/*******************************************************************************
 * Copyright (c) 2007, 2009 Intel Corporation, QNX Software Systems, 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:
 *     Intel Corporation - initial API and implementation
 *     Markus Schorn (Wind River Systems)
 *     Andrew Gvozdev
 *     QNX Software Systems - [271628] NPE in configs for project that failed to convert
 *******************************************************************************/
package org.eclipse.cdt.ui.newui;

import java.io.File;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IFolder;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Preferences;
import org.eclipse.core.runtime.QualifiedName;
import org.eclipse.help.HelpSystem;
import org.eclipse.help.IContext;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.dialogs.ProgressMonitorDialog;
import org.eclipse.jface.operation.IRunnableWithProgress;
import org.eclipse.jface.preference.IPreferencePageContainer;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Group;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.MessageBox;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.TabFolder;
import org.eclipse.swt.widgets.TabItem;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.IWorkbenchPartReference;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.actions.WorkspaceModifyDelegatingOperation;
import org.eclipse.ui.dialogs.PropertyPage;

import org.eclipse.cdt.core.CCorePlugin;
import org.eclipse.cdt.core.model.CoreModel;
import org.eclipse.cdt.core.model.ICElement;
import org.eclipse.cdt.core.model.ICProject;
import org.eclipse.cdt.core.model.util.CDTListComparator;
import org.eclipse.cdt.core.settings.model.CConfigurationStatus;
import org.eclipse.cdt.core.settings.model.ICConfigurationDescription;
import org.eclipse.cdt.core.settings.model.ICFolderDescription;
import org.eclipse.cdt.core.settings.model.ICMultiItemsHolder;
import org.eclipse.cdt.core.settings.model.ICProjectDescription;
import org.eclipse.cdt.core.settings.model.ICResourceDescription;
import org.eclipse.cdt.core.settings.model.ICSettingEntry;
import org.eclipse.cdt.core.settings.model.MultiItemsHolder;
import org.eclipse.cdt.ui.CUIPlugin;
import org.eclipse.cdt.ui.PreferenceConstants;
import org.eclipse.cdt.utils.ui.controls.ControlFactory;

import org.eclipse.cdt.internal.ui.CPluginImages;
import org.eclipse.cdt.internal.ui.dialogs.OptionalMessageDialog;

/**
 * It is a parent for all standard CDT property pages
 * in new CDT model. 
 * 
 * Although it is enough for new page to implement
 * "IWorkbenchPropertyPage" interface, it would be
 * better to extend it from "AbstractPage".
 * 
 * In this case, we'll able to use:
 * - dynamic tabs support via cPropertyTab extension point
 * - a lot of utility methods: see ICPropertyProvider interface
 * - mechanism of messages sent to all pages and all tabs in them
 * 
 * In fact, descendants of AbstractPage have to implement
 * the only method:
 * 		protected boolean isSingle(); 
 * It it returns false, current page can contain multiple tabs
 * (obtained through "cPropertyTab" extension point).
 * If it returns true, only one content tab is possible. If
 * more than 1 tabs refer to this pas as a parent, only 1st
 * one would be taken into account, others will be ignored. 
 */
public abstract class AbstractPage extends PropertyPage 
implements
		IPreferencePageContainer, // dynamic pages
		ICPropertyProvider // utility methods for tabs
{
	private static ICResourceDescription resd = null;
	private static ICConfigurationDescription[] cfgDescs = null;
	private static ICConfigurationDescription lastSelectedCfg = null;
	private static ICConfigurationDescription[] multiCfgs = null; // selected multi cfg
	// tabs
	private static final String EXTENSION_POINT_ID = "org.eclipse.cdt.ui.cPropertyTab"; //$NON-NLS-1$
	private static final String ELEMENT_NAME = "tab"; //$NON-NLS-1$
	private static final String CLASS_NAME = "class"; //$NON-NLS-1$
	private static final String PARENT_NAME = "parent"; //$NON-NLS-1$
	private static final String IMAGE_NAME = "icon"; //$NON-NLS-1$
	private static final String TIP_NAME = "tooltip"; //$NON-NLS-1$
	private static final String TEXT_NAME = "name"; //$NON-NLS-1$
	private static final String WEIGHT_NAME = "weight"; //$NON-NLS-1$
	private static final String HELPID_NAME = "helpId"; //$NON-NLS-1$

	private static final Object NOT_NULL = new Object();
	public static final String EMPTY_STR = "";  //$NON-NLS-1$
	
	private static final int SAVE_MODE_OK = 1;
	private static final int SAVE_MODE_APPLY = 2;
	private static final int SAVE_MODE_APPLYOK = 3;
	
	private static final String PREF_ASK_REINDEX = "askReindex"; //$NON-NLS-1$
	
	private final Image IMG_WARN = CPluginImages.get(CPluginImages.IMG_OBJS_REFACTORING_WARNING);
	/*
	 * Dialog widgets
	 */
	private Combo configSelector;
	private Button manageButton;
	private Button excludeFromBuildCheck;
	private Label errIcon;
	private Label errMessage;
	private Composite errPane;
	private Composite parentComposite;
	/*
	 * Bookeeping variables
	 */
	protected boolean noContentOnPage = false;
	protected boolean displayedConfig = false;
	protected IResource internalElement = null;
	protected boolean isProject = false;
	protected boolean isFolder  = false;
	protected boolean isFile    = false;
	
	// tabs
	protected TabFolder folder;
	protected ArrayList<InternalTab> itabs = new ArrayList<InternalTab>();
	protected ICPropertyTab currentTab;

	private static boolean isNewOpening = true;
	
	protected class InternalTab {
		Composite comp;
		String text;
		String tip;
		Image image;
		ICPropertyTab tab;
		
