Java Tutorial/SWT/TreeViewer
Содержание
Create CheckBoxTreeView and react to CheckStateListener
<source lang="java">
import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.util.ArrayList; import java.util.List; import org.eclipse.jface.viewers.CheckStateChangedEvent; import org.eclipse.jface.viewers.CheckboxTreeViewer; import org.eclipse.jface.viewers.ICheckStateListener; import org.eclipse.jface.viewers.ILabelProvider; import org.eclipse.jface.viewers.ILabelProviderListener; import org.eclipse.jface.viewers.ITreeContentProvider; import org.eclipse.jface.viewers.Viewer; import org.eclipse.jface.window.ApplicationWindow; import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.ruposite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class CheckFileTreeViewer {
public static void main(String[] args) {
CheckFileTree main = new CheckFileTree();
}
} class CheckFileTree extends ApplicationWindow{
public CheckFileTree() {
super(null);
// Don"t return from open() until window closes
setBlockOnOpen(true);
open();
Display.getCurrent().dispose();
}
protected void configureShell(Shell shell) {
super.configureShell(shell);
shell.setSize(400, 400);
}
/**
* Creates the main window"s contents
*
* @param parent the main window
* @return Control
*/
protected Control createContents(Composite parent) {
Composite composite = new Composite(parent, SWT.NONE);
composite.setLayout(new GridLayout(1, false));
// Create the tree viewer to display the file tree
final CheckboxTreeViewer tv = new CheckboxTreeViewer(composite);
tv.getTree().setLayoutData(new GridData(GridData.FILL_BOTH));
tv.setContentProvider(new FileTreeContentProvider());
tv.setLabelProvider(new FileTreeLabelProvider());
tv.setInput("root"); // pass a non-null that will be ignored
// When user checks a checkbox in the tree, check all its children
tv.addCheckStateListener(new ICheckStateListener() {
public void checkStateChanged(CheckStateChangedEvent event) {
if (event.getChecked()) {
tv.setSubtreeChecked(event.getElement(), true);
}
}
});
return composite;
}
}
class FileTreeContentProvider implements ITreeContentProvider {
public Object[] getChildren(Object arg0) {
return ((File) arg0).listFiles();
}
public Object getParent(Object arg0) {
return ((File) arg0).getParentFile();
}
public boolean hasChildren(Object arg0) {
Object[] obj = getChildren(arg0);
return obj == null ? false : obj.length > 0;
}
public Object[] getElements(Object arg0) {
return File.listRoots();
}
public void dispose() {
}
public void inputChanged(Viewer arg0, Object arg1, Object arg2) {
}
} class FileTreeLabelProvider implements ILabelProvider {
private List listeners;
private Image file;
private Image dir;
public FileTreeLabelProvider() {
listeners = new ArrayList();
try {
file = new Image(null, new FileInputStream("images/file.gif"));
dir = new Image(null, new FileInputStream("images/directory.gif"));
} catch (FileNotFoundException e) {
}
}
public Image getImage(Object arg0) {
return ((File) arg0).isDirectory() ? dir : file;
}
public String getText(Object arg0) {
String text = ((File) arg0).getName();
if (((File) arg0).getName().length() == 0) {
text = ((File) arg0).getPath();
}
return text;
}
public void addListener(ILabelProviderListener arg0) {
listeners.add(arg0);
}
public void dispose() {
// Dispose the images
if (dir != null)
dir.dispose();
if (file != null)
file.dispose();
}
public boolean isLabelProperty(Object arg0, String arg1) {
return false;
}
public void removeListener(ILabelProviderListener arg0) {
listeners.remove(arg0);
}
}</source>
Create TreeView based on your own tree node structure
<source lang="java">
import java.util.Vector; import org.eclipse.jface.viewers.ILabelProvider; import org.eclipse.jface.viewers.ILabelProviderListener; import org.eclipse.jface.viewers.ITreeContentProvider; import org.eclipse.jface.viewers.TreeViewer; import org.eclipse.jface.viewers.Viewer; import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Tree; import org.eclipse.swt.widgets.TreeItem; public class TreeViewBasedOnNode {
static Display display = new Display();
static Shell shell = new Shell(display);
static final Tree tree = new Tree(shell, SWT.BORDER);
static Vector nodes = new Vector();
public static void traditional() {
for (int i = 0; nodes != null && i < nodes.size(); i++) {
Node node = (Node) nodes.elementAt(i);
addNode(null, node);
}
}
private static void addNode(TreeItem parentItem, Node node) {
TreeItem item = null;
if (parentItem == null)
item = new TreeItem(tree, SWT.NONE);
else
item = new TreeItem(parentItem, SWT.NONE);
item.setText(node.getName());
Vector subs = node.getSubCategories();
for (int i = 0; subs != null && i < subs.size(); i++)
addNode(item, (Node) subs.elementAt(i));
}
public static void main(String[] args) {
Node category = new Node("A", null);
nodes.add(category);
category = new Node("a1", category);
new Node("a11", category);
new Node("a12", category);
category = new Node("B", null);
nodes.add(category);
new Node("b1", category);
new Node("b2", category);
TreeViewer treeViewer = new TreeViewer(tree);
treeViewer.setContentProvider(new MyTreeContentProvider());
treeViewer.setLabelProvider(new MyLabelProvider());
treeViewer.setInput(nodes);
tree.setSize(300, 200);
shell.setSize(300, 200);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
