org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/JavaEditorHoverConfigurationBlock.java - jdt/eclipse.jdt.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2011 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.jdt.internal.ui.preferences;

 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.StringTokenizer;

 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.KeyEvent;
 import org.eclipse.swt.events.KeyListener;
 import org.eclipse.swt.events.SelectionEvent;
 import org.eclipse.swt.events.SelectionListener;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.layout.GridLayout;
 import org.eclipse.swt.widgets.Button;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Label;
 import org.eclipse.swt.widgets.Table;
 import org.eclipse.swt.widgets.TableColumn;
 import org.eclipse.swt.widgets.TableItem;
 import org.eclipse.swt.widgets.Text;

 import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.IStatus;

 import org.eclipse.jface.action.Action;
 import org.eclipse.jface.dialogs.Dialog;
 import org.eclipse.jface.layout.PixelConverter;
 import org.eclipse.jface.preference.PreferencePage;
 import org.eclipse.jface.viewers.CheckboxTableViewer;
 import org.eclipse.jface.viewers.ColumnWeightData;
 import org.eclipse.jface.viewers.ILabelProviderListener;
 import org.eclipse.jface.viewers.IStructuredContentProvider;
 import org.eclipse.jface.viewers.ITableLabelProvider;
 import org.eclipse.jface.viewers.StructuredSelection;
 import org.eclipse.jface.viewers.TableLayout;
 import org.eclipse.jface.viewers.TableViewer;
 import org.eclipse.jface.viewers.Viewer;

 import org.eclipse.jdt.internal.corext.util.Messages;

 import org.eclipse.jdt.ui.PreferenceConstants;

 import org.eclipse.jdt.internal.ui.JavaPlugin;
 import org.eclipse.jdt.internal.ui.dialogs.StatusInfo;
 import org.eclipse.jdt.internal.ui.dialogs.StatusUtil;
 import org.eclipse.jdt.internal.ui.preferences.OverlayPreferenceStore.OverlayKey;
 import org.eclipse.jdt.internal.ui.text.java.hover.JavaEditorTextHoverDescriptor;
 import org.eclipse.jdt.internal.ui.util.SWTUtil;
 import org.eclipse.jdt.internal.ui.util.TableLayoutComposite;


 /**
  * Configures Java Editor hover preferences.
  *
  * @since 2.1
  */
 class JavaEditorHoverConfigurationBlock implements IPreferenceConfigurationBlock {

 	private static final String DELIMITER= PreferencesMessages.JavaEditorHoverConfigurationBlock_delimiter;

 	private static final int ENABLED_PROP= 0;
 	private static final int MODIFIER_PROP= 1;

 	// Data structure to hold the values which are edited by the user
 	private static class HoverConfig {

 		private String fModifierString;
 		private boolean fIsEnabled;
 		private int fStateMask;

 		private HoverConfig(String modifier, int stateMask, boolean enabled) {
 			fModifierString= modifier;
 			fIsEnabled= enabled;
 			fStateMask= stateMask;
 		}
 	}


 	private class JavaEditorTextHoverDescriptorLabelProvider implements ITableLabelProvider {

 		@Override
 		public Image getColumnImage(Object element, int columnIndex) {
 			return null;
 		}

 		@Override
 		public String getColumnText(Object element, int columnIndex) {
 			switch (columnIndex) {
 			case ENABLED_PROP:
 				return ((JavaEditorTextHoverDescriptor)element).getLabel();

 			case MODIFIER_PROP:
 				TableItem item= (TableItem)fHoverTableViewer.testFindItem(element);
 				int index= fHoverTable.indexOf(item);
 				return fHoverConfigs[index].fModifierString;

 			default:
 				break;
 			}

 			return null;
 		}

 		@Override
 		public void addListener(ILabelProviderListener listener) {
 		}

 		@Override
 		public void dispose() {
 		}

 		@Override
 		public boolean isLabelProperty(Object element, String property) {
 			return false;
 		}

 		@Override
 		public void removeListener(ILabelProviderListener listener) {
 		}
 	}


 	private static class JavaEditorTextHoverDescriptorContentProvider implements IStructuredContentProvider {

 		@Override
 		public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
 			// Do nothing since the viewer listens to resource deltas
 		}

 		@Override
 		public void dispose() {
 		}

 		@Override
 		public Object[] getElements(Object element) {
 			return (Object[])element;
 		}
 	}


 	private OverlayPreferenceStore fStore;
 	private HoverConfig[] fHoverConfigs;
 	private Text fModifierEditor;
 	private Table fHoverTable;
 	private TableViewer fHoverTableViewer;
 	private TableColumn fNameColumn;
 	private TableColumn fModifierColumn;
 	private Text fDescription;

 	private PreferencePage fMainPreferencePage;

 	private StatusInfo fStatus;

 	private Map<Button, String> fCheckBoxes= new HashMap<>();
 	private SelectionListener fCheckBoxListener= new SelectionListener() {
 		@Override
 		public void widgetDefaultSelected(SelectionEvent e) {
 			Button button= (Button) e.widget;
 			fStore.setValue(fCheckBoxes.get(button), button.getSelection());
 		}
 		@Override
 		public void widgetSelected(SelectionEvent e) {
 			Button button= (Button) e.widget;
 			fStore.setValue(fCheckBoxes.get(button), button.getSelection());
 		}
 	};


 	public JavaEditorHoverConfigurationBlock(PreferencePage mainPreferencePage, OverlayPreferenceStore store) {
 		Assert.isNotNull(mainPreferencePage);
 		Assert.isNotNull(store);
 		fMainPreferencePage= mainPreferencePage;
 		fStore= store;
 		fStore.addKeys(createOverlayStoreKeys());
 	}


 	private OverlayPreferenceStore.OverlayKey[] createOverlayStoreKeys() {

 		ArrayList<OverlayKey> overlayKeys= new ArrayList<>();

 		overlayKeys.add(new OverlayPreferenceStore.OverlayKey(OverlayPreferenceStore.BOOLEAN, PreferenceConstants.EDITOR_ANNOTATION_ROLL_OVER));

 		overlayKeys.add(new OverlayPreferenceStore.OverlayKey(OverlayPreferenceStore.STRING, PreferenceConstants.EDITOR_TEXT_HOVER_MODIFIERS));
 		overlayKeys.add(new OverlayPreferenceStore.OverlayKey(OverlayPreferenceStore.STRING, PreferenceConstants.EDITOR_TEXT_HOVER_MODIFIER_MASKS));

