dndexample.java

SWT开发例子

	b = new Button(parent, SWT.CHECK);
	b.setText("File Transfer");
	b.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			if (b.getSelection()) {
				addDropTransfer(FileTransfer.getInstance());			
			} else {
				removeDropTransfer(FileTransfer.getInstance());
			}
		}
	});
}

private void createDropWidget(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", "Text"});
	combo.select(LABEL);
	dropControlType = combo.getSelectionIndex();
	dropControl = createWidget(dropControlType, parent, "Drop Target");
	combo.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Object data = dropControl.getLayoutData();
			Composite parent = dropControl.getParent();
			dropControl.dispose();
			Combo c = (Combo)e.widget;
			dropControlType = c.getSelectionIndex(); 
			dropControl = createWidget(dropControlType, parent, "Drop Target");
			dropControl.setLayoutData(data);
			if (dropEnabled) createDropTarget();
			parent.layout();
		}
	});
	
	Button b = new Button(parent, SWT.CHECK);
	b.setText("DropTarget");
	b.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			Button b = (Button)e.widget;
			dropEnabled = b.getSelection();
			if (dropEnabled) {
				createDropTarget();
			} else {
				if (dropTarget != null){
					dropTarget.dispose();
				}
				dropTarget = 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);
	dropControl.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 Control createWidget(int type, Composite parent, String prefix){
	switch (type) {
		case BUTTON_CHECK: {
			Button button = new Button(parent, SWT.CHECK);
			button.setText(prefix+" Check box");
			return button;
		}
		case BUTTON_TOGGLE: {
			Button button = new Button(parent, SWT.TOGGLE);
			button.setText(prefix+" Toggle button");
			return button;
		}
		case BUTTON_RADIO: {
			Button button = new Button(parent, SWT.RADIO);
			button.setText(prefix+" Radio button");
			return button;
		}
		case TABLE: {
			Table table = new Table(parent, SWT.BORDER | SWT.MULTI);
			TableColumn column1 = new TableColumn(table, SWT.NONE);
			TableColumn column2 = new TableColumn(table, SWT.NONE);
			for (int i = 0; i < 10; i++) {
				TableItem item = new TableItem(table, SWT.NONE);
				item.setText(0, prefix+" name " + i);
				item.setText(1, prefix+" value " + i);
			}
			column1.pack();
			column2.pack();
			return table;
		}
		case TEXT: {
			Text text = new Text(parent, SWT.BORDER | SWT.MULTI | SWT.V_SCROLL | SWT.H_SCROLL);
			text.setText(prefix+" Text");
			return text;
		}
		case TREE: {
			Tree tree = new Tree(parent, SWT.BORDER);
			for (int i = 0; i < 3; i++) {
				TreeItem item = new TreeItem(tree, SWT.NONE);
				item.setText(prefix+" item " + i);
				for (int j = 0; j < 3; j++) {
					TreeItem subItem = new TreeItem(item, SWT.NONE);
					subItem.setText(prefix+" item " + j);
					for (int k = 0; k < 3; k++) {
						TreeItem subsubItem = new TreeItem(subItem, SWT.NONE);
						subsubItem.setText(prefix+" item " + k);
					}
				}
			}
			return tree;
		}
		case CANVAS: {
			Canvas canvas = new Canvas(parent, SWT.BORDER);
			canvas.setData("STRINGS", new String[] {prefix+" Canvas widget"});
			canvas.addPaintListener(new PaintListener() {
				public void paintControl(PaintEvent e) {
					Canvas c = (Canvas)e.widget;
					Image image = (Image)c.getData("IMAGE");
					if (image != null) {
						e.gc.drawImage(image, 5, 5);
					} else {
						String[] strings = (String[])c.getData("STRINGS");
						if (strings != null) {
							FontMetrics metrics = e.gc.getFontMetrics();
							int height = metrics.getHeight();
							int y = 5;
							for(int i = 0; i < strings.length; i++) {
								e.gc.drawString(strings[i], 5, y);
								y += height + 5;
							}
						}
					}
				}
			});
			return canvas;
		}
		case LABEL: {
			Label label = new Label(parent, SWT.BORDER);
			label.setText(prefix+" Label");
			return label;
		}
		case LIST: {
			List list = new List(parent, SWT.BORDER);
			list.setItems(new String[] {prefix+" Item a", prefix+" Item b",  prefix+" Item c",  prefix+" Item d"});
			return list;
		}
		default:
			throw new SWTError(SWT.ERROR_NOT_IMPLEMENTED);
	}
}

private void open() {
	Display display = new Display();
	Shell shell = new Shell(display);
	shell.setText("Drag and Drop Example");
	shell.setLayout(new FormLayout());
	
