r/org.eclipse.statet.r.ui/src/org/eclipse/statet/internal/r/ui/rhelp/RHelpInfoHoverCreator.java - statet/org.eclipse.statet-r - Git at Google

 /*=============================================================================#
  # Copyright (c) 2010, 2019 Stephan Wahlbrink and others.
  #
  # This program and the accompanying materials are made available under the
  # terms of the Eclipse Public License 2.0 which is available at
  # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
  # which is available at https://www.apache.org/licenses/LICENSE-2.0.
  #
  # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
  #
  # Contributors:
  #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
  #=============================================================================*/

 package org.eclipse.statet.internal.r.ui.rhelp;

 import static org.eclipse.debug.ui.IDebugUIConstants.PREF_DETAIL_PANE_FONT;
 import static org.eclipse.statet.ltk.ui.sourceediting.assist.InfoHover.MODE_FOCUS;

 import java.net.URI;
 import java.net.URISyntaxException;

 import org.eclipse.core.commands.ExecutionException;
 import org.eclipse.core.commands.IHandler2;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.jface.action.Separator;
 import org.eclipse.jface.action.ToolBarManager;
 import org.eclipse.jface.internal.text.html.BrowserInformationControl;
 import org.eclipse.jface.resource.JFaceResources;
 import org.eclipse.jface.text.AbstractInformationControl;
 import org.eclipse.jface.text.AbstractReusableInformationControlCreator;
 import org.eclipse.jface.text.IInformationControl;
 import org.eclipse.jface.text.IInformationControlCreator;
 import org.eclipse.jface.text.IInformationControlExtension2;
 import org.eclipse.jface.util.IPropertyChangeListener;
 import org.eclipse.jface.util.PropertyChangeEvent;
 import org.eclipse.jface.viewers.StyledString;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.browser.Browser;
 import org.eclipse.swt.browser.LocationEvent;
 import org.eclipse.swt.browser.LocationListener;
 import org.eclipse.swt.browser.OpenWindowListener;
 import org.eclipse.swt.browser.ProgressEvent;
 import org.eclipse.swt.browser.ProgressListener;
 import org.eclipse.swt.browser.TitleEvent;
 import org.eclipse.swt.browser.TitleListener;
 import org.eclipse.swt.browser.WindowEvent;
 import org.eclipse.swt.custom.StyledText;
 import org.eclipse.swt.events.KeyEvent;
 import org.eclipse.swt.events.KeyListener;
 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.FontMetrics;
 import org.eclipse.swt.graphics.GC;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.layout.GridLayout;
 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.Menu;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.swt.widgets.Text;
 import org.eclipse.ui.IWorkbenchCommandConstants;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.menus.CommandContributionItemParameter;
 import org.eclipse.ui.services.IServiceLocator;

 import org.eclipse.statet.ecommons.ui.SharedUIResources;
 import org.eclipse.statet.ecommons.ui.actions.HandlerCollection;
 import org.eclipse.statet.ecommons.ui.actions.HandlerContributionItem;
 import org.eclipse.statet.ecommons.ui.actions.SimpleContributionItem;
 import org.eclipse.statet.ecommons.ui.mpbv.BrowserHandler.IBrowserProvider;
 import org.eclipse.statet.ecommons.ui.mpbv.BrowserHandler.NavigateBackHandler;
 import org.eclipse.statet.ecommons.ui.mpbv.BrowserHandler.NavigateForwardHandler;
 import org.eclipse.statet.ecommons.ui.util.InformationDispatchHandler;
 import org.eclipse.statet.ecommons.ui.util.LayoutUtils;
 import org.eclipse.statet.ecommons.ui.util.PixelConverter;
 import org.eclipse.statet.ecommons.ui.util.UIAccess;

 import org.eclipse.statet.r.core.RCore;
 import org.eclipse.statet.r.ui.RUI;
 import org.eclipse.statet.rhelp.core.http.RHelpHttpService;


 public class RHelpInfoHoverCreator extends AbstractReusableInformationControlCreator {


 	public static final boolean isAvailable(final Composite parent) {
 		return BrowserInformationControl.isAvailable(parent);
 	}


 	public static class Data {

 		private final Control control;

 		final Object helpObject;
 		final URI httpUrl;

 		public Data(final Control control, final Object helpObject, final URI httpUrl) {
 			this.control= control;
 			this.helpObject= helpObject;
 			this.httpUrl= httpUrl;
 		}


 		public Control getControl() {
 			return this.control;
 		}

 	}


 	private final int mode;


 	public RHelpInfoHoverCreator(final int mode) {
 		this.mode= mode;
 	}


 	@Override
 	protected IInformationControl doCreateInformationControl(final Shell parent) {
 		return ((this.mode & MODE_FOCUS) != 0) ?
 				new RHelpInfoControl(parent, this.mode, true) :
 				new RHelpInfoControl(parent, this.mode);
 	}

