bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/dialogs/ViewsPreferencePage.java - platform/eclipse.platform.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2017 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
  *     Erik Chou <ekchou@ymail.com> - Bug 425962
  *     Lars Vogel <Lars.Vogel@vogella.com> - Bug 445664, 442278, 472654
  *     Andrey Loskutov <loskutov@gmx.de> - Bug 388476
  *     Patrik Suzzi - <psuzzi@gmail.com> - Bug 515265
  *******************************************************************************/

 package org.eclipse.ui.internal.dialogs;

 import static org.eclipse.jface.viewers.LabelProvider.createTextProvider;
 import static org.eclipse.swt.events.SelectionListener.widgetSelectedAdapter;
 import static org.eclipse.ui.internal.registry.IWorkbenchRegistryConstants.ATT_COLOR_AND_FONT_ID;
 import static org.eclipse.ui.internal.registry.IWorkbenchRegistryConstants.ATT_OS_VERSION;
 import static org.eclipse.ui.internal.registry.IWorkbenchRegistryConstants.ATT_THEME_ASSOCIATION;
 import static org.eclipse.ui.internal.registry.IWorkbenchRegistryConstants.ATT_THEME_ID;

 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtension;
 import org.eclipse.core.runtime.IExtensionPoint;
 import org.eclipse.core.runtime.IExtensionRegistry;
 import org.eclipse.core.runtime.RegistryFactory;
 import org.eclipse.core.runtime.preferences.IEclipsePreferences;
 import org.eclipse.core.runtime.preferences.InstanceScope;
 import org.eclipse.e4.core.contexts.IEclipseContext;
 import org.eclipse.e4.ui.css.swt.theme.ITheme;
 import org.eclipse.e4.ui.css.swt.theme.IThemeEngine;
 import org.eclipse.e4.ui.internal.workbench.swt.E4Application;
 import org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine;
 import org.eclipse.e4.ui.model.application.MApplication;
 import org.eclipse.e4.ui.workbench.renderers.swt.CTabRendering;
 import org.eclipse.e4.ui.workbench.renderers.swt.StackRenderer;
 import org.eclipse.jface.dialogs.Dialog;
 import org.eclipse.jface.fieldassist.ControlDecoration;
 import org.eclipse.jface.fieldassist.FieldDecorationRegistry;
 import org.eclipse.jface.notifications.AbstractNotificationPopup;
 import org.eclipse.jface.preference.IPreferenceStore;
 import org.eclipse.jface.preference.PreferencePage;
 import org.eclipse.jface.util.Util;
 import org.eclipse.jface.viewers.ArrayContentProvider;
 import org.eclipse.jface.viewers.ComboViewer;
 import org.eclipse.jface.viewers.ISelection;
 import org.eclipse.jface.viewers.LabelProvider;
 import org.eclipse.jface.viewers.StructuredSelection;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.layout.GridLayout;
 import org.eclipse.swt.layout.RowLayout;
 import org.eclipse.swt.widgets.Button;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Label;
 import org.eclipse.swt.widgets.Link;
 import org.eclipse.ui.IWorkbench;
 import org.eclipse.ui.IWorkbenchPreferenceConstants;
 import org.eclipse.ui.IWorkbenchPreferencePage;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.internal.WorkbenchMessages;
 import org.eclipse.ui.internal.WorkbenchPlugin;
 import org.eclipse.ui.internal.themes.IThemeDescriptor;
 import org.eclipse.ui.internal.util.PrefUtil;
 import org.eclipse.ui.themes.IThemeManager;
 import org.osgi.service.prefs.BackingStoreException;

 /**
  * The ViewsPreferencePage is the page used to set preferences for the
  * appearance of the workbench. Originally this applied only to views but now
  * applies to the overall appearance, hence the name.
  */
 public class ViewsPreferencePage extends PreferencePage implements IWorkbenchPreferencePage {
 	private static final String E4_THEME_EXTENSION_POINT = "org.eclipse.e4.ui.css.swt.theme"; //$NON-NLS-1$

 	/** The workbench theme engine; may be {@code null} if no engine */
 	private IThemeEngine engine;
 	private ComboViewer themeIdCombo;
 	private ControlDecoration themeComboDecorator;
 	private ITheme currentTheme;
 	private String defaultTheme;
 	private Button useRoundTabs;
 	private Button enableMru;
 	private Button useColoredLabels;

 	private ComboViewer colorsAndFontsThemeCombo;
 	private ControlDecoration colorFontsDecorator;
 	private ColorsAndFontsTheme currentColorsAndFontsTheme;
 	private Map<String, String> themeAssociations;
 	private boolean highContrastMode;

 	private Button themingEnabled;

 	private NotificationPopUp notificationPopUp;

 	@Override
 	protected Control createContents(Composite parent) {
 		initializeDialogUnits(parent);

 		Composite comp = new Composite(parent, SWT.NONE);

 		themingEnabled = createCheckButton(comp, WorkbenchMessages.ThemingEnabled, engine != null);

 		// if started with "-cssTheme none", CSS settings should be disabled
 		// but other appearance settings should be *not* disabled
 		if (engine == null) {
 			GridLayout layout = new GridLayout(1, false);
 			layout.horizontalSpacing = 10;
 			comp.setLayout(layout);
 			createThemeIndependentComposits(comp);
 			return comp;
 		}