display.dispose();
}
} class MyLabelProvider implements ILabelProvider {
public String getText(Object element) {
return ((Node) element).getName();
}
public Image getImage(Object arg0) {
return null;
}
public void addListener(ILabelProviderListener arg0) {
}
public void dispose() {
}
public boolean isLabelProperty(Object arg0, String arg1) {
return false;
}
public void removeListener(ILabelProviderListener arg0) {
}
}
class MyTreeContentProvider implements ITreeContentProvider{
public Object[] getChildren(Object parentElement) {
Vector subcats = ((Node) parentElement).getSubCategories();
return subcats == null ? new Object[0] : subcats.toArray();
}
public Object getParent(Object element) {
return ((Node) element).getParent();
}
public boolean hasChildren(Object element) {
return ((Node) element).getSubCategories() != null;
}
public Object[] getElements(Object inputElement) {
if (inputElement != null && inputElement instanceof Vector) {
return ((Vector) inputElement).toArray();
}
return new Object[0];
}
public void dispose() {
}
public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
}
}
class Node {
private String name;
private Vector subCategories;
private Node parent;
public Node(String name, Node parent) {
this.name = name;
this.parent = parent;
if (parent != null)
parent.addSubCategory(this);
}
public Vector getSubCategories() {
return subCategories;
}
private void addSubCategory(Node subcategory) {
if (subCategories == null)
subCategories = new Vector();
if (!subCategories.contains(subcategory))
subCategories.add(subcategory);
}
public String getName() {
return name;
}
public Node getParent() {
return parent;
}
}</source>
Tree Viewers
JFace wraps SWT"s Tree widget with a class called TreeViewer.
Creating a TreeViewer
TreeViewer treeViewer = new TreeViewer(shell);
<source lang="java">
Create a TreeViewer to wrap an existing Tree control, like this: Tree tree = new Tree(shell, SWT.SINGLE); TreeViewer treeViewer = new TreeViewer(tree);</source>
Using a TreeViewer
The general way to use a TreeViewer:
- Creating a TreeViewer
- Creating a content provider class and setting it on the TreeViewer using setContentProvider()
- Creating a label provider class and setting it on the TreeViewer using setLabelProvider()
- Setting the root input for the tree using setInput()
<source lang="java">
import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.util.ArrayList; import java.util.List; import org.eclipse.jface.viewers.ILabelProvider; import org.eclipse.jface.viewers.ILabelProviderListener; import org.eclipse.jface.viewers.ITreeContentProvider; import org.eclipse.jface.viewers.TreeViewer; import org.eclipse.jface.viewers.Viewer; import org.eclipse.jface.window.ApplicationWindow; import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.layout.FillLayout; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.widgets.ruposite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Shell; public class FileTreeWindowApplication {
public static void main(String[] args) {
FileTreeWindow main = new FileTreeWindow();
}
} class FileTreeWindow extends ApplicationWindow {
public FileTreeWindow() {
super(null);
// Don"t return from open() until window closes
setBlockOnOpen(true);
open();
Display.getCurrent().dispose();
}
protected void configureShell(Shell shell) {
super.configureShell(shell);
shell.setSize(400, 400);
}
protected Control createContents(Composite parent) {
Composite composite = new Composite(parent, SWT.NONE);
composite.setLayout(new FillLayout());
final TreeViewer tv = new TreeViewer(composite);
tv.getTree().setLayoutData(new GridData(GridData.FILL_BOTH));
tv.setContentProvider(new FileTreeContentProvider());
tv.setLabelProvider(new FileTreeLabelProvider());
tv.setInput("root");
return composite;
}
} class FileTreeContentProvider implements ITreeContentProvider {
public Object[] getChildren(Object arg0) {
return ((File) arg0).listFiles();
}
public Object getParent(Object arg0) {
return ((File) arg0).getParentFile();
}
public boolean hasChildren(Object arg0) {
Object[] obj = getChildren(arg0);
return obj == null ? false : obj.length > 0;
}
public Object[] getElements(Object arg0) {
return File.listRoots();
}
public void dispose() {
}
public void inputChanged(Viewer arg0, Object arg1, Object arg2) {
}
} class FileTreeLabelProvider implements ILabelProvider {
private List listeners;
private Image file;
private Image dir;
public FileTreeLabelProvider() {
listeners = new ArrayList();
try {
file = new Image(null, new FileInputStream("images/file.gif"));
dir = new Image(null, new FileInputStream("images/directory.gif"));
} catch (FileNotFoundException e) {
}
}
public Image getImage(Object arg0) {
return ((File) arg0).isDirectory() ? dir : file;
}
public String getText(Object arg0) {
String text = ((File) arg0).getName();
if (((File) arg0).getName().length() == 0) {
text = ((File) arg0).getPath();
}
return text;
}
public void addListener(ILabelProviderListener arg0) {
listeners.add(arg0);
}
public void dispose() {
// Dispose the images
if (dir != null)
dir.dispose();
if (file != null)
file.dispose();
}
public boolean isLabelProperty(Object arg0, String arg1) {
return false;
}
public void removeListener(ILabelProviderListener arg0) {
listeners.remove(arg0);
}
}</source>