 }

 class RHelpInfoControl extends AbstractInformationControl implements IInformationControlExtension2,
 		IPropertyChangeListener, OpenWindowListener, LocationListener, ProgressListener, TitleListener,
 		IBrowserProvider {


 	/** Action id (command) to navigate one page back. */
 	protected static final String NAVIGATE_BACK_COMMAND_ID= IWorkbenchCommandConstants.NAVIGATE_BACK;
 	/** Action id (command) to navigate one page forward. */
 	protected static final String NAVIGATE_FORWARD_COMMAND_ID= IWorkbenchCommandConstants.NAVIGATE_FORWARD;


 	/**
 	 * Cached scroll bar width and height
 	 */
 	private static Point gScrollBarSize;


 	private final int mode;

 	private RHelpLabelProvider labelProvider;

 	private Composite contentComposite;
 	private Label titleImage;
 	private StyledText titleText;
 	private Browser infoBrowser;

 	private final HandlerCollection handlerCollection= new HandlerCollection();

 	private boolean layoutWorkaround;
 	private boolean layoutHint;

 	private RHelpInfoHoverCreator.Data input;
 	private boolean inputChanged;

 	private boolean loadingCompleted;
 	private String browserTitle;

 	private boolean hide;


 	RHelpInfoControl(final Shell shell, final int mode) {
 		super(shell, ""); //$NON-NLS-1$
 		assert ((mode & MODE_FOCUS) == 0);
 		this.mode= mode;

 		JFaceResources.getFontRegistry().addListener(this);
 		create();
 	}

 	RHelpInfoControl(final Shell shell, final int mode, final boolean dummy) {
 		super(shell, new ToolBarManager(SWT.FLAT));
 		assert ((mode & MODE_FOCUS) != 0);
 		this.mode= mode;

 		create();
 	}


 	@Override
 	public void setInput(final Object input) {
 		this.inputChanged= true;
 		if (input instanceof RHelpInfoHoverCreator.Data) {
 			this.input= (RHelpInfoHoverCreator.Data) input;
 		}
 		else {
 			this.input= null;
 		}
 	}

 	@Override
 	public boolean hasContents() {
 		return (this.input != null);
 	}

 	@Override
 	protected void createContent(final Composite parent) {
 		this.contentComposite= new Composite(parent, SWT.NONE) {
 			@Override
 			public Point computeSize(final int width, final int height, final boolean changed) {
 				return super.computeSize(width, height, changed || width != getSize().x);
 			}
 		};
 		this.contentComposite.setBackgroundMode(SWT.INHERIT_FORCE);

 		final GridLayout gridLayout= LayoutUtils.newCompositeGrid(2);
 		gridLayout.horizontalSpacing= (int) ((gridLayout.horizontalSpacing) / 1.5);
 		this.contentComposite.setLayout(gridLayout);

 		final int vIndent= Math.max(1, LayoutUtils.defaultVSpacing() / 4);
 		final int hIndent= Math.max(3, LayoutUtils.defaultHSpacing() / 3);

 		{	// Title image
 			this.titleImage= new Label(this.contentComposite, SWT.NULL);
 			final Image image= SharedUIResources.getImages().get(SharedUIResources.PLACEHOLDER_IMAGE_ID);
 			this.titleImage.setImage(image);

 			final GridData textGd= new GridData(SWT.FILL, SWT.TOP, false, false);
 			this.titleText= new StyledText(this.contentComposite, SWT.MULTI | SWT.READ_ONLY | SWT.WRAP) {
 				@Override
 				public Point computeSize(int width, final int height, final boolean changed) {
 					if (!RHelpInfoControl.this.layoutHint && width <= 0 && RHelpInfoControl.this.contentComposite.getSize().x > 0) {
 						width= RHelpInfoControl.this.contentComposite.getSize().x -
 								LayoutUtils.defaultHMargin() - RHelpInfoControl.this.titleImage.getSize().x - LayoutUtils.defaultHSpacing() - 10;
 					}

 					final Point size= super.computeSize(width, -1, true);
 //					if (width >= 0) {
 //						size.x= Math.min(size.x, width);
 //					}
 					return size;
 				}
 			};