		InternalTab(Composite _comp, String _text, Image _image, ICPropertyTab _tab, String _tip) {
			comp  = _comp;
			text  = _text;
			image = _image;
			tab   = _tab;
			tip   = _tip;
		}

		public TabItem createOn(TabFolder f) {
			if (tab.canBeVisible()) {
				TabItem ti = new TabItem(f, SWT.NONE);
				ti.setText(text);
				if (tip != null) ti.setToolTipText(tip);
				if (image != null) ti.setImage(image);
				ti.setControl(comp);
				ti.setData(tab);
				return ti;
			}
			return null;
		}
	}
	
	/**
	 * Default constructor
	 */
	public AbstractPage() {
		if (CDTPropertyManager.getPagesCount() == 0) {
			cfgDescs = null;
			lastSelectedCfg = null;
			multiCfgs = null;
		}
	}
	
	@Override
	protected Control createContents(Composite parent) {
		//	Create the container we return to the property page editor
		Composite composite = new Composite(parent, SWT.NULL);
		composite.setFont(parent.getFont());
		GridLayout compositeLayout = new GridLayout();
		compositeLayout.numColumns = 1;
		compositeLayout.marginHeight = 0;
		compositeLayout.marginWidth = 0;
		composite.setLayout( compositeLayout );

		String s = null;
		if (!checkElement()) {
			s = UIMessages.getString("AbstractPage.0"); //$NON-NLS-1$
		} else if (!isApplicable()) {
			return null;
		} else if (!isCDTProject(getProject())) {
			s = UIMessages.getString("AbstractPage.2"); //$NON-NLS-1$
		}
		
	    if (s == null) {
	    	contentForCDT(composite);
	    	return composite;
	    }
		
		// no contents
		Label label = new Label(composite, SWT.LEFT);
		label.setText(s);
		label.setFont(composite.getFont());
		noContentOnPage = true;
		noDefaultAndApplyButton();
		return composite;
	}
	
	protected void contentForCDT(Composite composite) {
		GridData gd;

		if (showsConfig()) {
			// Add a config selection area
			Group configGroup = ControlFactory.createGroup(composite, EMPTY_STR, 1);
			gd = new GridData(GridData.HORIZONTAL_ALIGN_FILL);
			gd.grabExcessHorizontalSpace = true;
			gd.widthHint= 150;
			configGroup.setLayoutData(gd);
			configGroup.setLayout(new GridLayout(3, false));

			Label configLabel = new Label(configGroup, SWT.NONE);
			configLabel.setText(UIMessages.getString("AbstractPage.6")); //$NON-NLS-1$
			configLabel.setLayoutData(new GridData(GridData.BEGINNING));

			configSelector = new Combo(configGroup, SWT.READ_ONLY | SWT.DROP_DOWN);
			configSelector.addListener(SWT.Selection, new Listener() {
				public void handleEvent(Event e) {
					handleConfigSelection();
				}
			});
			gd = new GridData(GridData.FILL_BOTH);
			configSelector.setLayoutData(gd);

			if (!CDTPrefUtil.getBool(CDTPrefUtil.KEY_NOMNG)) {
				manageButton = new Button(configGroup, SWT.PUSH);
				manageButton.setText(UIMessages.getString("AbstractPage.12")); //$NON-NLS-1$
				gd = new GridData(GridData.END);
				gd.minimumWidth = 150;
				manageButton.setLayoutData(gd);
				manageButton.addSelectionListener(new SelectionAdapter() {
					@Override
					public void widgetSelected(SelectionEvent e) {
						IProject[] obs = new IProject[] { getProject() };
						IConfigManager cm = ManageConfigSelector.getManager(obs);
						if (cm != null && cm.manage(obs, false)) {
							cfgDescs = null;
							populateConfigurations();					
						}
					}
				});
			} else { // dummy object to avoid breaking layout
				new Label(configGroup, SWT.NONE).setLayoutData(new GridData(GridData.END));
			}

			errPane = new Composite(configGroup, SWT.NONE);
			gd = new GridData(GridData.FILL_HORIZONTAL);
			gd.horizontalSpan = 3;
			errPane.setLayoutData(gd);
			GridLayout gl = new GridLayout(2, false);
			gl.marginHeight = 0;
			gl.marginWidth = 0;
			gl.verticalSpacing = 0;
			gl.horizontalSpacing = 0;
			errPane.setLayout(gl);

			errIcon = new Label(errPane, SWT.LEFT);
			errIcon.setLayoutData(new GridData(GridData.BEGINNING));
			errIcon.setImage(IMG_WARN);

			errMessage = new Label(errPane, SWT.LEFT);
			errMessage.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));

			if (isForFolder() || isForFile()) {
				excludeFromBuildCheck = new Button(configGroup, SWT.CHECK);
				excludeFromBuildCheck.setText(UIMessages.getString("AbstractPage.7")); //$NON-NLS-1$
				gd = new GridData(GridData.FILL_HORIZONTAL);
				gd.horizontalSpan = 3;
				excludeFromBuildCheck.setLayoutData(gd);
				excludeFromBuildCheck.addSelectionListener(new SelectionAdapter() {
					@Override
					public void widgetSelected(SelectionEvent e) {
						getResDesc().setExcluded(excludeFromBuildCheck.getSelection());
					}
				});
			}
		}

		//	Update the contents of the configuration widget
		populateConfigurations();
		if (excludeFromBuildCheck != null) {
			excludeFromBuildCheck.setSelection(getResDesc().isExcluded());
		}
		//	Create the Specific objects for each page
		createWidgets(composite);
	}

	public void createWidgets(Composite c) {
		GridData gd;
		parentComposite = new Composite(c, SWT.NONE);
		parentComposite.setLayoutData(gd= new GridData(GridData.FILL_BOTH));
		gd.widthHint= 200;
		itabs.clear(); 
		if (!isSingle()) {
			parentComposite.setLayout(new FillLayout());
			folder = new TabFolder(parentComposite, SWT.NONE);
//			folder.setBackground(Display.getDefault().getSystemColor(SWT.COLOR_DARK_GRAY));
		}
		loadExtensionsSynchronized(parentComposite);
		