 		OverlayPreferenceStore.OverlayKey[] keys= new OverlayPreferenceStore.OverlayKey[overlayKeys.size()];
 		overlayKeys.toArray(keys);
 		return keys;
 	}

 	/**
 	 * Creates page for hover preferences.
 	 *
 	 * @param parent the parent composite
 	 * @return the control for the preference page
 	 */
 	@Override
 	public Control createControl(Composite parent) {

 		ScrolledPageContent scrolled= new ScrolledPageContent(parent, SWT.H_SCROLL | SWT.V_SCROLL);
 		scrolled.setExpandHorizontal(true);
 		scrolled.setExpandVertical(true);


 		Composite hoverComposite= new Composite(scrolled, SWT.NONE);
 		GridLayout layout= new GridLayout();
 		layout.numColumns= 2;
 		layout.marginWidth= 0;
 		layout.marginHeight= 0;
 		hoverComposite.setLayout(layout);

 		String rollOverLabel= PreferencesMessages.JavaEditorHoverConfigurationBlock_annotationRollover;
 		addCheckBox(hoverComposite, rollOverLabel, PreferenceConstants.EDITOR_ANNOTATION_ROLL_OVER, 0);

 		addFiller(hoverComposite);

 		Label label= new Label(hoverComposite, SWT.NONE);
 		label.setText(PreferencesMessages.JavaEditorHoverConfigurationBlock_hoverPreferences);
 		GridData gd= new GridData(GridData.FILL_HORIZONTAL);
 		gd.horizontalAlignment= GridData.BEGINNING;
 		gd.horizontalSpan= 2;
 		label.setLayoutData(gd);

 		TableLayoutComposite layouter= new TableLayoutComposite(hoverComposite, SWT.NONE);
 		addColumnLayoutData(layouter);

 		// Hover table
 		fHoverTable= new Table(layouter, SWT.H_SCROLL | SWT.V_SCROLL | SWT.SINGLE | SWT.BORDER | SWT.FULL_SELECTION | SWT.CHECK);
 		fHoverTable.setHeaderVisible(true);
 		fHoverTable.setLinesVisible(true);

 		gd= new GridData(GridData.FILL_HORIZONTAL);
 		gd.heightHint= SWTUtil.getTableHeightHint(fHoverTable, 10);
 		gd.horizontalSpan= 2;
 		gd.widthHint= new PixelConverter(parent).convertWidthInCharsToPixels(30);
 		layouter.setLayoutData(gd);

 		fHoverTable.addSelectionListener(new SelectionListener() {
 			@Override
 			public void widgetSelected(SelectionEvent e) {
 				handleHoverListSelection();
 			}
 			@Override
 			public void widgetDefaultSelected(SelectionEvent e) {
 			}
 		});

 		TableLayout tableLayout= new TableLayout();
 		fHoverTable.setLayout(tableLayout);

 		fNameColumn= new TableColumn(fHoverTable, SWT.NONE);
 		fNameColumn.setText(PreferencesMessages.JavaEditorHoverConfigurationBlock_nameColumnTitle);
 		fNameColumn.setResizable(true);

 		fModifierColumn= new TableColumn(fHoverTable, SWT.NONE);
 		fModifierColumn.setText(PreferencesMessages.JavaEditorHoverConfigurationBlock_modifierColumnTitle);
 		fModifierColumn.setResizable(true);

 		fHoverTableViewer= new CheckboxTableViewer(fHoverTable);
 		fHoverTableViewer.setUseHashlookup(true);
 		fHoverTableViewer.setContentProvider(new JavaEditorTextHoverDescriptorContentProvider());
 		fHoverTableViewer.setLabelProvider(new JavaEditorTextHoverDescriptorLabelProvider());

 		((CheckboxTableViewer)fHoverTableViewer).addCheckStateListener(event -> {
 			String id= ((JavaEditorTextHoverDescriptor)event.getElement()).getId();
 			if (id == null)
 				return;
 			JavaEditorTextHoverDescriptor[] descriptors= getContributedHovers();
 			HoverConfig hoverConfig= null;
 			int i= 0, length= fHoverConfigs.length;
 			while (i < length) {
 				if (id.equals(descriptors[i].getId())) {
 					hoverConfig= fHoverConfigs[i];
 					hoverConfig.fIsEnabled= event.getChecked();
 					fModifierEditor.setEnabled(event.getChecked());
 					fHoverTableViewer.setSelection(new StructuredSelection(descriptors[i]));
 				}
 				i++;
 			}
 			handleHoverListSelection();
 			updateStatus(hoverConfig);
 		});

 		// Text field for modifier string
 		label= new Label(hoverComposite, SWT.LEFT);
 		label.setText(PreferencesMessages.JavaEditorHoverConfigurationBlock_keyModifier);
 		fModifierEditor= new Text(hoverComposite, SWT.BORDER);
 		gd= new GridData(GridData.HORIZONTAL_ALIGN_FILL);
 		fModifierEditor.setLayoutData(gd);

 		fModifierEditor.addKeyListener(new KeyListener() {
 			private boolean isModifierCandidate;
 			@Override
 			public void keyPressed(KeyEvent e) {
 				isModifierCandidate= e.keyCode > 0 && e.character == 0 && e.stateMask == 0;
 			}

