dndexample.java

SWT开发例子

			FileDialog dialog = new FileDialog(fileList.getShell(), SWT.OPEN | SWT.MULTI);
			String result = dialog.open();
			if (result != null && result.length() > 0){
				fileList.removeAll();
				String separator = System.getProperty("file.separator");
				String path = dialog.getFilterPath();
				String[] names = dialog.getFileNames();
				for (int i = 0; i < names.length; i++) {
					fileList.add(path+separator+names[i]);
				}
			}
		}
	});
	fileList = new List(c, SWT.BORDER | SWT.H_SCROLL | SWT.V_SCROLL);
	GridData data = new GridData();
	data.grabExcessHorizontalSpace = true;
	data.horizontalAlignment = GridData.FILL;
	data.verticalAlignment = GridData.BEGINNING;
	fileList.setLayoutData(data);
}

private void createDragWidget(Composite parent) {
	parent.setLayout(new FormLayout());
	Combo combo = new Combo(parent, SWT.READ_ONLY);
	combo.setItems(new String[] {"Toggle Button", "Radio Button", "Checkbox", "Canvas", "Label", "List", "Table", "Tree"});
	combo.select(LABEL);
	dragControlType = combo.getSelectionIndex();
	dragControl = createWidget(dragControlType, parent, "Drag Source");
	
	combo.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Object data = dragControl.getLayoutData();
			Composite parent = dragControl.getParent();
			dragControl.dispose();
			Combo c = (Combo)e.widget; 
			dragControlType = c.getSelectionIndex();
			dragControl = createWidget(dragControlType, parent, "Drag Source");
			dragControl.setLayoutData(data);
			if (dragEnabled) createDragSource();
			parent.layout();
		}
	});
	
	Button b = new Button(parent, SWT.CHECK);
	b.setText("DragSource");
	b.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			dragEnabled = b.getSelection();
			if (dragEnabled) {
				createDragSource();
			} else {
				if (dragSource != null){
					dragSource.dispose();
				}
				dragSource = null;
			}
		}
	});
	
	FormData data = new FormData();
	data.top = new FormAttachment(0, 10);
	data.bottom = new FormAttachment(combo, -10);
	data.left = new FormAttachment(0, 10);
	data.right = new FormAttachment(100, -10);
	dragControl.setLayoutData(data);
	
	data = new FormData();
	data.bottom = new FormAttachment(b, -10);
	data.left = new FormAttachment(0, 10);
	combo.setLayoutData(data);
	
	data = new FormData();
	data.bottom = new FormAttachment(100, -10);
	data.left = new FormAttachment(0, 10);
	b.setLayoutData(data);
}

private void createDropOperations(Composite parent) {
	parent.setLayout(new RowLayout(SWT.VERTICAL));
	final Button moveButton = new Button(parent, SWT.CHECK);
	moveButton.setText("DND.DROP_MOVE");
	moveButton.setSelection(true);
	dropOperation = DND.DROP_MOVE;
	moveButton.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			if (b.getSelection()) {
				dropOperation |= DND.DROP_MOVE;			
			} else {
				dropOperation = dropOperation & ~DND.DROP_MOVE;
				if (dropOperation == 0 || (dropDefaultOperation & DND.DROP_MOVE) != 0) {
					dropOperation |= DND.DROP_MOVE;
					moveButton.setSelection(true);
				}
			}
			if (dropEnabled) {
				createDropTarget();
			}
		}
	});
	

	final Button copyButton = new Button(parent, SWT.CHECK);
	copyButton.setText("DND.DROP_COPY");
	copyButton.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			if (b.getSelection()) {
				dropOperation |= DND.DROP_COPY;			
			} else {
				dropOperation = dropOperation & ~DND.DROP_COPY;
				if (dropOperation == 0 || (dropDefaultOperation & DND.DROP_COPY) != 0) {
					dropOperation = DND.DROP_COPY;
					copyButton.setSelection(true);
				}
			}
			if (dropEnabled) {
				createDropTarget();
			}
		}
	});