		// Set listener after data load, to avoid firing
		// selection event on not-initialized tab items 
		if (folder != null) {
		    folder.addSelectionListener(new SelectionAdapter() {
			      @Override
				public void widgetSelected(org.eclipse.swt.events.SelectionEvent event) {
			    	  if (folder.getSelection().length > 0 ) {
			    		  ICPropertyTab newTab = (ICPropertyTab)folder.getSelection()[0].getData();
			    		  if (newTab != null && currentTab != newTab) {
				    		  if (currentTab != null) currentTab.handleTabEvent(ICPropertyTab.VISIBLE, null);			    			  
				    		  currentTab = newTab;
				    		  currentTab.handleTabEvent(ICPropertyTab.VISIBLE, NOT_NULL);
			    		  }
			    	  }
			      }
			    });
		    if (folder.getItemCount() > 0) folder.setSelection(0);
		}
	}
	/**
	 * 
	 */
	public IProject getProject() {
		Object element = getElement();
		if (element != null) { 
			if (element instanceof IFile ||
				element instanceof IProject ||
				element instanceof IFolder)
				{
			IResource f = (IResource) element;
			return f.getProject();
				}
			else if (element instanceof ICProject)
				return ((ICProject)element).getProject();
		}
		return null;
	}

	/*
	 * Event Handlers
	 */
	private void handleConfigSelection() {
		// If there is nothing in config selection widget just bail
		if (configSelector.getItemCount() == 0) return;
		int selectionIndex = configSelector.getSelectionIndex();
		if (selectionIndex == -1) return;
		if (cfgDescs == null || cfgDescs.length == 0) return;

		// Check if the user has selected the "all / multiple" configuration
		if (selectionIndex >= cfgDescs.length) {
			if (selectionIndex == cfgDescs.length) {  // all
				multiCfgs = cfgDescs;
			} else { // multiple
				// Check previous state of variables figuring out if need to pop up selection dialog
				// areCfgsStillThere() covers deletions by a user in Manage Configurations dialog
				boolean enterMultiCfgsDialog = (multiCfgs == null)
						|| (multiCfgs == cfgDescs) || !areCfgsStillThere(multiCfgs);
				if (enterMultiCfgsDialog) {
					ICConfigurationDescription[] mcfgs = ConfigMultiSelectionDialog.select(cfgDescs);
					if (mcfgs == null || mcfgs.length == 0) {
						// return back to previous selection
						int cfgIndex = -1;
						if (multiCfgs == cfgDescs) { // return to choice "All"
							cfgIndex = cfgDescs.length;
						} else {
							cfgIndex = getCfgIndex(lastSelectedCfg);
						}
						configSelector.select(cfgIndex);
						return;
					}
					multiCfgs = mcfgs;
				}
					
			}
			lastSelectedCfg = null;

			cfgChanged(MultiItemsHolder.createCDescription(multiCfgs));
			return;
		}
		multiCfgs = null;
		
		String id1 = getResDesc() == null ? null : getResDesc().getId();
		lastSelectedCfg = cfgDescs[selectionIndex];
		String id2 = lastSelectedCfg.getId();
		if (id2 != null && !id2.equals(id1)) {
			cfgChanged(lastSelectedCfg);
		}
	}

	/**
	 * Find index of configuration description in the internal array of
	 * configuration descriptions.
	 * 
	 * @param cfgd
	 * @return index of found configuration description or index of active
	 *         configuration.
	 */
	private static int getCfgIndex(ICConfigurationDescription cfgd) {
		int index = 0;
		for (int i = 0; i < cfgDescs.length; ++i) {
			if (cfgd != null) {
				if (cfgd.getId().equals(cfgDescs[i].getId())) {
					return i;
				}
			} else if (cfgDescs[i].isActive()) {
				index = i;
			}
		}
		return index;
	}

	/**
	 * Find index of active configuration description in the internal array of
	 * configuration descriptions.
	 * 
	 * @return index of active configuration description.
	 */
	private static int getActiveCfgIndex() {
		return getCfgIndex(null);
	}
	
	/**
	 * Check if all configuration descriptions are present in the internal array of
	 * configuration descriptions.
	 * @param cfgs
	 * @return true if all present, false otherwise
	 */
	private static boolean areCfgsStillThere(ICConfigurationDescription[] cfgs) {
		if (cfgs==null || cfgDescs==null) return false;
		
		for (ICConfigurationDescription multiCfg : cfgs) {
			boolean foundOne = false;
			for (ICConfigurationDescription cfgDesc : cfgDescs) {
				if (multiCfg.getId().equals(cfgDesc.getId())) {
					foundOne = true;
					break;
				}
			}
			if (!foundOne) {
				return false;
			}
		}
		return true;
	}
	
    @Override
	public boolean performCancel() {
		if (! noContentOnPage && displayedConfig) forEach(ICPropertyTab.CANCEL);
		
		CDTPropertyManager.performCancel(this);
		
        return true;
    }
	@Override
	public void performDefaults() {
		if (! noContentOnPage && displayedConfig) forEach(ICPropertyTab.DEFAULTS);
	}
    @Override
	public void performApply() { performSave(SAVE_MODE_APPLY); }
    
    /**
     * There are 2 ways to perform OK for CDT property pages.
     * 1st (default): 
     *   All pages use the same editable copy of ICProjectDescription.
     *   When OK occurs, this object is simply set.
     *   
     * 2nd:  
     *   When OK occurs, each page must copy its data to new instance
     *   of ICProjectDescription, like it occurs during Apply event.
     *   It allows to avoid collisions with other property pages, 
     *   which do not share ICProjectDescription instance.
     *   But some changes may be saved wrong if they are affected
     *   by data from another property pages (Discovery options etc).