 			@Override
 			public void keyReleased(KeyEvent e) {
 				if (isModifierCandidate && e.stateMask > 0 && e.character == 0) {// && e.time -time < 1000) {
 					String text= fModifierEditor.getText();
 					Point selection= fModifierEditor.getSelection();
 					int i= selection.x - 1;
 					while (i > -1 && Character.isWhitespace(text.charAt(i))) {
 						i--;
 					}
 					boolean needsPrefixDelimiter= i > -1 && !String.valueOf(text.charAt(i)).equals(DELIMITER);

 					i= selection.y;
 					while (i < text.length() && Character.isWhitespace(text.charAt(i))) {
 						i++;
 					}
 					boolean needsPostfixDelimiter= i < text.length() && !String.valueOf(text.charAt(i)).equals(DELIMITER);

 					String insertString;

 					if (needsPrefixDelimiter && needsPostfixDelimiter)
 						insertString= Messages.format(PreferencesMessages.JavaEditorHoverConfigurationBlock_insertDelimiterAndModifierAndDelimiter, new String[] {Action.findModifierString(e.stateMask)});
 					else if (needsPrefixDelimiter)
 						insertString= Messages.format(PreferencesMessages.JavaEditorHoverConfigurationBlock_insertDelimiterAndModifier, new String[] {Action.findModifierString(e.stateMask)});
 					else if (needsPostfixDelimiter)
 						insertString= Messages.format(PreferencesMessages.JavaEditorHoverConfigurationBlock_insertModifierAndDelimiter, new String[] {Action.findModifierString(e.stateMask)});
 					else
 						insertString= Action.findModifierString(e.stateMask);

 					if (insertString != null)
 						fModifierEditor.insert(insertString);
 				}
 			}
 		});

 		fModifierEditor.addModifyListener(e -> handleModifierModified());

 		// Description
 		Label descriptionLabel= new Label(hoverComposite, SWT.LEFT);
 		descriptionLabel.setText(PreferencesMessages.JavaEditorHoverConfigurationBlock_description);
 		gd= new GridData(GridData.VERTICAL_ALIGN_BEGINNING);
 		gd.horizontalSpan= 2;
 		descriptionLabel.setLayoutData(gd);
 		fDescription= new Text(hoverComposite, SWT.LEFT | SWT.WRAP | SWT.MULTI | SWT.READ_ONLY | SWT.BORDER);
 		SWTUtil.fixReadonlyTextBackground(fDescription);
 		gd= new GridData(GridData.FILL_BOTH);
 		gd.horizontalSpan= 2;
 		fDescription.setLayoutData(gd);

 		initialize();

 		scrolled.setContent(hoverComposite);
 		final Point size= hoverComposite.computeSize(SWT.DEFAULT, SWT.DEFAULT);
 		scrolled.setMinSize(size.x, size.y);

 		Dialog.applyDialogFont(scrolled);

 		return scrolled;

 	}

 	private void addColumnLayoutData(TableLayoutComposite layouter) {
 		layouter.addColumnData(new ColumnWeightData(40, true));
 		layouter.addColumnData(new ColumnWeightData(60, true));
 	}

 	private JavaEditorTextHoverDescriptor[] getContributedHovers() {
 		return JavaPlugin.getDefault().getJavaEditorTextHoverDescriptors();
 	}

 	@Override
 	public void initialize() {
 		JavaEditorTextHoverDescriptor[] hoverDescs= getContributedHovers();
 		fHoverConfigs= new HoverConfig[hoverDescs.length];
 		for (int i= 0; i < hoverDescs.length; i++)
 			fHoverConfigs[i]= new HoverConfig(hoverDescs[i].getModifierString(), hoverDescs[i].getStateMask(), hoverDescs[i].isEnabled());

 		fHoverTableViewer.setInput(hoverDescs);

 		initializeFields();
 	}

 	void initializeFields() {
 		fModifierEditor.setEnabled(false);

 		Iterator<Button> e= fCheckBoxes.keySet().iterator();
 		while (e.hasNext()) {
 			Button b= e.next();
 			String key= fCheckBoxes.get(b);
 			b.setSelection(fStore.getBoolean(key));
 		}

 		for (int i= 0; i < fHoverConfigs.length; i++)
 			fHoverTable.getItem(i).setChecked(fHoverConfigs[i].fIsEnabled);
 		fHoverTableViewer.refresh();
 	}

 	@Override
 	public void performOk() {
 		StringBuilder buf= new StringBuilder();
 		StringBuilder maskBuf= new StringBuilder();
 		for (int i= 0; i < fHoverConfigs.length; i++) {
 			buf.append(getContributedHovers()[i].getId());
 			buf.append(JavaEditorTextHoverDescriptor.VALUE_SEPARATOR);
 			if (!fHoverConfigs[i].fIsEnabled)
 				buf.append(JavaEditorTextHoverDescriptor.DISABLED_TAG);
 			String modifier= fHoverConfigs[i].fModifierString;
 			if (modifier == null || modifier.length() == 0)
 				modifier= JavaEditorTextHoverDescriptor.NO_MODIFIER;
 			buf.append(modifier);
 			buf.append(JavaEditorTextHoverDescriptor.VALUE_SEPARATOR);

 			maskBuf.append(getContributedHovers()[i].getId());
 			maskBuf.append(JavaEditorTextHoverDescriptor.VALUE_SEPARATOR);
 			maskBuf.append(fHoverConfigs[i].fStateMask);
 			maskBuf.append(JavaEditorTextHoverDescriptor.VALUE_SEPARATOR);
 		}
 		fStore.setValue(PreferenceConstants.EDITOR_TEXT_HOVER_MODIFIERS, buf.toString());
 		fStore.setValue(PreferenceConstants.EDITOR_TEXT_HOVER_MODIFIER_MASKS, maskBuf.toString());

 		JavaPlugin.getDefault().resetJavaEditorTextHoverDescriptors();
 	}

 	@Override
 	public void performDefaults() {
 		restoreFromPreferences();
 		initializeFields();
 		updateStatus(null);
 	}

 	private void restoreFromPreferences() {
 		String compiledTextHoverModifiers= fStore.getString(PreferenceConstants.EDITOR_TEXT_HOVER_MODIFIERS);