	Label dragLabel = new Label(shell, SWT.LEFT);
	dragLabel.setText("Drag Source:");
	
	Group dragWidgetGroup = new Group(shell, SWT.NONE);
	dragWidgetGroup.setText("Widget");
	createDragWidget(dragWidgetGroup);
	
	Group dragOperationsGroup = new Group(shell, SWT.NONE);
	dragOperationsGroup.setText("Allowed Operation(s):");
	createDragOperations(dragOperationsGroup);
	
	Group dragTypesGroup = new Group(shell, SWT.NONE);
	dragTypesGroup.setText("Transfer Type(s):");
	createDragTypes(dragTypesGroup);
	
	dragConsole = new Text(shell, SWT.READ_ONLY | SWT.BORDER |SWT.V_SCROLL | SWT.H_SCROLL | SWT.MULTI);
	Menu menu = new Menu (shell, SWT.POP_UP);
	MenuItem item = new MenuItem (menu, SWT.PUSH);
	item.setText ("Clear");
	item.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			dragConsole.setText("");
		}
	});
	item = new MenuItem (menu, SWT.CHECK);
	item.setText ("Show Event detail");
	item.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			MenuItem item = (MenuItem)e.widget;
			dragEventDetail = item.getSelection();
		}
	});
	dragConsole.setMenu(menu);
	
	Label dropLabel = new Label(shell, SWT.LEFT);
	dropLabel.setText("Drop Target:");
	
	Group dropWidgetGroup = new Group(shell, SWT.NONE);
	dropWidgetGroup.setText("Widget");
	createDropWidget(dropWidgetGroup);
	
	Group dropOperationsGroup = new Group(shell, SWT.NONE);
	dropOperationsGroup.setText("Allowed Operation(s):");
	createDropOperations(dropOperationsGroup);
	
	Group dropTypesGroup = new Group(shell, SWT.NONE);
	dropTypesGroup.setText("Transfer Type(s):");
	createDropTypes(dropTypesGroup);
	
	dropConsole = new Text(shell, SWT.READ_ONLY | SWT.BORDER |SWT.V_SCROLL | SWT.H_SCROLL | SWT.MULTI);
	menu = new Menu (shell, SWT.POP_UP);
	item = new MenuItem (menu, SWT.PUSH);
	item.setText ("Clear");
	item.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			dropConsole.setText("");
		}
	});
	item = new MenuItem (menu, SWT.CHECK);
	item.setText ("Show Event detail");
	item.addSelectionListener(new SelectionAdapter() {
		public void widgetSelected(SelectionEvent e) {
			MenuItem item = (MenuItem)e.widget;
			dropEventDetail = item.getSelection();
		}
	});
	dropConsole.setMenu(menu);
	
	int height = 300;
	FormData data = new FormData();
	data.top = new FormAttachment(0, 10);
	data.left = new FormAttachment(0, 10);
	dragLabel.setLayoutData(data);
	
	data = new FormData();
	data.top = new FormAttachment(dragLabel, 10);
	data.left = new FormAttachment(0, 10);
	data.right = new FormAttachment(50, -10);
	data.height = height;
	dragWidgetGroup.setLayoutData(data);
	
	data = new FormData();
	data.top = new FormAttachment(dragWidgetGroup, 10);
	data.left = new FormAttachment(0, 10);
	data.right = new FormAttachment(50, -10);
	//data.bottom = new FormAttachment(dropTypesGroup, -10);
	dragOperationsGroup.setLayoutData(data);
	
	data = new FormData();
	data.top = new FormAttachment(dragOperationsGroup, 10);
	data.left = new FormAttachment(0, 10);
	data.right = new FormAttachment(50, -10);
	dragTypesGroup.setLayoutData(data);
	
	data = new FormData();
	data.top = new FormAttachment(dragTypesGroup, 10);
	data.bottom = new FormAttachment(100, -10);
	data.left = new FormAttachment(0, 10);
	data.right = new FormAttachment(50, -10);
	dragConsole.setLayoutData(data);
	
	data = new FormData();
	data.top = new FormAttachment(0, 10);
	data.left = new FormAttachment(dragTypesGroup, 10);
	dropLabel.setLayoutData(data);
	
