add double click on titleBar to min/maximize application

src/main/java/org/cryptomator/ui/mainwindow/MainWindowTitleController.java

@@ -1,5 +1,12 @@
 package org.cryptomator.ui.mainwindow;
 
+import javafx.beans.binding.Bindings;
+import javafx.beans.binding.BooleanBinding;
+import javafx.beans.property.ReadOnlyBooleanProperty;
+import javafx.fxml.FXML;
+import javafx.scene.input.MouseButton;
+import javafx.scene.layout.HBox;
+import javafx.stage.Stage;
 import org.cryptomator.common.LicenseHolder;
 import org.cryptomator.common.settings.Settings;
 import org.cryptomator.ui.common.FxController;
@@ -12,12 +19,6 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import javax.inject.Inject;
-import javafx.beans.binding.Bindings;
-import javafx.beans.binding.BooleanBinding;
-import javafx.beans.property.ReadOnlyBooleanProperty;
-import javafx.fxml.FXML;
-import javafx.scene.layout.HBox;
-import javafx.stage.Stage;
 
 @MainWindowScoped
 public class MainWindowTitleController implements FxController {
@@ -58,6 +59,18 @@ public class MainWindowTitleController implements FxController {
 		titleBar.setOnMousePressed(event -> {
 			xOffset = event.getSceneX();
 			yOffset = event.getSceneY();
+
+		});
+		titleBar.setOnMouseClicked(event -> {
+			if (event.getButton().equals(MouseButton.PRIMARY)) {
+				if (event.getClickCount() == 2) {
+					if (window.isFullScreen()) {
+						window.setFullScreen(false);
+					} else {
+						window.setFullScreen(true);
+					}
+				}
+			}
 		});
 		titleBar.setOnMouseDragged(event -> {
 			window.setX(event.getScreenX() - xOffset);