Used Typed new Generics for selection in TreeViewer DnD Classes #155

As we now have more typed lists the handling of selections and the resulting DnD actions can be implemented more nicely. Addresses: #155
eclipse · Sep 30, 2024 · 84c468d · 84c468d
1 parent 89fae40
commit 84c468d
Show file tree

Hide file tree

Showing 3 changed files with 28 additions and 40 deletions.
diff --git a/org.eclipse.gef/src/org/eclipse/gef/ui/parts/TreeViewerTransfer.java b/org.eclipse.gef/src/org/eclipse/gef/ui/parts/TreeViewerTransfer.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2010 IBM Corporation and others.
+ * Copyright (c) 2000, 2024 IBM Corporation and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
@@ -60,6 +60,7 @@ protected String[] getTypeNames() {
 	 *
 	 * @return The viewer where the drag started
 	 */
+	@SuppressWarnings("static-method")
 	public EditPartViewer getViewer() {
 		return viewer;
 	}
@@ -69,6 +70,7 @@ public EditPartViewer getViewer() {
 	 *
 	 * @param epv The viewer
 	 */
+	@SuppressWarnings("static-method")
 	public void setViewer(EditPartViewer epv) {
 		viewer = epv;
 	}

diff --git a/org.eclipse.gef/src/org/eclipse/gef/ui/parts/TreeViewerTransferDragListener.java b/org.eclipse.gef/src/org/eclipse/gef/ui/parts/TreeViewerTransferDragListener.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2010 IBM Corporation and others.
+ * Copyright (c) 2000, 2024 IBM Corporation and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
@@ -12,7 +12,6 @@
  *******************************************************************************/
 package org.eclipse.gef.ui.parts;
 
-import java.util.ArrayList;
 import java.util.List;
 
 import org.eclipse.swt.dnd.DragSourceEvent;
@@ -26,7 +25,7 @@
 
 class TreeViewerTransferDragListener extends AbstractTransferDragSourceListener {
 
-	private List modelSelection;
+	private List<Object> modelSelection;
 
 	public TreeViewerTransferDragListener(EditPartViewer viewer) {
 		super(viewer, TreeViewerTransfer.getInstance());
@@ -48,7 +47,7 @@ public void dragSetData(DragSourceEvent event) {
 	@Override
 	public void dragStart(DragSourceEvent event) {
 		TreeViewerTransfer.getInstance().setViewer(getViewer());
-		List selection = getViewer().getSelectedEditParts();
+		List<? extends EditPart> selection = getViewer().getSelectedEditParts();
 		TreeViewerTransfer.getInstance().setObject(selection);
 		saveModelSelection(selection);
 	}
@@ -65,24 +64,13 @@ public void dragFinished(DragSourceEvent event) {
 	}
 
 	protected void revertModelSelection() {
-		List list = new ArrayList();
-		Object editpart;
-		for (int i = 0; i < modelSelection.size(); i++) {
-			editpart = getViewer().getEditPartForModel(modelSelection.get(i));
-			if (editpart != null) {
-				list.add(editpart);
-			}
-		}
+		List<EditPart> list = modelSelection.stream().map(m -> getViewer().getEditPartForModel(m)).toList();
 		getViewer().setSelection(new StructuredSelection(list));
 		modelSelection = null;
 	}
 
-	protected void saveModelSelection(List editPartSelection) {
-		modelSelection = new ArrayList();
-		for (int i = 0; i < editPartSelection.size(); i++) {
-			EditPart editpart = (EditPart) editPartSelection.get(i);
-			modelSelection.add(editpart.getModel());
-		}
+	protected void saveModelSelection(List<? extends EditPart> editPartSelection) {
+		modelSelection = editPartSelection.stream().map(EditPart::getModel).toList();
 	}
 
 }
diff --git a/org.eclipse.gef/src/org/eclipse/gef/ui/parts/TreeViewerTransferDropListener.java b/org.eclipse.gef/src/org/eclipse/gef/ui/parts/TreeViewerTransferDropListener.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2023 IBM Corporation and others.
+ * Copyright (c) 2000, 2024 IBM Corporation and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
@@ -14,7 +14,6 @@
 
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Iterator;
 import java.util.List;
 
 import org.eclipse.swt.dnd.DND;
@@ -40,23 +39,17 @@ public TreeViewerTransferDropListener(EditPartViewer viewer) {
 	@Override
 	protected Request createTargetRequest() {
 		ChangeBoundsRequest request = new ChangeBoundsRequest(RequestConstants.REQ_MOVE);
-		request.setEditParts((List) TreeViewerTransfer.getInstance().getObject());
+		request.setEditParts(getTransferedEditParts());
 		return request;
 	}
 
 	@Override
 	protected Command getCommand() {
-		CompoundCommand command = new CompoundCommand();
-
-		Iterator iter = ((List) TreeViewerTransfer.getInstance().getObject()).iterator();
-
-		Request request = getTargetRequest();
+		final CompoundCommand command = new CompoundCommand();
+		final Request request = getTargetRequest();
 		request.setType(isMove() ? RequestConstants.REQ_MOVE : RequestConstants.REQ_ORPHAN);
 
-		while (iter.hasNext()) {
-			EditPart editPart = (EditPart) iter.next();
-			command.add(editPart.getCommand(request));
-		}
+		getTransferedEditParts().stream().forEach(ep -> command.add(ep.getCommand(request)));
 
 		// If reparenting, add all editparts to target editpart.
 		if (!isMove()) {
@@ -85,6 +78,12 @@ protected Collection<EditPart> getExclusionSet() {
 		return exclude;
 	}
 
+	@SuppressWarnings("unchecked") // we are putting a List<? extends EditPart> into the object of the transfer so
+									// casting is save
+	private static List<? extends EditPart> getTransferedEditParts() {
+		return (List<? extends EditPart>) TreeViewerTransfer.getInstance().getObject();
+	}
+
 	@Override
 	protected void handleDragOver() {
 		if (TreeViewerTransfer.getInstance().getViewer() != getViewer()) {
@@ -95,18 +94,19 @@ protected void handleDragOver() {
 		super.handleDragOver();
 	}
 
+	@SuppressWarnings("static-method")
 	protected EditPart getSourceEditPart() {
-		List selection = (List) TreeViewerTransfer.getInstance().getObject();
-		if (selection == null || selection.isEmpty() || !(selection.get(0) instanceof EditPart)) {
+		List<? extends EditPart> selection = getTransferedEditParts();
+		if (selection == null || selection.isEmpty()) {
 			return null;
 		}
-		return (EditPart) selection.get(0);
+		return selection.get(0);
 	}
 
-	protected List includeChildren(List list) {
+	protected List<EditPart> includeChildren(List<? extends EditPart> list) {
 		List<EditPart> result = new ArrayList<>();
-		for (Object element : list) {
-			List<? extends EditPart> children = ((EditPart) element).getChildren();
+		for (EditPart element : list) {
+			List<? extends EditPart> children = element.getChildren();
 			result.addAll(children);
 			result.addAll(includeChildren(children));
 		}
@@ -123,9 +123,7 @@ public boolean isEnabled(DropTargetEvent event) {
 
 	protected boolean isMove() {
 		EditPart source = getSourceEditPart();
-		List selection = (List) TreeViewerTransfer.getInstance().getObject();
-		for (Object element : selection) {
-			EditPart ep = (EditPart) element;
+		for (EditPart ep : getTransferedEditParts()) {
 			if (ep.getParent() != source.getParent()) {
 				return false;
 			}