 		GridLayout layout = new GridLayout(2, false);
 		layout.horizontalSpacing = 10;
 		comp.setLayout(layout);

 		new Label(comp, SWT.NONE).setText(WorkbenchMessages.ViewsPreferencePage_Theme);
 		highContrastMode = parent.getDisplay().getHighContrast();

 		themeIdCombo = new ComboViewer(comp, SWT.READ_ONLY);
 		themeIdCombo.setLabelProvider(createTextProvider(element -> ((ITheme) element).getLabel()));
 		themeIdCombo.setContentProvider(ArrayContentProvider.getInstance());
 		themeIdCombo.setInput(getCSSThemes(highContrastMode));
 		themeIdCombo.getCombo().setEnabled(!highContrastMode);
 		themeIdCombo.getControl().setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
 		this.currentTheme = engine.getActiveTheme();
 		if (this.currentTheme != null) {
 			themeIdCombo.setSelection(new StructuredSelection(currentTheme));
 		}
 		themeComboDecorator = new ControlDecoration(themeIdCombo.getCombo(), SWT.TOP | SWT.LEFT);
 		themeIdCombo.addSelectionChangedListener(event -> {
 			ITheme selection = getSelectedTheme();
 			if (!selection.equals(currentTheme)) {
 				themeComboDecorator.setDescriptionText(WorkbenchMessages.ThemeChangeWarningText);
 				Image decorationImage = FieldDecorationRegistry.getDefault()
 						.getFieldDecoration(FieldDecorationRegistry.DEC_WARNING).getImage();
 				themeComboDecorator.setImage(decorationImage);
 				themeComboDecorator.show();
 			} else {
 				themeComboDecorator.hide();
 			}
 			selectColorsAndFontsTheme(getColorAndFontThemeIdByThemeId(selection.getId()));
 		});

 		currentColorsAndFontsTheme = getCurrentColorsAndFontsTheme();
 		createColorsAndFontsThemeCombo(comp);

 		createThemeIndependentComposits(comp);

 		if (currentTheme != null) {
 			String colorsAndFontsThemeId = getColorAndFontThemeIdByThemeId(currentTheme.getId());
 			if (colorsAndFontsThemeId != null && !currentColorsAndFontsTheme.getId().equals(colorsAndFontsThemeId)) {
 				colorsAndFontsThemeId = currentColorsAndFontsTheme.getId();
 			}
 			selectColorsAndFontsTheme(colorsAndFontsThemeId);
 		}

 		Dialog.applyDialogFont(comp);
 		return comp;
 	}

 	private void createThemeIndependentComposits(Composite comp) {
 		createUseRoundTabs(comp);
 		createColoredLabelsPref(comp);
 		createEnableMruPref(comp);
 	}

 	private List<ITheme> getCSSThemes(boolean highContrastMode) {
 		ArrayList<ITheme> themes = new ArrayList<>();
 		for (ITheme theme : engine.getThemes()) {
 			/*
 			 * When we have Win32 OS - when the high contrast mode is enabled on the
 			 * platform, we display the 'high-contrast' special theme only. If not, we don't
 			 * want to mess the themes combo with the theme since it is the special
 			 * variation of the 'classic' one
 			 *
 			 * When we have GTK - we have to display the entire list of the themes since we
 			 * are not able to figure out if the high contrast mode is enabled on the
 			 * platform. The user has to manually select the theme if they need it
 			 */
 			if (!highContrastMode && !Util.isGtk() && theme.getId().equals(E4Application.HIGH_CONTRAST_THEME_ID)) {
 				continue;
 			}
 			themes.add(theme);
 		}
 		themes.sort((ITheme t1, ITheme t2) -> t1.getLabel().compareTo(t2.getLabel()));
 		return themes;
 	}

 	private void createColoredLabelsPref(Composite composite) {
 		IPreferenceStore apiStore = PrefUtil.getAPIPreferenceStore();

 		useColoredLabels = createCheckButton(composite, WorkbenchMessages.ViewsPreference_useColoredLabels,
 				apiStore.getBoolean(IWorkbenchPreferenceConstants.USE_COLORED_LABELS));
 	}

 	private Button createCheckButton(Composite composite, String text, boolean selection) {
 		Button button = new Button(composite, SWT.CHECK);
 		GridData data = new GridData(SWT.BEGINNING, SWT.CENTER, false, false, 2, 1);
 		button.setLayoutData(data);
 		button.setText(text);
 		button.setSelection(selection);
 		return button;
 	}

 	private Label createLabel(Composite composite, String text) {
 		Label label = new Label(composite, SWT.NONE);
 		GridData data = new GridData(SWT.BEGINNING, SWT.CENTER, false, false, 2, 1);
 		label.setLayoutData(data);
 		label.setText(text);
 		return label;
 	}

 	protected void createUseRoundTabs(Composite composite) {
 		IEclipsePreferences prefs = getSwtRendererPreferences();
 		boolean enabled = prefs.getBoolean(CTabRendering.USE_ROUND_TABS, CTabRendering.USE_ROUND_TABS_DEFAULT);
 		useRoundTabs = createCheckButton(composite, WorkbenchMessages.ViewsPreference_useRoundTabs, enabled);
 	}

 	protected void createEnableMruPref(Composite composite) {
 		createLabel(composite, ""); //$NON-NLS-1$
 		createLabel(composite, WorkbenchMessages.ViewsPreference_visibleTabs_description);
 		IEclipsePreferences prefs = getSwtRendererPreferences();
 		boolean defaultValue = getDefaultMRUValue();
 		boolean actualValue = prefs.getBoolean(StackRenderer.MRU_KEY, defaultValue);
 		enableMru = createCheckButton(composite, WorkbenchMessages.ViewsPreference_enableMRU, actualValue);
 	}


 	/** @return the currently selected theme or null if there are no themes */
 	private ITheme getSelectedTheme() {
 		return (ITheme) (themeIdCombo.getStructuredSelection().getFirstElement());
 	}