 		StringTokenizer tokenizer= new StringTokenizer(compiledTextHoverModifiers, JavaEditorTextHoverDescriptor.VALUE_SEPARATOR);
 		HashMap<String, String> idToModifier= new HashMap<>(tokenizer.countTokens() / 2);

 		while (tokenizer.hasMoreTokens()) {
 			String id= tokenizer.nextToken();
 			if (tokenizer.hasMoreTokens())
 				idToModifier.put(id, tokenizer.nextToken());
 		}

 		String compiledTextHoverModifierMasks= JavaPlugin.getDefault().getPreferenceStore().getString(PreferenceConstants.EDITOR_TEXT_HOVER_MODIFIER_MASKS);

 		tokenizer= new StringTokenizer(compiledTextHoverModifierMasks, JavaEditorTextHoverDescriptor.VALUE_SEPARATOR);
 		HashMap<String, String> idToModifierMask= new HashMap<>(tokenizer.countTokens() / 2);

 		while (tokenizer.hasMoreTokens()) {
 			String id= tokenizer.nextToken();
 			if (tokenizer.hasMoreTokens())
 				idToModifierMask.put(id, tokenizer.nextToken());
 		}

 		for (int i= 0; i < fHoverConfigs.length; i++) {
 			String modifierString= idToModifier.get(getContributedHovers()[i].getId());
 			boolean enabled= true;
 			if (modifierString == null)
 				modifierString= JavaEditorTextHoverDescriptor.DISABLED_TAG;

 			if (modifierString.startsWith(JavaEditorTextHoverDescriptor.DISABLED_TAG)) {
 				enabled= false;
 				modifierString= modifierString.substring(1);
 			}

 			if (modifierString.equals(JavaEditorTextHoverDescriptor.NO_MODIFIER))
 				modifierString= ""; //$NON-NLS-1$

 			fHoverConfigs[i].fModifierString= modifierString;
 			fHoverConfigs[i].fIsEnabled= enabled;
 			fHoverConfigs[i].fStateMask= JavaEditorTextHoverDescriptor.computeStateMask(modifierString);

 			if (fHoverConfigs[i].fStateMask == -1) {
 				try {
 					fHoverConfigs[i].fStateMask= Integer.parseInt(idToModifierMask.get(getContributedHovers()[i].getId()));
 				} catch (NumberFormatException ex) {
 					fHoverConfigs[i].fStateMask= -1;
 				}
 			}
 		}
 	}

 	private void handleModifierModified() {
 		int i= fHoverTable.getSelectionIndex();
 		if (i == -1)
 			return;

 		String modifiers= fModifierEditor.getText();
 		fHoverConfigs[i].fModifierString= modifiers;
 		fHoverConfigs[i].fStateMask= JavaEditorTextHoverDescriptor.computeStateMask(modifiers);

 		// update table
 		fHoverTableViewer.refresh(getContributedHovers()[i]);

 		updateStatus(fHoverConfigs[i]);
 	}

 	private void handleHoverListSelection() {
 		int i= fHoverTable.getSelectionIndex();

 		if (i == -1) {
 			if (fHoverTable.getSelectionCount() == 0)
 				fModifierEditor.setEnabled(false);
 			return;
 		}

 		boolean enabled= fHoverConfigs[i].fIsEnabled;
 		fModifierEditor.setEnabled(enabled);
 		fModifierEditor.setText(fHoverConfigs[i].fModifierString);
 		String description= getContributedHovers()[i].getDescription();
 		if (description == null)
 			description= ""; //$NON-NLS-1$
 		fDescription.setText(description);
 	}

 	IStatus getStatus() {
 		if (fStatus == null)
 			fStatus= new StatusInfo();
 		return fStatus;
 	}

 	private void updateStatus(HoverConfig hoverConfig) {
 		if (hoverConfig != null && hoverConfig.fIsEnabled && hoverConfig.fStateMask == -1)
 			fStatus= new StatusInfo(IStatus.ERROR, Messages.format(PreferencesMessages.JavaEditorHoverConfigurationBlock_modifierIsNotValid, hoverConfig.fModifierString));
 		else
 			fStatus= new StatusInfo();

 		int i= 0;
 		HashMap<Integer, String> stateMasks= new HashMap<>(fHoverConfigs.length);
 		while (fStatus.isOK() && i < fHoverConfigs.length) {
 			if (fHoverConfigs[i].fIsEnabled) {
 				String label= getContributedHovers()[i].getLabel();
 				Integer stateMask= fHoverConfigs[i].fStateMask;
 				if (fHoverConfigs[i].fStateMask == -1)
 					fStatus= new StatusInfo(IStatus.ERROR, Messages.format(PreferencesMessages.JavaEditorHoverConfigurationBlock_modifierIsNotValidForHover, new String[] {fHoverConfigs[i].fModifierString, label}));
 				else if (stateMasks.containsKey(stateMask))
 					fStatus= new StatusInfo(IStatus.ERROR, Messages.format(PreferencesMessages.JavaEditorHoverConfigurationBlock_duplicateModifier, new String[] {label, stateMasks.get(stateMask)}));
 				else
 					stateMasks.put(stateMask, label);
 			}
 			i++;
 		}

 		fMainPreferencePage.setValid(fStatus.isOK());
 		StatusUtil.applyToStatusLine(fMainPreferencePage, fStatus);
 	}

 	private Button addCheckBox(Composite parent, String label, String key, int indentation) {
 		Button checkBox= new Button(parent, SWT.CHECK);
 		checkBox.setText(label);

 		GridData gd= new GridData(GridData.HORIZONTAL_ALIGN_BEGINNING);
 		gd.horizontalIndent= indentation;
 		gd.horizontalSpan= 2;
 		checkBox.setLayoutData(gd);
 		checkBox.addSelectionListener(fCheckBoxListener);

 		fCheckBoxes.put(checkBox, key);

 		return checkBox;
 	}

 	private void addFiller(Composite composite) {
 		PixelConverter pixelConverter= new PixelConverter(composite);
 		Label filler= new Label(composite, SWT.LEFT );
 		GridData gd= new GridData(GridData.HORIZONTAL_ALIGN_FILL);
 		gd.horizontalSpan= 2;
 		gd.heightHint= pixelConverter.convertHeightInCharsToPixels(1) / 2;
 		filler.setLayoutData(gd);
 	}

