Find Method Picker (CodeEditApp#322)

### Description

Added find method picker that changes the method by which text is found.
Options include:
- Contains
- Match Word
- Starts With
- Ends With
- Regular Expression

### Related Issues

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<!--- If this PR resolves the issue please specify (e.g. * closes CodeEditApp#123)
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<!--- If this PR addresses multiple issues, these issues must be related
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* CodeEditApp/CodeEditTextView#1

### Checklist

- [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


https://github.com/user-attachments/assets/8d68602a-13ec-4422-8c5c-518a5b0b9b67

<img width="782" alt="image"
src="https://github.com/user-attachments/assets/ae1984f1-d5f0-4ec2-a706-5bb553b17063"
/>

<img width="782" alt="image"
src="https://github.com/user-attachments/assets/81bc1e77-7adf-4d9c-976c-d695d53a0f0e"
/>

<img width="493" alt="image"
src="https://github.com/user-attachments/assets/01bea694-6ba8-43fb-9e73-1445f031548b"
/>

<img width="493" alt="image"
src="https://github.com/user-attachments/assets/5877859c-817f-4c0c-9412-bd8f2f27ce34"
/>

---------

Co-authored-by: Khan Winter <35942988+thecoolwinter@users.noreply.github.com>

Author: austincondiff

Sources/CodeEditSourceEditor/Find/FindMethod.swift

@@ -0,0 +1,29 @@
+//
+//  FindMethod.swift
+//  CodeEditSourceEditor
+//
+//  Created by Austin Condiff on 5/2/25.
+//
+
+enum FindMethod: CaseIterable {
+    case contains
+    case matchesWord
+    case startsWith
+    case endsWith
+    case regularExpression
+
+    var displayName: String {
+        switch self {
+        case .contains:
+            return "Contains"
+        case .matchesWord:
+            return "Matches Word"
+        case .startsWith:
+            return "Starts With"
+        case .endsWith:
+            return "Ends With"
+        case .regularExpression:
+            return "Regular Expression"
+        }
+    }
+}

