Fixed some performance issues (#182)

<!--- IMPORTANT: If this PR addresses multiple unrelated issues, it will
be closed until separated. -->

### Description

This PR fixes an issue where the view would be reloaded too often. This
happened because `updateNSViewController` is called too often. This
mostly happens because of a change in the environment, which gets passed
to the NSViewControllerRepresentable in the `context` variable.

Manual diffing is applied to check if any variables that matter have
changed. If not, nothing is updated.

The initializer has also changed, a few variables are now just values
instead of bindings. These don't have to be bindings, as the textview
won't update variables.

### Related Issues

CodeEditApp/CodeEdit#1247

### Checklist

<!--- Add things that are not yet implemented above -->

- [x] I read and understood the [contributing
guide](https://github.com/CodeEditApp/CodeEdit/blob/main/CONTRIBUTING.md)
as well as the [code of
conduct](https://github.com/CodeEditApp/CodeEdit/blob/main/CODE_OF_CONDUCT.md)
- [x] The issues this PR addresses are related to each other
- [x] My changes generate no new warnings
- [x] My code builds and runs on my machine
- [x] My changes are all related to the related issue above
- [x] I documented my code

### Screenshots

<!--- REQUIRED: if issue is UI related -->

<!--- IMPORTANT: Fill out all required fields. Otherwise we might close
this PR temporarily -->

Signed-off-by: Wouter01 <[email protected]>

Author: Wouter01

Sources/CodeEditTextView/CodeEditTextView.swift

@@ -36,13 +36,13 @@ public struct CodeEditTextView: NSViewControllerRepresentable {
     public init(
         _ text: Binding<String>,
         language: CodeLanguage,
-        theme: Binding<EditorTheme>,
-        font: Binding<NSFont>,
-        tabWidth: Binding<Int>,
-        indentOption: Binding<IndentOption> = .constant(.spaces(count: 4)),
-        lineHeight: Binding<Double>,
-        wrapLines: Binding<Bool>,
-        editorOverscroll: Binding<Double> = .constant(0.0),
+        theme: EditorTheme,
+        font: NSFont,
+        tabWidth: Int,
+        indentOption: IndentOption = .spaces(count: 4),
+        lineHeight: Double,
+        wrapLines: Bool,
+        editorOverscroll: Double = 0.0,
         cursorPosition: Binding<(Int, Int)>,
         useThemeBackground: Bool = true,
         highlightProvider: HighlightProviding? = nil,
@@ -52,14 +52,14 @@ public struct CodeEditTextView: NSViewControllerRepresentable {
     ) {
         self._text = text
         self.language = language
-        self._theme = theme
+        self.theme = theme
         self.useThemeBackground = useThemeBackground
-        self._font = font
-        self._tabWidth = tabWidth
-        self._indentOption = indentOption
-        self._lineHeight = lineHeight
-        self._wrapLines = wrapLines
-        self._editorOverscroll = editorOverscroll
+        self.font = font
+        self.tabWidth = tabWidth
+        self.indentOption = indentOption
+        self.lineHeight = lineHeight
+        self.wrapLines = wrapLines
+        self.editorOverscroll = editorOverscroll
         self._cursorPosition = cursorPosition
         self.highlightProvider = highlightProvider
         self.contentInsets = contentInsets
@@ -69,13 +69,13 @@ public struct CodeEditTextView: NSViewControllerRepresentable {
 
     @Binding private var text: String
     private var language: CodeLanguage
-    @Binding private var theme: EditorTheme
-    @Binding private var font: NSFont
-    @Binding private var tabWidth: Int
-    @Binding private var indentOption: IndentOption
-    @Binding private var lineHeight: Double
-    @Binding private var wrapLines: Bool
-    @Binding private var editorOverscroll: Double
+    private var theme: EditorTheme
+    private var font: NSFont
+    private var tabWidth: Int
+    private var indentOption: IndentOption
+    private var lineHeight: Double
+    private var wrapLines: Bool
+    private var editorOverscroll: Double
     @Binding private var cursorPosition: (Int, Int)
     private var useThemeBackground: Bool
     private var highlightProvider: HighlightProviding?
@@ -107,6 +107,12 @@ public struct CodeEditTextView: NSViewControllerRepresentable {
     }
 
     public func updateNSViewController(_ controller: NSViewControllerType, context: Context) {
+        // Do manual diffing to reduce the amount of reloads.
+        // This helps a lot in view performance, as it otherwise gets triggered on each environment change.
+        guard !paramsAreEqual(controller: controller) else {
+            return
+        }
+
         controller.font = font
         controller.wrapLines = wrapLines
         controller.useThemeBackground = useThemeBackground
@@ -134,4 +140,18 @@ public struct CodeEditTextView: NSViewControllerRepresentable {
         controller.reloadUI()
         return
     }
+
+    func paramsAreEqual(controller: NSViewControllerType) -> Bool {
+        controller.font == font &&
+        controller.wrapLines == wrapLines &&
+        controller.useThemeBackground == useThemeBackground &&
+        controller.lineHeightMultiple == lineHeight &&
+        controller.editorOverscroll == editorOverscroll &&
+        controller.contentInsets == contentInsets &&
+        controller.language.id == language.id &&
+        controller.theme == theme &&
+        controller.indentOption == indentOption &&
+        controller.tabWidth == tabWidth &&
+        controller.letterSpacing == letterSpacing
+    }
 }

Sources/CodeEditTextView/Extensions/NSEdgeInsets+Equatable.swift

@@ -0,0 +1,17 @@
+//
+//  NSEdgeInsets+Equatable.swift
+//  
+//
+//  Created by Wouter Hennen on 29/04/2023.
+//
+
+import Foundation
+
+extension NSEdgeInsets: Equatable {
+    public static func == (lhs: NSEdgeInsets, rhs: NSEdgeInsets) -> Bool {
+        lhs.bottom == rhs.bottom &&
+        lhs.top == rhs.top &&
+        lhs.left == rhs.left &&
+        lhs.right == rhs.right
+    }
+}