Add `Image` implementation to the GTK renderer (#343)

* Add rudimentary Image support

* Added Image implementation and sample image

* Updated sample and scaled down image

* Removed commented code

* Update main.swift

Co-authored-by: Morten Bek Ditlevsen <morten@ka-ching.dk>

Package.swift

@@ -96,7 +96,8 @@ let package = Package(
     ),
     .target(
       name: "TokamakGTKDemo",
-      dependencies: ["TokamakGTK"]
+      dependencies: ["TokamakGTK"],
+      resources: [.copy("logo-header.png")]
     ),
     .target(
       name: "TokamakStaticHTML",

Sources/TokamakGTK/Core.swift

@@ -93,6 +93,7 @@ public typealias GeometryReader = TokamakCore.GeometryReader
 public typealias GridItem = TokamakCore.GridItem
 public typealias Group = TokamakCore.Group
 public typealias HStack = TokamakCore.HStack
+public typealias Image = TokamakCore.Image
 public typealias LazyHGrid = TokamakCore.LazyHGrid
 public typealias LazyVGrid = TokamakCore.LazyVGrid
 public typealias List = TokamakCore.List

Sources/TokamakGTK/Views/Image.swift

@@ -0,0 +1,40 @@
+// Copyright 2020 Tokamak contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//  Created by Morten Bek Ditlevsen on 14/12/2020.
+//
+
+import CGTK
+import Foundation
+import TokamakCore
+
+extension Image: AnyWidget {
+  func new(_ application: UnsafeMutablePointer<GtkApplication>) -> UnsafeMutablePointer<GtkWidget> {
+    let proxy = _ImageProxy(self)
+    let imagePath = proxy.path ?? proxy.name
+    let img = gtk_image_new_from_file(imagePath)!
+    return img
+  }
+
+  func update(widget: Widget) {
+    if case let .widget(w) = widget.storage {
+      let proxy = _ImageProxy(self)
+      let imagePath = proxy.path ?? proxy.name
+
+      w.withMemoryRebound(to: GtkImage.self, capacity: 1) {
+        gtk_image_set_from_file($0, imagePath)
+      }
+    }
+  }
+}

Sources/TokamakGTKDemo/main.swift

@@ -49,6 +49,7 @@ struct TokamakGTKDemo: App {
   var body: some Scene {
     WindowGroup("Test Scene") {
       List {
+        Image("logo-header.png", bundle: Bundle.module, label: Text("Tokamak Demo"))
         Counter()
         PickerDemo()
         ForEach(1..<100) {