ALL: Move Clipboard support to OSystem

Commit adds kFeatureClipboardSupport. hasTextInClipboard() and
getTextFromClipboard().

OSystem_SDL has this feature if SDL2 is used.

EditableWidget and StorageWizardDialog use g_system to access clipboard
now.

1 files changed, 31 insertions, 1 deletions

diff --git a/common/system.h b/common/system.h
index 3cbeee7d82..805eba68ed 100644
--- a/common/system.h
+++ b/common/system.h
@@ -314,7 +314,15 @@ public:
 		 *
 		 * This feature has no associated state.
 		 */
-		kFeatureDisplayLogFile
+		kFeatureDisplayLogFile,
+
+		/**
+		* The presence of this feature indicates whether the hasTextInClipboard()
+		* and getTextFromClipboard() calls are supported.
+		*
+		* This feature has no associated state.
+		*/
+		kFeatureClipboardSupport
 	};
 
 	/**
@@ -1239,6 +1247,28 @@ public:
 	virtual bool displayLogFile() { return false; }
 
 	/**
+	* Returns whether there is text available in the clipboard.
+	*
+	* The kFeatureClipboardSupport feature flag can be used to
+	* test whether this call has been implemented by the active
+	* backend.
+	*
+	* @return true if there is text in the clipboard, false otherwise
+	*/
+	virtual bool hasTextInClipboard() { return false; }
+
+	/**
+	* Returns clipboard contents as a String.
+	*
+	* The kFeatureClipboardSupport feature flag can be used to
+	* test whether this call has been implemented by the active
+	* backend.
+	*
+	* @return clipboard contents ("" if hasTextInClipboard() == false)
+	*/
+	virtual Common::String getTextFromClipboard() { return ""; }
+
+	/**
 	 * Returns the locale of the system.
 	 *
 	 * This returns the currently set up locale of the system, on which