 	/*
 	 * @see DialogPage#dispose()
 	 */
 	@Override
 	public void dispose() {
 		// nothing to dispose
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2011 IBM Corporation and others.
	*
	* This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License 2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.jdt.internal.ui.preferences;

	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.Iterator;
	import java.util.Map;
	import java.util.StringTokenizer;

	import org.eclipse.swt.SWT;
	import org.eclipse.swt.events.KeyEvent;
	import org.eclipse.swt.events.KeyListener;
	import org.eclipse.swt.events.SelectionEvent;
	import org.eclipse.swt.events.SelectionListener;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.layout.GridData;
	import org.eclipse.swt.layout.GridLayout;
	import org.eclipse.swt.widgets.Button;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Label;
	import org.eclipse.swt.widgets.Table;
	import org.eclipse.swt.widgets.TableColumn;
	import org.eclipse.swt.widgets.TableItem;
	import org.eclipse.swt.widgets.Text;

	import org.eclipse.core.runtime.Assert;
	import org.eclipse.core.runtime.IStatus;

	import org.eclipse.jface.action.Action;
	import org.eclipse.jface.dialogs.Dialog;
	import org.eclipse.jface.layout.PixelConverter;
	import org.eclipse.jface.preference.PreferencePage;
	import org.eclipse.jface.viewers.CheckboxTableViewer;
	import org.eclipse.jface.viewers.ColumnWeightData;
	import org.eclipse.jface.viewers.ILabelProviderListener;
	import org.eclipse.jface.viewers.IStructuredContentProvider;
	import org.eclipse.jface.viewers.ITableLabelProvider;
	import org.eclipse.jface.viewers.StructuredSelection;
	import org.eclipse.jface.viewers.TableLayout;
	import org.eclipse.jface.viewers.TableViewer;
	import org.eclipse.jface.viewers.Viewer;

	import org.eclipse.jdt.internal.corext.util.Messages;

	import org.eclipse.jdt.ui.PreferenceConstants;

	import org.eclipse.jdt.internal.ui.JavaPlugin;
	import org.eclipse.jdt.internal.ui.dialogs.StatusInfo;
	import org.eclipse.jdt.internal.ui.dialogs.StatusUtil;
	import org.eclipse.jdt.internal.ui.preferences.OverlayPreferenceStore.OverlayKey;
	import org.eclipse.jdt.internal.ui.text.java.hover.JavaEditorTextHoverDescriptor;
	import org.eclipse.jdt.internal.ui.util.SWTUtil;
	import org.eclipse.jdt.internal.ui.util.TableLayoutComposite;


	/**
	* Configures Java Editor hover preferences.
	*
	* @since 2.1
	*/
	class JavaEditorHoverConfigurationBlock implements IPreferenceConfigurationBlock {

	private static final String DELIMITER= PreferencesMessages.JavaEditorHoverConfigurationBlock_delimiter;

	private static final int ENABLED_PROP= 0;
	private static final int MODIFIER_PROP= 1;

	// Data structure to hold the values which are edited by the user
	private static class HoverConfig {

	private String fModifierString;
	private boolean fIsEnabled;
	private int fStateMask;

	private HoverConfig(String modifier, int stateMask, boolean enabled) {
	fModifierString= modifier;
	fIsEnabled= enabled;
	fStateMask= stateMask;
	}
	}


	private class JavaEditorTextHoverDescriptorLabelProvider implements ITableLabelProvider {

	@Override
	public Image getColumnImage(Object element, int columnIndex) {
	return null;
	}

	@Override
	public String getColumnText(Object element, int columnIndex) {
	switch (columnIndex) {
	case ENABLED_PROP:
	return ((JavaEditorTextHoverDescriptor)element).getLabel();

	case MODIFIER_PROP:
	TableItem item= (TableItem)fHoverTableViewer.testFindItem(element);
	int index= fHoverTable.indexOf(item);
	return fHoverConfigs[index].fModifierString;

	default:
	break;
	}

	return null;
	}

	@Override
	public void addListener(ILabelProviderListener listener) {
	}

	@Override
	public void dispose() {
	}

	@Override
	public boolean isLabelProperty(Object element, String property) {
	return false;
	}

	@Override
	public void removeListener(ILabelProviderListener listener) {
	}
	}


	private static class JavaEditorTextHoverDescriptorContentProvider implements IStructuredContentProvider {

	@Override
	public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
	// Do nothing since the viewer listens to resource deltas
	}

	@Override
	public void dispose() {
	}

	@Override
	public Object[] getElements(Object element) {
	return (Object[])element;
	}
	}


	private OverlayPreferenceStore fStore;
	private HoverConfig[] fHoverConfigs;
	private Text fModifierEditor;
	private Table fHoverTable;
	private TableViewer fHoverTableViewer;
	private TableColumn fNameColumn;
	private TableColumn fModifierColumn;
	private Text fDescription;

	private PreferencePage fMainPreferencePage;

	private StatusInfo fStatus;

	private Map<Button, String> fCheckBoxes= new HashMap<>();
	private SelectionListener fCheckBoxListener= new SelectionListener() {
	@Override
	public void widgetDefaultSelected(SelectionEvent e) {
	Button button= (Button) e.widget;
	fStore.setValue(fCheckBoxes.get(button), button.getSelection());
	}
	@Override
	public void widgetSelected(SelectionEvent e) {
	Button button= (Button) e.widget;
	fStore.setValue(fCheckBoxes.get(button), button.getSelection());
	}
	};


	public JavaEditorHoverConfigurationBlock(PreferencePage mainPreferencePage, OverlayPreferenceStore store) {
	Assert.isNotNull(mainPreferencePage);
	Assert.isNotNull(store);
	fMainPreferencePage= mainPreferencePage;
	fStore= store;
	fStore.addKeys(createOverlayStoreKeys());
	}


	private OverlayPreferenceStore.OverlayKey[] createOverlayStoreKeys() {

	ArrayList<OverlayKey> overlayKeys= new ArrayList<>();

	overlayKeys.add(new OverlayPreferenceStore.OverlayKey(OverlayPreferenceStore.BOOLEAN, PreferenceConstants.EDITOR_ANNOTATION_ROLL_OVER));

	overlayKeys.add(new OverlayPreferenceStore.OverlayKey(OverlayPreferenceStore.STRING, PreferenceConstants.EDITOR_TEXT_HOVER_MODIFIERS));
	overlayKeys.add(new OverlayPreferenceStore.OverlayKey(OverlayPreferenceStore.STRING, PreferenceConstants.EDITOR_TEXT_HOVER_MODIFIER_MASKS));