	final Button linkButton = new Button(parent, SWT.CHECK);
	linkButton.setText("DND.DROP_LINK");
	linkButton.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			if (b.getSelection()) {
				dropOperation |= DND.DROP_LINK;			
			} else {
				dropOperation = dropOperation & ~DND.DROP_LINK;
				if (dropOperation == 0 || (dropDefaultOperation & DND.DROP_LINK) != 0) {
					dropOperation = DND.DROP_LINK;
					linkButton.setSelection(true);
				}
			}
			if (dropEnabled) {
				createDropTarget();
			}
		}
	});
	
	Button b = new Button(parent, SWT.CHECK);
	b.setText("DND.DROP_DEFAULT");
	defaultParent = new Composite(parent, SWT.NONE);
	b.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			if (b.getSelection()) {
				dropOperation |= DND.DROP_DEFAULT;
				defaultParent.setVisible(true);			
			} else {
				dropOperation = dropOperation & ~DND.DROP_DEFAULT;
				defaultParent.setVisible(false);
			}
			if (dropEnabled) {
				createDropTarget();
			}
		}
	});
	
	defaultParent.setVisible(false);
	GridLayout layout = new GridLayout();
	layout.marginWidth = 20;
	defaultParent.setLayout(layout);
	Label label = new Label(defaultParent, SWT.NONE);
	label.setText("Value for default operation is:");
	b = new Button(defaultParent, SWT.RADIO);
	b.setText("DND.DROP_MOVE");
	b.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			if (b.getSelection()) {
				dropDefaultOperation = DND.DROP_MOVE;
				dropOperation |= DND.DROP_MOVE;
				moveButton.setSelection(true);
				if (dropEnabled) {
					createDropTarget();
				}
			}
		}
	});
	
	b = new Button(defaultParent, SWT.RADIO);
	b.setText("DND.DROP_COPY");
	b.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			if (b.getSelection()) {
				dropDefaultOperation = DND.DROP_COPY;
				dropOperation |= DND.DROP_COPY;
				copyButton.setSelection(true);
				if (dropEnabled) {
					createDropTarget();
				}
			}
		}
	});

	b = new Button(defaultParent, SWT.RADIO);
	b.setText("DND.DROP_LINK");
	b.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			if (b.getSelection()) {
				dropDefaultOperation = DND.DROP_LINK;
				dropOperation |= DND.DROP_LINK;
				linkButton.setSelection(true);
				if (dropEnabled) {
					createDropTarget();
				}
			}
		}
	});
	
	b = new Button(defaultParent, SWT.RADIO);
	b.setText("DND.DROP_NONE");
	b.setSelection(true);
	b.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			if (b.getSelection()) {
				dropDefaultOperation = DND.DROP_NONE;
				dropOperation &= ~DND.DROP_DEFAULT;
				if (dropEnabled) {
					createDropTarget();
				}
			}
		}
	});
}

private void createDropTarget() {
	if (dropTarget != null) dropTarget.dispose();
	dropTarget = new DropTarget(dropControl, dropOperation);
	dropTarget.setTransfer(dropTypes);
	dropTarget.addDropListener(new DropTargetListener() {
		public void dragEnter(DropTargetEvent event) {
			dropConsole.append(">>dragEnter\n");
			printEvent(event);
			if (event.detail == DND.DROP_DEFAULT) {
				event.detail = dropDefaultOperation;
			}
		}
		public void dragLeave(DropTargetEvent event) {
			dropConsole.append(">>dragLeave\n");
			printEvent(event);
		}
		public void dragOperationChanged(DropTargetEvent event) {
			dropConsole.append(">>dragOperationChanged\n");
			printEvent(event);
			if (event.detail == DND.DROP_DEFAULT) {
				event.detail = dropDefaultOperation;
			}
		}
		public void dragOver(DropTargetEvent event) {
			dropConsole.append(">>dragOver\n");
			printEvent(event);
		}
		public void drop(DropTargetEvent event) {
			dropConsole.append(">>drop\n");
			printEvent(event);
			String[] strings = null;
			if (TextTransfer.getInstance().isSupportedType(event.currentDataType) ||
			    RTFTransfer.getInstance().isSupportedType(event.currentDataType)) {
			    strings = new String[] {(String)event.data};
			}
			if (FileTransfer.getInstance().isSupportedType(event.currentDataType)) {
				strings = (String[])event.data;
			}
			if (strings == null || strings.length == 0) {
				dropConsole.append("!!Invalid data dropped");
				return;
			}
			
