Java tutorial
// ============================================================================ // // Copyright (C) 2006-2018 Talend Inc. - www.talend.com // // This source code is available under agreement available at // %InstallDIR%\features\org.talend.rcp.branding.%PRODUCTNAME%\%PRODUCTNAME%license.txt // // You should have received a copy of the agreement // along with this program; if not, write to Talend SA // 9 rue Pages 92150 Suresnes, France // // ============================================================================ package org.talend.designer.esb.runcontainer.preferences; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import org.eclipse.jface.preference.FieldEditor; import org.eclipse.jface.preference.PreferencePage; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.jface.util.IPropertyChangeListener; import org.eclipse.jface.util.PropertyChangeEvent; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; /** * A special abstract preference page to host field editors and eny other controls with flexible layout. */ public abstract class FieldLayoutPreferencePage extends PreferencePage implements IPropertyChangeListener { /** * The field editors. */ private List<FieldEditor> m_fields = new ArrayList<FieldEditor>(); /** * The first invalid field editor, or <code>null</code> if all field editors are valid. */ private FieldEditor m_invalidFieldEditor; // ////////////////////////////////////////////////////////////////////////// // // Constructors // // ////////////////////////////////////////////////////////////////////////// /** * Creates a new field editor preference page with an empty title, and no image. */ protected FieldLayoutPreferencePage() { // Create a new field editor preference page with an empty title, and no image } /** * Creates a new field editor preference page with the given title, but no image. * * @param title the title of this preference page */ protected FieldLayoutPreferencePage(String title) { super(title); } /** * Creates a new field editor preference page with the given image, and style. * * @param title the title of this preference page * @param image the image for this preference page, or <code>null</code> if none */ protected FieldLayoutPreferencePage(String title, ImageDescriptor image) { super(title, image); } // ////////////////////////////////////////////////////////////////////////// // // Fields // // ////////////////////////////////////////////////////////////////////////// /** * Adds the given field editor to this page. * * @param editor the field editor */ protected void addField(FieldEditor editor) { m_fields.add(editor); } /** * Recomputes the page's error state by calling <code>isValid</code> for every field editor. */ protected void checkState() { boolean valid = true; m_invalidFieldEditor = null; // The state can only be set to true if all // field editors contain a valid value. So we must check them all if (m_fields != null) { int size = m_fields.size(); for (int i = 0; i < size; i++) { FieldEditor editor = m_fields.get(i); valid = valid && editor.isValid(); if (!valid) { m_invalidFieldEditor = editor; break; } } } setValid(true); } /* * (non-Javadoc) Method declared on PreferencePage. */ @Override protected Control createContents(Composite parent) { Control contens = createPageContents(parent); initialize(); checkState(); return contens; } /** * Creates and returns the SWT control for the customized body of this preference page under the given parent * composite. * <p> * This framework method must be implemented by concrete subclasses. Any subclass returning a <code>Composite</code> * object whose <code>Layout</code> has default margins (for example, a <code>GridLayout</code>) are expected to set * the margins of this <code>Layout</code> to 0 pixels. * </p> * * @param parent the parent composite * @return the new control */ protected abstract Control createPageContents(Composite parent); /** * The field editor preference page implementation of an <code>IDialogPage</code> method disposes of this page's * controls and images. Subclasses may override to release their own allocated SWT resources, but must call * <code>super.dispose</code>. */ @Override public void dispose() { super.dispose(); if (m_fields != null) { Iterator<FieldEditor> I = m_fields.iterator(); while (I.hasNext()) { FieldEditor editor = I.next(); editor.setPage(null); editor.setPropertyChangeListener(null); editor.setPreferenceStore(null); } } } /** * Initializes all field editors. */ protected void initialize() { if (m_fields != null) { Iterator<FieldEditor> I = m_fields.iterator(); while (I.hasNext()) { FieldEditor editor = I.next(); editor.setPage(null); editor.setPropertyChangeListener(this); editor.setPreferenceStore(getPreferenceStore()); editor.load(); } } } /** * The field editor preference page implementation of a <code>PreferencePage</code> method loads all the field * editors with their default values. */ @Override protected void performDefaults() { if (m_fields != null) { Iterator<FieldEditor> I = m_fields.iterator(); while (I.hasNext()) { FieldEditor editor = I.next(); editor.loadDefault(); } } // Force a recalculation of my error state. checkState(); super.performDefaults(); } /** * The field editor preference page implementation of this <code>PreferencePage</code> method saves all field * editors by calling <code>FieldEditor.store</code>. Note that this method does not save the preference store * itself; it just stores the values back into the preference store. * * @see FieldEditor#store() */ @Override public boolean performOk() { if (m_fields != null) { Iterator<FieldEditor> I = m_fields.iterator(); while (I.hasNext()) { FieldEditor editor = I.next(); editor.store(); } } return true; } /** * The field editor preference page implementation of this <code>IPreferencePage</code> (and * <code>IPropertyChangeListener</code>) method intercepts <code>IS_VALID</code> events but passes other events on * to its superclass. */ @Override public void propertyChange(PropertyChangeEvent event) { if (event.getProperty().equals(FieldEditor.IS_VALID)) { boolean newValue = ((Boolean) event.getNewValue()).booleanValue(); // If the new value is true then we must check all field editors. // If it is false, then the page is invalid in any case. if (newValue) { checkState(); } else { m_invalidFieldEditor = (FieldEditor) event.getSource(); setValid(newValue); } } } /* * (non-Javadoc) Method declared on IDialog. */ @Override public void setVisible(boolean visible) { super.setVisible(visible); if (visible && m_invalidFieldEditor != null) { m_invalidFieldEditor.setFocus(); } } public List<FieldEditor> getFieldEditors() { return m_fields; } }