 	@Override
 	public void init(IWorkbench workbench) {
 		MApplication application = workbench.getService(MApplication.class);
 		IEclipseContext context = application.getContext();
 		defaultTheme = (String) context.get(E4Application.THEME_ID);
 		engine = context.get(IThemeEngine.class);
 	}

 	@Override
 	public boolean performOk() {
 		if (engine != null) {
 			ITheme theme = getSelectedTheme();
 			if (theme != null) {
 				engine.setTheme(getSelectedTheme(), !highContrastMode);
 			}
 		}

 		IPreferenceStore apiStore = PrefUtil.getAPIPreferenceStore();
 		apiStore.setValue(IWorkbenchPreferenceConstants.USE_COLORED_LABELS, useColoredLabels.getSelection());

 		IEclipsePreferences prefs = getSwtRendererPreferences();
 		prefs.putBoolean(StackRenderer.MRU_KEY, enableMru.getSelection());
 		boolean themingEnabledChanged = prefs.getBoolean(PartRenderingEngine.ENABLED_THEME_KEY, true) != themingEnabled
 				.getSelection();
 		prefs.putBoolean(PartRenderingEngine.ENABLED_THEME_KEY, themingEnabled.getSelection());

 		prefs.putBoolean(CTabRendering.USE_ROUND_TABS, useRoundTabs.getSelection());
 		try {
 			prefs.flush();
 		} catch (BackingStoreException e) {
 			WorkbenchPlugin.log("Failed to set SWT renderer preferences", e); //$NON-NLS-1$
 		}

 		if (engine != null) {
 			ITheme theme = getSelectedTheme();
 			boolean themeChanged = theme != null && !theme.equals(currentTheme);
 			boolean colorsAndFontsThemeChanged = !PlatformUI.getWorkbench().getThemeManager().getCurrentTheme().getId()
 					.equals(currentColorsAndFontsTheme.getId());

 			if (theme != null) {
 				currentTheme = theme;
 			}

 			ColorsAndFontsTheme colorsAndFontsTheme = getSelectedColorsAndFontsTheme();
 			if (colorsAndFontsTheme != null) {
 				currentColorsAndFontsTheme = colorsAndFontsTheme;
 			}

 			themeComboDecorator.hide();
 			colorFontsDecorator.hide();

 			if (themeChanged || colorsAndFontsThemeChanged) {
 				if (notificationPopUp == null) {
 					notificationPopUp = new NotificationPopUp(getShell().getDisplay());
 					notificationPopUp.open();
 				}
 			}
 		} else if (themingEnabledChanged) {
 			if (notificationPopUp == null) {
 				notificationPopUp = new NotificationPopUp(getShell().getDisplay());
 				notificationPopUp.open();
 			}
 		}

 		return super.performOk();
 	}

 	private IEclipsePreferences getSwtRendererPreferences() {
 		return InstanceScope.INSTANCE.getNode("org.eclipse.e4.ui.workbench.renderers.swt"); //$NON-NLS-1$
 	}

 	private boolean getDefaultMRUValue() {
 		return getSwtRendererPreferences().getBoolean(StackRenderer.MRU_KEY_DEFAULT, StackRenderer.MRU_DEFAULT);
 	}

 	private void setColorsAndFontsTheme(ColorsAndFontsTheme theme) {
 		org.eclipse.ui.themes.ITheme currentTheme = PlatformUI.getWorkbench().getThemeManager().getCurrentTheme();
 		if (theme != null && !currentTheme.getId().equals(theme.getId())) {
 			PlatformUI.getWorkbench().getThemeManager().setCurrentTheme(theme.getId());
 		}
 	}

 	@Override
 	protected void performDefaults() {
 		if (engine != null) {
 			setColorsAndFontsTheme(currentColorsAndFontsTheme);

 			engine.setTheme(defaultTheme, true);
 			if (engine.getActiveTheme() != null) {
 				themeIdCombo.setSelection(new StructuredSelection(engine.getActiveTheme()));
 			}
 		}
 		IPreferenceStore apiStore = PrefUtil.getAPIPreferenceStore();
 		useColoredLabels.setSelection(apiStore.getDefaultBoolean(IWorkbenchPreferenceConstants.USE_COLORED_LABELS));

 		useRoundTabs.setSelection(CTabRendering.USE_ROUND_TABS_DEFAULT);
 		enableMru.setSelection(getDefaultMRUValue());
 		super.performDefaults();
 	}

 	@Override
 	public boolean performCancel() {
 		if (engine != null) {
 			setColorsAndFontsTheme(currentColorsAndFontsTheme);

 			if (currentTheme != null) {
 				engine.setTheme(currentTheme, false);
 			}
 		}

 		return super.performCancel();
 	}

 	private void createColorsAndFontsThemeCombo(Composite composite) {
 		new Label(composite, SWT.NONE).setText(WorkbenchMessages.ViewsPreference_currentTheme);
 		colorsAndFontsThemeCombo = new ComboViewer(composite, SWT.READ_ONLY);
 		colorsAndFontsThemeCombo.getControl().setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false));
 		colorsAndFontsThemeCombo.setLabelProvider(new LabelProvider() {
 			@Override
 			public String getText(Object element) {
 				return ((ColorsAndFontsTheme) element).getLabel();
 			}
 		});
 		colorFontsDecorator = new ControlDecoration(colorsAndFontsThemeCombo.getCombo(), SWT.TOP | SWT.LEFT);
 		colorsAndFontsThemeCombo.setContentProvider(ArrayContentProvider.getInstance());
 		colorsAndFontsThemeCombo.setInput(getColorsAndFontsThemes());
 		colorsAndFontsThemeCombo.getControl().setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
 		colorsAndFontsThemeCombo.addSelectionChangedListener(event -> {
 			ColorsAndFontsTheme colorsAndFontsTheme = getSelectedColorsAndFontsTheme();
 			if (!colorsAndFontsTheme.equals(currentColorsAndFontsTheme)) {
 				Image decorationImage = FieldDecorationRegistry.getDefault()
 						.getFieldDecoration(FieldDecorationRegistry.DEC_WARNING).getImage();
 				colorFontsDecorator.setImage(decorationImage);
 				colorFontsDecorator.setDescriptionText(WorkbenchMessages.ThemeChangeWarningText);
 				colorFontsDecorator.show();
 			} else
 				colorFontsDecorator.hide();
 			setColorsAndFontsTheme(colorsAndFontsTheme);
 		});
 	}

