weidagang2046的專欄

package ?net.advanced.eclipse.sample.views;

import ?org.eclipse.swt.SWT;
import ?org.eclipse.swt.dnd.DND;
import ?org.eclipse.swt.dnd.DragSource;
import ?org.eclipse.swt.dnd.DragSourceEvent;
import ?org.eclipse.swt.dnd.DragSourceListener;
import ?org.eclipse.swt.dnd.DropTarget;
import ?org.eclipse.swt.dnd.DropTargetEvent;
import ?org.eclipse.swt.dnd.DropTargetListener;
import ?org.eclipse.swt.dnd.FileTransfer;
import ?org.eclipse.swt.dnd.TextTransfer;
import ?org.eclipse.swt.dnd.Transfer;
import ?org.eclipse.swt.widgets.Composite;
import ?org.eclipse.swt.widgets.Table;
import ?org.eclipse.swt.widgets.TableColumn;
import ?org.eclipse.swt.widgets.TableItem;
import ?org.eclipse.swt.widgets.Tree;
import ?org.eclipse.swt.widgets.TreeItem;
import ?org.eclipse.ui.part.ViewPart;

/**
?*?@Title:?DragAndDrop.java
?*?@Copyright:
?*?@Company:
?*?@Created?on?2005-12-02?14:34:40
?*? @author ?孫其弘
?*? @version ?$Revision:?1.11?$
?*? @since ?1.0
? */

public ? class ?DragAndDrop? extends ?ViewPart{
???? private ?Tree?dragTree;
???? private ?Table?dropTable;
???? private ?TextTransfer?textTransfer;
???? private ?FileTransfer?fileTransfer;

???? public ? void ?createPartControl(Composite?parent){
???????? /* ?Transfer是一個可以提供數(shù)據(jù)在Java?representation與platform?specific?representation
?????????*?之間交互的抽象類.下面是幾個format：
?????????*?TextTransfer?String?"hello?world"?
?????????*?RTFTransfer?String?"{\\rtf1\\b\\i?hello?world}"?
?????????*?FileTransfer?String[]?new?String[]?{file1.getAbsolutePath(),?file2.getAbsolutePath()}?
?????????*?
?????????*?TransferData包含了很多特定于平臺的公用的屬性，應用不應該直接去訪問這些屬性。
?????????*?如果真的有必要去訪問這些屬性，那么我們可以通過擴展Transfer類來完成對特定平臺的額外操作。
????????? */
????????textTransfer = TextTransfer.getInstance();
????????fileTransfer = FileTransfer.getInstance();

????????dragTree = new ?Tree(parent,SWT.FULL_SELECTION | SWT.SINGLE);
???????? for ( int ?i = 0 ;i < 10 ;i ++ ){
????????????TreeItem?item = new ?TreeItem(dragTree,SWT.NONE);
????????????item.setText( " treeitem " + i);
???????????? for ( int ?i2 = 0 ;i2 < 5 ;i2 ++ ){
????????????????TreeItem?subitem = new ?TreeItem(item,SWT.NONE);
????????????????subitem.setText( " subtreeitem " + i2);
????????????}
????????}

???????? // 將dragLabel指定為DragSource(一個widget只能幫定在一個DragSource)，
???????? // 并允許數(shù)據(jù)可以從DragSource被MOVE或COPY
????????DragSource?source = new ?DragSource(dragTree,DND.DROP_MOVE | DND.DROP_COPY);
????????source.setTransfer( new ?Transfer[]?{?textTransfer?}); // ?指定允許的傳輸類型
????????source.addDragListener( new ?MyDragSourceListener());

????????dropTable = new ?Table(parent,SWT.BORDER | SWT.FULL_SELECTION | SWT.SINGLE);
????????fillTable();

???????? // ?將dropTable指定為Drop?Target,
????????DropTarget?target = new ?DropTarget(dropTable,DND.DROP_MOVE | DND.DROP_COPY | DND.DROP_DEFAULT);
????????target.setTransfer( new ?Transfer[]?{textTransfer?});
????????target.addDropListener( new ?MyDropTargetListener());
????}

???? class ?MyDragSourceListener? implements ?DragSourceListener{
???????? // ?指定拖動開始的執(zhí)行策略。
???????? public ? void ?dragStart(DragSourceEvent?event){
???????????? if (((DragSource)event.widget).getControl()? instanceof ?Tree){
????????????????TreeItem?selection? = ?DragAndDrop. this .dragTree.getSelection()[ 0 ];
???????????????? if (selection.getText().length() == 0 ){
????????????????????event.doit = false ;
????????????????}?
????????????}
????????}

???????? // dragSetData方法在dragStart通過之后才被調(diào)用。這個方法可能會因為同一種傳輸類型多次set或
???????? // 不同的多種傳輸類型的set而被多次調(diào)用，象windows等有些平臺中，dropTarget可以在鼠標移動的
???????? // 過程中請求數(shù)據(jù)，但是在Motif等平臺中，只可以在drop操作完成之后才可以請求數(shù)據(jù)，所以在這個方
???????? // 法中不要假設drag?and?drop操作已經(jīng)完成.在這個方法中是無法知道data將被drop到哪里.
???????? // set的Data也要符合指定的Transfer的format類型。
???????? public ? void ?dragSetData(DragSourceEvent?event){
???????????? if (TextTransfer.getInstance().isSupportedType(event.dataType)){
???????????????? if (((DragSource)event.widget).getControl()? instanceof ?Tree){
????????????????????TreeItem?selection? = ?DragAndDrop. this .dragTree.getSelection()[ 0 ];
????????????????????event.data = selection.getText();
????????????????}
????????????}
????????}

???????? // ?根據(jù)事先指定好的操作類型來處理操作結果
???????? public ? void ?dragFinished(DragSourceEvent?event){
???????????? if (event.detail == DND.DROP_MOVE){
???????????????? if (((DragSource)event.widget).getControl()? instanceof ?Tree){
????????????????????TreeItem?selection? = ?DragAndDrop. this .dragTree.getSelection()[ 0 ];
????????????????????selection.removeAll();
????????????????}
????????????}
????????}
????}

???? class ?MyDropTargetListener? implements ?DropTargetListener{
???????? // dragEnter事件在drag?and?drop動作開始，并且鼠標進入了target?widget的范圍內(nèi)時被調(diào)用。
???????? public ? void ?dragEnter(DropTargetEvent?event){
???????????? // 在dragEnter中應用可以定義default?operation.如果一個drop?target在創(chuàng)建的時候被指定為
???????????? // 帶有DND.DROP_DEFAULT,那么在拖動的過程中如果沒有輔助按鍵被按下，則drop?target就是DND.DROP_DEFAULT的。
???????????? // 應用可以通過改變event.detail來指定default?operation。如果應用沒有具體指定DND.DROP_DEFAULT的操作，
???????????? // 平臺會默認將DND.DROP_DEFAULT設置為DND.DROP_MOVE。
???????????? // 另外DND.DROP_DEFAULT的值也可以在dragOperationChanged中設置。
????????????
???????????? if (event.detail == DND.DROP_DEFAULT){
???????????????? // 給event.detail賦的值必須是event.operations中的一個,event.operations中
???????????????? // 的操作都是DragSource所支持的.?
???????????????? if ((event.operations & DND.DROP_COPY) != 0 ){
????????????????????event.detail = DND.DROP_COPY;
????????????????} else {
????????????????????event.detail = DND.DROP_NONE;
????????????????}
????????????}
????????????
???????????? // drop?target可以選擇性的按照傳輸類型來處理.dragEnter?event有兩個屬性
???????????? // event.currentType?是應用設置的默認類型，以TransferData對象形式表現(xiàn),
???????????? // event.dataTypes?是drag?source支持的所有類型的列表，以TransferData數(shù)組形式表現(xiàn),?
???????????? // 我們可以將event.currentType設置成event.dataTypes中的任意一個。
???????????? // 這些屬性也可以在dragOver,?dragOperationChanged以及dropAccept事件中設置。

???????????? for ( int ?i = 0 ;i < event.dataTypes.length;i ++ ){
???????????????? if (textTransfer.isSupportedType(event.dataTypes[i])){
????????????????????event.currentDataType = event.dataTypes[i];
???????????????????? // 只允許COPY
???????????????????? if (event.detail != DND.DROP_COPY){
????????????????????????event.detail = DND.DROP_NONE;
????????????????????}
???????????????????? break ;
????????????????}
????????????}
????????}