	OverlayPreferenceStore.OverlayKey[] keys= new OverlayPreferenceStore.OverlayKey[overlayKeys.size()];
	overlayKeys.toArray(keys);
	return keys;
	}

	/**
	* Creates page for hover preferences.
	*
	* @param parent the parent composite
	* @return the control for the preference page
	*/
	@Override
	public Control createControl(Composite parent) {

	ScrolledPageContent scrolled= new ScrolledPageContent(parent, SWT.H_SCROLL \| SWT.V_SCROLL);
	scrolled.setExpandHorizontal(true);
	scrolled.setExpandVertical(true);


	Composite hoverComposite= new Composite(scrolled, SWT.NONE);
	GridLayout layout= new GridLayout();
	layout.numColumns= 2;
	layout.marginWidth= 0;
	layout.marginHeight= 0;
	hoverComposite.setLayout(layout);

	String rollOverLabel= PreferencesMessages.JavaEditorHoverConfigurationBlock_annotationRollover;
	addCheckBox(hoverComposite, rollOverLabel, PreferenceConstants.EDITOR_ANNOTATION_ROLL_OVER, 0);

	addFiller(hoverComposite);

	Label label= new Label(hoverComposite, SWT.NONE);
	label.setText(PreferencesMessages.JavaEditorHoverConfigurationBlock_hoverPreferences);
	GridData gd= new GridData(GridData.FILL_HORIZONTAL);
	gd.horizontalAlignment= GridData.BEGINNING;
	gd.horizontalSpan= 2;
	label.setLayoutData(gd);

	TableLayoutComposite layouter= new TableLayoutComposite(hoverComposite, SWT.NONE);
	addColumnLayoutData(layouter);

	// Hover table
	fHoverTable= new Table(layouter, SWT.H_SCROLL \| SWT.V_SCROLL \| SWT.SINGLE \| SWT.BORDER \| SWT.FULL_SELECTION \| SWT.CHECK);
	fHoverTable.setHeaderVisible(true);
	fHoverTable.setLinesVisible(true);

	gd= new GridData(GridData.FILL_HORIZONTAL);
	gd.heightHint= SWTUtil.getTableHeightHint(fHoverTable, 10);
	gd.horizontalSpan= 2;
	gd.widthHint= new PixelConverter(parent).convertWidthInCharsToPixels(30);
	layouter.setLayoutData(gd);

	fHoverTable.addSelectionListener(new SelectionListener() {
	@Override
	public void widgetSelected(SelectionEvent e) {
	handleHoverListSelection();
	}
	@Override
	public void widgetDefaultSelected(SelectionEvent e) {
	}
	});

	TableLayout tableLayout= new TableLayout();
	fHoverTable.setLayout(tableLayout);

	fNameColumn= new TableColumn(fHoverTable, SWT.NONE);
	fNameColumn.setText(PreferencesMessages.JavaEditorHoverConfigurationBlock_nameColumnTitle);
	fNameColumn.setResizable(true);

	fModifierColumn= new TableColumn(fHoverTable, SWT.NONE);
	fModifierColumn.setText(PreferencesMessages.JavaEditorHoverConfigurationBlock_modifierColumnTitle);
	fModifierColumn.setResizable(true);

	fHoverTableViewer= new CheckboxTableViewer(fHoverTable);
	fHoverTableViewer.setUseHashlookup(true);
	fHoverTableViewer.setContentProvider(new JavaEditorTextHoverDescriptorContentProvider());
	fHoverTableViewer.setLabelProvider(new JavaEditorTextHoverDescriptorLabelProvider());

	((CheckboxTableViewer)fHoverTableViewer).addCheckStateListener(event -> {
	String id= ((JavaEditorTextHoverDescriptor)event.getElement()).getId();
	if (id == null)
	return;
	JavaEditorTextHoverDescriptor[] descriptors= getContributedHovers();
	HoverConfig hoverConfig= null;
	int i= 0, length= fHoverConfigs.length;
	while (i < length) {
	if (id.equals(descriptors[i].getId())) {
	hoverConfig= fHoverConfigs[i];
	hoverConfig.fIsEnabled= event.getChecked();
	fModifierEditor.setEnabled(event.getChecked());
	fHoverTableViewer.setSelection(new StructuredSelection(descriptors[i]));
	}
	i++;
	}
	handleHoverListSelection();
	updateStatus(hoverConfig);
	});

	// Text field for modifier string
	label= new Label(hoverComposite, SWT.LEFT);
	label.setText(PreferencesMessages.JavaEditorHoverConfigurationBlock_keyModifier);
	fModifierEditor= new Text(hoverComposite, SWT.BORDER);
	gd= new GridData(GridData.HORIZONTAL_ALIGN_FILL);
	fModifierEditor.setLayoutData(gd);

	fModifierEditor.addKeyListener(new KeyListener() {
	private boolean isModifierCandidate;
	@Override
	public void keyPressed(KeyEvent e) {
	isModifierCandidate= e.keyCode > 0 && e.character == 0 && e.stateMask == 0;
	}