Sources/CodeEditSourceEditor/Find/PanelView/FindMethodPicker.swift

@@ -0,0 +1,222 @@
+//
+//  FindMethodPicker.swift
+//  CodeEditSourceEditor
+//
+//  Created by Austin Condiff on 5/2/25.
+//
+
+import SwiftUI
+
+/// A SwiftUI view that provides a method picker for the find panel.
+///
+/// The `FindMethodPicker` view is responsible for:
+/// - Displaying a dropdown menu to switch between different find methods
+/// - Managing the selected find method
+/// - Providing a visual indicator for the current method
+/// - Adapting its appearance based on the control's active state
+/// - Handling method selection
+struct FindMethodPicker: NSViewRepresentable {
+    @Binding var method: FindMethod
+    @Environment(\.controlActiveState) var activeState
+    var condensed: Bool = false
+
+    private func createPopupButton(context: Context) -> NSPopUpButton {
+        let popup = NSPopUpButton(frame: .zero, pullsDown: false)
+        popup.bezelStyle = .regularSquare
+        popup.isBordered = false
+        popup.controlSize = .small
+        popup.font = .systemFont(ofSize: NSFont.systemFontSize(for: .small))
+        popup.autoenablesItems = false
+        popup.setContentHuggingPriority(.defaultHigh, for: .horizontal)
+        popup.setContentCompressionResistancePriority(.defaultHigh, for: .horizontal)
+        popup.title = method.displayName
+        if condensed {
+            popup.isTransparent = true
+            popup.alphaValue = 0
+        }
+        return popup
+    }
+
+    private func createIconLabel() -> NSImageView {
+        let imageView = NSImageView()
+        let symbolName = method == .contains
+            ? "line.horizontal.3.decrease.circle"
+            : "line.horizontal.3.decrease.circle.fill"
+        imageView.image = NSImage(systemSymbolName: symbolName, accessibilityDescription: nil)?
+            .withSymbolConfiguration(.init(pointSize: 14, weight: .regular))
+        imageView.contentTintColor = method == .contains
+            ? (activeState == .inactive ? .tertiaryLabelColor : .labelColor)
+            : (activeState == .inactive ? .tertiaryLabelColor : .controlAccentColor)
+        return imageView
+    }
+
+    private func createChevronLabel() -> NSImageView {
+        let imageView = NSImageView()
+        imageView.image = NSImage(systemSymbolName: "chevron.down", accessibilityDescription: nil)?
+            .withSymbolConfiguration(.init(pointSize: 8, weight: .black))
+        imageView.contentTintColor = activeState == .inactive ? .tertiaryLabelColor : .secondaryLabelColor
+        return imageView
+    }
+
+    private func createMenu(context: Context) -> NSMenu {
+        let menu = NSMenu()
+
+        // Add method items
+        FindMethod.allCases.forEach { method in
+            let item = NSMenuItem(
+                title: method.displayName,
+                action: #selector(Coordinator.methodSelected(_:)),
+                keyEquivalent: ""
+            )
+            item.target = context.coordinator
+            item.tag = FindMethod.allCases.firstIndex(of: method) ?? 0
+            item.state = method == self.method ? .on : .off
+            menu.addItem(item)
+        }
+
+        // Add separator before regular expression
+        menu.insertItem(.separator(), at: 4)
+
+        return menu
+    }
+
+    private func setupConstraints(
+        container: NSView,
+        popup: NSPopUpButton,
+        iconLabel: NSImageView? = nil,
+        chevronLabel: NSImageView? = nil
+    ) {
+        popup.translatesAutoresizingMaskIntoConstraints = false
+        iconLabel?.translatesAutoresizingMaskIntoConstraints = false
+        chevronLabel?.translatesAutoresizingMaskIntoConstraints = false
+
+        var constraints: [NSLayoutConstraint] = []
+
+        if condensed {
+            constraints += [
+                popup.leadingAnchor.constraint(equalTo: container.leadingAnchor),
+                popup.trailingAnchor.constraint(equalTo: container.trailingAnchor),
+                popup.topAnchor.constraint(equalTo: container.topAnchor),
+                popup.bottomAnchor.constraint(equalTo: container.bottomAnchor),
+                popup.widthAnchor.constraint(equalToConstant: 36),
+                popup.heightAnchor.constraint(equalToConstant: 20)
+            ]
+        } else {
+            constraints += [
+                popup.leadingAnchor.constraint(equalTo: container.leadingAnchor, constant: 4),
+                popup.trailingAnchor.constraint(equalTo: container.trailingAnchor, constant: -4),
+                popup.topAnchor.constraint(equalTo: container.topAnchor),
+                popup.bottomAnchor.constraint(equalTo: container.bottomAnchor)
+            ]
+        }
+
+        if let iconLabel = iconLabel {
+            constraints += [
+                iconLabel.leadingAnchor.constraint(equalTo: container.leadingAnchor, constant: 8),
+                iconLabel.centerYAnchor.constraint(equalTo: container.centerYAnchor),
+                iconLabel.widthAnchor.constraint(equalToConstant: 14),
+                iconLabel.heightAnchor.constraint(equalToConstant: 14)
+            ]
+        }
+
+        if let chevronLabel = chevronLabel {
+            constraints += [
+                chevronLabel.trailingAnchor.constraint(equalTo: container.trailingAnchor, constant: -6),
+                chevronLabel.centerYAnchor.constraint(equalTo: container.centerYAnchor),
+                chevronLabel.widthAnchor.constraint(equalToConstant: 8),
+                chevronLabel.heightAnchor.constraint(equalToConstant: 8)
+            ]
+        }
+
+        NSLayoutConstraint.activate(constraints)
+    }
+
+    func makeNSView(context: Context) -> NSView {
+        let container = NSView()
+        container.wantsLayer = true
+
+        let popup = createPopupButton(context: context)
+        popup.menu = createMenu(context: context)
+        popup.selectItem(at: FindMethod.allCases.firstIndex(of: method) ?? 0)
+
+        container.addSubview(popup)
+
+        if condensed {
+            let iconLabel = createIconLabel()
+            let chevronLabel = createChevronLabel()
+            container.addSubview(iconLabel)
+            container.addSubview(chevronLabel)
+            setupConstraints(container: container, popup: popup, iconLabel: iconLabel, chevronLabel: chevronLabel)
+        } else {
+            setupConstraints(container: container, popup: popup)
+        }
+
+        return container
+    }
+
+    func updateNSView(_ container: NSView, context: Context) {
+        guard let popup = container.subviews.first as? NSPopUpButton else { return }
+
+        // Update selection, title, and color
+        popup.selectItem(at: FindMethod.allCases.firstIndex(of: method) ?? 0)
+        popup.title = method.displayName
+        popup.contentTintColor = activeState == .inactive ? .tertiaryLabelColor : .labelColor
+        if condensed {
+            popup.isTransparent = true
+            popup.alphaValue = 0
+        } else {
+            popup.isTransparent = false
+            popup.alphaValue = 1
+        }
+
+        // Update menu items state
+        popup.menu?.items.forEach { item in
+            let index = item.tag
+            if index < FindMethod.allCases.count {
+                item.state = FindMethod.allCases[index] == method ? .on : .off
+            }
+        }
+
+        // Update icon and chevron colors
+        if condensed {
+            if let iconLabel = container.subviews[1] as? NSImageView {
+                let symbolName = method == .contains
+                    ? "line.horizontal.3.decrease.circle"
+                    : "line.horizontal.3.decrease.circle.fill"
+                iconLabel.image = NSImage(systemSymbolName: symbolName, accessibilityDescription: nil)?
+                    .withSymbolConfiguration(.init(pointSize: 14, weight: .regular))
+                iconLabel.contentTintColor = method == .contains
+                    ? (activeState == .inactive ? .tertiaryLabelColor : .labelColor)
+                    : (activeState == .inactive ? .tertiaryLabelColor : .controlAccentColor)
+            }
+            if let chevronLabel = container.subviews[2] as? NSImageView {
+                chevronLabel.contentTintColor = activeState == .inactive ? .tertiaryLabelColor : .secondaryLabelColor
+            }
+        }
+    }
+
+    func makeCoordinator() -> Coordinator {
+        Coordinator(method: $method)
+    }
+
+    var body: some View {
+        self.fixedSize()
+    }
+
+    class Coordinator: NSObject {
+        @Binding var method: FindMethod
+
+        init(method: Binding<FindMethod>) {
+            self._method = method
+        }
+
+        @objc func methodSelected(_ sender: NSMenuItem) {
+            method = FindMethod.allCases[sender.tag]
+        }
+    }
+}
+
+#Preview("Find Method Picker") {
+    FindMethodPicker(method: .constant(.contains))
+        .padding()
+}

