Java Tutorial/SWT/Tree Event

Get TreeItem from Mouse position in mouse down event

   <source lang="java">

import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Tree; import org.eclipse.swt.widgets.TreeItem; public class TreeItemMousePostion {

 public static void main(String[] args) {
   Display display = new Display();
   Shell shell = new Shell(display);
   final Tree tree = new Tree(shell, SWT.BORDER | SWT.MULTI);
   for (int i = 0; i < 12; i++) {
     TreeItem treeItem = new TreeItem(tree, SWT.NONE);
     treeItem.setText("Item " + i);
   }
   tree.addListener(SWT.MouseDown, new Listener() {
     public void handleEvent(Event event) {
       Point point = new Point(event.x, event.y);
       TreeItem item = tree.getItem(point);
       if (item != null) {
         System.out.println("Mouse down: " + item);
       }
     }
   });
   tree.setSize(200, 200);
   shell.setSize(300, 300);
   shell.open();
   while (!shell.isDisposed()) {
     if (!display.readAndDispatch())
       display.sleep();
   }
   display.dispose();
 }

}</source>

Limit selection to items that match a pattern

   <source lang="java">

/*******************************************************************************

* Copyright (c) 2000, 2004 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
*     IBM Corporation - initial API and implementation
*******************************************************************************/

//package org.eclipse.swt.snippets; /*

* Tree example snippet: limit selection to items that match a pattern
* 
* For a list of all SWT example snippets see
* http://www.eclipse.org/swt/snippets/
*/

import org.eclipse.swt.SWT; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.layout.FillLayout; 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 TreeSelectionPattern {

 public static void main(String[] args) {
   final Display display = new Display();
   final Shell shell = new Shell(display);
   shell.setLayout(new FillLayout());
   final Tree tree = new Tree(shell, SWT.BORDER | SWT.MULTI);
   for (int i = 0; i < 2; i++) {
     TreeItem item = new TreeItem(tree, SWT.NONE);
     item.setText("item " + i);
     for (int j = 0; j < 2; j++) {
       TreeItem subItem = new TreeItem(item, SWT.NONE);
       subItem.setText("item " + j);
       for (int k = 0; k < 2; k++) {
         TreeItem subsubItem = new TreeItem(subItem, SWT.NONE);
         subsubItem.setText("item " + k);
       }
     }
   }
   tree.addSelectionListener(new SelectionAdapter() {
     public void widgetSelected(SelectionEvent e) {
       TreeItem[] selection = tree.getSelection();
       TreeItem[] revisedSelection = new TreeItem[0];
       for (int i = 0; i < selection.length; i++) {
         String text = selection[i].getText();
         if (text.indexOf("1") > 0) {
           TreeItem[] newSelection = new TreeItem[revisedSelection.length + 1];
           System.arraycopy(revisedSelection, 0, newSelection, 0, revisedSelection.length);
           newSelection[revisedSelection.length] = selection[i];
           revisedSelection = newSelection;
         }
       }
       tree.setSelection(revisedSelection);
     }
   });
   shell.setSize(300, 300);
   shell.open();
   while (!shell.isDisposed()) {
     if (!display.readAndDispatch())
       display.sleep();
   }
   display.dispose();
 }

}</source>

Tree default selection listener

   <source lang="java">

import org.eclipse.swt.SWT; import org.eclipse.swt.layout.FillLayout; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Tree; import org.eclipse.swt.widgets.TreeItem; public class TreeNodeDefaultSelectionListener {

 public static void main(String[] args) {
   Display display = new Display();
   Shell shell = new Shell(display);
   shell.setLayout(new FillLayout());
   final Tree tree = new Tree(shell, SWT.BORDER | SWT.MULTI | SWT.V_SCROLL);
   for (int i = 0; i < 4; i++) {
     TreeItem item0 = new TreeItem(tree, 0);
     item0.setText("Item " + i);
     for (int j = 0; j < 4; j++) {
       TreeItem item1 = new TreeItem(item0, 0);
       item1.setText("SubItem " + i + " " + j);
       for (int k = 0; k < 4; k++) {
         TreeItem item2 = new TreeItem(item1, 0);
         item2.setText("SubItem " + i + " " + j + " " + k);
       }
     }
   }
   tree.addListener(SWT.DefaultSelection, new Listener() {
     public void handleEvent(Event e) {
       String string = "";
       TreeItem[] selection = tree.getSelection();
       for (int i = 0; i < selection.length; i++)
         string += selection[i] + " ";
       System.out.println("DefaultSelection={" + string + "}");
     }
   });
   tree.getItems()[0].setExpanded(true);
   shell.pack();
   shell.open();
   while (!shell.isDisposed()) {
     if (!display.readAndDispatch())
       display.sleep();
   }
   display.dispose();
 }