 	@SuppressWarnings("unchecked")
 	private void selectColorsAndFontsTheme(String colorAndFontThemeId) {
 		if (colorAndFontThemeId == null) {
 			colorAndFontThemeId = currentColorsAndFontsTheme.getId();
 		}

 		for (ColorsAndFontsTheme theme : (List<ColorsAndFontsTheme>) colorsAndFontsThemeCombo.getInput()) {
 			if (theme.getId().equals(colorAndFontThemeId)) {
 				ISelection selection = new StructuredSelection(theme);
 				colorsAndFontsThemeCombo.setSelection(selection);
 				break;
 			}
 		}
 	}

 	private String getColorAndFontThemeIdByThemeId(String themeId) {
 		if (themeAssociations == null) {
 			themeAssociations = createThemeAssociations();
 		}

 		// first get by exact matching (together with os_version)
 		String result = themeAssociations.get(themeId);

 		if (result == null) {
 			for (Map.Entry<String, String> entry : themeAssociations.entrySet()) {
 				if (themeId.startsWith(entry.getKey())) {
 					return entry.getValue();
 				}
 			}
 		}

 		return result;
 	}

 	private Map<String, String> createThemeAssociations() {
 		Map<String, String> result = new HashMap<>();
 		IExtensionRegistry registry = RegistryFactory.getRegistry();
 		IExtensionPoint extPoint = registry.getExtensionPoint(E4_THEME_EXTENSION_POINT);

 		for (IExtension e : extPoint.getExtensions()) {
 			for (IConfigurationElement ce : e.getConfigurationElements()) {
 				if (ce.getName().equals(ATT_THEME_ASSOCIATION)) {
 					String themeId = ce.getAttribute(ATT_THEME_ID);
 					String osVersion = ce.getAttribute(ATT_OS_VERSION);
 					result.put(osVersion != null ? themeId + osVersion : themeId,
 							ce.getAttribute(ATT_COLOR_AND_FONT_ID));
 				}
 			}
 		}
 		return result;
 	}

 	private List<ColorsAndFontsTheme> getColorsAndFontsThemes() {
 		List<ColorsAndFontsTheme> result = new ArrayList<>();
 		org.eclipse.ui.themes.ITheme currentTheme = PlatformUI.getWorkbench().getThemeManager().getCurrentTheme();

 		IThemeDescriptor[] descs = WorkbenchPlugin.getDefault().getThemeRegistry().getThemes();
 		String defaultThemeString = PlatformUI.getWorkbench().getThemeManager().getTheme(IThemeManager.DEFAULT_THEME)
 				.getLabel();
 		if (currentTheme.getId().equals(IThemeManager.DEFAULT_THEME)) {
 			defaultThemeString = NLS.bind(WorkbenchMessages.ViewsPreference_currentThemeFormat,
 					new Object[] { defaultThemeString });
 		}
 		result.add(new ColorsAndFontsTheme(IThemeManager.DEFAULT_THEME, defaultThemeString));

 		String themeString;
 		for (IThemeDescriptor themeDescriptor : descs) {
 			themeString = themeDescriptor.getName();
 			if (themeDescriptor.getId().equals(currentTheme.getId())) {
 				themeString = NLS.bind(WorkbenchMessages.ViewsPreference_currentThemeFormat,
 						new Object[] { themeString });
 			}
 			result.add(new ColorsAndFontsTheme(themeDescriptor.getId(), themeString));
 		}
 		return result;
 	}

 	private ColorsAndFontsTheme getSelectedColorsAndFontsTheme() {
 		return (ColorsAndFontsTheme) colorsAndFontsThemeCombo.getStructuredSelection().getFirstElement();
 	}

 	private ColorsAndFontsTheme getCurrentColorsAndFontsTheme() {
 		org.eclipse.ui.themes.ITheme theme = PlatformUI.getWorkbench().getThemeManager().getCurrentTheme();

 		return new ColorsAndFontsTheme(theme.getId(), theme.getLabel());
 	}

 	private static class ColorsAndFontsTheme {
 		private String label;
 		private String id;

 		public ColorsAndFontsTheme(String id, String label) {
 			this.id = id;
 			this.label = label;
 		}

 		public String getId() {
 			return id;
 		}

 		public String getLabel() {
 			return label;
 		}

 		@Override
 		public int hashCode() {
 			return Objects.hashCode(id);
 		}

 		@Override
 		public boolean equals(Object obj) {
 			if (this == obj)
 				return true;
 			if (obj == null)
 				return false;
 			if (getClass() != obj.getClass())
 				return false;
 			ColorsAndFontsTheme other = (ColorsAndFontsTheme) obj;
 			return Objects.equals(id, other.id);
 		}

 	}

 	private class NotificationPopUp extends AbstractNotificationPopup {

 		public NotificationPopUp(Display display) {
 			super(display);
 			setDelayClose(0);
 			setParentShell(PlatformUI.getWorkbench().getActiveWorkbenchWindow().getShell());
 		}

 		@Override
 		protected String getPopupShellTitle() {
 			return WorkbenchMessages.ThemeChangeWarningTitle;
 		}