	@Override
	public void keyReleased(KeyEvent e) {
	if (isModifierCandidate && e.stateMask > 0 && e.character == 0) {// && e.time -time < 1000) {
	String text= fModifierEditor.getText();
	Point selection= fModifierEditor.getSelection();
	int i= selection.x - 1;
	while (i > -1 && Character.isWhitespace(text.charAt(i))) {
	i--;
	}
	boolean needsPrefixDelimiter= i > -1 && !String.valueOf(text.charAt(i)).equals(DELIMITER);

	i= selection.y;
	while (i < text.length() && Character.isWhitespace(text.charAt(i))) {
	i++;
	}
	boolean needsPostfixDelimiter= i < text.length() && !String.valueOf(text.charAt(i)).equals(DELIMITER);

	String insertString;

	if (needsPrefixDelimiter && needsPostfixDelimiter)
	insertString= Messages.format(PreferencesMessages.JavaEditorHoverConfigurationBlock_insertDelimiterAndModifierAndDelimiter, new String[] {Action.findModifierString(e.stateMask)});
	else if (needsPrefixDelimiter)
	insertString= Messages.format(PreferencesMessages.JavaEditorHoverConfigurationBlock_insertDelimiterAndModifier, new String[] {Action.findModifierString(e.stateMask)});
	else if (needsPostfixDelimiter)
	insertString= Messages.format(PreferencesMessages.JavaEditorHoverConfigurationBlock_insertModifierAndDelimiter, new String[] {Action.findModifierString(e.stateMask)});
	else
	insertString= Action.findModifierString(e.stateMask);

	if (insertString != null)
	fModifierEditor.insert(insertString);
	}
	}
	});

	fModifierEditor.addModifyListener(e -> handleModifierModified());

	// Description
	Label descriptionLabel= new Label(hoverComposite, SWT.LEFT);
	descriptionLabel.setText(PreferencesMessages.JavaEditorHoverConfigurationBlock_description);
	gd= new GridData(GridData.VERTICAL_ALIGN_BEGINNING);
	gd.horizontalSpan= 2;
	descriptionLabel.setLayoutData(gd);
	fDescription= new Text(hoverComposite, SWT.LEFT \| SWT.WRAP \| SWT.MULTI \| SWT.READ_ONLY \| SWT.BORDER);
	SWTUtil.fixReadonlyTextBackground(fDescription);
	gd= new GridData(GridData.FILL_BOTH);
	gd.horizontalSpan= 2;
	fDescription.setLayoutData(gd);

	initialize();

	scrolled.setContent(hoverComposite);
	final Point size= hoverComposite.computeSize(SWT.DEFAULT, SWT.DEFAULT);
	scrolled.setMinSize(size.x, size.y);

	Dialog.applyDialogFont(scrolled);

	return scrolled;

	}

	private void addColumnLayoutData(TableLayoutComposite layouter) {
	layouter.addColumnData(new ColumnWeightData(40, true));
	layouter.addColumnData(new ColumnWeightData(60, true));
	}

	private JavaEditorTextHoverDescriptor[] getContributedHovers() {
	return JavaPlugin.getDefault().getJavaEditorTextHoverDescriptors();
	}

	@Override
	public void initialize() {
	JavaEditorTextHoverDescriptor[] hoverDescs= getContributedHovers();
	fHoverConfigs= new HoverConfig[hoverDescs.length];
	for (int i= 0; i < hoverDescs.length; i++)
	fHoverConfigs[i]= new HoverConfig(hoverDescs[i].getModifierString(), hoverDescs[i].getStateMask(), hoverDescs[i].isEnabled());

	fHoverTableViewer.setInput(hoverDescs);

	initializeFields();
	}

	void initializeFields() {
	fModifierEditor.setEnabled(false);

	Iterator<Button> e= fCheckBoxes.keySet().iterator();
	while (e.hasNext()) {
	Button b= e.next();
	String key= fCheckBoxes.get(b);
	b.setSelection(fStore.getBoolean(key));
	}

	for (int i= 0; i < fHoverConfigs.length; i++)
	fHoverTable.getItem(i).setChecked(fHoverConfigs[i].fIsEnabled);
	fHoverTableViewer.refresh();
	}

	@Override
	public void performOk() {
	StringBuilder buf= new StringBuilder();
	StringBuilder maskBuf= new StringBuilder();
	for (int i= 0; i < fHoverConfigs.length; i++) {
	buf.append(getContributedHovers()[i].getId());
	buf.append(JavaEditorTextHoverDescriptor.VALUE_SEPARATOR);
	if (!fHoverConfigs[i].fIsEnabled)
	buf.append(JavaEditorTextHoverDescriptor.DISABLED_TAG);
	String modifier= fHoverConfigs[i].fModifierString;
	if (modifier == null \|\| modifier.length() == 0)
	modifier= JavaEditorTextHoverDescriptor.NO_MODIFIER;
	buf.append(modifier);
	buf.append(JavaEditorTextHoverDescriptor.VALUE_SEPARATOR);

	maskBuf.append(getContributedHovers()[i].getId());
	maskBuf.append(JavaEditorTextHoverDescriptor.VALUE_SEPARATOR);
	maskBuf.append(fHoverConfigs[i].fStateMask);
	maskBuf.append(JavaEditorTextHoverDescriptor.VALUE_SEPARATOR);
	}
	fStore.setValue(PreferenceConstants.EDITOR_TEXT_HOVER_MODIFIERS, buf.toString());
	fStore.setValue(PreferenceConstants.EDITOR_TEXT_HOVER_MODIFIER_MASKS, maskBuf.toString());

	JavaPlugin.getDefault().resetJavaEditorTextHoverDescriptors();
	}

	@Override
	public void performDefaults() {
	restoreFromPreferences();
	initializeFields();
	updateStatus(null);
	}

	private void restoreFromPreferences() {
	String compiledTextHoverModifiers= fStore.getString(PreferenceConstants.EDITOR_TEXT_HOVER_MODIFIERS);