     *   To enable 2nd mode, just create the following file:
     *   <workspace>/.metadata/.plugins/org.eclipse.cdt.ui/apply_mode
     */
    
    @Override
	public boolean performOk() {
    	File f = CUIPlugin.getDefault().getStateLocation().append("apply_mode").toFile(); //$NON-NLS-1$
    	if (f.exists()) 
        	return performSave(SAVE_MODE_APPLYOK);
		return performSave(SAVE_MODE_OK); 
        	
    }

    /**
     * Searches in the prj for the config description with the same ID as for given cfg.
     * If there's no such cfgd, it will be created.
     *  
     *  @param prj - project description where we'll search (or create) config description
     *  @param cfg - config description belonging to another project description, 
     *               it is a sample for search and base for possile creation
     *               of resulting configuration description.
     *                  
     *  @return the configuration description (found or created) or null in case of error
     */
    private ICConfigurationDescription findCfg(ICProjectDescription prj, ICConfigurationDescription cfg) {
    	String id = cfg.getId();
    	// find config with the same ID as original one
		ICConfigurationDescription c = prj.getConfigurationById(id);
		// if there's no cfg found, try to create it
		if (c == null) {
			try {
				c = prj.createConfiguration(id, cfg.getName(), cfg);
				c.setDescription(cfg.getDescription());
			} catch (CoreException e) { 
				/* do nothing: c is already null */ 
			}
		}
		// if creation failed, report an error and return null
		if (c == null) {
			MessageBox mb = new MessageBox(getShell());
			mb.setMessage(UIMessages.getString("AbstractPage.3")); //$NON-NLS-1$
			mb.open();
		}
    	return c;
    }
    
    /**
     * The same code used to perform OK and Apply 
     */
    private boolean performSave(int mode)	{
    	final int finalMode = mode;
		if (noContentOnPage || !displayedConfig) return true;
		if ((mode == SAVE_MODE_OK || mode == SAVE_MODE_APPLYOK) && CDTPropertyManager.isSaveDone()) return true; // do not duplicate
		
		final boolean needs = (mode != SAVE_MODE_OK);
		final ICProjectDescription local_prjd = needs ? CoreModel.getDefault().getProjectDescription(getProject()) : null;
		
		ICResourceDescription lc = null;
		
		if (needs) { 
			if (isMultiCfg()) {
				ICResourceDescription[] rds = (ICResourceDescription[])((ICMultiItemsHolder)resd).getItems();
				for (int i=0; i<rds.length; i++) {
					ICConfigurationDescription c = local_prjd.getConfigurationById(rds[i].getConfiguration().getId());
					rds[i] = getResDesc(c);
				}
				lc = MultiItemsHolder.createRDescription(rds);
			} else {
				ICConfigurationDescription c = findCfg(local_prjd, resd.getConfiguration());
				if (c == null) 
					return false; // cannot save: no cfg found
				lc = getResDesc(c);
			}
		}
		final ICResourceDescription local_cfgd = lc;
		
		final boolean rebuildIndex= isIndexerAffected();
		IRunnableWithProgress runnable = new IRunnableWithProgress() {
			
			private void sendOK() {
				for (int j=0; j<CDTPropertyManager.getPagesCount(); j++) {
					Object p = CDTPropertyManager.getPage(j);
					if (p != null && p instanceof AbstractPage) { 
						AbstractPage ap = (AbstractPage)p;
						if (ap.displayedConfig) ap.forEach(ICPropertyTab.OK, null);
					}
				}
			}
			
			public void run(IProgressMonitor monitor) {
				// ask all tabs to store changes in cfg
				switch (finalMode) {
				case SAVE_MODE_APPLYOK:
					sendOK();
					ICConfigurationDescription[] olds = CDTPropertyManager.getProjectDescription(AbstractPage.this, getProject()).getConfigurations();
					for (ICConfigurationDescription old : olds) {
							resd = getResDesc(old);
							ICResourceDescription r = getResDesc(local_prjd.getConfigurationById(old.getId()));
							for (int j=0; j<CDTPropertyManager.getPagesCount(); j++) {
								Object p = CDTPropertyManager.getPage(j);
								if (p != null && p instanceof AbstractPage) { 
									AbstractPage ap = (AbstractPage)p;
									if (ap.displayedConfig) {
										ap.forEach(ICPropertyTab.UPDATE, resd);
										ap.forEach(ICPropertyTab.APPLY, r);
									}
								}
							}
						}
					break;
				case SAVE_MODE_APPLY:
					forEach(ICPropertyTab.APPLY, local_cfgd);
					break;
				case SAVE_MODE_OK:
					sendOK();
					break;
				} // end switch
				try {
					if (needs) // 
						CoreModel.getDefault().setProjectDescription(getProject(), local_prjd);
					else
						CDTPropertyManager.performOk(AbstractPage.this);
				} catch (CoreException e) {
					CUIPlugin.getDefault().logErrorMessage(UIMessages.getString("AbstractPage.11") + e.getLocalizedMessage()); //$NON-NLS-1$
				}
				updateViews(internalElement);
			}
		};
		IRunnableWithProgress op = new WorkspaceModifyDelegatingOperation(runnable);
		try {
			new ProgressMonitorDialog(getShell()).run(false, true, op);
		} catch (InvocationTargetException e) {
			Throwable e1 = e.getTargetException();
			CUIPlugin.errorDialog(getShell(), 
					UIMessages.getString("AbstractPage.8"),  //$NON-NLS-1$
					UIMessages.getString("AbstractPage.9"), e1, true); //$NON-NLS-1$
			return false;
		} catch (InterruptedException e) {}
		
		if (rebuildIndex)
			rebuildIndex();
		return true;
	}

	private boolean isIndexerAffected() {
		ICProjectDescription desc= CoreModel.getDefault().getProjectDescription(getProject(), false);
		if (desc == null || desc.isCdtProjectCreating())
			return false;