 			this.titleText.setFont(JFaceResources.getDialogFont());
 			final GC gc= new GC(this.titleText);
 			final FontMetrics fontMetrics= gc.getFontMetrics();
 			final GridData imageGd= new GridData(SWT.FILL, SWT.TOP, false, false);
 			imageGd.horizontalIndent= hIndent - 2;
 			final int textHeight= fontMetrics.getAscent() + fontMetrics.getLeading();
 			final int imageHeight= image.getBounds().height;
 			final int shift= Math.max(3, (int) ((fontMetrics.getDescent()) / 1.5));
 			if (textHeight+shift < imageHeight) {
 				imageGd.verticalIndent= vIndent+shift;
 				textGd.verticalIndent= vIndent+(imageHeight-textHeight);
 			}
 			else {
 				imageGd.verticalIndent= vIndent+(textHeight-imageHeight)+shift;
 				textGd.verticalIndent= vIndent;
 			}
 			this.titleImage.setLayoutData(imageGd);
 			this.titleText.setLayoutData(textGd);
 			this.layoutWorkaround= true;

 			gc.dispose();
 		}

 		this.infoBrowser= new Browser(this.contentComposite, SWT.NONE);

 		this.infoBrowser.addOpenWindowListener(this);
 		this.infoBrowser.addLocationListener(this);
 		this.infoBrowser.addProgressListener(this);
 		this.infoBrowser.addTitleListener(this);

 		this.infoBrowser.addOpenWindowListener(new OpenWindowListener() {
 			@Override
 			public void open(final WindowEvent event) {
 				event.required= true;
 			}
 		});
 		// Disable context menu
 		this.infoBrowser.setMenu(new Menu(getShell(), SWT.NONE));

 		final GridData gd= new GridData(SWT.FILL, SWT.FILL, true, true, 2, 1);
 //		gd.widthHint= LayoutUtils.hintWidth(fInfoText, INFO_FONT, 50);
 		this.infoBrowser.setLayoutData(gd);

 		this.infoBrowser.addKeyListener(new KeyListener() {
 			@Override
 			public void keyPressed(final KeyEvent e)  {
 				if (e.character == SWT.ESC) {
 					dispose();
 				}
 			}
 			@Override
 			public void keyReleased(final KeyEvent e) {}
 		});

 		setBackgroundColor(getShell().getDisplay().getSystemColor(SWT.COLOR_INFO_BACKGROUND));
 		setForegroundColor(getShell().getDisplay().getSystemColor(SWT.COLOR_INFO_FOREGROUND));

 		if ((this.mode & MODE_FOCUS) != 0) {
 			initActions(this.handlerCollection);
 			final ToolBarManager toolBarManager= getToolBarManager();
 			contributeToActionBars(PlatformUI.getWorkbench(), toolBarManager, this.handlerCollection);
 			toolBarManager.update(true);
 		}

 		updateInput();
 	}

 	protected void initActions(final HandlerCollection handlers) {
 		{	final IHandler2 handler= new NavigateBackHandler(this);
 			handlers.add(NAVIGATE_BACK_COMMAND_ID, handler);
 //			handlerService.activateHandler(NAVIGATE_BACK_COMMAND_ID, handler);
 //			handlerService.activateHandler(IWorkbenchCommandConstants.NAVIGATE_BACKWARD_HISTORY, handler);
 		}
 		{	final IHandler2 handler= new NavigateForwardHandler(this);
 			handlers.add(NAVIGATE_FORWARD_COMMAND_ID, handler);
 //			handlerService.activateHandler(NAVIGATE_FORWARD_COMMAND_ID, handler);
 //			handlerService.activateHandler(IWorkbenchCommandConstants.NAVIGATE_FORWARD_HISTORY, handler);
 		}
 	}

 	protected void contributeToActionBars(final IServiceLocator serviceLocator,
 			final ToolBarManager toolBarManager, final HandlerCollection handlers) {
 		toolBarManager.add(
 				new HandlerContributionItem(new CommandContributionItemParameter(
 						serviceLocator, null, NAVIGATE_BACK_COMMAND_ID, HandlerContributionItem.STYLE_PUSH),
 						handlers.get(NAVIGATE_BACK_COMMAND_ID) ));
 		toolBarManager.add(
 				new HandlerContributionItem(new CommandContributionItemParameter(
 						serviceLocator, null, NAVIGATE_FORWARD_COMMAND_ID, HandlerContributionItem.STYLE_PUSH),
 						handlers.get(NAVIGATE_FORWARD_COMMAND_ID) ));

