[UI] Refactor JavaFX composites

* `AF3FXViewParts` no longer implement the `ICompositeFXContainer`
interface. Instead they are reduced to a minimum, referencing a
(potentially hierarchic) `ICompositeFXContainer` with all the layout and
logic.
* FXML layouts are no longer loaded in the constructor of the
`CompositeFXControllerBase`, but in its `initialize` method (executed in
`getOrLoadLayout`).

Issue-Ref: 3437
Issue-Url: https://af3-developer.fortiss.org/issues/3437



Signed-off-by: Tiziano Munaro <munaro@fortiss.org>

org.fortiss.tooling.common.ui/src/org/fortiss/tooling/common/ui/javafx/.ratings

-AF3FXViewPart.java 67cc6f943239c695bf2965502ccc05091f3dd346 GREEN
+AF3FXViewPart.java 66e5e5d93b3e03cc2202c9213ee2636d40fb6833 YELLOW

org.fortiss.tooling.common.ui/src/org/fortiss/tooling/common/ui/javafx/AF3FXViewPart.java

@@ -15,108 +15,78 @@
 +--------------------------------------------------------------------------*/
 package org.fortiss.tooling.common.ui.javafx;
 
-import static org.fortiss.tooling.common.ui.javafx.util.JavaFXUtils.loadFXML;
+import static javafx.scene.layout.AnchorPane.setBottomAnchor;
+import static javafx.scene.layout.AnchorPane.setLeftAnchor;
+import static javafx.scene.layout.AnchorPane.setRightAnchor;
+import static javafx.scene.layout.AnchorPane.setTopAnchor;
 
-import java.io.IOException;
-import java.lang.reflect.InvocationTargetException;
 import java.net.URL;
-import java.util.ResourceBundle;
 
 import org.apache.commons.lang3.SystemUtils;
 import org.eclipse.fx.ui.workbench3.FXViewPart;
 import org.fortiss.tooling.common.ui.javafx.layout.ICompositeFXController;
 
 import javafx.application.Platform;
-import javafx.fxml.Initializable;
 import javafx.scene.Node;
 import javafx.scene.Scene;
 import javafx.scene.layout.AnchorPane;
 import javafx.scene.layout.Pane;
 
 /**
- * Base class to create eclipse (SWT-based) views using JavaFX GUI elements. This class requires
- * FXML file that defines the GUI elements of the view.
+ * Base class to create eclipse (SWT-based) views using JavaFX GUI elements.
  * 
- * @author diewald
+ * @author munaro
  */
-public abstract class AF3FXViewPart extends FXViewPart
-		implements ICompositeFXController, Initializable {
+public abstract class AF3FXViewPart extends FXViewPart {
+
 	/** For later use, if we need to define different styles. */
 	private String cssLocation;
 
 	/** Flag that indicates if a custom style sheet has been applied. */
 	private boolean isCustomStyleSheetApplied;
 
-	/** References the stub that defines the FXML file defining the layout and controller. */
-	private Class<? extends AF3FXViewPart> viewerClass;
-
 	/** References the root {@link Pane} to which GUI elements must be added to be displayed. */
 	private Pane root;
 
-	/** {@link ICompositeFXController}s to be added to a container node within the view part. */
-	private ICompositeFXController[] containments;
+	/** Specifies the view part's layout and logic. */
+	private ICompositeFXController controller;
 
