Eclipseプラグインの一部としてツリービューアを備えたコードがあります。コードはここにあります（これはEclipse PDEサンプルツリービューから直接取得されます）：
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();
}
どういうわけか、ツリー上のすべてのノードを個別に調べて、それらが展開または折りたたまれる方法を制御できるようにしたいと思います。基本的には、ツリー上のすべてのノードを反復処理して設定を個別に調整する方法を知りたいだけです。
これは単純な問題であるはずですが、機能するものが見つからないようです... TreeViewerオブジェクトのgetItem（）がどのように正確に機能するかを理解しようとしています。しかし、問題は、アイテムを入手したとしても、それを変更できない（または方法がわからない）ことです。
助けてくれてありがとう