???????? // dragOver?event在光標進入drop?target?widget時會被重復不停的調(diào)用.?
???????? // 如果光標是靜止的,dragOver?event依然會有規(guī)則的按一定時間間隔被調(diào)用.?
???????? // 這個方法一般在drop?target是table或tree時用得比較多，可以根據(jù)不同的item而改變操作.
???????? public ? void ?dragOver(DropTargetEvent?event){
???????????? // event.feedback設置當widget處于光標下時應該給用戶一個什么樣的feedback.?
???????????? // dragOver?event.feedback?值描述?
???????????? // DND.FEEDBACK_SELECT??使光標下的item被選中，限于table?and?trees.?
???????????? // DND.FEEDBACK_SCROLL??使widget可以滾動以便于用戶可以drop在當前看不見的item上，限于table?and?trees.??
???????????? // DND.FEEDBACK_EXPAND??使當前光標下的item展開以便于用戶在sub?item上drop，限于trees.?
???????????? // DND.FEEDBACK_INSERT_BEFORE??在item處于光標下之前顯示一個插入標記，限于tables?and?trees.?
???????????? // DND.FEEDBACK_INSERT_AFTER???在item處于光標下之后顯示一個插入標記，限于tables?and?trees.??
???????????? // DND.FEEDBACK_NONE????沒有任何效果.?
????????????event.feedback = DND.FEEDBACK_SELECT | DND.FEEDBACK_SCROLL;
???????????? if (textTransfer.isSupportedType(event.currentDataType)){
????????????????String?t = (String)(textTransfer.nativeToJava(event.currentDataType));
???????????????? if (t != null ){
????????????????????System.out.println(t);
????????????????}
????????????}
????????}

???????? // 當用戶按下或放開輔助按鍵時，例如Ctrl,?Shift,?Command,?Option。則dragOperationChanged事件發(fā)生。
???????? // 輔助按鍵可以改變即將進行的操作。例如：
???????? // Ctrl?key?is?down,?a?copy?is?requested,
???????? // Ctrl?and?Shift?keys?are?both?down,?a?link?is?requested
???????? // Shift?key?is?down,?a?move?is?requested
???????? // When?no?modifier?keys?are?pressed,?the?default?operation?is?requested.?
???????? public ? void ?dragOperationChanged(DropTargetEvent?event){
???????????? if (event.detail == DND.DROP_DEFAULT){
????????????????event.detail = DND.DROP_COPY;
????????????} else {
????????????????event.detail = DND.DROP_NONE;
????????????}

???????????? // ?allow?text?to?be?moved?but?files?should?only?be?copied
???????????? if (fileTransfer.isSupportedType(event.currentDataType)){
???????????????? if (event.detail != DND.DROP_COPY){
????????????????????event.detail = DND.DROP_NONE;
????????????????}
????????????}
????????}

???????? // 當光標離開drop?target?widget時，dragLeave事件發(fā)生.?如果你在dragEnter中分配了一些資源，
???????? // 就應該在dragLeave中釋放.dragLeave事件在用戶通過Escape鍵取消Drag?and?Drop操作時也會發(fā)生
???????? // 剛好在drop操作被執(zhí)行之前.
???????? public ? void ?dragLeave(DropTargetEvent?event){
????????}

???????? // dropAccept事件為應用提供了最后一次定義數(shù)據(jù)類型的機會，定義的數(shù)據(jù)類型將被返回到drop事件.?
???????? // 這些是通過向event.currentDataType賦event.dataTypes中的值來實現(xiàn)的.
???????? public ? void ?dropAccept(DropTargetEvent?event){
????????}

???????? // 如果在之前的事件中得到了有效的操作和currentDataType，那么當用戶在drop?target上松開鼠標時，drop事件會發(fā)生。
???????? // event.data屬性包含了請求到的數(shù)據(jù)，event.type包含了Transfer的類型.?
???????? // data是event.currentDataType中定義的類型.
???????? public ? void ?drop(DropTargetEvent?event){
???????????? if (textTransfer.isSupportedType(event.currentDataType)){
????????????????String?text = (String)event.data;
????????????????TableItem?item = new ?TableItem(dropTable,SWT.NONE);
????????????????item.setText(text);
????????????}
???????????? if (fileTransfer.isSupportedType(event.currentDataType)){
????????????????String[]?files = (String[])event.data;
???????????????? for ( int ?i = 0 ;i < files.length;i ++ ){
????????????????????TableItem?item = new ?TableItem(dropTable,SWT.NONE);
????????????????????item.setText(files[i]);
????????????????}
????????????}
????????}
????}
????
???? public ? void ?fillTable(){
????????dropTable.setHeaderVisible( true );
????????dropTable.setLinesVisible( true );
????????
????????TableColumn?partName? = new ?TableColumn(dropTable,SWT.LEFT);
????????partName.setResizable( true );
????????partName.setText( " NAME " );
????????partName.setWidth( 250 );
????????
????????TableColumn?employeeName = new ?TableColumn(dropTable,SWT.LEFT);
????????employeeName.setResizable( true );
????????employeeName.setText( " SIZE " );
????????employeeName.setWidth( 120 );
????????
???????? for ( int ?i = 0 ;i < 10 ;i ++ ){
????????????TableItem?item = new ?TableItem(dropTable,SWT.NONE);
????????????item.setText( new ?String[]{ " tableitem " + i, 100 + i + "" });
????????}
????}
????
???? public ? void ?setFocus(){

????}
}