 		toolBarManager.add(new Separator());
 		toolBarManager.add(new SimpleContributionItem(
 				"Show in R Help View", "V",
 				RUI.getImageDescriptor(RUI.IMG_OBJ_R_HELP_SEARCH), null ) {
 			@Override
 			protected void execute() throws ExecutionException {
 				if (UIAccess.isOkToUse(RHelpInfoControl.this.infoBrowser)) {
 					try {
 						final String urlString= RHelpInfoControl.this.infoBrowser.getUrl();
 						final IWorkbenchPage page= UIAccess.getActiveWorkbenchPage(true);
 						final RHelpView view= (RHelpView) page.showView(RUI.R_HELP_VIEW_ID);
 						final URI browseUrl= RCore.getRHelpHttpService().toHttpUrl(urlString,
 								null, RHelpHttpService.BROWSE_TARGET );
 						if (browseUrl != null) {
 							view.openUrl(browseUrl, null);
 						}
 						else {
 							view.openUrl(urlString, null);
 						}
 					}
 					catch (final Exception e) {}
 				}
 			}
 		});
 	}


 	@Override
 	public Browser getBrowser() {
 		return this.infoBrowser;
 	}

 	@Override
 	public void showMessage(final IStatus status) {
 	}

 	@Override
 	public void changing(final LocationEvent event) {
 		if (event.location.startsWith("http://")) { //$NON-NLS-1$
 			try {
 				if (RCore.getRHelpHttpService().isDynamicUrl(new URI(event.location))) {
 					return;
 				}
 			}
 			catch (final Exception e) {}
 		}
 		if (event.location.equals("about:blank")) { //$NON-NLS-1$
 			return;
 		}
 		event.doit= false;
 	}

 	@Override
 	public void changed(final LocationEvent event) {
 		if (!event.top) {
 			return;
 		}
 		final String url= this.infoBrowser.getUrl();
 		final Object obj= RCore.getRHelpHttpService().getContentOfUrl(url);
 		updateTitle(obj, this.browserTitle);
 	}

 	@Override
 	public void changed(final ProgressEvent event) {
 		this.handlerCollection.update(null);
 	}

 	@Override
 	public void completed(final ProgressEvent event) {
 		this.loadingCompleted= true;
 		this.handlerCollection.update(null);
 	}

 	@Override
 	public void changed(final TitleEvent event) {
 		String title= event.title;
 		if (title == null) {
 			title= ""; //$NON-NLS-1$
 		}
 		else if (title.startsWith("http://")) { //$NON-NLS-1$
 			final int idx= title.lastIndexOf('/');
 			if (idx >= 0) {
 				title= title.substring(idx+1);
 			}
 		}
 		this.browserTitle= title;
 	}

 	@Override
 	public void open(final WindowEvent event) {
 		event.required= true;
 	}


 	@Override
 	public void setBackgroundColor(final Color background) {
 		super.setBackgroundColor(background);
 		this.contentComposite.setBackground(background);
 		this.infoBrowser.setBackground(background);
 	}

 	@Override
 	public void setForegroundColor(final Color foreground) {
 		super.setForegroundColor(foreground);
 		this.contentComposite.setForeground(foreground);
 		this.titleText.setForeground(foreground);
 		this.infoBrowser.setForeground(foreground);
 	}

 	@Override
 	public void setSize(final int width, final int height) {
 		this.infoBrowser.setRedraw(false); // avoid flickering
 		try {
 			super.setSize(width, height);
 		}
 		finally {
 			this.infoBrowser.setRedraw(true);
 		}
 	}


 	@Override
 	public Rectangle computeTrim() {
 		final Rectangle trim= super.computeTrim();

 		final Rectangle textTrim= this.infoBrowser.computeTrim(0, 0, 0, 0);
 		if ((this.mode & MODE_FOCUS) != 0 && textTrim.width == 0) {
 			if (gScrollBarSize == null) {
 				final Text text= new Text(this.contentComposite, SWT.MULTI | SWT.V_SCROLL | SWT.H_SCROLL | SWT.BORDER);
 				gScrollBarSize= new Point(
 						text.getVerticalBar().getSize().x,
 						text.getHorizontalBar().getSize().y);
 				text.dispose();
 			}
 			textTrim.x= 0;
 			textTrim.y= 0;
 			textTrim.width= gScrollBarSize.x;
 			textTrim.height= gScrollBarSize.y;
 		}
 		trim.x+= textTrim.x;
 		trim.y+= textTrim.y;
 		trim.width+= textTrim.width;
 		trim.height+= textTrim.height;

 		return trim;
 	}

 	@Override
 	public Point computeSizeHint() {
 		updateInput();
 		final Point sizeConstraints= getSizeConstraints();
 		final Rectangle trim= computeTrim();