		Iterator<InternalTab> it = itabs.iterator();
		while(it.hasNext()) {
			InternalTab tab = it.next();
			if (tab != null) {
				ICPropertyTab tabtab = tab.tab;
				if (tabtab instanceof AbstractLangsListTab) {
					final AbstractLangsListTab langListTab = (AbstractLangsListTab) tabtab;
					switch(langListTab.getKind()) {
					case ICSettingEntry.INCLUDE_PATH:
					case ICSettingEntry.MACRO:
					case ICSettingEntry.INCLUDE_FILE:
					case ICSettingEntry.MACRO_FILE:
						if (langListTab.hadSomeModification()) {
							return true;
						}
						break;
					}
				} else if (tabtab instanceof AbstractCPropertyTab){
					// attempt to access API that will be introduced in CDT 6.1 (bug 144085)
					try {
						Class<?> clazz= tabtab.getClass();
						Method meth = clazz.getDeclaredMethod("isIndexerAffected"); //$NON-NLS-1$
						if (meth != null) {
							Object result = meth.invoke(tabtab);
							if (result instanceof Boolean && ((Boolean) result).booleanValue())
								return true;
						}
					} catch (SecurityException e) {
					} catch (NoSuchMethodException e) {
					} catch (IllegalArgumentException e) {
					} catch (IllegalAccessException e) {
					} catch (InvocationTargetException e) {
						// the method was called and has thrown an exception.
						CUIPlugin.log(e);
					}
				}
			}
		}
		return false;
	}

	private void rebuildIndex() {
		final Shell shell= getShell();
		final String title= getTitle();
		final String msg= UIMessages.getString("AbstractPage.rebuildIndex.question"); //$NON-NLS-1$
		int result= OptionalMessageDialog.open(PREF_ASK_REINDEX,
				shell, title, null /* default image */, msg, MessageDialog.QUESTION, 
				new String[] {IDialogConstants.YES_LABEL, IDialogConstants.NO_LABEL}, 0);
		if (result == OptionalMessageDialog.NOT_SHOWN) {
			result= OptionalMessageDialog.getDialogDetail(PREF_ASK_REINDEX);
		} else if (result != SWT.DEFAULT) {
			OptionalMessageDialog.setDialogDetail(PREF_ASK_REINDEX, result);
		}
		if (result == 0) { // first button
			final IProject project = getProject();
			CCorePlugin.getIndexManager().reindex(CoreModel.getDefault().create(project));
		}
	}

	private void populateConfigurations() {
		IProject prj = getProject();
		// Do nothing in case of Preferences page.
		if (prj == null)
			return;

		// Do not re-read if list already created by another page
		if (cfgDescs == null) {
			ICProjectDescription pDesc = CDTPropertyManager.getProjectDescription(this, prj);
			cfgDescs = (pDesc == null)? null : pDesc.getConfigurations();
			if (cfgDescs == null || cfgDescs.length == 0) return;
			Arrays.sort(cfgDescs, CDTListComparator.getInstance());
			
		} else {
			if (cfgDescs.length == 0) return;
			// just register in CDTPropertyManager;
			CDTPropertyManager.getProjectDescription(this, prj);
		}
		
		// Do nothing if widget not created yet.
		if (configSelector == null)	{
			lastSelectedCfg = cfgDescs[getActiveCfgIndex()];
			cfgChanged(lastSelectedCfg); 
			return;
		}

		// Clear and replace the contents of the selector widget
		configSelector.removeAll();
		for (int i = 0; i < cfgDescs.length; ++i) {
			String name = cfgDescs[i].getName();
			if (cfgDescs[i].isActive()) {
				name = name + "  " + UIMessages.getString("AbstractPage.16"); //$NON-NLS-1$ //$NON-NLS-2$
			}
			configSelector.add(name);
		}

		int cfgIndex = -1;
		
		// "All cfgs" - shown if at least 2 cfgs available
		if (cfgDescs.length > 1) {
			configSelector.add(UIMessages.getString("AbstractPage.4")); //$NON-NLS-1$
			if (multiCfgs == cfgDescs) {
				cfgIndex = cfgDescs.length;
			}
		}
		// "Multi cfgs" - shown if at least 3 cfgs available
		if (cfgDescs.length > 2) {
			configSelector.add(UIMessages.getString("AbstractPage.5")); //$NON-NLS-1$
			if (multiCfgs != null && multiCfgs != cfgDescs) {
				cfgIndex = cfgDescs.length + 1;
			}
		}

		if (cfgIndex<0) {
			cfgIndex = getActiveCfgIndex();
		}

		configSelector.select(cfgIndex);
		handleConfigSelection();
	}

	public void updateButtons() {}
	public void updateMessage() { }
	public void updateTitle() {	}
	public void updateContainer() {	}

	@Override
	public boolean isValid() {
		updateContainer();
		return super.isValid();
	}
	