}</source>

Tree event: Measure TreeItem, Paint TreeItem and Erase TreeItem

   <source lang="java">

/*******************************************************************************

* Copyright (c) 2000, 2006 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
*     IBM Corporation - initial API and implementation
*******************************************************************************/

//package org.eclipse.swt.snippets; /*

* Tree example snippet: Images on the right side of the TreeItem
*
* For a list of all SWT example snippets see
* http://www.eclipse.org/swt/snippets/
* 
* @since 3.2
*/

import org.eclipse.swt.SWT; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.layout.FillLayout; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Tree; import org.eclipse.swt.widgets.TreeColumn; import org.eclipse.swt.widgets.TreeItem; public class TreeEventMeasurePaintErase {

 public static void main(String[] args) {
   Display display = new Display();
   final Image image = display.getSystemImage(SWT.ICON_INFORMATION);
   Shell shell = new Shell(display);
   shell.setText("Images on the right side of the TreeItem");
   shell.setLayout(new FillLayout());
   Tree tree = new Tree(shell, SWT.MULTI | SWT.FULL_SELECTION);
   tree.setHeaderVisible(true);
   tree.setLinesVisible(true);
   int columnCount = 4;
   for (int i = 0; i < columnCount; i++) {
     TreeColumn column = new TreeColumn(tree, SWT.NONE);
     column.setText("Column " + i);
   }
   int itemCount = 3;
   for (int i = 0; i < itemCount; i++) {
     TreeItem item1 = new TreeItem(tree, SWT.NONE);
     item1.setText("item " + i);
     for (int c = 1; c < columnCount; c++) {
       item1.setText(c, "item [" + i + "-" + c + "]");
     }
     for (int j = 0; j < itemCount; j++) {
       TreeItem item2 = new TreeItem(item1, SWT.NONE);
       item2.setText("item [" + i + " " + j + "]");
       for (int c = 1; c < columnCount; c++) {
         item2.setText(c, "item [" + i + " " + j + "-" + c + "]");
       }
       for (int k = 0; k < itemCount; k++) {
         TreeItem item3 = new TreeItem(item2, SWT.NONE);
         item3.setText("item [" + i + " " + j + " " + k + "]");
         for (int c = 1; c < columnCount; c++) {
           item3.setText(c, "item [" + i + " " + j + " " + k + "-" + c + "]");
         }
       }
     }
   }
   /*
    * NOTE: MeasureItem, PaintItem and EraseItem are called repeatedly.
    * Therefore, it is critical for performance that these methods be as
    * efficient as possible.
    */
   Listener paintListener = new Listener() {
     public void handleEvent(Event event) {
       switch (event.type) {
       case SWT.MeasureItem: {
         Rectangle rect = image.getBounds();
         event.width += rect.width;
         event.height = Math.max(event.height, rect.height + 2);
         break;
       }
       case SWT.PaintItem: {
         int x = event.x + event.width;
         Rectangle rect = image.getBounds();
         int offset = Math.max(0, (event.height - rect.height) / 2);
         event.gc.drawImage(image, x, event.y + offset);
         break;
       }
       }
     }
   };
   tree.addListener(SWT.MeasureItem, paintListener);
   tree.addListener(SWT.PaintItem, paintListener);
   for (int i = 0; i < columnCount; i++) {
     tree.getColumn(i).pack();
   }
   shell.setSize(500, 200);
   shell.open();
   while (!shell.isDisposed()) {
     if (!display.readAndDispatch())
       display.sleep();
   }
   if (image != null)
     image.dispose();
   display.dispose();
 }

}</source>

Tree Exapand listener

   <source lang="java">

import org.eclipse.swt.SWT; import org.eclipse.swt.layout.FillLayout; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Tree; import org.eclipse.swt.widgets.TreeItem; public class TreeExpandListener {

 public static void main(String[] args) {
   Display display = new Display();
   Shell shell = new Shell(display);
   shell.setLayout(new FillLayout());
   final Tree tree = new Tree(shell, SWT.BORDER | SWT.MULTI | SWT.V_SCROLL);
   for (int i = 0; i < 4; i++) {
     TreeItem item0 = new TreeItem(tree, 0);
     item0.setText("Item " + i);
     for (int j = 0; j < 4; j++) {
       TreeItem item1 = new TreeItem(item0, 0);
       item1.setText("SubItem " + i + " " + j);
       for (int k = 0; k < 4; k++) {
         TreeItem item2 = new TreeItem(item1, 0);
         item2.setText("SubItem " + i + " " + j + " " + k);
       }
     }
   }
   tree.addListener(SWT.Expand, new Listener() {
     public void handleEvent(Event e) {
       System.out.println("Expand={" + e.item + "}");
     }
   });

   tree.getItems()[0].setExpanded(true);
   shell.pack();
   shell.open();
   while (!shell.isDisposed()) {
     if (!display.readAndDispatch())
       display.sleep();
   }
   display.dispose();
 }