 		this.titleText.setFont(JFaceResources.getDialogFont());
 		final PixelConverter converter= new PixelConverter(this.titleText);
 		int widthHint= converter.convertWidthInCharsToPixels(60);
 		final GC gc= new GC(this.contentComposite);
 		gc.setFont(JFaceResources.getTextFont());
 		widthHint= Math.max(widthHint, gc.getFontMetrics().getAverageCharWidth() * 60);
 		gc.dispose();

 		final int heightHint= this.titleText.getLineHeight() * 12;

 		final int widthMax= ((sizeConstraints != null && sizeConstraints.x != SWT.DEFAULT) ?
 				sizeConstraints.x : widthHint+100) - trim.width;
 		final int heightMax= ((sizeConstraints != null && sizeConstraints.y != SWT.DEFAULT) ?
 				sizeConstraints.y : this.titleText.getLineHeight()*12) - trim.height;

 		final Point size= new Point(widthHint, heightHint);
 		size.y+= LayoutUtils.defaultVSpacing();
 		size.x= Math.max(Math.min(size.x, widthMax), 200) + trim.width;
 		size.y= Math.max(Math.min(size.y, heightMax), 100) + trim.height;
 		return size;
 	}

 	@Override
 	public Point computeSizeConstraints(final int widthInChars, final int heightInChars) {
 		final int width= LayoutUtils.hintWidth(this.titleText, JFaceResources.DIALOG_FONT, widthInChars);
 		final int lineHeight= this.titleText.getLineHeight();

 		return new Point(width, lineHeight * heightInChars + LayoutUtils.defaultVSpacing());
 	}

 	@Override
 	public void setVisible(final boolean visible) {
 		if (visible) {
 			this.hide= false;
 			updateInput();
 			waitCompleted();
 			if (this.hide || !UIAccess.isOkToUse(getShell())) {
 				return;
 			}

 			if (this.layoutWorkaround) {
 				this.contentComposite.layout(true, true);
 				this.layoutWorkaround= false;
 			}

 			if (Platform.WS_WIN32.equals(SWT.getPlatform())) {
 				getShell().moveAbove(null);
 			}
 		}
 		else {
 			this.hide= true;
 		}
 		super.setVisible(visible);
 	}

 	private void waitCompleted() {
 		final Display display= Display.getCurrent();
 		display.timerExec(200, new Runnable() {
 			@Override
 			public void run() {
 				RHelpInfoControl.this.loadingCompleted= true;
 			}
 		});
 		while (!this.loadingCompleted) {
 			// Drive the event loop to process the events required to load the browser widget's contents:
 			if (!display.readAndDispatch()) {
 				display.sleep();
 			}
 		}
 	}

 	@Override
 	public void setFocus() {
 		this.infoBrowser.setFocus();
 	}

 	private void updateInput() {
 		if (this.infoBrowser == null || !this.inputChanged) {
 			return;
 		}
 		if (this.labelProvider == null) {
 			this.labelProvider= new RHelpLabelProvider(RHelpLabelProvider.WITH_TITLE | RHelpLabelProvider.WITH_QUALIFIER | RHelpLabelProvider.HEADER);
 		}
 		this.loadingCompleted= false;
 		this.inputChanged= false;
 		this.browserTitle= null;
 		updateTitle(this.input.helpObject, null);
 		if (this.input != null && this.input.httpUrl != null) {
 			URI url= this.input.httpUrl;
 			if ((this.mode & MODE_FOCUS) == 0) { // disable scrollbars
 				try {
 					url= new URI(url.toString() +
 							'?' + RHelpUIServlet.STYLE_PARAM + '=' + RHelpUIServlet.HOVER_STYLE );
 				}
 				catch (final URISyntaxException e) {}
 			}
 			this.infoBrowser.setUrl(url.toString());
 		}
 		else {
 			this.infoBrowser.setUrl("about:blank"); //$NON-NLS-1$
 		}
 		if ((this.mode & MODE_FOCUS) == 0) {
 			setStatusText((this.input.getControl() != null
 							&& this.input.getControl().isFocusControl() ) ?
 					InformationDispatchHandler.getAffordanceString(this.mode) : "" ); //$NON-NLS-1$
 		}
 	}

 	private void updateTitle(final Object helpObject, final String alt) {
 		if (helpObject != null) {
 			final Image image= this.labelProvider.getImage(helpObject);
 			this.titleImage.setImage((image != null) ? image : SharedUIResources.getImages().get(SharedUIResources.PLACEHOLDER_IMAGE_ID));
 			final StyledString styleString= this.labelProvider.getStyledText(helpObject);
 			this.titleText.setText(styleString.getString());
 			this.titleText.setStyleRanges(styleString.getStyleRanges());
 		}
 		else {
 			this.titleImage.setImage(SharedUIResources.getImages().get(SharedUIResources.PLACEHOLDER_IMAGE_ID));
 			this.titleText.setText((alt != null) ? alt : ""); //$NON-NLS-1$
 		}
 	}