	@Override
	public void setVisible(boolean visible) {
		super.setVisible(visible);
		if (visible) {
			handleResize(true);
			displayedConfig = true;
			if (excludeFromBuildCheck != null && resd != null)
				excludeFromBuildCheck.setSelection(resd.isExcluded());
			populateConfigurations();
		}

		if (itabs.size() < 1) return;
		
		if (currentTab == null && folder.getItemCount() > 0)	{
			Object ob = folder.getItem(0).getData();
			currentTab = (ICPropertyTab)ob;
		}
		if (currentTab != null)
			currentTab.handleTabEvent(ICPropertyTab.VISIBLE, visible ? NOT_NULL : null);
	}
	
	protected void handleResize(boolean visible) {
		if (visible && !isNewOpening) return; // do not duplicate
		if (visible) 
			isNewOpening = false;
		
		int saveMode = CDTPrefUtil.getInt(CDTPrefUtil.KEY_POSSAVE);
		if (saveMode == CDTPrefUtil.POSITION_SAVE_NONE) return;
		
		if (internalElement == null && !checkElement()) 
			return; // not initialized. Do not process
		IProject prj = getProject();
		if (prj == null) 
			return;	// preferences. Do not process. 
		QualifiedName WIDTH  = new QualifiedName(prj.getName(),".property.page.width"); //$NON-NLS-1$
		QualifiedName HEIGHT = new QualifiedName(prj.getName(),".property.page.height"); //$NON-NLS-1$
		QualifiedName XKEY = new QualifiedName(prj.getName(),".property.page.x"); //$NON-NLS-1$
		QualifiedName YKEY = new QualifiedName(prj.getName(),".property.page.y"); //$NON-NLS-1$
		Rectangle r = getShell().getBounds();
		try {
			if (visible) {
				String w = prj.getPersistentProperty(WIDTH);
				String h = prj.getPersistentProperty(HEIGHT);
				if (w != null) r.width  = Integer.parseInt(w);
				if (h != null) r.height = Integer.parseInt(h);
				if (saveMode == CDTPrefUtil.POSITION_SAVE_BOTH) {
					String x = prj.getPersistentProperty(XKEY);
					String y = prj.getPersistentProperty(YKEY);
					if (x != null) r.x = Integer.parseInt(x);
					if (y != null) r.y = Integer.parseInt(y);
				}
				getShell().setBounds(r);
			} else {
				prj.setPersistentProperty(WIDTH,  String.valueOf(r.width));
				prj.setPersistentProperty(HEIGHT, String.valueOf(r.height));
				prj.setPersistentProperty(XKEY, String.valueOf(r.x));
				prj.setPersistentProperty(YKEY, String.valueOf(r.y));
			}
		} catch (CoreException e) {}
	}

	@Override
	public IPreferenceStore getPreferenceStore() {
		return CUIPlugin.getDefault().getPreferenceStore();
	}

	public Preferences getPreferences()	{
		return CUIPlugin.getDefault().getPluginPreferences();
	}
	
	public void enableConfigSelection (boolean enable) {
		if (configSelector != null) configSelector.setEnabled(enable);
		if (manageButton != null) manageButton.setEnabled(enable);
	}
	
	/**
	 * Returns configuration descriptions for given project
	 */
	public ICConfigurationDescription[] getCfgsReadOnly(IProject p) {
		ICProjectDescription prjd = CoreModel.getDefault().getProjectDescription(p, false); 
		if (prjd != null) 
			return prjd.getConfigurations();
		return null;
	}

	/**
	 * Returns loaded configuration descriptions for current project
	 */
	public ICConfigurationDescription[] getCfgsEditable() {
		return cfgDescs;
	}
	
	/** Checks whether project is new CDT project
	 * 
	 * @param p - project to check
	 * @returns true if it's new-style project. 
	 */ 
	public static boolean isCDTPrj(IProject p) {
		ICProjectDescription prjd = CoreModel.getDefault().getProjectDescription(p, false); 
		if (prjd == null) return false; 
		ICConfigurationDescription[] cfgs = prjd.getConfigurations();
		return (cfgs != null && cfgs.length > 0);
	}
	
	public boolean isCDTProject(IProject p) {
		return isCDTPrj(p);
	}
	
	public ICResourceDescription getResDesc() {
		if (resd == null) {
			if (cfgDescs == null) {
				populateConfigurations();
			}
			if (lastSelectedCfg!=null) {
				resd = getResDesc(lastSelectedCfg);
			}
		}
		return resd;
	}

	public ICResourceDescription getResDesc(ICConfigurationDescription cf) {
		IAdaptable ad = getElement();
		
		if (isForProject()) 
			return cf.getRootFolderDescription();
		ICResourceDescription out = null;
		IResource res = (IResource)ad; 
		IPath p = res.getProjectRelativePath();
		if (isForFolder() || isForFile()) {
			if (cf instanceof ICMultiItemsHolder) {
				out = cf.getResourceDescription(p, isForFolder()); // sic ! 
			} else {
				out = cf.getResourceDescription(p, false);
				if (! p.equals(out.getPath()) ) {
					try {
						if (isForFolder())
							out = cf.createFolderDescription(p, (ICFolderDescription)out);
						else
							out = cf.createFileDescription(p, out);
					} catch (CoreException e) {
						System.out.println(UIMessages.getString("AbstractPage.10") + //$NON-NLS-1$
								p.toOSString() + "\n" + e.getLocalizedMessage()); //$NON-NLS-1$
					}
				}
			}
		}
		return out;
	}
	
	protected void cfgChanged(ICConfigurationDescription _cfgd) {
		
		CConfigurationStatus st = _cfgd.getConfigurationStatus();
		if (errPane != null && errMessage != null) {
			if (st.isOK()) {
				errPane.setVisible(false);
			} else {
				errMessage.setText(st.getMessage());
				errPane.setVisible(true);
			}
		}

		resd = getResDesc(_cfgd);
		
		if (excludeFromBuildCheck != null) {
			excludeFromBuildCheck.setEnabled(resd.canExclude(!resd.isExcluded()));
			excludeFromBuildCheck.setSelection(resd.isExcluded());
		}
		int x = CDTPropertyManager.getPagesCount();
		for (int i=0; i<x; i++) {
			Object p = CDTPropertyManager.getPage(i);
			if (p == null || !(p instanceof AbstractPage))
				continue;
			AbstractPage ap = (AbstractPage)p;
			if (ap.displayedConfig)
				ap.forEach(ICPropertyTab.UPDATE,getResDesc());
		}
	}
	