	data = new FormData();
	data.top = new FormAttachment(dropLabel, 10);
	data.left = new FormAttachment(dragTypesGroup, 10);
	data.right = new FormAttachment(100, -10);
	data.height = height;
	dropWidgetGroup.setLayoutData(data);
	
	data = new FormData();
	data.top = new FormAttachment(dropWidgetGroup, 10);
	data.left = new FormAttachment(dragTypesGroup, 10);
	data.right = new FormAttachment(100, -10);
	dropOperationsGroup.setLayoutData(data);
	
	data = new FormData();
	data.top = new FormAttachment(dropOperationsGroup, 10);
	data.left = new FormAttachment(dragTypesGroup, 10);
	data.right = new FormAttachment(100, -10);
	//data.bottom = new FormAttachment(dragConsole, -10);
	dropTypesGroup.setLayoutData(data);
	
	data = new FormData();
	data.top = new FormAttachment(dropTypesGroup, 10);
	data.bottom = new FormAttachment(100, -10);
	data.left = new FormAttachment(50, 10);
	data.right = new FormAttachment(100, -10);
	dropConsole.setLayoutData(data);
		
	shell.setSize(1000, 900);
	shell.open();
		
	while (!shell.isDisposed()) {
		if (!display.readAndDispatch())
			display.sleep();
	}	
}

private void printEvent(DragSourceEvent e) {
	if (!dragEventDetail) return;
	StringBuffer sb = new StringBuffer();
	sb.append("widget: "); sb.append(e.widget);
	sb.append(", time: "); sb.append(e.time);
	sb.append(", operation: "); sb.append(e.detail);
	sb.append(", type: "); sb.append(e.dataType != null ? e.dataType.type : 0);
	sb.append(", doit: "); sb.append(e.doit);
	sb.append(", data: "); sb.append(e.data);
	sb.append("\n");
	dragConsole.append(sb.toString());
}

private void printEvent(DropTargetEvent e) {
	if (!dropEventDetail) return;
	StringBuffer sb = new StringBuffer();
	sb.append("widget; "); sb.append(e.widget);
	sb.append(", time: "); sb.append(e.time);
	sb.append(", x: "); sb.append(e.x);
	sb.append(", y: "); sb.append(e.y);
	sb.append(", item: "); sb.append(e.item);
	sb.append(", operations: "); sb.append(e.operations);
	sb.append(", operation: "); sb.append(e.detail);
	sb.append(", feedback: "); sb.append(e.feedback);
	if (e.dataTypes != null) {
		for (int i = 0; i < e.dataTypes.length; i++) {
			sb.append(", dataType "); sb.append(i); sb.append(": "); sb.append(e.dataTypes[i].type);
		}
	} else {
		sb.append(", dataTypes: none");
	}
	sb.append(", currentDataType: "); sb.append(e.currentDataType);
	sb.append(", data: "); sb.append(e.data);
	sb.append("\n");
	dropConsole.append(sb.toString());
}

private void removeDragTransfer(Transfer transfer){
	if (dragTypes.length == 1) {
		dragTypes = new Transfer[0];
	} else {
		int index = -1;
		for(int i = 0; i < dragTypes.length; i++) {
			if (dragTypes[i] == transfer) {
				index = i;
				break;
			}
		}
		if (index == -1) return;
		Transfer[] newTypes = new Transfer[dragTypes.length - 1];
		System.arraycopy(dragTypes, 0, newTypes, 0, index);
		System.arraycopy(dragTypes, index + 1, newTypes, index, dragTypes.length - index - 1);
		dragTypes = newTypes;
	}
	if (dragSource != null) {
		dragSource.setTransfer(dragTypes);
	}
}

private void removeDropTransfer(Transfer transfer){
	if (dropTypes.length == 1) {
		dropTypes = new Transfer[0];
	} else {
		int index = -1;
		for(int i = 0; i < dropTypes.length; i++) {
			if (dropTypes[i] == transfer) {
				index = i;
				break;
			}
		}
		if (index == -1) return;
		Transfer[] newTypes = new Transfer[dropTypes.length - 1];
		System.arraycopy(dropTypes, 0, newTypes, 0, index);
		System.arraycopy(dropTypes, index + 1, newTypes, index, dropTypes.length - index - 1);
		dropTypes = newTypes;
	}
	if (dropTarget != null) {
		dropTarget.setTransfer(dropTypes);
	}
}
}