textcelleditor.java

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/*******************************************************************************
 * 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.jface.viewers;

import java.text.MessageFormat;	// Not using ICU to support standalone JFace scenario

import org.eclipse.jface.util.Assert;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.FocusAdapter;
import org.eclipse.swt.events.FocusEvent;
import org.eclipse.swt.events.KeyAdapter;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.events.MouseAdapter;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.TraverseEvent;
import org.eclipse.swt.events.TraverseListener;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Text;

/**
 * A cell editor that manages a text entry field.
 * The cell editor's value is the text string itself.
 * <p>
 * This class may be instantiated; it is not intended to be subclassed.
 * </p>
 */
public class TextCellEditor extends CellEditor {

    /**
     * The text control; initially <code>null</code>.
     */
    protected Text text;

    private ModifyListener modifyListener;

    /**
     * State information for updating action enablement
     */
    private boolean isSelection = false;

    private boolean isDeleteable = false;

    private boolean isSelectable = false;

    /**
     * Default TextCellEditor style
     * specify no borders on text widget as cell outline in table already
     * provides the look of a border.
     */
    private static final int defaultStyle = SWT.SINGLE;

    /**
     * Creates a new text string cell editor with no control
     * The cell editor value is the string itself, which is initially the empty
     * string. Initially, the cell editor has no cell validator.
     * 
     * @since 2.1
     */
    public TextCellEditor() {
        setStyle(defaultStyle);
    }

    /**
     * Creates a new text string cell editor parented under the given control.
     * The cell editor value is the string itself, which is initially the empty string. 
     * Initially, the cell editor has no cell validator.
     *
     * @param parent the parent control
     */
    public TextCellEditor(Composite parent) {
        this(parent, defaultStyle);
    }

    /**
     * Creates a new text string cell editor parented under the given control.
     * The cell editor value is the string itself, which is initially the empty string. 
     * Initially, the cell editor has no cell validator.
     *
     * @param parent the parent control
     * @param style the style bits
     * @since 2.1
     */
    public TextCellEditor(Composite parent, int style) {
        super(parent, style);
    }

    /**
     * Checks to see if the "deleteable" state (can delete/
     * nothing to delete) has changed and if so fire an
     * enablement changed notification.
     */
    private void checkDeleteable() {
        boolean oldIsDeleteable = isDeleteable;
        isDeleteable = isDeleteEnabled();
        if (oldIsDeleteable != isDeleteable) {
            fireEnablementChanged(DELETE);
        }
    }

    /**
     * Checks to see if the "selectable" state (can select)
     * has changed and if so fire an enablement changed notification.
     */
    private void checkSelectable() {
        boolean oldIsSelectable = isSelectable;
        isSelectable = isSelectAllEnabled();
        if (oldIsSelectable != isSelectable) {
            fireEnablementChanged(SELECT_ALL);
        }
    }

    /**
     * Checks to see if the selection state (selection /
     * no selection) has changed and if so fire an
     * enablement changed notification.
     */
    private void checkSelection() {
        boolean oldIsSelection = isSelection;
        isSelection = text.getSelectionCount() > 0;
        if (oldIsSelection != isSelection) {
            fireEnablementChanged(COPY);
            fireEnablementChanged(CUT);
        }
    }

    /* (non-Javadoc)
     * Method declared on CellEditor.
     */
    protected Control createControl(Composite parent) {
        text = new Text(parent, getStyle());
        text.addSelectionListener(new SelectionAdapter() {
            public void widgetDefaultSelected(SelectionEvent e) {
                handleDefaultSelection(e);
            }
        });
        text.addKeyListener(new KeyAdapter() {
            // hook key pressed - see PR 14201  
            public void keyPressed(KeyEvent e) {
                keyReleaseOccured(e);

                // as a result of processing the above call, clients may have
                // disposed this cell editor
                if ((getControl() == null) || getControl().isDisposed()) {
					return;
				}
                checkSelection(); // see explaination below
                checkDeleteable();
                checkSelectable();
            }
        });
        text.addTraverseListener(new TraverseListener() {
            public void keyTraversed(TraverseEvent e) {
                if (e.detail == SWT.TRAVERSE_ESCAPE
                        || e.detail == SWT.TRAVERSE_RETURN) {
                    e.doit = false;
                }
            }
        });
        // We really want a selection listener but it is not supported so we
        // use a key listener and a mouse listener to know when selection changes
        // may have occured
        text.addMouseListener(new MouseAdapter() {
            public void mouseUp(MouseEvent e) {
                checkSelection();
                checkDeleteable();
                checkSelectable();
            }
        });
        text.addFocusListener(new FocusAdapter() {
            public void focusLost(FocusEvent e) {
                TextCellEditor.this.focusLost();
            }
        });
        text.setFont(parent.getFont());
        text.setBackground(parent.getBackground());
        text.setText("");//$NON-NLS-1$
        text.addModifyListener(getModifyListener());
        return text;
    }

    /**
     * The <code>TextCellEditor</code> implementation of
     * this <code>CellEditor</code> framework method returns
     * the text string.
     *
     * @return the text string
     */
    protected Object doGetValue() {
        return text.getText();
    }

    /* (non-Javadoc)
     * Method declared on CellEditor.
     */
    protected void doSetFocus() {
        if (text != null) {
            text.selectAll();
            text.setFocus();
            checkSelection();
            checkDeleteable();
            checkSelectable();
        }
    }

    /**
     * The <code>TextCellEditor</code> implementation of
     * this <code>CellEditor</code> framework method accepts
     * a text string (type <code>String</code>).
     *
     * @param value a text string (type <code>String</code>)
     */
    protected void doSetValue(Object value) {
        Assert.isTrue(text != null && (value instanceof String));
        text.removeModifyListener(getModifyListener());
        text.setText((String) value);
        text.addModifyListener(getModifyListener());
    }

    /**
     * Processes a modify event that occurred in this text cell editor.
     * This framework method performs validation and sets the error message
     * accordingly, and then reports a change via <code>fireEditorValueChanged</code>.
     * Subclasses should call this method at appropriate times. Subclasses
     * may extend or reimplement.
     *