 	/**
-	 * Constructor.
+	 * Constructor. Allows to pass the view's FXML definition file.
 	 * 
-	 * @param viewerClass
-	 *            Class implementing the {@link AF3FXViewPart} to load resources from its containing
-	 *            bundle.
+	 * @param controller
+	 *            {@link ICompositeFXController} specifying the layout of the view part as well as
+	 *            its logic.
 	 * @param cssLocation
 	 *            style sheet file path for the appearance settings relative to the source
 	 *            (resource) folders. Pass {@code null} if the OS-native look shall be used.
-	 * @param containments
-	 *            Optional {@link ICompositeFXController}s to be added to a container node within
-	 *            the view
-	 *            part.
 	 * @throws Exception
 	 *             if the given FXML file path is not given or if it cannot be found in any of the
 	 *             source (resource) folders.
 	 */
-	public AF3FXViewPart(Class<? extends AF3FXViewPart> viewerClass, String cssLocation,
-			ICompositeFXController... containments) throws Exception {
+	public AF3FXViewPart(ICompositeFXController controller, String cssLocation) throws Exception {
 		Platform.setImplicitExit(false);
-		this.viewerClass = viewerClass;
 		this.cssLocation = cssLocation;
-		this.containments = containments;
+		this.controller = controller;
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	protected Scene createFxScene() {
-		if(getFXMLLocation() != null) {
-			URL fxmlResource = viewerClass.getResource(getFXMLLocation());
-			try {
-				root = loadFXML(fxmlResource, this);
-			} catch(IOException e) {
-				throw new RuntimeException(
-						"Cannot load the resource located at " + getFXMLLocation(), e);
-			}
-		} else {
-			root = new AnchorPane();
-			try {
-				viewerClass.getMethod("initialize", URL.class, ResourceBundle.class).invoke(this,
-						null, null);
-			} catch(IllegalAccessException | IllegalArgumentException | InvocationTargetException |
-					SecurityException e) {
-				throw new RuntimeException("The initialize method of the View " +
-						viewerClass.getSimpleName() + " threw an exception!", e);
-			} catch(NoSuchMethodException e) {
-				throw new RuntimeException("For single Controller views, an initialize method is " +
-						"required that creates the control! This cannot be done in constructors " +
-						"since the JavaFX toolkit is not initialized in that stage.", e);
-			}
-		}
+		Node layout = controller.getOrLoadLayout();
+
+		setTopAnchor(layout, 0.0);
+		setRightAnchor(layout, 0.0);
+		setBottomAnchor(layout, 0.0);
+		setLeftAnchor(layout, 0.0);
 
+		root = new AnchorPane(layout);
 		if(cssLocation != null) {
 			isCustomStyleSheetApplied = applyStyleSheet(root, getClass(), cssLocation);
 		}
 		if(!isCustomStyleSheetApplied) {
 			setNativeLook(root);
 		}
-
-		addContainments(containments);
-
 		Scene scene = new Scene(root);
 		return scene;
 	}
@@ -127,36 +97,6 @@ public abstract class AF3FXViewPart extends FXViewPart
 		// Not needed.
 	}
 
-	/**
-	 * Adds a single {@link Node} to this view. It embeds the given {@link Node} to the
-	 * {@link AnchorPane} of this view and stretches it to the borders of the view.
-	 * <p>
-	 * NOTE: This method may only be used for single-control views, not FXML-based ones.
-	 * 
-	 * @param fxNode
-	 *            {@link Node} to be added to the view.
-	 */
-	protected void setChildNodeFinal(Node fxNode) {
-		if(getFXMLLocation() != null) {
-			throw new RuntimeException("This method is intended for single-control views. It may" +
-					" not be used for FXML-based views.");
-		}
-		if(!root.getChildren().isEmpty()) {
-			throw new RuntimeException("The method setChildNodeFinal was invoked more than once." +
-					" This method is intended for single-control views. If more controls" +
-					"shall be added, please define an FXML layout file and call the appropriate" +
-					" constructors.");
-		}
-
-		root.getChildren().add(fxNode);
-		// Stretch the node to the borders of the view. In the createScene method, we a create a
-		// root pane that is an AnchorPane, so we can safely use these calls here.
-		AnchorPane.setTopAnchor(fxNode, 0.0);
-		AnchorPane.setRightAnchor(fxNode, 0.0);
-		AnchorPane.setBottomAnchor(fxNode, 0.0);
-		AnchorPane.setLeftAnchor(fxNode, 0.0);
-	}
-
 	/**
 	 * Sets the native look of the target platform to not break the UI experience. Most of the UI
 	 * code is based on SWT which uses a platform native look. Currently, Windows 8&10, Windows 7,
@@ -200,10 +140,4 @@ public abstract class AF3FXViewPart extends FXViewPart
 		}
 		return false;
 	}
-
-	/** {@inheritDoc} */
-	@Override
-	public Node getLayout() {
-		return root;
-	}
 }

org.fortiss.tooling.common.ui/src/org/fortiss/tooling/common/ui/javafx/layout/.ratings

