigin, .usesFontLeading], context: nil)
+                let maximumCollapsedHeight = font.lineHeight * Double(self.maximumNumberOfLines)
+                
+                if boundingSize.height.rounded() > maximumCollapsedHeight.rounded()
+                {
+                    var exclusionFrame = moreButtonFrame
+                    exclusionFrame.origin.y += self.moreButton.bounds.midY
+                    exclusionFrame.size.width = self.bounds.width // Extra wide to make sure it wraps to next line.
+                    self.textContainer.exclusionPaths = [UIBezierPath(rect: exclusionFrame)]
+                    
+                    self.moreButton.isHidden = false
+                }
+                else
+                {
+                    self.textContainer.exclusionPaths = []
+                    
+                    self.moreButton.isHidden = true
+                }
             }
             else
             {
+                self.textContainer.maximumNumberOfLines = 0
                 self.textContainer.exclusionPaths = []
                 
                 self.moreButton.isHidden = true
             }
-        }
-        else
-        {
-            self.textContainer.maximumNumberOfLines = 0
-            self.textContainer.exclusionPaths = []
             
-            self.moreButton.isHidden = true
+            self.invalidateIntrinsicContentSize()
         }
         
-        self.invalidateIntrinsicContentSize()
+        self.shouldResetLayout = false
+        self.previousSize = self.bounds.size
     }
 }