Question

我有一段代码与树查看器作为eclipse插件的一部分。代码在这里（这直接来自eclipse PDE示例树视图）：

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();
    }

我想以某种方式能够单独遍历树上的所有节点并控制它们展开或折叠的方式。基本上我只想知道如何能够迭代树上的所有节点来单独调整设置。

这应该是一个简单的问题，但我似乎没有发现任何有效的东西...... 我试图弄清楚TreeViewer对象的getItem（）究竟是如何工作的。但问题是即使我拿到了这个项目，我也不能（或者不确定如何）修改它。

感谢您的帮助

Answer 1

首先从查看器中获取基础树：

Tree tree = viewer.getTree();

然后获取树中的第一级项目：

TreeItem[] item = tree.getItems();

任何树项目都可以回答所有直接的孩子：

TreeItem[] item = aTreeItem.getItems();

获得树项目后，您可以展开或折叠它：

aTreeItem.setExpanded(true);

因此，对所有树项的访问必须是递归的。

在Eclipse Tree Viewer中单独选择树节点

1 个答案: