org.eclipse.swt.custom

Class TreeEditor

java.lang.Object

org.eclipse.swt.custom.ControlEditor

org.eclipse.swt.custom.TreeEditor

public class TreeEditor
extends ControlEditor

A TreeEditor is a manager for a Control that appears above a cell in a Tree and tracks with the moving and resizing of that cell. It can be used to display a text widget above a cell in a Tree so that the user can edit the contents of that cell. It can also be used to display a button that can launch a dialog for modifying the contents of the associated cell.

Here is an example of using a TreeEditor:

        final Tree tree = new Tree(shell, SWT.BORDER);
        for (int i = 0; i < 3; i++) {
                TreeItem item = new TreeItem(tree, SWT.NONE);
                item.setText("item " + i);
                for (int j = 0; j < 3; j++) {
                        TreeItem subItem = new TreeItem(item, SWT.NONE);
                        subItem.setText("item " + i + " " + j);
                }
        }
        
        final TreeEditor editor = new TreeEditor(tree);
        //The editor must have the same size as the cell and must
        //not be any smaller than 50 pixels.
        editor.horizontalAlignment = SWT.LEFT;
        editor.grabHorizontal = true;
        editor.minimumWidth = 50;
        
        tree.addSelectionListener(new SelectionAdapter() {
                public void widgetSelected(SelectionEvent e) {
                        // Clean up any previous editor control
                        Control oldEditor = editor.getEditor();
                        if (oldEditor != null) oldEditor.dispose();
        
                        // Identify the selected row
                        TreeItem item = (TreeItem)e.item;
                        if (item == null) return;
        
                        // The control that will be the editor must be a child of the Tree
                        Text newEditor = new Text(tree, SWT.NONE);
                        newEditor.setText(item.getText());
                        newEditor.addModifyListener(new ModifyListener() {
                                public void modifyText(ModifyEvent e) {
                                        Text text = (Text)editor.getEditor();
                                        editor.getItem().setText(text.getText());
                                }
                        });
                        newEditor.selectAll();
                        newEditor.setFocus();
                        editor.setEditor(newEditor, item);
                }
        });
 

See Also:

TreeEditor snippets, Sample code and further information

Structure Diagram

Field Summary

Fields

Modifier and Type	Field and Description
(package private) int	column
(package private) ControlListener	columnListener
(package private) TreeItem	item
(package private) static int	TIMEOUT
(package private) java.lang.Runnable	timer
(package private) Tree	tree
(package private) TreeListener	treeListener

Fields inherited from class org.eclipse.swt.custom.ControlEditor

editor, grabHorizontal, grabVertical, horizontalAlignment, minimumHeight, minimumWidth, parent, verticalAlignment

Constructor Summary

Constructors

Constructor and Description
TreeEditor(Tree tree) Creates a TreeEditor for the specified Tree.

Method Summary

Methods

Modifier and Type	Method and Description
(package private) Rectangle	computeBounds()
void	dispose() Removes all associations between the TreeEditor and the row in the tree.
int	getColumn() Returns the zero based index of the column of the cell being tracked by this editor.
TreeItem	getItem() Returns the TreeItem for the row of the cell being tracked by this editor.
void	layout() Lays out the control within the underlying composite.
(package private) void	resize()
void	setColumn(int column) Sets the zero based index of the column of the cell being tracked by this editor.
void	setEditor(Control editor) Specify the Control that is to be displayed.
void	setEditor(Control editor, TreeItem item) Specify the Control that is to be displayed and the cell in the tree that it is to be positioned above.
void	setEditor(Control editor, TreeItem item, int column) Specify the Control that is to be displayed and the cell in the tree that it is to be positioned above.
void	setItem(TreeItem item) Specifies the TreeItem that is to be edited.

Methods inherited from class org.eclipse.swt.custom.ControlEditor

getEditor, scroll

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

tree

Tree tree

item

TreeItem item

column

int column

columnListener

ControlListener columnListener

treeListener

TreeListener treeListener

timer

java.lang.Runnable timer

TIMEOUT

static final int TIMEOUT

See Also:

Constant Field Values

Constructor Detail

TreeEditor

public TreeEditor(Tree tree)

Creates a TreeEditor for the specified Tree.

Parameters:

tree - the Tree Control above which this editor will be displayed

Method Detail

computeBounds

Rectangle computeBounds()

Overrides:

computeBounds in class ControlEditor

dispose

public void dispose()

Removes all associations between the TreeEditor and the row in the tree. The tree and the editor Control are not disposed.

Overrides:

dispose in class ControlEditor

getColumn

public int getColumn()

Returns the zero based index of the column of the cell being tracked by this editor.

Returns:

the zero based index of the column of the cell being tracked by this editor

Since:

3.1

getItem

public TreeItem getItem()

Returns the TreeItem for the row of the cell being tracked by this editor.

Returns:

the TreeItem for the row of the cell being tracked by this editor

resize

void resize()

setColumn

public void setColumn(int column)

Sets the zero based index of the column of the cell being tracked by this editor.

Parameters:

column - the zero based index of the column of the cell being tracked by this editor

Since:

3.1

setItem

public void setItem(TreeItem item)

Specifies the TreeItem that is to be edited.

Parameters:

item - the item to be edited

setEditor

public void setEditor(Control editor,
             TreeItem item,
             int column)

Specify the Control that is to be displayed and the cell in the tree that it is to be positioned above.

Note: The Control provided as the editor must be created with its parent being the Tree control specified in the TreeEditor constructor.

Parameters:

editor - the Control that is displayed above the cell being edited

item - the TreeItem for the row of the cell being tracked by this editor

column - the zero based index of the column of the cell being tracked by this editor

Since:

3.1

setEditor

public void setEditor(Control editor)

Description copied from class: ControlEditor

Specify the Control that is to be displayed.

Note: The Control provided as the editor must be created with its parent being the Composite specified in the ControlEditor constructor.

Overrides:

setEditor in class ControlEditor

Parameters:

editor - the Control that is displayed above the composite being edited

setEditor

public void setEditor(Control editor,
             TreeItem item)

Specify the Control that is to be displayed and the cell in the tree that it is to be positioned above.

Note: The Control provided as the editor must be created with its parent being the Tree control specified in the TreeEditor constructor.

Parameters:

editor - the Control that is displayed above the cell being edited

item - the TreeItem for the row of the cell being tracked by this editor

layout

public void layout()

Description copied from class: ControlEditor

Lays out the control within the underlying composite. This method should be called after changing one or more fields to force the Editor to resize.

Overrides:

layout in class ControlEditor