 		@Override
 		protected void createContentArea(Composite parent) {
 			parent.setLayout(new RowLayout());

 			Link link = new Link(parent, SWT.WRAP);
 			link.setText(WorkbenchMessages.ThemeChangeWarningText);
 			link.addSelectionListener(widgetSelectedAdapter(e -> PlatformUI.getWorkbench().restart(true)));
 		}
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2000, 2017 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
	* Erik Chou <ekchou@ymail.com> - Bug 425962
	* Lars Vogel <Lars.Vogel@vogella.com> - Bug 445664, 442278, 472654
	* Andrey Loskutov <loskutov@gmx.de> - Bug 388476
	* Patrik Suzzi - <psuzzi@gmail.com> - Bug 515265
	*******************************************************************************/

	package org.eclipse.ui.internal.dialogs;

	import static org.eclipse.jface.viewers.LabelProvider.createTextProvider;
	import static org.eclipse.swt.events.SelectionListener.widgetSelectedAdapter;
	import static org.eclipse.ui.internal.registry.IWorkbenchRegistryConstants.ATT_COLOR_AND_FONT_ID;
	import static org.eclipse.ui.internal.registry.IWorkbenchRegistryConstants.ATT_OS_VERSION;
	import static org.eclipse.ui.internal.registry.IWorkbenchRegistryConstants.ATT_THEME_ASSOCIATION;
	import static org.eclipse.ui.internal.registry.IWorkbenchRegistryConstants.ATT_THEME_ID;

	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.Objects;
	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IExtension;
	import org.eclipse.core.runtime.IExtensionPoint;
	import org.eclipse.core.runtime.IExtensionRegistry;
	import org.eclipse.core.runtime.RegistryFactory;
	import org.eclipse.core.runtime.preferences.IEclipsePreferences;
	import org.eclipse.core.runtime.preferences.InstanceScope;
	import org.eclipse.e4.core.contexts.IEclipseContext;
	import org.eclipse.e4.ui.css.swt.theme.ITheme;
	import org.eclipse.e4.ui.css.swt.theme.IThemeEngine;
	import org.eclipse.e4.ui.internal.workbench.swt.E4Application;
	import org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine;
	import org.eclipse.e4.ui.model.application.MApplication;
	import org.eclipse.e4.ui.workbench.renderers.swt.CTabRendering;
	import org.eclipse.e4.ui.workbench.renderers.swt.StackRenderer;
	import org.eclipse.jface.dialogs.Dialog;
	import org.eclipse.jface.fieldassist.ControlDecoration;
	import org.eclipse.jface.fieldassist.FieldDecorationRegistry;
	import org.eclipse.jface.notifications.AbstractNotificationPopup;
	import org.eclipse.jface.preference.IPreferenceStore;
	import org.eclipse.jface.preference.PreferencePage;
	import org.eclipse.jface.util.Util;
	import org.eclipse.jface.viewers.ArrayContentProvider;
	import org.eclipse.jface.viewers.ComboViewer;
	import org.eclipse.jface.viewers.ISelection;
	import org.eclipse.jface.viewers.LabelProvider;
	import org.eclipse.jface.viewers.StructuredSelection;
	import org.eclipse.osgi.util.NLS;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.layout.GridData;
	import org.eclipse.swt.layout.GridLayout;
	import org.eclipse.swt.layout.RowLayout;
	import org.eclipse.swt.widgets.Button;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Display;
	import org.eclipse.swt.widgets.Label;
	import org.eclipse.swt.widgets.Link;
	import org.eclipse.ui.IWorkbench;
	import org.eclipse.ui.IWorkbenchPreferenceConstants;
	import org.eclipse.ui.IWorkbenchPreferencePage;
	import org.eclipse.ui.PlatformUI;
	import org.eclipse.ui.internal.WorkbenchMessages;
	import org.eclipse.ui.internal.WorkbenchPlugin;
	import org.eclipse.ui.internal.themes.IThemeDescriptor;
	import org.eclipse.ui.internal.util.PrefUtil;
	import org.eclipse.ui.themes.IThemeManager;
	import org.osgi.service.prefs.BackingStoreException;

	/**
	* The ViewsPreferencePage is the page used to set preferences for the
	* appearance of the workbench. Originally this applied only to views but now
	* applies to the overall appearance, hence the name.
	*/
	public class ViewsPreferencePage extends PreferencePage implements IWorkbenchPreferencePage {
	private static final String E4_THEME_EXTENSION_POINT = "org.eclipse.e4.ui.css.swt.theme"; //$NON-NLS-1$

	/** The workbench theme engine; may be {@code null} if no engine */
	private IThemeEngine engine;
	private ComboViewer themeIdCombo;
	private ControlDecoration themeComboDecorator;
	private ITheme currentTheme;
	private String defaultTheme;
	private Button useRoundTabs;
	private Button enableMru;
	private Button useColoredLabels;

	private ComboViewer colorsAndFontsThemeCombo;
	private ControlDecoration colorFontsDecorator;
	private ColorsAndFontsTheme currentColorsAndFontsTheme;
	private Map<String, String> themeAssociations;
	private boolean highContrastMode;

	private Button themingEnabled;

	private NotificationPopUp notificationPopUp;

	@Override
	protected Control createContents(Composite parent) {
	initializeDialogUnits(parent);

	Composite comp = new Composite(parent, SWT.NONE);

	themingEnabled = createCheckButton(comp, WorkbenchMessages.ThemingEnabled, engine != null);

	// if started with "-cssTheme none", CSS settings should be disabled
	// but other appearance settings should be not disabled
	if (engine == null) {
	GridLayout layout = new GridLayout(1, false);
	layout.horizontalSpacing = 10;
	comp.setLayout(layout);
	createThemeIndependentComposits(comp);
	return comp;
	}