	StringTokenizer tokenizer= new StringTokenizer(compiledTextHoverModifiers, JavaEditorTextHoverDescriptor.VALUE_SEPARATOR);
	HashMap<String, String> idToModifier= new HashMap<>(tokenizer.countTokens() / 2);

	while (tokenizer.hasMoreTokens()) {
	String id= tokenizer.nextToken();
	if (tokenizer.hasMoreTokens())
	idToModifier.put(id, tokenizer.nextToken());
	}

	String compiledTextHoverModifierMasks= JavaPlugin.getDefault().getPreferenceStore().getString(PreferenceConstants.EDITOR_TEXT_HOVER_MODIFIER_MASKS);

	tokenizer= new StringTokenizer(compiledTextHoverModifierMasks, JavaEditorTextHoverDescriptor.VALUE_SEPARATOR);
	HashMap<String, String> idToModifierMask= new HashMap<>(tokenizer.countTokens() / 2);

	while (tokenizer.hasMoreTokens()) {
	String id= tokenizer.nextToken();
	if (tokenizer.hasMoreTokens())
	idToModifierMask.put(id, tokenizer.nextToken());
	}

	for (int i= 0; i < fHoverConfigs.length; i++) {
	String modifierString= idToModifier.get(getContributedHovers()[i].getId());
	boolean enabled= true;
	if (modifierString == null)
	modifierString= JavaEditorTextHoverDescriptor.DISABLED_TAG;

	if (modifierString.startsWith(JavaEditorTextHoverDescriptor.DISABLED_TAG)) {
	enabled= false;
	modifierString= modifierString.substring(1);
	}

	if (modifierString.equals(JavaEditorTextHoverDescriptor.NO_MODIFIER))
	modifierString= ""; //$NON-NLS-1$

	fHoverConfigs[i].fModifierString= modifierString;
	fHoverConfigs[i].fIsEnabled= enabled;
	fHoverConfigs[i].fStateMask= JavaEditorTextHoverDescriptor.computeStateMask(modifierString);

	if (fHoverConfigs[i].fStateMask == -1) {
	try {
	fHoverConfigs[i].fStateMask= Integer.parseInt(idToModifierMask.get(getContributedHovers()[i].getId()));
	} catch (NumberFormatException ex) {
	fHoverConfigs[i].fStateMask= -1;
	}
	}
	}
	}

	private void handleModifierModified() {
	int i= fHoverTable.getSelectionIndex();
	if (i == -1)
	return;

	String modifiers= fModifierEditor.getText();
	fHoverConfigs[i].fModifierString= modifiers;
	fHoverConfigs[i].fStateMask= JavaEditorTextHoverDescriptor.computeStateMask(modifiers);

	// update table
	fHoverTableViewer.refresh(getContributedHovers()[i]);

	updateStatus(fHoverConfigs[i]);
	}

	private void handleHoverListSelection() {
	int i= fHoverTable.getSelectionIndex();

	if (i == -1) {
	if (fHoverTable.getSelectionCount() == 0)
	fModifierEditor.setEnabled(false);
	return;
	}

	boolean enabled= fHoverConfigs[i].fIsEnabled;
	fModifierEditor.setEnabled(enabled);
	fModifierEditor.setText(fHoverConfigs[i].fModifierString);
	String description= getContributedHovers()[i].getDescription();
	if (description == null)
	description= ""; //$NON-NLS-1$
	fDescription.setText(description);
	}

	IStatus getStatus() {
	if (fStatus == null)
	fStatus= new StatusInfo();
	return fStatus;
	}

	private void updateStatus(HoverConfig hoverConfig) {
	if (hoverConfig != null && hoverConfig.fIsEnabled && hoverConfig.fStateMask == -1)
	fStatus= new StatusInfo(IStatus.ERROR, Messages.format(PreferencesMessages.JavaEditorHoverConfigurationBlock_modifierIsNotValid, hoverConfig.fModifierString));
	else
	fStatus= new StatusInfo();

	int i= 0;
	HashMap<Integer, String> stateMasks= new HashMap<>(fHoverConfigs.length);
	while (fStatus.isOK() && i < fHoverConfigs.length) {
	if (fHoverConfigs[i].fIsEnabled) {
	String label= getContributedHovers()[i].getLabel();
	Integer stateMask= fHoverConfigs[i].fStateMask;
	if (fHoverConfigs[i].fStateMask == -1)
	fStatus= new StatusInfo(IStatus.ERROR, Messages.format(PreferencesMessages.JavaEditorHoverConfigurationBlock_modifierIsNotValidForHover, new String[] {fHoverConfigs[i].fModifierString, label}));
	else if (stateMasks.containsKey(stateMask))
	fStatus= new StatusInfo(IStatus.ERROR, Messages.format(PreferencesMessages.JavaEditorHoverConfigurationBlock_duplicateModifier, new String[] {label, stateMasks.get(stateMask)}));
	else
	stateMasks.put(stateMask, label);
	}
	i++;
	}

	fMainPreferencePage.setValid(fStatus.isOK());
	StatusUtil.applyToStatusLine(fMainPreferencePage, fStatus);
	}

	private Button addCheckBox(Composite parent, String label, String key, int indentation) {
	Button checkBox= new Button(parent, SWT.CHECK);
	checkBox.setText(label);

	GridData gd= new GridData(GridData.HORIZONTAL_ALIGN_BEGINNING);
	gd.horizontalIndent= indentation;
	gd.horizontalSpan= 2;
	checkBox.setLayoutData(gd);
	checkBox.addSelectionListener(fCheckBoxListener);

	fCheckBoxes.put(checkBox, key);

	return checkBox;
	}

	private void addFiller(Composite composite) {
	PixelConverter pixelConverter= new PixelConverter(composite);
	Label filler= new Label(composite, SWT.LEFT );
	GridData gd= new GridData(GridData.HORIZONTAL_ALIGN_FILL);
	gd.horizontalSpan= 2;
	gd.heightHint= pixelConverter.convertHeightInCharsToPixels(1) / 2;
	filler.setLayoutData(gd);
	}

	/*
	* @see DialogPage#dispose()
	*/
	@Override
	public void dispose() {
	// nothing to dispose
	}
	}