Java tutorial
/******************************************************************************* * Copyright (c) 2004, 2007 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.internal.intro.impl.model; import org.eclipse.core.runtime.IRegistryChangeEvent; import org.eclipse.core.runtime.PerformanceStats; import org.eclipse.jface.action.Action; import org.eclipse.jface.action.IToolBarManager; import org.eclipse.swt.widgets.Composite; import org.eclipse.ui.IActionBars; import org.eclipse.ui.IMemento; import org.eclipse.ui.dialogs.ElementTreeSelectionDialog; import org.eclipse.ui.internal.intro.impl.IIntroConstants; import org.eclipse.ui.internal.intro.impl.IntroPlugin; import org.eclipse.ui.internal.intro.impl.Messages; import org.eclipse.ui.internal.intro.impl.model.viewer.IntroModelContentProvider; import org.eclipse.ui.internal.intro.impl.model.viewer.IntroModelLabelProvider; import org.eclipse.ui.internal.intro.impl.util.ImageUtil; import org.eclipse.ui.internal.intro.impl.util.Log; import org.eclipse.ui.internal.intro.impl.util.Util; import org.eclipse.ui.intro.IIntroPart; import org.eclipse.ui.intro.config.CustomizableIntroPart; /** * UI Implementation class that represents a Presentation Part. This class is * instantiated from plugin markup and so we need a default constructor, * including in subclasses. It has some base methods, including maintaining a * history of navigation locations. Also, dynamic awarness is honored here. * */ public abstract class AbstractIntroPartImplementation { // CustomizableIntroPart instance. private CustomizableIntroPart introPart = null; // IMemento for restoring state. private IMemento memento; protected History history = new History(); // flag used to enable logging of perf data for full UI creation only once. // Since standbyStateChanged is called several times, flag is used in method // to filter out all subsequent calls. boolean logUIcreationTime = true; // Global actions protected Action backAction = new Action() { { setToolTipText(Messages.Browser_backwardButton_tooltip); setImageDescriptor(ImageUtil.createImageDescriptor("full/elcl16/backward_nav.gif")); //$NON-NLS-1$ setDisabledImageDescriptor(ImageUtil.createImageDescriptor("full/dlcl16/backward_nav.gif")); //$NON-NLS-1$ } public void run() { navigateBackward(); } }; protected Action forwardAction = new Action() { { setToolTipText(Messages.Browser_forwardButton_tooltip); setImageDescriptor(ImageUtil.createImageDescriptor("full/elcl16/forward_nav.gif")); //$NON-NLS-1$ setDisabledImageDescriptor(ImageUtil.createImageDescriptor("full/dlcl16/forward_nav.gif")); //$NON-NLS-1$ } public void run() { navigateForward(); } }; protected Action homeAction = new Action() { { setToolTipText(Messages.Browser_homeButton_tooltip); setImageDescriptor(ImageUtil.createImageDescriptor("full/elcl16/home_nav.gif")); //$NON-NLS-1$ setDisabledImageDescriptor(ImageUtil.createImageDescriptor("full/dlcl16/home_nav.gif")); //$NON-NLS-1$ } public void run() { navigateHome(); } }; protected Action viewIntroModelAction = new Action() { { setToolTipText(Messages.IntroPart_showContentButton_tooltip); setImageDescriptor(ImageUtil.createImageDescriptor("contents_view.gif")); //$NON-NLS-1$ } public void run() { ElementTreeSelectionDialog treeViewer = new ElementTreeSelectionDialog( getIntroPart().getIntroSite().getShell(), new IntroModelLabelProvider(), new IntroModelContentProvider()); treeViewer.setInput(getModel()); treeViewer.open(); } }; /** * Creates the UI based on this implementation class. . * * @param parent */ public abstract void createPartControl(Composite parent); /** * Called when the init method is called in the IIntroPart. Subclasses may * extend, for example to get the passed Memento. When extending, make sure * you include a call to super. * * @param introPart */ public void init(IIntroPart introPart, IMemento memento) { // we know the class type to cast to. this.introPart = (CustomizableIntroPart) introPart; this.memento = memento; } /** * @return */ public IntroModelRoot getModel() { return IntroPlugin.getDefault().getIntroModelRoot(); } /** * @return Returns the introPart. */ public CustomizableIntroPart getIntroPart() { return introPart; } /** * Updates the UI navigation history with either a real URL. * * @param location */ public void updateHistory(String location) { history.updateHistory(location); updateNavigationActionsState(); } /** * Updates the UI navigation history with a page ID. * * @param pageId */ public void updateHistory(AbstractIntroPage page) { history.updateHistory(page); updateNavigationActionsState(); } /** * Subclasses must implement to set the state of the navigation actions in * the toolbar. * */ public abstract void setFocus(); /** * Subclasses must implement to update the intro view actions when history * is updated. * */ protected abstract void updateNavigationActionsState(); public abstract boolean navigateBackward(); public abstract boolean navigateForward(); public abstract boolean navigateHome(); /** * Called when the IntroPart is disposed. Subclasses should override to * dispose of resources. By default, this implementation does nothing. */ public void dispose() { // no-op } /* * Add the Intro Model Viewer as an action