Add Clipboard handling (#8)

* add getClipboardText()

* Add Clipboard protocol

* Provide SDLClipboard implementation

* Test clipboard interaction

* Remove unused function

Co-authored-by: Christian Treffs <ctreffs@gmail.com>

Author: UnGast

Sources/FirebladePAL/Clipboard.swift

@@ -0,0 +1,17 @@
+//
+// Clipboard.swift
+// Fireblade PAL
+//
+// Copyright © 2018-2021 Fireblade Team. All rights reserved.
+// Licensed under MIT License. See LICENSE file for details.
+
+public protocol Clipboard {
+    /// Get UTF-8 text from the clipboard.
+    func getText() throws -> String
+
+    /// Put UTF-8 text into the clipboard.
+    func setText(_ text: String) throws
+
+    /// Query whether the clipboard exists and contains a non-empty text string.
+    func hasText() -> Bool
+}

Sources/FirebladePAL/Platform.swift

@@ -68,4 +68,18 @@ public enum Platform {
         #endif
         }
     }
+
+    public static var clipboard: Clipboard {
+        switch implementation {
+        #if FRB_PLATFORM_SDL
+            case .sdl:
+                return SDLClipboard()
+        #endif
+
+        #if FRB_PLATFORM_APPL
+            case .apple:
+                fatalError("not implemented")
+        #endif
+        }
+    }
 }

Sources/FirebladePAL/Platform/SDL/SDLClipboard.swift

@@ -0,0 +1,34 @@
+//
+// SDLClipboard.swift
+// Fireblade PAL
+//
+// Copyright © 2018-2021 Fireblade Team. All rights reserved.
+// Licensed under MIT License. See LICENSE file for details.
+
+#if FRB_PLATFORM_SDL
+
+    @_implementationOnly import SDL2
+
+    public struct SDLClipboard: Clipboard {
+        init() {}
+
+        public func getText() throws -> String {
+            guard let pText = SDL_GetClipboardText() else {
+                throw SDLError()
+            }
+            defer { SDL_free(pText) }
+            return String(cString: pText)
+        }
+
+        public func setText(_ text: String) throws {
+            if SDL_SetClipboardText(text) < 0 {
+                throw SDLError()
+            }
+        }
+
+        public func hasText() -> Bool {
+            SDL_HasClipboardText() == SDL_TRUE
+        }
+    }
+
+#endif

Tests/FirebladePALTests/FirebladePALTests.swift

@@ -9,17 +9,29 @@
 import XCTest
 
 final class FirebladePALTests: XCTestCase {
-    func testPlatformSetup() throws {
+    override func setUp() {
+        super.setUp()
         Platform.initialize()
+    }
+
+    override class func tearDown() {
+        super.tearDown()
+        Platform.quit()
+    }
 
+    func testPlatformSetup() throws {
         #if FRB_ENABLE_PLATFORM_SDL
             XCTAssertEqual(Platform.implementation, .sdl)
         #endif
 
         #if FRB_ENABLE_PLATFORM_APPL
             XCTAssertEqual(Platform.implementation, .apple)
         #endif
+    }
 
-        Platform.quit()
+    func testClipboard() throws {
+        try Platform.clipboard.setText("Hello World!")
+        XCTAssertTrue(Platform.clipboard.hasText())
+        XCTAssertEqual(try Platform.clipboard.getText(), "Hello World!")
     }
 }

Tests/FirebladePALTests/XCTestManifests.swift

@@ -6,6 +6,7 @@
         //   `swift test --generate-linuxmain`
         // to regenerate.
         static let __allTests__FirebladePALTests = [
+            ("testClipboard", testClipboard),
             ("testPlatformSetup", testPlatformSetup),
         ]
     }