-CompositeFXControllerBase.java 7b4d3b7511e4ef146528cb2095856e4aa43e965f GREEN
-ICompositeFXController.java d2c239d857aa1b125097fe0feb8ebb7dfe7f7072 GREEN
+CompositeFXControllerBase.java 82fa7fdeb260e7469df2f7140a16b9b4201716cd YELLOW
+ICompositeFXController.java 8da8c709bc6a8232f7d9dfc0a4e76cea2d6f6879 YELLOW

org.fortiss.tooling.common.ui/src/org/fortiss/tooling/common/ui/javafx/layout/CompositeFXControllerBase.java

@@ -15,6 +15,10 @@
 +--------------------------------------------------------------------------*/
 package org.fortiss.tooling.common.ui.javafx.layout;
 
+import static javafx.scene.layout.AnchorPane.setBottomAnchor;
+import static javafx.scene.layout.AnchorPane.setLeftAnchor;
+import static javafx.scene.layout.AnchorPane.setRightAnchor;
+import static javafx.scene.layout.AnchorPane.setTopAnchor;
 import static org.fortiss.tooling.common.ui.javafx.util.JavaFXUtils.loadFXML;
 
 import java.io.IOException;
@@ -22,6 +26,7 @@ import java.net.URL;
 
 import javafx.fxml.FXML;
 import javafx.scene.Node;
+import javafx.scene.layout.AnchorPane;
 
 /**
  * JavaFX node which can be hierarchically composed. It can be included within another
@@ -37,19 +42,32 @@ public abstract class CompositeFXControllerBase implements ICompositeFXControlle
 	 */
 	private Node layout;
 
+	/**
+	 * {@link ICompositeFXController}s to be added to the {@link Node} by the
+	 * {@code addContainments} method.
+	 */
+	private ICompositeFXController[] containments;
+
 	/** Constructor. */
-	public CompositeFXControllerBase(CompositeFXControllerBase... containments) throws IOException {
-		URL fxmlResource = getClass().getResource(getFXMLLocation());
-		layout = loadFXML(fxmlResource, this);
-		addContainments(containments);
+	public CompositeFXControllerBase(ICompositeFXController... containments) {
+		this.containments = containments;
+		this.layout = null;
 	}
 
-	/**
-	 * Returns a JavaFX {@link Node} with the layout specified in the {@link FXML} resource and
-	 * associated with a controller of type {@code T}.
-	 */
+	/** {@inheritDoc} */
 	@Override
-	public Node getLayout() {
+	public Node getOrLoadLayout() {
+		if(layout == null) {
+			URL fxmlResource = getClass().getResource(getFXMLLocation());
+			try {
+				layout = loadFXML(fxmlResource, this);
+			} catch(IOException e) {
+				throw new RuntimeException(
+						"Cannot load the resource located at " + getFXMLLocation(), e);
+			}
+			initialize();
+			addContainments(containments);
+		}
 		return layout;
 	}
 
@@ -60,4 +78,17 @@ public abstract class CompositeFXControllerBase implements ICompositeFXControlle
 	/** {@inheritDoc} */
 	@Override
 	public abstract void addContainments(ICompositeFXController[] containments);
+
+	/**
+	 * If the container is an {@link AnchorPane}, all margins are removed so as to fit the child to
+	 * the anchor pane's size.
+	 */
+	protected void fitToParent(Node child) {
+		if(child.getParent() instanceof AnchorPane) {
+			setBottomAnchor(child, 0.0);
+			setTopAnchor(child, 0.0);
+			setLeftAnchor(child, 0.0);
+			setRightAnchor(child, 0.0);
+		}
+	}
 }

org.fortiss.tooling.common.ui/src/org/fortiss/tooling/common/ui/javafx/layout/ICompositeFXController.java

@@ -26,14 +26,16 @@ import javafx.scene.Node;
 public interface ICompositeFXController {
 
 	/**
-	 * Returns a JavaFX {@link Node} with the layout specified in the {@link FXML} resource and
-	 * associated with a controller of type {@code T}.
+	 * Loads the a JavaFX {@link Node} from the specified {@link FXML} resource.
 	 */
-	public Node getLayout();
+	public Node getOrLoadLayout();
 
 	/** Returns the location of the {@link FXML} resource with the view's layout. */
 	public String getFXMLLocation();
 
 	/** Adds the {@link ICompositeFXController}s to the container. */
 	public void addContainments(ICompositeFXController[] containments);
+
+	/** Performs further actions on the layout. */
+	public void initialize();
 }