	GridLayout layout = new GridLayout(2, false);
	layout.horizontalSpacing = 10;
	comp.setLayout(layout);

	new Label(comp, SWT.NONE).setText(WorkbenchMessages.ViewsPreferencePage_Theme);
	highContrastMode = parent.getDisplay().getHighContrast();

	themeIdCombo = new ComboViewer(comp, SWT.READ_ONLY);
	themeIdCombo.setLabelProvider(createTextProvider(element -> ((ITheme) element).getLabel()));
	themeIdCombo.setContentProvider(ArrayContentProvider.getInstance());
	themeIdCombo.setInput(getCSSThemes(highContrastMode));
	themeIdCombo.getCombo().setEnabled(!highContrastMode);
	themeIdCombo.getControl().setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
	this.currentTheme = engine.getActiveTheme();
	if (this.currentTheme != null) {
	themeIdCombo.setSelection(new StructuredSelection(currentTheme));
	}
	themeComboDecorator = new ControlDecoration(themeIdCombo.getCombo(), SWT.TOP \| SWT.LEFT);
	themeIdCombo.addSelectionChangedListener(event -> {
	ITheme selection = getSelectedTheme();
	if (!selection.equals(currentTheme)) {
	themeComboDecorator.setDescriptionText(WorkbenchMessages.ThemeChangeWarningText);
	Image decorationImage = FieldDecorationRegistry.getDefault()
	.getFieldDecoration(FieldDecorationRegistry.DEC_WARNING).getImage();
	themeComboDecorator.setImage(decorationImage);
	themeComboDecorator.show();
	} else {
	themeComboDecorator.hide();
	}
	selectColorsAndFontsTheme(getColorAndFontThemeIdByThemeId(selection.getId()));
	});

	currentColorsAndFontsTheme = getCurrentColorsAndFontsTheme();
	createColorsAndFontsThemeCombo(comp);

	createThemeIndependentComposits(comp);

	if (currentTheme != null) {
	String colorsAndFontsThemeId = getColorAndFontThemeIdByThemeId(currentTheme.getId());
	if (colorsAndFontsThemeId != null && !currentColorsAndFontsTheme.getId().equals(colorsAndFontsThemeId)) {
	colorsAndFontsThemeId = currentColorsAndFontsTheme.getId();
	}
	selectColorsAndFontsTheme(colorsAndFontsThemeId);
	}

	Dialog.applyDialogFont(comp);
	return comp;
	}

	private void createThemeIndependentComposits(Composite comp) {
	createUseRoundTabs(comp);
	createColoredLabelsPref(comp);
	createEnableMruPref(comp);
	}

	private List<ITheme> getCSSThemes(boolean highContrastMode) {
	ArrayList<ITheme> themes = new ArrayList<>();
	for (ITheme theme : engine.getThemes()) {
	/*
	* When we have Win32 OS - when the high contrast mode is enabled on the
	* platform, we display the 'high-contrast' special theme only. If not, we don't
	* want to mess the themes combo with the theme since it is the special
	* variation of the 'classic' one
	*
	* When we have GTK - we have to display the entire list of the themes since we
	* are not able to figure out if the high contrast mode is enabled on the
	* platform. The user has to manually select the theme if they need it
	*/
	if (!highContrastMode && !Util.isGtk() && theme.getId().equals(E4Application.HIGH_CONTRAST_THEME_ID)) {
	continue;
	}
	themes.add(theme);
	}
	themes.sort((ITheme t1, ITheme t2) -> t1.getLabel().compareTo(t2.getLabel()));
	return themes;
	}

	private void createColoredLabelsPref(Composite composite) {
	IPreferenceStore apiStore = PrefUtil.getAPIPreferenceStore();

	useColoredLabels = createCheckButton(composite, WorkbenchMessages.ViewsPreference_useColoredLabels,
	apiStore.getBoolean(IWorkbenchPreferenceConstants.USE_COLORED_LABELS));
	}

	private Button createCheckButton(Composite composite, String text, boolean selection) {
	Button button = new Button(composite, SWT.CHECK);
	GridData data = new GridData(SWT.BEGINNING, SWT.CENTER, false, false, 2, 1);
	button.setLayoutData(data);
	button.setText(text);
	button.setSelection(selection);
	return button;
	}

	private Label createLabel(Composite composite, String text) {
	Label label = new Label(composite, SWT.NONE);
	GridData data = new GridData(SWT.BEGINNING, SWT.CENTER, false, false, 2, 1);
	label.setLayoutData(data);
	label.setText(text);
	return label;
	}

	protected void createUseRoundTabs(Composite composite) {
	IEclipsePreferences prefs = getSwtRendererPreferences();
	boolean enabled = prefs.getBoolean(CTabRendering.USE_ROUND_TABS, CTabRendering.USE_ROUND_TABS_DEFAULT);
	useRoundTabs = createCheckButton(composite, WorkbenchMessages.ViewsPreference_useRoundTabs, enabled);
	}

	protected void createEnableMruPref(Composite composite) {
	createLabel(composite, ""); //$NON-NLS-1$
	createLabel(composite, WorkbenchMessages.ViewsPreference_visibleTabs_description);
	IEclipsePreferences prefs = getSwtRendererPreferences();
	boolean defaultValue = getDefaultMRUValue();
	boolean actualValue = prefs.getBoolean(StackRenderer.MRU_KEY, defaultValue);
	enableMru = createCheckButton(composite, WorkbenchMessages.ViewsPreference_enableMRU, actualValue);
	}


	/** @return the currently selected theme or null if there are no themes */
	private ITheme getSelectedTheme() {
	return (ITheme) (themeIdCombo.getStructuredSelection().getFirstElement());
	}