 	@Override
 	public IInformationControlCreator getInformationPresenterControlCreator() {
 		// enriched mode
 		return new RHelpInfoHoverCreator(this.mode | MODE_FOCUS);
 	}

 	@Override
 	public void propertyChange(final PropertyChangeEvent event) {
 		final String property= event.getProperty();
 		if (property.equals(PREF_DETAIL_PANE_FONT) || property.equals(JFaceResources.DEFAULT_FONT)) {
 			dispose();
 		}
 	}

 	@Override
 	public void dispose() {
 		JFaceResources.getFontRegistry().removeListener(this);
 		this.handlerCollection.dispose();
 		super.dispose();
 	}

 }
	/*=============================================================================#
	# Copyright (c) 2010, 2019 Stephan Wahlbrink and others.
	#
	# This program and the accompanying materials are made available under the
	# terms of the Eclipse Public License 2.0 which is available at
	# https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
	# which is available at https://www.apache.org/licenses/LICENSE-2.0.
	#
	# SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
	#
	# Contributors:
	# Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
	#=============================================================================*/

	package org.eclipse.statet.internal.r.ui.rhelp;

	import static org.eclipse.debug.ui.IDebugUIConstants.PREF_DETAIL_PANE_FONT;
	import static org.eclipse.statet.ltk.ui.sourceediting.assist.InfoHover.MODE_FOCUS;

	import java.net.URI;
	import java.net.URISyntaxException;

	import org.eclipse.core.commands.ExecutionException;
	import org.eclipse.core.commands.IHandler2;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.jface.action.Separator;
	import org.eclipse.jface.action.ToolBarManager;
	import org.eclipse.jface.internal.text.html.BrowserInformationControl;
	import org.eclipse.jface.resource.JFaceResources;
	import org.eclipse.jface.text.AbstractInformationControl;
	import org.eclipse.jface.text.AbstractReusableInformationControlCreator;
	import org.eclipse.jface.text.IInformationControl;
	import org.eclipse.jface.text.IInformationControlCreator;
	import org.eclipse.jface.text.IInformationControlExtension2;
	import org.eclipse.jface.util.IPropertyChangeListener;
	import org.eclipse.jface.util.PropertyChangeEvent;
	import org.eclipse.jface.viewers.StyledString;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.browser.Browser;
	import org.eclipse.swt.browser.LocationEvent;
	import org.eclipse.swt.browser.LocationListener;
	import org.eclipse.swt.browser.OpenWindowListener;
	import org.eclipse.swt.browser.ProgressEvent;
	import org.eclipse.swt.browser.ProgressListener;
	import org.eclipse.swt.browser.TitleEvent;
	import org.eclipse.swt.browser.TitleListener;
	import org.eclipse.swt.browser.WindowEvent;
	import org.eclipse.swt.custom.StyledText;
	import org.eclipse.swt.events.KeyEvent;
	import org.eclipse.swt.events.KeyListener;
	import org.eclipse.swt.graphics.Color;
	import org.eclipse.swt.graphics.FontMetrics;
	import org.eclipse.swt.graphics.GC;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.graphics.Rectangle;
	import org.eclipse.swt.layout.GridData;
	import org.eclipse.swt.layout.GridLayout;
	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.Menu;
	import org.eclipse.swt.widgets.Shell;
	import org.eclipse.swt.widgets.Text;
	import org.eclipse.ui.IWorkbenchCommandConstants;
	import org.eclipse.ui.IWorkbenchPage;
	import org.eclipse.ui.PlatformUI;
	import org.eclipse.ui.menus.CommandContributionItemParameter;
	import org.eclipse.ui.services.IServiceLocator;

	import org.eclipse.statet.ecommons.ui.SharedUIResources;
	import org.eclipse.statet.ecommons.ui.actions.HandlerCollection;
	import org.eclipse.statet.ecommons.ui.actions.HandlerContributionItem;
	import org.eclipse.statet.ecommons.ui.actions.SimpleContributionItem;
	import org.eclipse.statet.ecommons.ui.mpbv.BrowserHandler.IBrowserProvider;
	import org.eclipse.statet.ecommons.ui.mpbv.BrowserHandler.NavigateBackHandler;
	import org.eclipse.statet.ecommons.ui.mpbv.BrowserHandler.NavigateForwardHandler;
	import org.eclipse.statet.ecommons.ui.util.InformationDispatchHandler;
	import org.eclipse.statet.ecommons.ui.util.LayoutUtils;
	import org.eclipse.statet.ecommons.ui.util.PixelConverter;
	import org.eclipse.statet.ecommons.ui.util.UIAccess;

