device, discovereddevice, utils: use same method for generating 'unique' device strings

src/mconnect/device.vala

@@ -141,12 +141,15 @@ class Device : Object {
 	 * Generates a unique string for this device
 	 */
 	public string to_unique_string() {
-		return this.to_string().replace(" ", "-");
+		return make_unique_device_string(this.device_id,
+										 this.device_name,
+										 this.device_type,
+										 this.protocol_version);
 	}
 
 	public string to_string() {
-		return "%s-%s-%s-%u".printf(this.device_id, this.device_name,
-									this.device_type, this.protocol_version);
+		return make_device_string(this.device_id, this.device_name,
+								  this.device_type, this.protocol_version);
 	}
 
 	/**

src/mconnect/discovereddevice.vala

@@ -72,4 +72,11 @@ class DiscoveredDevice : Object {
 											   this.protocol_version);
 	}
 
+	public string to_unique_string() {
+		return make_unique_device_string(this.device_id,
+										 this.device_name,
+										 this.device_type,
+										 this.protocol_version);
+	}
+
 }

src/mconnect/utils.vala

@@ -55,3 +55,31 @@ void vdebug(string format, ...) {
 	}
 }
 
+/**
+ * make_unique_device_string:
+ * @id: device ID
+ * @name: device name
+ * @type: device type
+ * @pv: protocol version
+ *
+ * Generate device string that can be used as map index
+ */
+string make_unique_device_string(string id, string name,
+								 string type, uint pv) {
+	return make_device_string(id, name, type, pv).replace(" ", "-");
+}
+
+/**
+ * make_device_string:
+ * @id: device ID
+ * @name: device name
+ * @type: device type
+ * @pv: protocol version
+ *
+ * Generate device string
+ */
+string make_device_string(string id, string name,
+						  string type, uint pv) {
+	return "%s-%s-%s-%u".printf(id, name, type, pv);
+
+}