to all implementations. */ protected void addToolBarActions() { // Handle menus: IActionBars actionBars = getIntroPart().getIntroSite().getActionBars(); IToolBarManager toolBarManager = actionBars.getToolBarManager(); toolBarManager.add(viewIntroModelAction); toolBarManager.update(true); actionBars.updateActionBars(); } /** * Called when the Intro changes state. This method should not be * subclassed. It adds performance logging calls. Subclasses must implement * doStandbyStateChanged instead. * * @param standby */ public void standbyStateChanged(boolean standby, boolean isStandbyPartNeeded) { PerformanceStats setStandbyStateStats = null; long start = 0; if (Log.logPerformance) { if (logUIcreationTime && PerformanceStats.ENABLED) { PerformanceStats stats = PerformanceStats.getStats(IIntroConstants.PERF_UI_ZOOM, IIntroConstants.INTRO); stats.endRun(); Util.logPerformanceMessage( "(perf stats) time spent in UI code before content is displayed (standbyStateChanged event is fired) ", //$NON-NLS-1$ stats.getRunningTime()); stats.reset(); } // standby time. setStandbyStateStats = PerformanceStats.getStats(IIntroConstants.PERF_SET_STANDBY_STATE, IIntroConstants.INTRO); setStandbyStateStats.startRun(); start = System.currentTimeMillis(); } doStandbyStateChanged(standby, isStandbyPartNeeded); // now log performance if (Log.logPerformance) { if (PerformanceStats.ENABLED) { setStandbyStateStats.endRun(); Util.logPerformanceMessage("(perf stats) setting standby state (zooming, displaying content) took:", //$NON-NLS-1$ +setStandbyStateStats.getRunningTime()); setStandbyStateStats.reset(); } else Util.logPerformanceTime("setting standby state (zooming, generating content, setText() ) took:", //$NON-NLS-1$ +start); if (logUIcreationTime) { if (PerformanceStats.ENABLED) { PerformanceStats stats = PerformanceStats.getStats(IIntroConstants.PERF_VIEW_CREATION_TIME, IIntroConstants.INTRO); stats.endRun(); Util.logPerformanceMessage("END - (perf stats): creating CustomizableIntroPart view took:", //$NON-NLS-1$ +stats.getRunningTime()); stats.reset(); } else Util.logPerformanceTime("END: creating CustomizableIntroPart view took:", //$NON-NLS-1$ +IntroPlugin.getDefault().gettUICreationStartTime()); // prevent further logging of UI creation time. logUIcreationTime = false; } } } /* * Subclasses must implement the actual logic for the method. */ protected abstract void doStandbyStateChanged(boolean standby, boolean isStandbyPartNeeded); /** * Save the current state of the intro. Currently, we only store information * about the most recently visited intro page. In static case, the last HTML * page is remembered. In dynamic case, the last UI page or HTML page is * remembered. * * Note: This method saves the last visited intro page in a dynamic case. * Subclasses need to extend to get the desired behavior relavent to the * specific implementation. Broswer implementation needs to cache an http * web page, if it happens to be the last page visited. * * @param memento */ public void saveState(IMemento memento) { saveCurrentPage(memento); } /** * This method saves the most recently visited dynamic intro page in the * memento. If a given implementation requires saving alternative * information (e.g., information about the most recently visited static * page) it should override this method. * * @param memento */ protected void saveCurrentPage(IMemento memento) { IntroModelRoot model = getModel(); if (memento == null || model == null) return; String currentPage = model.getCurrentPageId(); if (currentPage != null && currentPage.length() > 0) { memento.putString(IIntroConstants.MEMENTO_CURRENT_PAGE_ATT, currentPage); } } /** * get the last page if it was stored in memento. This page is the last * visited intro page. It can be a intro page id, in the case of dynamic * intro. Or it can be an http in the case of static intro. It can also be * an http in the case of dynamic intro where the last visited page is a * url. */ protected String getCachedCurrentPage() { // Check to see if the start page has been overridden because // content String newContentPage = ExtensionMap.getInstance().getStartPage(); if (newContentPage != null) { return newContentPage; } IMemento memento = getMemento(); if (memento == null) { String startPageId = getModel().getStartPageId(); if (startPageId.length() > 0) { return startPageId; } else { return null; } } return memento.getString(IIntroConstants.MEMENTO_CURRENT_PAGE_ATT); } /** * @return Returns the memento passed on creation. */ public IMemento getMemento() { return memento; } /** * Support dynamic awarness. Clear cached models first, then update UI by * delegating to implementation. * * @see org.eclipse.core.runtime.IRegistryChangeListener#registryChanged(org.eclipse.core.runtime.IRegistryChangeEvent) */ public void registryChanged(IRegistryChangeEvent event) { history.clear(); // give implementation a chance to react to change. handleRegistryChanged(event); } /* * Handle reacting to plugin registry changes. This method will only be * called when regitry changes pertaining to Intro extension points is * detected. */ protected abstract void handleRegistryChanged(IRegistryChangeEvent event); public History getHistory() { return history; } }