Hello,
I am trying to have a common navigator that manages item edition and
drag and drop. So I set a ICellModifier. The drag and drop does not
work. It seems that my ICellModifier is called before the drag
interaction is activated.
I managed to reproduce the problem in the following code snippet. When I
press the left mouse button the edition is not activated but as soon as
I move the mouse (without releasing the button) the edition is activated
making it impossible to drag the item. Am I doing something wrong ?
Here is the code snippet:
import java.util.ArrayList;
import org.eclipse.jface.viewers.CellEditor;
import org.eclipse.jface.viewers.ICellModifier;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.TextCellEditor;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.DragSource;
import org.eclipse.swt.dnd.DragSourceAdapter;
import org.eclipse.swt.dnd.DragSourceEvent;
import org.eclipse.swt.dnd.DropTarget;
import org.eclipse.swt.dnd.DropTargetEvent;
import org.eclipse.swt.dnd.DropTargetListener;
import org.eclipse.swt.dnd.TextTransfer;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.TreeItem;
public class TreeViewerSnippet implements SelectionListener {
private TreeViewer viewer;
private class MyContentProvider implements ITreeContentProvider {
public Object[] getElements(Object inputElement) {
return ((MyModel) inputElement).child.toArray();
}
public void dispose() {
}
public void inputChanged(Viewer viewer, Object oldInput, Object
newInput) {
}
public Object[] getChildren(Object parentElement) {
return getElements(parentElement);
}
public Object getParent(Object element) {
if (element == null) {
return null;
}
return ((MyModel) element).parent;
}
public boolean hasChildren(Object element) {
return ((MyModel) element).child.size() > 0;
}
}
public class MyModel {
public MyModel parent;
public ArrayList child = new ArrayList();
public int counter;
public MyModel(int counter, MyModel parent) {
this.parent = parent;
this.counter = counter;
}
public String toString() {
String rv = "Item ";
if (parent != null) {
rv = parent.toString() + ".";
}
rv += counter;
return rv;
}
}
public TreeViewerSnippet(Shell shell) {
viewer = new TreeViewer(shell, SWT.BORDER);
viewer.setContentProvider(new MyContentProvider());
viewer.setCellEditors(new CellEditor[] { new TextCellEditor(viewer
.getTree()) });
viewer.setColumnProperties(new String[] { "name" });
viewer.setCellModifier(new ICellModifier() {
public boolean canModify(Object element, String property) {
return true;
}
public Object getValue(Object element, String property) {
return ((MyModel) element).counter + "";
}
public void modify(Object element, String property, Object
value) {
TreeItem item = (TreeItem) element;
((MyModel) item.getData()).counter = Integer.parseInt(value
.toString());
viewer.update(item.getData(), null);
}
});
DragSource source = new DragSource(viewer.getTree(),
DND.DROP_COPY);
source.setTransfer(new Transfer[] {TextTransfer.getInstance()});
source.addDragListener(new DragSourceAdapter() {
public void dragSetData(DragSourceEvent event) {
event.data = "Hello World";
}
});
DropTarget target = new DropTarget(viewer.getTree(),
DND.DROP_COPY | DND.DROP_DEFAULT);
target.setTransfer(new Transfer[] {TextTransfer.getInstance()});
target.addDropListener(new DropTargetListener() {
public void dragEnter(DropTargetEvent event) {
}
public void dragOperationChanged(DropTargetEvent event) {
}
public void dragOver(DropTargetEvent event) {
}
public void dragLeave(org.eclipse.swt.dnd.DropTargetEvent
event) {
}
public void drop(DropTargetEvent event) {
}
public void dropAccept(DropTargetEvent event) {
}
});
Menu menu = new Menu(viewer.getControl());
MenuItem renameItem = new MenuItem(menu, SWT.PUSH);
renameItem.addSelectionListener(this);
renameItem.setText("Rename");
viewer.getTree().setMenu(menu);
viewer.setInput(createModel());
}
public void widgetDefaultSelected(SelectionEvent e) {
}
public void widgetSelected(SelectionEvent e) {
IStructuredSelection selection = (IStructuredSelection) viewer
.getSelection();
if (selection != null) {
viewer.editElement(selection.getFirstElement(), 0);
}
}
private MyModel createModel() {
MyModel root = new MyModel(0, null);
root.counter = 0;
MyModel tmp;
for (int i = 1; i < 10; i++) {
tmp = new MyModel(i, root);
root.child.add(tmp);
for (int j = 1; j < i; j++) {
tmp.child.add(new MyModel(j, tmp));
}
}
return root;
}
public static void main(String[] args) {
Display display = new Display();
Shell shell = new Shell(display);
shell.setLayout(new FillLayout());
new TreeViewerSnippet(shell);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch())
display.sleep();
}
display.dispose();
}
}