Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2015 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.ui.part; import org.eclipse.core.runtime.Assert; import org.eclipse.core.runtime.IConfigurationElement; import org.eclipse.core.runtime.IProgressMonitor; import org.eclipse.ui.IEditorInput; import org.eclipse.ui.IEditorPart; import org.eclipse.ui.IEditorSite; import org.eclipse.ui.IPropertyListener; import org.eclipse.ui.IWorkbenchPartConstants; import org.eclipse.ui.IWorkbenchPartSite; import org.eclipse.ui.PartInitException; /** * Abstract base implementation of all workbench editors. * <p> * This class should be subclassed by clients wishing to define new editors. * The name of the subclass should be given as the <code>"class"</code> * attribute in a <code>editor</code> extension contributed to the workbench's * view extension point (named <code>"org.eclipse.ui.editors"</code>). * For example, the plug-in's XML markup might contain: * <pre> * <extension point="org.eclipse.ui.editors"> * <editor id="com.example.myplugin.ed" * name="My Editor" * icon="./images/cedit.gif" * extensions="foo" * class="com.example.myplugin.MyFooEditor" * contributorClass="com.example.myplugin.MyFooEditorContributor" * /> * </extension> * </pre> * where <code>com.example.myplugin.MyEditor</code> is the name of the * <code>EditorPart</code> subclass. * </p> * <p> * Subclasses must implement the following methods: * <ul> * <li><code>IEditorPart.init</code> - to initialize editor when assigned its site</li> * <li><code>IWorkbenchPart.createPartControl</code> - to create the editor's controls </li> * <li><code>IWorkbenchPart.setFocus</code> - to accept focus</li> * <li><code>IEditorPart.isDirty</code> - to decide whether a significant change has * occurred</li> * <li><code>IEditorPart.doSave</code> - to save contents of editor</li> * <li><code>IEditorPart.doSaveAs</code> - to save contents of editor</li> * <li><code>IEditorPart.isSaveAsAllowed</code> - to control Save As</li> * </ul> * </p> * <p> * Subclasses may extend or reimplement the following methods as required: * <ul> * <li><code>IExecutableExtension.setInitializationData</code> - extend to provide additional * initialization when editor extension is instantiated</li> * <li><code>IWorkbenchPart.dispose</code> - extend to provide additional cleanup</li> * <li><code>IAdaptable.getAdapter</code> - reimplement to make the editor * adaptable</li> * </ul> * </p> */ public abstract class EditorPart extends WorkbenchPart implements IEditorPart { /** * Editor input, or <code>null</code> if none. */ private IEditorInput editorInput = null; /** * Listens to PROP_TITLE property changes in this object until the first call to * setContentDescription. Used for compatibility with old parts that call setTitle * or overload getTitle instead of using setContentDescription. */ private IPropertyListener compatibilityTitleListener = new IPropertyListener() { @Override public void propertyChanged(Object source, int propId) { if (propId == IWorkbenchPartConstants.PROP_TITLE) { setDefaultPartName(); } } }; /** * Creates a new workbench editor. */ protected EditorPart() { super(); addPropertyListener(compatibilityTitleListener); } /* * Saves the contents of this editor. * <p> * Subclasses must override this method to implement the open-save-close * lifecycle for an editor. For greater details, see * <code>IEditorPart</code> * </p> * * @see IEditorPart */ @Override public abstract void doSave(IProgressMonitor monitor); /* * Saves the contents of this editor to another object. * <p> * Subclasses must override this method to implement the open-save-close * lifecycle for an editor. For greater details, see * <code>IEditorPart</code> * </p> * * @see IEditorPart */ @Override public abstract void doSaveAs(); @Override public IEditorInput getEditorInput() { return editorInput; } @Override public IEditorSite getEditorSite() { return (IEditorSite) getSite(); } @Override public String getTitleToolTip() { if (editorInput == null) { return super.getTitleToolTip(); } return editorInput.getToolTipText(); } /* * Initializes the editor part with a site and input. * <p> * Subclasses of <code>EditorPart</code> must implement this method. Within * the implementation subclasses should verify that the input type is acceptable * and then save the site and input. Here is sample code: * </p> * <pre> * if (!(input instanceof IFileEditorInput)) * throw new PartInitException("Invalid Input: Must be IFileEditorInput"); * setSite(site); * setInput(input); * </pre> */ @Override public abstract void init(IEditorSite site, IEditorInput input) throws PartInitException; /* Returns whether the contents of this editor have changed since the last save * operation. * <p> * Subclasses must override this method to implement the open-save-close lifecycle * for an editor. For greater details, see <code>IEditorPart</code> * </p> * * @see IEditorPart */ @Override public abstract boolean isDirty(); /* * Returns whether the "save as" operation is supported by this editor. * <p> * Subclasses must override this method to implement the open-save-close * lifecycle for an editor. For greater details, see * <code>IEditorPart</code> * </p> * * @see IEditorPart */ @Override public abstract boolean isSaveAsAllowed(); /* Returns whether the contents of this editor should be saved when the editor * is closed. * <p> * This method returns <code>true</code> if and only if the editor is dirty * (<code>isDirty</code>). * </p> */ @Override public boolean isSaveOnCloseNeeded() { return isDirty(); } /** * Sets the input to this editor. This method simply updates the internal * member variable. * * <p>Unlike most of the other set methods on this class, this method does * not fire a property change. Clients that call this method from a subclass * must ensure that they fire an IWorkbenchPartConstants.PROP_INPUT property * change after calling this method but before leaving whatever public method * they are in. Clients that expose this method as public API must fire * the property change within their implementation of setInput.</p> * * <p>Note that firing a property change may cause listeners to immediately * reach back and call methods on this editor. Care should be taken not to * fire the property change until the editor has fully updated its internal * state to reflect the new input.</p> * * @param input the editor input * * @see #setInputWithNotify(IEditorInput) */ protected void setInput(IEditorInput input) { Assert.isLegal(input != null); editorInput = input; } /** * Sets the input to this editor and fires a PROP_INPUT property change if * the input has changed. This is the convenience method implementation. * * <p>Note that firing a property change may cause other objects to reach back * and invoke methods on the editor. Care should be taken not to call this method * until the editor has fully updated its internal state to reflect the * new input.</p> * * @since 3.2 * * @param input the editor input */ protected void setInputWithNotify(IEditorInput input) { Assert.isLegal(input != null); editorInput = input; firePropertyChange(PROP_INPUT); } @Override protected void setContentDescription(String description) { if (compatibilityTitleListener != null) { removePropertyListener(compatibilityTitleListener); compatibilityTitleListener = null; } super.setContentDescription(description); } @Override protected void setPartName(String partName) { if (compatibilityTitleListener != null) { removePropertyListener(compatibilityTitleListener); compatibilityTitleListener = null; } super.setPartName(partName); } @Override public void setInitializationData(IConfigurationElement cfig, String propertyName, Object data) { super.setInitializationData(cfig, propertyName, data); setDefaultPartName(); } private void setDefaultPartName() { if (compatibilityTitleListener == null) { return; } internalSetPartName(getTitle()); } /** * Set the default title for the receiver. */ @Override void setDefaultTitle() { setTitle(getPartName()); } /** * Checks that the given site is valid for this type of part. * The site for an editor must be an <code>IEditorSite</code>. * * @param site the site to check * @since 3.1 */ @Override protected final void checkSite(IWorkbenchPartSite site) { super.checkSite(site); Assert.isTrue(site instanceof IEditorSite, "The site for an editor must be an IEditorSite"); //$NON-NLS-1$ } }