Java tutorial
/******************************************************************************* * Copyright (c) 2006-2010 eBay Inc. All Rights Reserved. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 *******************************************************************************/ /** * */ package org.ebayopensource.turmeric.eclipse.ui.components; import java.text.MessageFormat; import java.util.Arrays; import java.util.List; import org.apache.commons.lang.ArrayUtils; import org.eclipse.core.runtime.Assert; import org.eclipse.jface.viewers.CellEditor; import org.eclipse.swt.SWT; import org.eclipse.swt.custom.CCombo; 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.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.events.TraverseEvent; import org.eclipse.swt.events.TraverseListener; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; /** * <p> * This cell editor combines both comboBox and Dialog. It would open a Dialog if * user select the last item: "...". * </p> * * <p> * This class would automatically append an item "..." in the end, so no need to * add it yourself. * </p> * * @author yayu * @see org.eclipse.jface.viewers.ComboBoxCellEditor * @since 1.0.0 */ public abstract class SOAComboDialogCellEditor extends CellEditor { /** The Constant DIALOG_BUTTON_LABEL. */ public static final String DIALOG_BUTTON_LABEL = "Browse Types..."; /** * The list of items to present in the combo box. */ private String[] items; /** The value;. */ Object selectedValue; /** * The custom combo box control. */ CCombo comboBox; /** * Default ComboBoxCellEditor style */ private static final int defaultStyle = SWT.READ_ONLY; /** * Instantiates a new sOA combo dialog cell editor. */ public SOAComboDialogCellEditor() { super(); setStyle(defaultStyle); } /** * Instantiates a new sOA combo dialog cell editor. * * @param parent the parent * @param items the items */ public SOAComboDialogCellEditor(Composite parent, String[] items) { this(parent, items, defaultStyle); } /** * Instantiates a new sOA combo dialog cell editor. * * @param parent the parent * @param items the items * @param style the style */ public SOAComboDialogCellEditor(Composite parent, String[] items, int style) { super(parent, style); setItems(items); } /** * Gets the item list. * * @return the item list */ protected List<String> getItemList() { return Arrays.asList(getItems()); } /** * Returns the list of choices for the combo box. * * @return the list of choices for the combo box */ public String[] getItems() { return items; } /** * Sets the list of choices for the combo box. * * @param items the list of choices for the combo box */ public void setItems(String[] items) { Assert.isNotNull(items); this.items = (String[]) ArrayUtils.add(items, DIALOG_BUTTON_LABEL); fillcomboBox(); } /** * {@inheritDoc} */ @Override protected Control createControl(Composite parent) { comboBox = new CCombo(parent, getStyle()); comboBox.setFont(parent.getFont()); fillcomboBox(); comboBox.addKeyListener(new KeyAdapter() { @Override public void keyPressed(KeyEvent e) { keyReleaseOccured(e); } }); comboBox.addSelectionListener(new SelectionAdapter() { /** * in order to avoid twice pop up, using "lose focus" to trigger * "postEditing". if users selected "browse type..." item, then * force focus on parent (must be table because this is a table cell * editor). Then combo will lose focus and the focus lost event will * be triggered. */ @Override public void widgetDefaultSelected(SelectionEvent event) { Object newValue = comboBox.getText(); Composite parent = comboBox.getParent(); if (DIALOG_BUTTON_LABEL.equals(newValue) && ((parent == null) == false) && (parent.isDisposed() == false)) { parent.forceFocus(); } } @Override public void widgetSelected(SelectionEvent event) { Object newValue = comboBox.getText(); Composite parent = comboBox.getParent(); if (DIALOG_BUTTON_LABEL.equals(newValue) && ((parent == null) == false) && (parent.isDisposed() == false)) { parent.forceFocus(); } } }); comboBox.addTraverseListener(new TraverseListener() { @Override public void keyTraversed(TraverseEvent e) { if (e.detail == SWT.TRAVERSE_ESCAPE || e.detail == SWT.TRAVERSE_RETURN) { e.doit = false; } } }); comboBox.addFocusListener(new FocusAdapter() { @Override public void focusLost(FocusEvent e) { SOAComboDialogCellEditor.this.focusLost(); } }); return comboBox; } /** * return selected value. * * @return the object */ @Override protected Object doGetValue() { return selectedValue; } /** * {@inheritDoc} */ @Override protected void doSetFocus() { comboBox.setFocus(); } /** * if combobox contains no item, set its default width to 60, otherwise, set * its mini width to ten characters. * * @return the layout data */ @Override public LayoutData getLayoutData() { LayoutData data = super.getLayoutData(); data.minimumWidth = 60; if ((comboBox != null) && (comboBox.isDisposed() == false)) { GC gc = new GC(comboBox); data.minimumWidth = (gc.getFontMetrics().getAverageCharWidth() * 10) + 10; gc.dispose(); } return data; } /** * {@inheritDoc} */ @Override protected void doSetValue(Object value) { Assert.isTrue((comboBox != null) && (value != null)); int selection = ArrayUtils.indexOf(getItems(), value); if (selection < 0) { // data from the dialog and not present in the combo comboBox.setText(value.toString()); } else { // data from drop down list comboBox.select(selection); } } /** * Updates the list of choices for the combo box for the current control. */ private void fillcomboBox() { if (comboBox != null && items != null) { comboBox.removeAll(); for (int i = 0; i < items.length; i++) { comboBox.add(items[i], i); } setValueValid(true); if (items.length > 0) { selectedValue = items[0]; comboBox.setVisibleItemCount(Math.min(items.length, 10)); } } } /** * Applies the currently selected value and deactivates the cell editor. */ protected void postEditing() { Object newValue = comboBox.getText(); if (DIALOG_BUTTON_LABEL.equals(newValue)) { // the last item newValue = openDialogBox(comboBox); } if (newValue == null) { comboBox.setText(getValueText(selectedValue)); return; } else { comboBox.setText(newValue.toString()); } markDirty(); boolean isValid = isCorrect(newValue); setValueValid(isValid); if (isValid) { selectedValue = newValue; } else { setErrorMessage(MessageFormat.format(getErrorMessage(), new Object[] { selectedValue })); } fireApplyEditorValue(); deactivate(); } /** * The child class can override this method in the case that the toString() * method of the value's class is not implemented properly. * * @param value the value * @return the value text */ protected String getValueText(Object value) { return String.valueOf(value); } /** * {@inheritDoc} */ @Override protected void focusLost() { if (isActivated()) { postEditing(); } } /** * {@inheritDoc} */ @Override protected void keyReleaseOccured(KeyEvent keyEvent) { if (keyEvent.character == '\u001b') { // Escape character fireCancelEditor(); } else if (keyEvent.character == '\t') { // tab key postEditing(); } } /** * pop up a dialog when users selected Browse Types... * * @param cellEditorWindow the cell editor window * @return the object */ protected abstract Object openDialogBox(Control cellEditorWindow); }