Java tutorial
/******************************************************************************* * Copyright (c) 2007 IBM Corporation. * 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: * Robert Fuhrer (rfuhrer@watson.ibm.com) - initial API and implementation *******************************************************************************/ package org.eclipse.imp.preferences.fields; import org.eclipse.imp.preferences.IPreferencesService; import org.eclipse.imp.preferences.PreferencesTab; import org.eclipse.imp.preferences.PreferencesUtilities; import org.eclipse.jface.dialogs.IDialogConstants; import org.eclipse.jface.preference.PreferencePage; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.jface.util.Assert; import org.eclipse.swt.SWT; import org.eclipse.swt.events.DisposeEvent; import org.eclipse.swt.events.DisposeListener; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Shell; import org.eclipse.swt.widgets.Text; public abstract class StringButtonFieldEditor extends StringFieldEditor { public StringButtonFieldEditor(PreferencePage page, PreferencesTab tab, IPreferencesService service, String level, String name, String labelText, int width, int strategy, Composite parent) { super(page, tab, service, level, name, labelText, width, strategy, parent); } /** * Creates a IMP string button field editor. * Use the method <code>setTextLimit</code> to limit the text. * * @param name the name of the preference this field editor works on * @param labelText the label text of the field editor * @param width the width of the text input field in characters, * or <code>UNLIMITED</code> for no limit * @param parent the parent of the field editor's control */ public StringButtonFieldEditor(PreferencePage page, PreferencesTab tab, IPreferencesService service, String level, String name, String labelText, int width, Composite parent) { super(page, tab, service, level, name, labelText, width, org.eclipse.jface.preference.StringFieldEditor.VALIDATE_ON_KEY_STROKE, parent); } /** * Creates a IMP string button field editor. * Use the method <code>setTextLimit</code> to limit the text. * * @param name the name of the preference this field editor works on * @param labelText the label text of the field editor * @param parent the parent of the field editor's control */ public StringButtonFieldEditor(PreferencePage page, PreferencesTab tab, IPreferencesService service, String level, String name, String labelText, Composite parent) { super(page, tab, service, level, name, labelText, parent); } /** * Informs this field editor's listener, if it has one, about a change * to the value (<code>VALUE</code> property) provided that the old and * new values are different. * <p> * This hook is <em>not</em> called when the text is initialized * (or reset to the default value) from the preference store. * </p> * This extension sets converts any inherited field to a local one. * This is done because we don't want to allow inehrited fields to * be edited as such. This extension also maintains the local copy * of the previous value. */ protected boolean valueChanged() { return super.valueChanged(); } /* * Following is all copied from org.eclipse.jface.StringButtonFieldEditor */ /** * The change button, or <code>null</code> if none * (before creation and after disposal). */ private Button changeButton; /** * The text for the change button, or <code>null</code> if missing. */ private String changeButtonText; /* (non-Javadoc) * Method declared on FieldEditor. */ protected void adjustForNumColumns(int numColumns) { ((GridData) getTextControl(parent).getLayoutData()).horizontalSpan = numColumns - 2; } /** * Notifies that this field editor's change button has been pressed. * <p> * Subclasses must implement this method to provide a corresponding * new string for the text field. If the returned value is <code>null</code>, * the currently displayed value remains. * </p> * * @return the new string to display, or <code>null</code> to leave the * old string showing */ protected abstract String changePressed(); /* (non-Javadoc) * Method declared on StringFieldEditor (and FieldEditor). */ protected void doFillIntoGrid(Composite parent, int numColumns) { super.doFillIntoGrid(parent, numColumns - 1); changeButton = getChangeControl(parent); GridData gd = new GridData(); gd.horizontalAlignment = GridData.FILL; int widthHint = convertHorizontalDLUsToPixels(changeButton, IDialogConstants.BUTTON_WIDTH); gd.widthHint = Math.max(widthHint, changeButton.computeSize(SWT.DEFAULT, SWT.DEFAULT, true).x); changeButton.setLayoutData(gd); } /** * Get the change control. Create it in parent if required. * @param parent * @return Button */ public Button getChangeControl(Composite parent) { if (changeButton == null) { // Set enabled according to the associated text // field, if defined boolean enabled = false; Control[] children = parent.getChildren(); for (int i = 0; i < children.length; i++) { if (children[i] instanceof Text) { enabled = children[i].isEnabled(); } } changeButton = new Button(parent, SWT.PUSH); if (changeButtonText == null) changeButtonText = JFaceResources.getString("openChange"); //$NON-NLS-1$ changeButton.setText(changeButtonText); changeButton.setFont(parent.getFont()); changeButton.setEnabled(enabled); // added changeButton.addSelectionListener(new SelectionAdapter() { public void widgetSelected(SelectionEvent evt) { String newValue = changePressed(); if (newValue != null) { // SMS 28 Nov 2006 // Added setting of fields where setStringValue(..) is called // and (below) setting of background color levelFromWhichLoaded = preferencesLevel; setInherited(false); setPresentsDefaultValue(false); setStringValue(newValue); Text text = getTextControl(); text.setBackground(PreferencesUtilities.colorWhite); } } }); changeButton.addDisposeListener(new DisposeListener() { public void widgetDisposed(DisposeEvent event) { changeButton = null; } }); } else { checkParent(changeButton, parent); } return changeButton; } /* (non-Javadoc) * Method declared on FieldEditor. */ public int getNumberOfControls() { return 3; } /** * Returns this field editor's shell. * * @return the shell */ protected Shell getShell() { if (changeButton == null) return null; return changeButton.getShell(); } /** * Sets the text of the change button. * * @param text the new text */ public void setChangeButtonText(String text) { Assert.isNotNull(text); changeButtonText = text; if (changeButton != null) changeButton.setText(text); } /* (non-Javadoc) * @see org.eclipse.jface.preference.FieldEditor#setEnabled(boolean, org.eclipse.swt.widgets.Composite) */ public void setEnabled(boolean enabled, Composite parent) { super.setEnabled(enabled, parent); if (changeButton != null) { changeButton.setEnabled(enabled); } } }