	import org.eclipse.statet.r.core.RCore;
	import org.eclipse.statet.r.ui.RUI;
	import org.eclipse.statet.rhelp.core.http.RHelpHttpService;


	public class RHelpInfoHoverCreator extends AbstractReusableInformationControlCreator {


	public static final boolean isAvailable(final Composite parent) {
	return BrowserInformationControl.isAvailable(parent);
	}


	public static class Data {

	private final Control control;

	final Object helpObject;
	final URI httpUrl;

	public Data(final Control control, final Object helpObject, final URI httpUrl) {
	this.control= control;
	this.helpObject= helpObject;
	this.httpUrl= httpUrl;
	}


	public Control getControl() {
	return this.control;
	}

	}


	private final int mode;


	public RHelpInfoHoverCreator(final int mode) {
	this.mode= mode;
	}


	@Override
	protected IInformationControl doCreateInformationControl(final Shell parent) {
	return ((this.mode & MODE_FOCUS) != 0) ?
	new RHelpInfoControl(parent, this.mode, true) :
	new RHelpInfoControl(parent, this.mode);
	}

	}

	class RHelpInfoControl extends AbstractInformationControl implements IInformationControlExtension2,
	IPropertyChangeListener, OpenWindowListener, LocationListener, ProgressListener, TitleListener,
	IBrowserProvider {


	/** Action id (command) to navigate one page back. */
	protected static final String NAVIGATE_BACK_COMMAND_ID= IWorkbenchCommandConstants.NAVIGATE_BACK;
	/** Action id (command) to navigate one page forward. */
	protected static final String NAVIGATE_FORWARD_COMMAND_ID= IWorkbenchCommandConstants.NAVIGATE_FORWARD;


	/**
	* Cached scroll bar width and height
	*/
	private static Point gScrollBarSize;


	private final int mode;

	private RHelpLabelProvider labelProvider;

	private Composite contentComposite;
	private Label titleImage;
	private StyledText titleText;
	private Browser infoBrowser;

	private final HandlerCollection handlerCollection= new HandlerCollection();

	private boolean layoutWorkaround;
	private boolean layoutHint;

	private RHelpInfoHoverCreator.Data input;
	private boolean inputChanged;

	private boolean loadingCompleted;
	private String browserTitle;

	private boolean hide;


	RHelpInfoControl(final Shell shell, final int mode) {
	super(shell, ""); //$NON-NLS-1$
	assert ((mode & MODE_FOCUS) == 0);
	this.mode= mode;

	JFaceResources.getFontRegistry().addListener(this);
	create();
	}

	RHelpInfoControl(final Shell shell, final int mode, final boolean dummy) {
	super(shell, new ToolBarManager(SWT.FLAT));
	assert ((mode & MODE_FOCUS) != 0);
	this.mode= mode;

	create();
	}


	@Override
	public void setInput(final Object input) {
	this.inputChanged= true;
	if (input instanceof RHelpInfoHoverCreator.Data) {
	this.input= (RHelpInfoHoverCreator.Data) input;
	}
	else {
	this.input= null;
	}
	}

	@Override
	public boolean hasContents() {
	return (this.input != null);
	}

	@Override
	protected void createContent(final Composite parent) {
	this.contentComposite= new Composite(parent, SWT.NONE) {
	@Override
	public Point computeSize(final int width, final int height, final boolean changed) {
	return super.computeSize(width, height, changed \|\| width != getSize().x);
	}
	};
	this.contentComposite.setBackgroundMode(SWT.INHERIT_FORCE);

	final GridLayout gridLayout= LayoutUtils.newCompositeGrid(2);
	gridLayout.horizontalSpacing= (int) ((gridLayout.horizontalSpacing) / 1.5);
	this.contentComposite.setLayout(gridLayout);

	final int vIndent= Math.max(1, LayoutUtils.defaultVSpacing() / 4);
	final int hIndent= Math.max(3, LayoutUtils.defaultHSpacing() / 3);