	@Override
	public void init(IWorkbench workbench) {
	MApplication application = workbench.getService(MApplication.class);
	IEclipseContext context = application.getContext();
	defaultTheme = (String) context.get(E4Application.THEME_ID);
	engine = context.get(IThemeEngine.class);
	}

	@Override
	public boolean performOk() {
	if (engine != null) {
	ITheme theme = getSelectedTheme();
	if (theme != null) {
	engine.setTheme(getSelectedTheme(), !highContrastMode);
	}
	}

	IPreferenceStore apiStore = PrefUtil.getAPIPreferenceStore();
	apiStore.setValue(IWorkbenchPreferenceConstants.USE_COLORED_LABELS, useColoredLabels.getSelection());

	IEclipsePreferences prefs = getSwtRendererPreferences();
	prefs.putBoolean(StackRenderer.MRU_KEY, enableMru.getSelection());
	boolean themingEnabledChanged = prefs.getBoolean(PartRenderingEngine.ENABLED_THEME_KEY, true) != themingEnabled
	.getSelection();
	prefs.putBoolean(PartRenderingEngine.ENABLED_THEME_KEY, themingEnabled.getSelection());

	prefs.putBoolean(CTabRendering.USE_ROUND_TABS, useRoundTabs.getSelection());
	try {
	prefs.flush();
	} catch (BackingStoreException e) {
	WorkbenchPlugin.log("Failed to set SWT renderer preferences", e); //$NON-NLS-1$
	}

	if (engine != null) {
	ITheme theme = getSelectedTheme();
	boolean themeChanged = theme != null && !theme.equals(currentTheme);
	boolean colorsAndFontsThemeChanged = !PlatformUI.getWorkbench().getThemeManager().getCurrentTheme().getId()
	.equals(currentColorsAndFontsTheme.getId());

	if (theme != null) {
	currentTheme = theme;
	}

	ColorsAndFontsTheme colorsAndFontsTheme = getSelectedColorsAndFontsTheme();
	if (colorsAndFontsTheme != null) {
	currentColorsAndFontsTheme = colorsAndFontsTheme;
	}

	themeComboDecorator.hide();
	colorFontsDecorator.hide();

	if (themeChanged \|\| colorsAndFontsThemeChanged) {
	if (notificationPopUp == null) {
	notificationPopUp = new NotificationPopUp(getShell().getDisplay());
	notificationPopUp.open();
	}
	}
	} else if (themingEnabledChanged) {
	if (notificationPopUp == null) {
	notificationPopUp = new NotificationPopUp(getShell().getDisplay());
	notificationPopUp.open();
	}
	}

	return super.performOk();
	}

	private IEclipsePreferences getSwtRendererPreferences() {
	return InstanceScope.INSTANCE.getNode("org.eclipse.e4.ui.workbench.renderers.swt"); //$NON-NLS-1$
	}

	private boolean getDefaultMRUValue() {
	return getSwtRendererPreferences().getBoolean(StackRenderer.MRU_KEY_DEFAULT, StackRenderer.MRU_DEFAULT);
	}

	private void setColorsAndFontsTheme(ColorsAndFontsTheme theme) {
	org.eclipse.ui.themes.ITheme currentTheme = PlatformUI.getWorkbench().getThemeManager().getCurrentTheme();
	if (theme != null && !currentTheme.getId().equals(theme.getId())) {
	PlatformUI.getWorkbench().getThemeManager().setCurrentTheme(theme.getId());
	}
	}

	@Override
	protected void performDefaults() {
	if (engine != null) {
	setColorsAndFontsTheme(currentColorsAndFontsTheme);

	engine.setTheme(defaultTheme, true);
	if (engine.getActiveTheme() != null) {
	themeIdCombo.setSelection(new StructuredSelection(engine.getActiveTheme()));
	}
	}
	IPreferenceStore apiStore = PrefUtil.getAPIPreferenceStore();
	useColoredLabels.setSelection(apiStore.getDefaultBoolean(IWorkbenchPreferenceConstants.USE_COLORED_LABELS));

	useRoundTabs.setSelection(CTabRendering.USE_ROUND_TABS_DEFAULT);
	enableMru.setSelection(getDefaultMRUValue());
	super.performDefaults();
	}

	@Override
	public boolean performCancel() {
	if (engine != null) {
	setColorsAndFontsTheme(currentColorsAndFontsTheme);

	if (currentTheme != null) {
	engine.setTheme(currentTheme, false);
	}
	}

	return super.performCancel();
	}

	private void createColorsAndFontsThemeCombo(Composite composite) {
	new Label(composite, SWT.NONE).setText(WorkbenchMessages.ViewsPreference_currentTheme);
	colorsAndFontsThemeCombo = new ComboViewer(composite, SWT.READ_ONLY);
	colorsAndFontsThemeCombo.getControl().setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false));
	colorsAndFontsThemeCombo.setLabelProvider(new LabelProvider() {
	@Override
	public String getText(Object element) {
	return ((ColorsAndFontsTheme) element).getLabel();
	}
	});
	colorFontsDecorator = new ControlDecoration(colorsAndFontsThemeCombo.getCombo(), SWT.TOP \| SWT.LEFT);
	colorsAndFontsThemeCombo.setContentProvider(ArrayContentProvider.getInstance());
	colorsAndFontsThemeCombo.setInput(getColorsAndFontsThemes());
	colorsAndFontsThemeCombo.getControl().setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
	colorsAndFontsThemeCombo.addSelectionChangedListener(event -> {
	ColorsAndFontsTheme colorsAndFontsTheme = getSelectedColorsAndFontsTheme();
	if (!colorsAndFontsTheme.equals(currentColorsAndFontsTheme)) {
	Image decorationImage = FieldDecorationRegistry.getDefault()
	.getFieldDecoration(FieldDecorationRegistry.DEC_WARNING).getImage();
	colorFontsDecorator.setImage(decorationImage);
	colorFontsDecorator.setDescriptionText(WorkbenchMessages.ThemeChangeWarningText);
	colorFontsDecorator.show();
	} else
	colorFontsDecorator.hide();
	setColorsAndFontsTheme(colorsAndFontsTheme);
	});
	}

