1、拖拽Label的文字。
public static void main (String [] args) {
Display display = new Display ();
final Shell shell = new Shell (display);
shell.setLayout(new FillLayout());
final Label label1 = new Label (shell, SWT.BORDER);
label1.setText ("TEXT");
final Label label2 = new Label (shell, SWT.BORDER);
setDragDrop (label1);
setDragDrop (label2);
shell.setSize (200, 200);
shell.open ();
while (!shell.isDisposed ()) {
if (!display.readAndDispatch ()) display.sleep ();
}
display.dispose ();
}
public static void setDragDrop (final Label label) {
Transfer[] types = new Transfer[] {TextTransfer.getInstance()};
int operations = DND.DROP_MOVE | DND.DROP_COPY | DND.DROP_LINK;
final DragSource source = new DragSource (label, operations);
source.setTransfer(types);
source.addDragListener (new DragSourceListener () {
public void dragStart(DragSourceEvent event) {
event.doit = (label.getText ().length () != 0);
}
public void dragSetData (DragSourceEvent event) {
event.data = label.getText ();
}
public void dragFinished(DragSourceEvent event) {
if (event.detail == DND.DROP_MOVE)
label.setText ("");
}
});
DropTarget target = new DropTarget(label, operations);
target.setTransfer(types);
target.addDropListener (new DropTargetAdapter() {
public void drop(DropTargetEvent event) {
if (event.data == null) {
event.detail = DND.DROP_NONE;
return;
}
label.setText ((String) event.data);
}
});
}
2、随意拖拽Tree子节点。
public static void main (String [] args) {
final Display display = new Display ();
final Shell shell = new Shell (display);
shell.setLayout(new FillLayout());
//建立用于拖拽的树
final Tree tree = new Tree(shell, SWT.BORDER);
for (int i = 0; i < 3; i++) {
TreeItem item = new TreeItem(tree, SWT.NONE);
item.setText("item "+i);
for (int j = 0; j < 3; j++) {
TreeItem subItem = new TreeItem(item, SWT.NONE);
subItem.setText("item "+i+" "+j);
for (int k = 0; k < 3; k++) {
TreeItem subsubItem = new TreeItem(subItem, SWT.NONE);
subsubItem.setText("item "+i+" "+j+" "+k);
}
}
}
Transfer[] types = new Transfer[] {TextTransfer.getInstance()};
int operations = DND.DROP_MOVE | DND.DROP_COPY | DND.DROP_LINK;
//建立拖拽 源————树tree对象
final DragSource source = new DragSource (tree, operations);
source.setTransfer(types);
final TreeItem[] dragSourceItem = new TreeItem[1];
source.addDragListener (new DragSourceListener () {
public void dragStart(DragSourceEvent event) {
TreeItem[] selection = tree.getSelection(); // 获取所选tree的节点
if (selection.length > 0 && selection[0].getItemCount() == 0) //判断所选节点是否存在并且为末端节点
{
event.doit = true; //启动拖拽功能
dragSourceItem[0] = selection[0]; //保存拖拽节点信息
} else {
event.doit = false;
}
};
public void dragSetData (DragSourceEvent event) {
event.data = dragSourceItem[0].getText(); //保存拖拽节点信息到事件数据中
}
public void dragFinished(DragSourceEvent event) {
if (event.detail == DND.DROP_MOVE)
dragSourceItem[0].dispose();
dragSourceItem[0] = null;
}
});
//建立拖拽 目的————树tree对象
DropTarget target = new DropTarget(tree, operations);
target.setTransfer(types);
target.addDropListener (new DropTargetAdapter() {
//处理拖拽到目的上空时的方法
public void dragOver(DropTargetEvent event) {
event.feedback = DND.FEEDBACK_EXPAND | DND.FEEDBACK_SCROLL; //响应拖拽动作，FEEDBACK_EXPAND表示拖拽到可以展开的节点时展开相应节点。
if (event.item != null) {
TreeItem item = (TreeItem)event.item;
//处理拖拽动作响应，根据拖拽的位置不同产生不同的响应
Point pt = display.map(null, tree, event.x, event.y); //获取拖拽当前位置点
Rectangle bounds = item.getBounds(); //获取目的节点的边框
//根据拖拽当前位置点与目的节点的边框位置设置响应，如显示为FEEDBACK_INSERT_BEFORE、FEEDBACK_INSERT_AFTER
if (pt.y < bounds.y + bounds.height/3) {
event.feedback |= DND.FEEDBACK_INSERT_BEFORE;
} else if (pt.y > bounds.y + 2*bounds.height/3) {
event.feedback |= DND.FEEDBACK_INSERT_AFTER;
} else {
event.feedback |= DND.FEEDBACK_SELECT;
}
}
}
//处理放下时的方法
public void drop(DropTargetEvent event) {
if (event.data == null) {
event.detail = DND.DROP_NONE;
return;
}
String text = (String)event.data;
//如果放下的位置没有节点，则新建立一个节点，以根节点为父节点
if (event.item == null)
{
TreeItem item = new TreeItem(tree, SWT.NONE);
item.setText(text);
}
//如果放下的位置有节点
else
{
TreeItem item = (TreeItem)event.item;
Point pt = display.map(null, tree, event.x, event.y);
Rectangle bounds = item.getBounds();
TreeItem parent = item.getParentItem();
if (parent != null) {
TreeItem[] items = parent.getItems();
int index = 0;
for (int i = 0; i < items.length; i++) {
if (items[i] == item) {
index = i;
break;
}
}
if (pt.y < bounds.y + bounds.height/3) {
//以当前节点的父节点为父建立一个子节点，并且插入到当前节点前
TreeItem newItem = new TreeItem(parent, SWT.NONE, index);
newItem.setText(text);
} else if (pt.y > bounds.y + 2*bounds.height/3) {
//以当前节点的父节点为父建立一个子节点，并且插入到当前节点前
TreeItem newItem = new TreeItem(parent, SWT.NONE, index+1);
newItem.setText(text);
} else {
//以当前为父节点建立一个子节点
TreeItem newItem = new TreeItem(item, SWT.NONE);
newItem.setText(text);
}
} else {
TreeItem[] items = tree.getItems();
int index = 0;
for (int i = 0; i < items.length; i++) {
if (items[i] == item) {
index = i;
break;
}
}
if (pt.y < bounds.y + bounds.height/3) {
TreeItem newItem = new TreeItem(tree, SWT.NONE, index);
newItem.setText(text);
} else if (pt.y > bounds.y + 2*bounds.height/3) {
TreeItem newItem = new TreeItem(tree, SWT.NONE, index+1);
newItem.setText(text);
} else {
TreeItem newItem = new TreeItem(item, SWT.NONE);
newItem.setText(text);
}
}
}
}
});
shell.setSize (400, 400);
shell.open ();
while (!shell.isDisposed ()) {
if (!display.readAndDispatch ()) display.sleep ();
}
display.dispose ();
}