在Eclipse Tree Viewer中分別選擇樹節點

Question

我有一個樹瀏覽器的代碼作為eclipse插件的一部分。 代碼在這里（直接從Eclipse PDE示例樹視圖中獲取）：

public class SampleView extends ViewPart {

    /**
     * The ID of the view as specified by the extension.
     */
    public static final String ID = "com.test2.views.SampleView";

    private TreeViewer viewer;
    private DrillDownAdapter drillDownAdapter;
    private Action action1;
    private Action action2;
    private Action doubleClickAction;

    /*
     * The content provider class is responsible for
     * providing objects to the view. It can wrap
     * existing objects in adapters or simply return
     * objects as-is. These objects may be sensitive
     * to the current input of the view, or ignore
     * it and always show the same content 
     * (like Task List, for example).
     */

    class TreeObject implements IAdaptable {
        private String name;
        private TreeParent parent;

        public TreeObject(String name) {
            this.name = name;
        }
        public String getName() {
            return name;
        }
        public void setParent(TreeParent parent) {
            this.parent = parent;
        }
        public TreeParent getParent() {
            return parent;
        }
        public String toString() {
            return getName();
        }
        public Object getAdapter(Class key) {
            return null;
        }
    }

    class TreeParent extends TreeObject {
        private ArrayList children;
        public TreeParent(String name) {
            super(name);
            children = new ArrayList();
        }
        public void addChild(TreeObject child) {
            children.add(child);
            child.setParent(this);
        }
        public void removeChild(TreeObject child) {
            children.remove(child);
            child.setParent(null);
        }
        public TreeObject [] getChildren() {
            return (TreeObject [])children.toArray(new TreeObject[children.size()]);
        }
        public boolean hasChildren() {
            return children.size()>0;
        }
    }

    class ViewContentProvider implements IStructuredContentProvider, 
                                           ITreeContentProvider {
        private TreeParent invisibleRoot;

        public void inputChanged(Viewer v, Object oldInput, Object newInput) {
        }
        public void dispose() {
        }
        public Object[] getElements(Object parent) {
            if (parent.equals(getViewSite())) {
                if (invisibleRoot==null) initialize();
                return getChildren(invisibleRoot);
            }
            return getChildren(parent);
        }
        public Object getParent(Object child) {
            if (child instanceof TreeObject) {
                return ((TreeObject)child).getParent();
            }
            return null;
        }
        public Object [] getChildren(Object parent) {
            if (parent instanceof TreeParent) {
                return ((TreeParent)parent).getChildren();
            }
            return new Object[0];
        }
        public boolean hasChildren(Object parent) {
            if (parent instanceof TreeParent)
                return ((TreeParent)parent).hasChildren();
            return false;
        }
/*
 * We will set up a dummy model to initialize tree heararchy.
 * In a real code, you will connect to a real model and
 * expose its hierarchy.
 */
        private void initialize() {
            TreeObject to1 = new TreeObject("Leaf 1");
            TreeObject to2 = new TreeObject("Leaf 2");
            TreeObject to3 = new TreeObject("Leaf 3");
            TreeParent p1 = new TreeParent("Parent 1");
            p1.addChild(to1);
            p1.addChild(to2);
            p1.addChild(to3);

            TreeObject to4 = new TreeObject("Leaf 4");
            TreeParent p2 = new TreeParent("Parent 2");
            p2.addChild(to4);

            TreeParent root = new TreeParent("Root");
            root.addChild(p1);
            root.addChild(p2);

            invisibleRoot = new TreeParent("");
            invisibleRoot.addChild(root);
        }
    }
    class ViewLabelProvider extends LabelProvider {

        public String getText(Object obj) {
            return obj.toString();
        }
        public Image getImage(Object obj) {
            String imageKey = ISharedImages.IMG_OBJ_ELEMENT;
            if (obj instanceof TreeParent)
               imageKey = ISharedImages.IMG_OBJ_FOLDER;
            return PlatformUI.getWorkbench().getSharedImages().getImage(imageKey);
        }
    }
    class NameSorter extends ViewerSorter {
    }

    /**
     * The constructor.
     */
    public SampleView() {
    }

    /**
     * This is a callback that will allow us
     * to create the viewer and initialize it.
     */
    public void createPartControl(Composite parent) {
        viewer = new TreeViewer(parent, SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL);
        drillDownAdapter = new DrillDownAdapter(viewer);
        viewer.setContentProvider(new ViewContentProvider());
        viewer.setLabelProvider(new ViewLabelProvider());
        viewer.setSorter(new NameSorter());
        viewer.setInput(getViewSite());

        // Create the help context id for the viewer's control
        PlatformUI.getWorkbench().getHelpSystem().setHelp(viewer.getControl(), "com.test2.viewer");
        makeActions();
        hookContextMenu();
        hookDoubleClickAction();
        contributeToActionBars();
    }

我希望能夠以某種方式分別遍歷樹上的所有節點並控制它們的展開或折疊方式。 基本上，我只想知道如何遍歷樹上的所有節點以分別調整設置。

這應該是一個簡單的問題，但是我似乎還沒有找到任何可行的方法……我試圖弄清楚TreeViewer對象的getItem（）是如何工作的。 但是然后的問題是，即使我得到了該物品，也無法（或不確定如何修改）它。

謝謝你的幫助

Answer 1

首先從查看器獲取基礎樹：

Tree tree = viewer.getTree();

然后獲取樹中的第一級項目：

TreeItem[] item = tree.getItems();

任何樹項都可以回答其所有直接子項：

TreeItem[] item = aTreeItem.getItems();

獲得樹項后，可以展開或折疊它：

aTreeItem.setExpanded(true);

因此，對所有樹項的訪問必須是遞歸的。