	@Override
	public void dispose() {
		if (displayedConfig) forEach(ICPropertyTab.DISPOSE);

		if (!isNewOpening)
			handleResize(false); // save page size 
		isNewOpening = true;
		// Remove this page from the property manager
		CDTPropertyManager.remove(this);
		// clear static variables
		if (CDTPropertyManager.getPagesCount() == 0) {
			resd = null;
			cfgDescs = null;
		}
	}

	/**
	 * The only method to be redefined in descendants
	 * @return 
	 * 		true if single page is required
	 * 		false if multiple pages are possible
	 */
	abstract protected boolean isSingle(); 
	
	/**
	 * Defines whether the configurations control is shown or not.
	 * Subclasses may override this.
	 * @return true, if the configurations control should be shown (default); false otherwise
	 */
	protected boolean showsConfig() { return true;	}

	/**
	 * Apply specified method to all tabs
	 */
	protected void forEach(int m) { forEach(m, null); }
	protected void forEach(int m, Object pars) {
		Iterator<InternalTab> it = itabs.iterator();
		while(it.hasNext()) {
			InternalTab tab = it.next();
			if (tab != null) tab.tab.handleTabEvent(m, pars);
		}
	}
	
	// redefine page width
	/*
	public Point computeSize() {
		Point p = super.computeSize();
		if (p.x > MAX_WIDTH) p.x = MAX_WIDTH;
		return p;
	}
	*/
	
	public static String getWeight(IConfigurationElement e) {
		String s = e.getAttribute(WEIGHT_NAME);
		return (s == null) ? EMPTY_STR : s;
	}
	
	private synchronized void loadExtensionsSynchronized(Composite parent) {
		// Get the extensions
		IExtensionPoint extensionPoint = Platform.getExtensionRegistry()
				.getExtensionPoint(EXTENSION_POINT_ID);
		if (extensionPoint == null) return;
		IExtension[] extensions = extensionPoint.getExtensions();
		if (extensions == null) return;

		List<IConfigurationElement> elements = new ArrayList<IConfigurationElement>();
		for (IExtension ext : extensions)
			elements.addAll(Arrays.asList(ext.getConfigurationElements()));
		Collections.sort(elements, CDTUIListComparator.getInstance());

		for (IConfigurationElement element : elements) {
			if (element.getName().equals(ELEMENT_NAME)) {
				if (loadTab(element, parent)) return;
			} else {
				System.out.println(UIMessages.getString("AbstractPage.13") + element.getName()); //$NON-NLS-1$
			}
		}
	}

	/**
	 * 
	 * @param element
	 * @param parent
	 * @return true if we should exit (no more loadings)
	 *         false if we should continue extensions scan.  
	 * @throws BuildException
	 */
	private boolean loadTab(IConfigurationElement element, Composite parent) {
		//	MBSCustomPageData currentPageData;
		// Check whether it's our tab
		if (!this.getClass().getName().equals(element.getAttribute(PARENT_NAME))) return false;
		
		ICPropertyTab page = null;
		try {
			page = (ICPropertyTab) element.createExecutableExtension(CLASS_NAME);
		} catch (CoreException e) {
			System.out.println(UIMessages.getString("AbstractPage.14") +  //$NON-NLS-1$
					e.getLocalizedMessage());
			return false; 
		}
		if (page == null) return false;
		
		String helpId = element.getAttribute(HELPID_NAME);
		if (helpId != null && helpId.length() > 0 
   		    // TODO: in next version: refer to ICPropertyTab instead of AbstractCPropertyTab
			&& page instanceof AbstractCPropertyTab) {
			((AbstractCPropertyTab)page).setHelpContextId(helpId);
		}
		
		Image _img = getIcon(element);
		if (_img != null) page.handleTabEvent(ICPropertyTab.SET_ICON, _img);
		
		if (isSingle()) {
			// note that name, image and tooltip
			// are ignored for single page.
			page.createControls(parent, this);
			InternalTab itab = new InternalTab(parent, EMPTY_STR, null, page, null);
			itabs.add(itab);
			currentTab = page;
			return true; // don't load other tabs
		}
		String _name   = element.getAttribute(TEXT_NAME);
		String _tip = element.getAttribute(TIP_NAME);

		Composite _comp = new Composite(folder, SWT.NONE);
		page.createControls(_comp, this);	    
		InternalTab itab = new InternalTab(_comp, _name, _img, page, _tip);
		itab.createOn(folder);
		itabs.add(itab);
		return false;
	}
	
	private Image getIcon(IConfigurationElement config) {
		ImageDescriptor idesc = null;
		try {
			String iconName = config.getAttribute(IMAGE_NAME);
			if (iconName != null) {
				URL pluginInstallUrl = Platform.getBundle(config.getDeclaringExtension().getContributor().getName()).getEntry("/"); //$NON-NLS-1$			
				idesc = ImageDescriptor.createFromURL(new URL(pluginInstallUrl, iconName));
			}
		} catch (MalformedURLException exception) {}
		return (idesc == null) ? null : idesc.createImage();
	}
	
	public void informAll(int code, Object data) {
		for (int i=0; i<CDTPropertyManager.getPagesCount(); i++) {
			Object p = CDTPropertyManager.getPage(i);
			if (p == null || !(p instanceof AbstractPage))
				continue;
			AbstractPage ap = (AbstractPage)p;
			ap.forEach(code, data);
		}
	}

	public void informPages(int code, Object data) {
		for (int i=0; i<CDTPropertyManager.getPagesCount(); i++) {
			Object p = CDTPropertyManager.getPage(i);
			if (p == null || !(p instanceof AbstractPage))
				continue;
			AbstractPage ap = (AbstractPage)p;
			ap.handleMessage(code, data);
		}
	}