	@SuppressWarnings("unchecked")
	private void selectColorsAndFontsTheme(String colorAndFontThemeId) {
	if (colorAndFontThemeId == null) {
	colorAndFontThemeId = currentColorsAndFontsTheme.getId();
	}

	for (ColorsAndFontsTheme theme : (List<ColorsAndFontsTheme>) colorsAndFontsThemeCombo.getInput()) {
	if (theme.getId().equals(colorAndFontThemeId)) {
	ISelection selection = new StructuredSelection(theme);
	colorsAndFontsThemeCombo.setSelection(selection);
	break;
	}
	}
	}

	private String getColorAndFontThemeIdByThemeId(String themeId) {
	if (themeAssociations == null) {
	themeAssociations = createThemeAssociations();
	}

	// first get by exact matching (together with os_version)
	String result = themeAssociations.get(themeId);

	if (result == null) {
	for (Map.Entry<String, String> entry : themeAssociations.entrySet()) {
	if (themeId.startsWith(entry.getKey())) {
	return entry.getValue();
	}
	}
	}

	return result;
	}

	private Map<String, String> createThemeAssociations() {
	Map<String, String> result = new HashMap<>();
	IExtensionRegistry registry = RegistryFactory.getRegistry();
	IExtensionPoint extPoint = registry.getExtensionPoint(E4_THEME_EXTENSION_POINT);

	for (IExtension e : extPoint.getExtensions()) {
	for (IConfigurationElement ce : e.getConfigurationElements()) {
	if (ce.getName().equals(ATT_THEME_ASSOCIATION)) {
	String themeId = ce.getAttribute(ATT_THEME_ID);
	String osVersion = ce.getAttribute(ATT_OS_VERSION);
	result.put(osVersion != null ? themeId + osVersion : themeId,
	ce.getAttribute(ATT_COLOR_AND_FONT_ID));
	}
	}
	}
	return result;
	}

	private List<ColorsAndFontsTheme> getColorsAndFontsThemes() {
	List<ColorsAndFontsTheme> result = new ArrayList<>();
	org.eclipse.ui.themes.ITheme currentTheme = PlatformUI.getWorkbench().getThemeManager().getCurrentTheme();

	IThemeDescriptor[] descs = WorkbenchPlugin.getDefault().getThemeRegistry().getThemes();
	String defaultThemeString = PlatformUI.getWorkbench().getThemeManager().getTheme(IThemeManager.DEFAULT_THEME)
	.getLabel();
	if (currentTheme.getId().equals(IThemeManager.DEFAULT_THEME)) {
	defaultThemeString = NLS.bind(WorkbenchMessages.ViewsPreference_currentThemeFormat,
	new Object[] { defaultThemeString });
	}
	result.add(new ColorsAndFontsTheme(IThemeManager.DEFAULT_THEME, defaultThemeString));

	String themeString;
	for (IThemeDescriptor themeDescriptor : descs) {
	themeString = themeDescriptor.getName();
	if (themeDescriptor.getId().equals(currentTheme.getId())) {
	themeString = NLS.bind(WorkbenchMessages.ViewsPreference_currentThemeFormat,
	new Object[] { themeString });
	}
	result.add(new ColorsAndFontsTheme(themeDescriptor.getId(), themeString));
	}
	return result;
	}

	private ColorsAndFontsTheme getSelectedColorsAndFontsTheme() {
	return (ColorsAndFontsTheme) colorsAndFontsThemeCombo.getStructuredSelection().getFirstElement();
	}

	private ColorsAndFontsTheme getCurrentColorsAndFontsTheme() {
	org.eclipse.ui.themes.ITheme theme = PlatformUI.getWorkbench().getThemeManager().getCurrentTheme();

	return new ColorsAndFontsTheme(theme.getId(), theme.getLabel());
	}

	private static class ColorsAndFontsTheme {
	private String label;
	private String id;

	public ColorsAndFontsTheme(String id, String label) {
	this.id = id;
	this.label = label;
	}

	public String getId() {
	return id;
	}

	public String getLabel() {
	return label;
	}

	@Override
	public int hashCode() {
	return Objects.hashCode(id);
	}

	@Override
	public boolean equals(Object obj) {
	if (this == obj)
	return true;
	if (obj == null)
	return false;
	if (getClass() != obj.getClass())
	return false;
	ColorsAndFontsTheme other = (ColorsAndFontsTheme) obj;
	return Objects.equals(id, other.id);
	}

	}

	private class NotificationPopUp extends AbstractNotificationPopup {

	public NotificationPopUp(Display display) {
	super(display);
	setDelayClose(0);
	setParentShell(PlatformUI.getWorkbench().getActiveWorkbenchWindow().getShell());
	}

	@Override
	protected String getPopupShellTitle() {
	return WorkbenchMessages.ThemeChangeWarningTitle;
	}


	@Override
	protected void createContentArea(Composite parent) {
	parent.setLayout(new RowLayout());

	Link link = new Link(parent, SWT.WRAP);
	link.setText(WorkbenchMessages.ThemeChangeWarningText);
	link.addSelectionListener(widgetSelectedAdapter(e -> PlatformUI.getWorkbench().restart(true)));
	}
	}

	}