			if (strings.length == 1 && (dropControlType == TABLE || 
			                            dropControlType == TREE || 
			                            dropControlType == LIST)) {
				// convert string separated by "\n" into an array of strings 
				String string = strings[0];
				int count = 0;
				int offset = string.indexOf("\n", 0);
				while (offset > 0) {
					count++;
					offset = string.indexOf("\n", offset + 1);
				}
				if (count > 0) {
					strings = new String[count + 1];
					int start = 0;
					int end = string.indexOf("\n");
					int index = 0;
					while (start < end) {
						strings[index++] = string.substring(start, end);
						start = end + 1;
						end = string.indexOf("\n", start);
						if (end == -1) end = string.length();
					}
				}
			}
			switch(dropControlType) {
				case BUTTON_CHECK:
				case BUTTON_TOGGLE:
				case BUTTON_RADIO: {
					Button b = (Button)dropControl;
					b.setText(strings[0]);
					break;
				}
				case TABLE: {
					Table table = (Table)dropControl;
					for(int i = 0; i < strings.length; i++) {
						TableItem item = new TableItem(table, SWT.NONE);
						item.setText(0, strings[i]);
						item.setText(1, "dropped item");
					}
					TableColumn[] columns = table.getColumns();
					for (int i = 0; i < columns.length; i++) {
						columns[i].pack();
					}
					break;
				}
				case TEXT: {
					Text text = (Text)dropControl;
					for(int i = 0; i < strings.length; i++) {
						text.append(strings[i]+"\n");
					}
					break;
				}
				case TREE: {
					Tree tree = (Tree)dropControl;
					for(int i = 0; i < strings.length; i++) {
						TreeItem item = new TreeItem(tree, SWT.NONE);
						item.setText(strings[i]);
					}
					break;
				}
				case CANVAS: {
					dropControl.setData("STRINGS", strings);
					dropControl.redraw();
					break;
				}
				case LABEL: {
					Label label = (Label)dropControl;
					label.setText(strings[0]);
					break;
				}
				case LIST: {
					List list = (List)dropControl;
					for(int i = 0; i < strings.length; i++) {
						list.add(strings[i]);
					}
					break;
				}
				default:
					throw new SWTError(SWT.ERROR_NOT_IMPLEMENTED);
			}
		}
		public void dropAccept(DropTargetEvent event) {
			dropConsole.append(">>dropAccept\n");
			printEvent(event);
		}
	});
}

private void createDropTypes(Composite parent) {
	parent.setLayout(new RowLayout(SWT.VERTICAL));
	Button b = new Button(parent, SWT.CHECK);
	b.setText("Text Transfer");
	b.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			if (b.getSelection()) {
				addDropTransfer(TextTransfer.getInstance());			
			} else {
				removeDropTransfer(TextTransfer.getInstance());
			}
		}
	});
	
	b = new Button(parent, SWT.CHECK);
	b.setText("RTF Transfer");
	b.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			if (b.getSelection()) {
				addDropTransfer(RTFTransfer.getInstance());			
			} else {
				removeDropTransfer(RTFTransfer.getInstance());
			}
		}
	});