	public void handleMessage(int code, Object data) {
		switch (code) {
			// First re-check visibility of all tabs.
		    // While tab deletion can be made on the fly,
		    // tabs adding will be made by re-creation
		    // of all elements, to preserve their order 
			case ICPropertyTab.MANAGEDBUILDSTATE:
				if (folder == null) {
					if (itabs == null || itabs.size() == 0) 
						return;
					ICPropertyTab t = itabs.get(0).tab;
					if (! t.canBeVisible())
						t.handleTabEvent(ICPropertyTab.VISIBLE, null);
					return;
				}
				boolean willAdd = false;
				TabItem[] ts = folder.getItems();
				int x = folder.getSelectionIndex();
				String currHeader = (x == -1) ? null : ts[x].getText();
				for (int i=0; i<itabs.size(); i++) {
					InternalTab itab = itabs.get(i);
					TabItem ti = null;
					for (TabItem element2 : ts) {
						if (element2.isDisposed()) continue;
						if (element2.getData() == itab.tab) {
							ti = element2;
							break;
						}
					}
					if (itab.tab.canBeVisible()) {
						if (ti == null)	{
							willAdd = true;
							break;
						}
					} else {
						if (ti != null) ti.dispose();
					}
				}
				// in case of new tab added, 
				// we have to dispose and re-create all tabs
				if (willAdd) {
					for (int j=0; j<ts.length; j++) 
						if (ts[j] != null && !ts[j].isDisposed())
							ts[j].dispose();
					TabItem ti = null;
					for (int i=0; i<itabs.size(); i++) {
						InternalTab itab = itabs.get(i);
						if (itab.tab.canBeVisible()) {
							TabItem currTI = itab.createOn(folder);
							if (currHeader != null && currHeader.equals(itab.text))
								ti = currTI;
						}
					}
					if (ti != null) folder.setSelection(ti);
				}
				break;
		}
	}
	
	/**
	 * Performs conversion of incoming element to internal representation.
	 */
	protected boolean checkElement() {
		IAdaptable el = super.getElement();
		if (el instanceof ICElement) 
			internalElement = ((ICElement)el).getResource();
		else if (el instanceof IResource) 
			internalElement = (IResource)el;
		if (internalElement == null) return false;
		isProject = internalElement instanceof IProject;
		isFolder  = internalElement instanceof IFolder;
		isFile    = internalElement instanceof IFile;
		return true;
	}
	
	// override parent's method to use proper class
	@Override
	public IAdaptable getElement() {
		if (internalElement == null && !checkElement()) 
			throw (new NullPointerException(UIMessages.getString("AbstractPage.15"))); //$NON-NLS-1$
		return internalElement; 
	}
	
	public boolean isForProject()  { return isProject; }
	public boolean isForFolder()   { return isFolder; }
	public boolean isForFile()     { return isFile; }
	public boolean isForPrefs()    { return false; }
	public boolean isMultiCfg()    { return resd instanceof ICMultiItemsHolder; }
	
	/**
	 * Checks whether CDT property pages can be open for given object.
	 * In particular, header files and text files are not allowed.
	 * 
	 * Note, that org.eclipse.cdt.ui.plugin.xml contains appropriate
	 * filters to avoid displaying CDT pages for unwanted objects. 
	 * So this check is only backup, it would prevent from NullPointer
	 * exceptions in case when xml filters were modified somehow.  
	 * 
	 * @return - true if element is applicable to CDT pages.
	 */
	public boolean isApplicable() {
		if (internalElement == null && !checkElement())
			return false; // unknown element
		if (isForFile()) // only source files are applicable
			return true; //CoreModel.isValidSourceUnitName(getProject(), internalElement.getName());
		return true; // Projects and folders are always applicable
	}

	/**
	 * update views (in particular, display resource configurations)
	 */
	public static void updateViews(IResource res) {
		if (res == null) return;  
		IWorkbenchPartReference refs[] = CUIPlugin.getActiveWorkbenchWindow().getActivePage().getViewReferences();
		for (IWorkbenchPartReference ref : refs) {
			IWorkbenchPart part = ref.getPart(false);
			if (part != null && part instanceof IPropertyChangeListener)
				((IPropertyChangeListener)part).propertyChange(new PropertyChangeEvent(res, PreferenceConstants.PREF_SHOW_CU_CHILDREN, null, null));
		}
	}

	/**
	 * Adjusts form size according to contents dimensions
	 */
	public void resize() {
		Shell sh = parentComposite.getShell();
		Point p0 = sh.getLocation();
		Point p1 = sh.computeSize(SWT.DEFAULT, SWT.DEFAULT, true);
		Rectangle r = sh.getDisplay().getClientArea();
		p1.x = Math.min(p1.x, (r.width - p0.x));
		p1.y = Math.min(p1.y, (r.height - p0.y));
		sh.setSize(p1);
	}

	/**
	 * Returns Apply button widget
	 * Allows public access to it.
	 */
	public Button getAButton() {
		return getApplyButton();
	}
	
	/**
	 * Returns Default button widget.
	 * Allows public access to it.
	 */
	public Button getDButton() {
		return getDefaultsButton();
	}

	@Override
	public void performHelp() {
	    // TODO: in next version: refer to ICPropertyTab instead of AbstractCPropertyTab
		if (currentTab != null && currentTab instanceof AbstractCPropertyTab) {
			String s = ((AbstractCPropertyTab)currentTab).getHelpContextId();
			if (s != null && s.length() > 0) {
				IContext context= HelpSystem.getContext(s);
				if (context != null)
					PlatformUI.getWorkbench().getHelpSystem().displayHelp(context);
				else
					PlatformUI.getWorkbench().getHelpSystem().displayDynamicHelp();
			}
		}
	}
	
}