}</source>

Tree node Collapse listener

   <source lang="java">

import org.eclipse.swt.SWT; import org.eclipse.swt.layout.FillLayout; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Tree; import org.eclipse.swt.widgets.TreeItem; public class TreeNodeCollapseListener {

 public static void main(String[] args) {
   Display display = new Display();
   Shell shell = new Shell(display);
   shell.setLayout(new FillLayout());
   final Tree tree = new Tree(shell, SWT.BORDER | SWT.MULTI | SWT.V_SCROLL);
   for (int i = 0; i < 4; i++) {
     TreeItem item0 = new TreeItem(tree, 0);
     item0.setText("Item " + i);
     for (int j = 0; j < 4; j++) {
       TreeItem item1 = new TreeItem(item0, 0);
       item1.setText("SubItem " + i + " " + j);
       for (int k = 0; k < 4; k++) {
         TreeItem item2 = new TreeItem(item1, 0);
         item2.setText("SubItem " + i + " " + j + " " + k);
       }
     }
   }
   tree.addListener(SWT.Collapse, new Listener() {
     public void handleEvent(Event e) {
       System.out.println("Collapse={" + e.item + "}");
     }
   });

   tree.getItems()[0].setExpanded(true);
   shell.pack();
   shell.open();
   while (!shell.isDisposed()) {
     if (!display.readAndDispatch())
       display.sleep();
   }
   display.dispose();
 }

}</source>

Tree node selection event

   <source lang="java">

import org.eclipse.swt.SWT; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Tree; import org.eclipse.swt.widgets.TreeItem; public class TreeNodeSelection {

 public static void main(String[] args) {
   Display display = new Display();
   Shell shell = new Shell(display);
   Tree tree = new Tree(shell, SWT.BORDER | SWT.V_SCROLL | SWT.H_SCROLL);
   for (int i = 0; i < 12; i++) {
     TreeItem item = new TreeItem(tree, SWT.NONE);
     item.setText("Item " + i);
     for(int l = 0;l<12;l++){
       TreeItem litem = new TreeItem(item, SWT.NONE);
       litem.setText("Item " + i);
     }
     
   }
   tree.setSize(100, 100);
   tree.addListener(SWT.Selection, new Listener() {
     public void handleEvent(Event event) {
       String string = event.detail == SWT.CHECK ? "Checked" : "Selected";
       System.out.println(event.item + " " + string);
     }
   });
   shell.setSize(200, 200);
   shell.open();
   while (!shell.isDisposed()) {
     if (!display.readAndDispatch())
       display.sleep();
   }
   display.dispose();
 }

}</source>

Tree node selection listener

   <source lang="java">

import org.eclipse.swt.SWT; import org.eclipse.swt.layout.FillLayout; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Listener; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Tree; import org.eclipse.swt.widgets.TreeItem; public class TreeNodeSelectionListener {

 public static void main(String[] args) {
   Display display = new Display();
   Shell shell = new Shell(display);
   shell.setLayout(new FillLayout());
   final Tree tree = new Tree(shell, SWT.BORDER | SWT.MULTI | SWT.V_SCROLL);
   for (int i = 0; i < 4; i++) {
     TreeItem item0 = new TreeItem(tree, 0);
     item0.setText("Item " + i);
     for (int j = 0; j < 4; j++) {
       TreeItem item1 = new TreeItem(item0, 0);
       item1.setText("SubItem " + i + " " + j);
       for (int k = 0; k < 4; k++) {
         TreeItem item2 = new TreeItem(item1, 0);
         item2.setText("SubItem " + i + " " + j + " " + k);
       }
     }
   }
   tree.addListener(SWT.Selection, new Listener() {
     public void handleEvent(Event e) {
       String string = "";
       TreeItem[] selection = tree.getSelection();
       for (int i = 0; i < selection.length; i++)
         string += selection[i] + " ";
       System.out.println("Selection={" + string + "}");
     }
   });
   tree.getItems()[0].setExpanded(true);
   shell.pack();
   shell.open();
   while (!shell.isDisposed()) {
     if (!display.readAndDispatch())
       display.sleep();
   }
   display.dispose();
 }

}</source>