Sources/CodeEditSourceEditor/Find/PanelView/FindSearchField.swift

@@ -94,6 +94,8 @@ struct FindSearchField: View {
                         .frame(width: 30, height: 20)
                 })
                 .toggleStyle(.icon)
+                Divider()
+                FindMethodPicker(method: $viewModel.findMethod, condensed: condensed)
             },
             helperText: helperText,
             clearable: true

Sources/CodeEditSourceEditor/Find/ViewModel/FindPanelViewModel+Find.swift

@@ -20,22 +20,52 @@ extension FindPanelViewModel {
         }
 
         // Set case sensitivity based on matchCase property
-        let findOptions: NSRegularExpression.Options = matchCase ? [] : [.caseInsensitive]
-        let escapedQuery = NSRegularExpression.escapedPattern(for: findText)
+        var findOptions: NSRegularExpression.Options = matchCase ? [] : [.caseInsensitive]
 
-        guard let regex = try? NSRegularExpression(pattern: escapedQuery, options: findOptions) else {
+        // Add multiline options for regular expressions
+        if findMethod == .regularExpression {
+            findOptions.insert(.dotMatchesLineSeparators)
+            findOptions.insert(.anchorsMatchLines)
+        }
+
+        let pattern: String
+
+        switch findMethod {
+        case .contains:
+            // Simple substring match, escape special characters
+            pattern = NSRegularExpression.escapedPattern(for: findText)
+
+        case .matchesWord:
+            // Match whole words only using word boundaries
+            pattern = "\\b" + NSRegularExpression.escapedPattern(for: findText) + "\\b"
+
+        case .startsWith:
+            // Match at the start of a line or after a word boundary
+            pattern = "(?:^|\\b)" + NSRegularExpression.escapedPattern(for: findText)
+
+        case .endsWith:
+            // Match at the end of a line or before a word boundary
+            pattern = NSRegularExpression.escapedPattern(for: findText) + "(?:$|\\b)"
+
+        case .regularExpression:
+            // Use the pattern directly without additional escaping
+            pattern = findText
+        }
+
+        guard let regex = try? NSRegularExpression(pattern: pattern, options: findOptions) else {
             self.findMatches = []
-            self.currentFindMatchIndex = 0
+            self.currentFindMatchIndex = nil
             return
         }
 
         let text = target.textView.string
-        let matches = regex.matches(in: text, range: NSRange(location: 0, length: text.utf16.count))
+        let range = target.textView.documentRange
+        let matches = regex.matches(in: text, range: range).filter { !$0.range.isEmpty }
 
         self.findMatches = matches.map(\.range)
 
         // Find the nearest match to the current cursor position
-        currentFindMatchIndex = getNearestEmphasisIndex(matchRanges: findMatches) ?? 0
+        currentFindMatchIndex = getNearestEmphasisIndex(matchRanges: findMatches)
 
         // Only add emphasis layers if the find panel is focused
         if isFocused {

Sources/CodeEditSourceEditor/Find/ViewModel/FindPanelViewModel.swift

@@ -24,6 +24,13 @@ class FindPanelViewModel: ObservableObject {
             self.target?.findPanelModeDidChange(to: mode)
         }
     }
+    @Published var findMethod: FindMethod = .contains {
+        didSet {
+            if !findText.isEmpty {
+                find()
+            }
+        }
+    }
 
     @Published var isFocused: Bool = false