Add support for text editors

Sources/Core/View/TextEditor.swift

@@ -0,0 +1,105 @@
+//
+//  TextEditor.swift
+//  Adwaita
+//
+//  Created by david-swift on 09.08.25.
+//
+
+import CAdw
+
+/// A text editor widget.
+public typealias TextEditor = TextView
+
+/// A text editor widget.
+public struct TextView: AdwaitaWidget {
+
+    /// The editor's content.
+    @Binding var text: String
+    /// The padding between the border and the content.
+    var padding = 0
+    /// The edges affected by the padding.
+    var paddingEdges: Set<Edge> = []
+
+    /// Initialize a text editor.
+    /// - Parameter text: The editor's content.
+    public init(text: Binding<String>) {
+        self._text = text
+    }
+
+    /// Get the editor's view storage.
+    /// - Parameters:
+    ///     - data: The widget data.
+    ///     - type: The view render data type.
+    /// - Returns: The view storage.
+    public func container<Data>(data: WidgetData, type: Data.Type) -> ViewStorage {
+        let buffer = ViewStorage(gtk_text_buffer_new(nil)?.opaque())
+        let editor = ViewStorage(
+            gtk_text_view_new_with_buffer(buffer.opaquePointer?.cast())?.opaque(),
+            content: ["buffer": [buffer]]
+        )
+        update(editor, data: data, updateProperties: true, type: type)
+        return editor
+    }
+
+    /// Update a view storage to the editor.
+    /// - Parameters:
+    ///     - storage: The view storage.
+    ///     - data: The widget data.
+    ///     - updateProperties: Whether to update the view's properties.
+    ///     - type: The view render data type.
+    public func update<Data>(_ storage: ViewStorage, data: WidgetData, updateProperties: Bool, type: Data.Type) {
+        if let buffer = storage.content["buffer"]?.first {
+            buffer.connectSignal(name: "changed") {
+                let text = getText(buffer: buffer)
+                if self.text != text {
+                    self.text = text
+                }
+            }
+            if updateProperties {
+                if getText(buffer: buffer) != self.text {
+                    gtk_text_buffer_set_text(buffer.opaquePointer?.cast(), text, -1)
+                }
+            }
+        }
+        if updateProperties {
+            if paddingEdges.contains(.top) {
+                gtk_text_view_set_top_margin(storage.opaquePointer?.cast(), padding.cInt)
+            }
+            if paddingEdges.contains(.bottom) {
+                gtk_text_view_set_bottom_margin(storage.opaquePointer?.cast(), padding.cInt)
+            }
+            if paddingEdges.contains(.leading) {
+                gtk_text_view_set_left_margin(storage.opaquePointer?.cast(), padding.cInt)
+            }
+            if paddingEdges.contains(.trailing) {
+                gtk_text_view_set_right_margin(storage.opaquePointer?.cast(), padding.cInt)
+            }
+        }
+    }
+
+    /// Get the text view's content.
+    /// - Parameter buffer: The text view's buffer.
+    /// - Returns: The content.
+    func getText(buffer: ViewStorage) -> String {
+        let startIter: UnsafeMutablePointer<GtkTextIter> = .allocate(capacity: 1)
+        let endIter: UnsafeMutablePointer<GtkTextIter> = .allocate(capacity: 1)
+        gtk_text_buffer_get_start_iter(buffer.opaquePointer?.cast(), startIter)
+        gtk_text_buffer_get_end_iter(buffer.opaquePointer?.cast(), endIter)
+        return .init(
+            cString: gtk_text_buffer_get_text(buffer.opaquePointer?.cast(), startIter, endIter, true.cBool)
+        )
+    }
+
+    /// Add padding between the editor's content and border.
+    /// - Parameters:
+    ///     - padding: The padding's value.
+    ///     - edges: The affected edges.
+    /// - Returns: The editor.
+    public func innerPadding(_ padding: Int = 10, edges: Set<Edge> = .all) -> Self {
+        var newSelf = self
+        newSelf.padding = padding
+        newSelf.paddingEdges = edges
+        return newSelf
+    }
+
+}

Sources/Demo/Page.swift

@@ -32,6 +32,7 @@ enum Page: String, Identifiable, CaseIterable, Codable, CustomStringConvertible
     case picture
     case idle
     case fixed
+    case textEditor
 
     var id: Self {
         self
@@ -49,6 +50,8 @@ enum Page: String, Identifiable, CaseIterable, Codable, CustomStringConvertible
             return "Alert Dialog"
         case .passwordChecker:
             return "Password Checker"
+        case .textEditor:
+            return "Text Editor"
         default:
             return rawValue.capitalized
         }
@@ -105,6 +108,8 @@ enum Page: String, Identifiable, CaseIterable, Codable, CustomStringConvertible
             return "Update UI from an asynchronous context"
         case .fixed:
             return "Place widgets in a coordinate system"
+        case .textEditor:
+            return "A simple text editor"
         }
     }
 
@@ -152,6 +157,8 @@ enum Page: String, Identifiable, CaseIterable, Codable, CustomStringConvertible
             IdleDemo()
         case .fixed:
             FixedDemo()
+        case .textEditor:
+            TextEditorDemo()
         }
     }
     // swiftlint:enable cyclomatic_complexity

Sources/Demo/TextEditorDemo.swift

@@ -0,0 +1,38 @@
+//
+//  TextEditorDemo.swift
+//  Adwaita
+//
+//  Created by david-swift on 09.08.25.
+//
+
+// swiftlint:disable missing_docs
+
+import Adwaita
+import Foundation
+
+struct TextEditorDemo: View {
+
+    @State private var text = "Hello, world!"
+
+    var view: Body {
+        VStack(spacing: 20) {
+            TextEditor(text: $text)
+                .innerPadding(20)
+                .frame(minHeight: 60)
+                .card()
+            VStack {
+                Text(text)
+                    .selectable()
+                    .wrap()
+                    .hexpand()
+                    .padding(20)
+                    .halign(.fill)
+            }
+            .card()
+        }
+        .frame(maxWidth: 500)
+    }
+
+}
+
+// swiftlint:enable missing_docs