	{ // Title image
	this.titleImage= new Label(this.contentComposite, SWT.NULL);
	final Image image= SharedUIResources.getImages().get(SharedUIResources.PLACEHOLDER_IMAGE_ID);
	this.titleImage.setImage(image);

	final GridData textGd= new GridData(SWT.FILL, SWT.TOP, false, false);
	this.titleText= new StyledText(this.contentComposite, SWT.MULTI \| SWT.READ_ONLY \| SWT.WRAP) {
	@Override
	public Point computeSize(int width, final int height, final boolean changed) {
	if (!RHelpInfoControl.this.layoutHint && width <= 0 && RHelpInfoControl.this.contentComposite.getSize().x > 0) {
	width= RHelpInfoControl.this.contentComposite.getSize().x -
	LayoutUtils.defaultHMargin() - RHelpInfoControl.this.titleImage.getSize().x - LayoutUtils.defaultHSpacing() - 10;
	}

	final Point size= super.computeSize(width, -1, true);
	// if (width >= 0) {
	// size.x= Math.min(size.x, width);
	// }
	return size;
	}
	};

	this.titleText.setFont(JFaceResources.getDialogFont());
	final GC gc= new GC(this.titleText);
	final FontMetrics fontMetrics= gc.getFontMetrics();
	final GridData imageGd= new GridData(SWT.FILL, SWT.TOP, false, false);
	imageGd.horizontalIndent= hIndent - 2;
	final int textHeight= fontMetrics.getAscent() + fontMetrics.getLeading();
	final int imageHeight= image.getBounds().height;
	final int shift= Math.max(3, (int) ((fontMetrics.getDescent()) / 1.5));
	if (textHeight+shift < imageHeight) {
	imageGd.verticalIndent= vIndent+shift;
	textGd.verticalIndent= vIndent+(imageHeight-textHeight);
	}
	else {
	imageGd.verticalIndent= vIndent+(textHeight-imageHeight)+shift;
	textGd.verticalIndent= vIndent;
	}
	this.titleImage.setLayoutData(imageGd);
	this.titleText.setLayoutData(textGd);
	this.layoutWorkaround= true;

	gc.dispose();
	}

	this.infoBrowser= new Browser(this.contentComposite, SWT.NONE);

	this.infoBrowser.addOpenWindowListener(this);
	this.infoBrowser.addLocationListener(this);
	this.infoBrowser.addProgressListener(this);
	this.infoBrowser.addTitleListener(this);

	this.infoBrowser.addOpenWindowListener(new OpenWindowListener() {
	@Override
	public void open(final WindowEvent event) {
	event.required= true;
	}
	});
	// Disable context menu
	this.infoBrowser.setMenu(new Menu(getShell(), SWT.NONE));

	final GridData gd= new GridData(SWT.FILL, SWT.FILL, true, true, 2, 1);
	// gd.widthHint= LayoutUtils.hintWidth(fInfoText, INFO_FONT, 50);
	this.infoBrowser.setLayoutData(gd);

	this.infoBrowser.addKeyListener(new KeyListener() {
	@Override
	public void keyPressed(final KeyEvent e) {
	if (e.character == SWT.ESC) {
	dispose();
	}
	}
	@Override
	public void keyReleased(final KeyEvent e) {}
	});

	setBackgroundColor(getShell().getDisplay().getSystemColor(SWT.COLOR_INFO_BACKGROUND));
	setForegroundColor(getShell().getDisplay().getSystemColor(SWT.COLOR_INFO_FOREGROUND));

	if ((this.mode & MODE_FOCUS) != 0) {
	initActions(this.handlerCollection);
	final ToolBarManager toolBarManager= getToolBarManager();
	contributeToActionBars(PlatformUI.getWorkbench(), toolBarManager, this.handlerCollection);
	toolBarManager.update(true);
	}

	updateInput();
	}

	protected void initActions(final HandlerCollection handlers) {
	{ final IHandler2 handler= new NavigateBackHandler(this);
	handlers.add(NAVIGATE_BACK_COMMAND_ID, handler);
	// handlerService.activateHandler(NAVIGATE_BACK_COMMAND_ID, handler);
	// handlerService.activateHandler(IWorkbenchCommandConstants.NAVIGATE_BACKWARD_HISTORY, handler);
	}
	{ final IHandler2 handler= new NavigateForwardHandler(this);
	handlers.add(NAVIGATE_FORWARD_COMMAND_ID, handler);
	// handlerService.activateHandler(NAVIGATE_FORWARD_COMMAND_ID, handler);
	// handlerService.activateHandler(IWorkbenchCommandConstants.NAVIGATE_FORWARD_HISTORY, handler);
	}
	}

	protected void contributeToActionBars(final IServiceLocator serviceLocator,
	final ToolBarManager toolBarManager, final HandlerCollection handlers) {
	toolBarManager.add(
	new HandlerContributionItem(new CommandContributionItemParameter(
	serviceLocator, null, NAVIGATE_BACK_COMMAND_ID, HandlerContributionItem.STYLE_PUSH),
	handlers.get(NAVIGATE_BACK_COMMAND_ID) ));
	toolBarManager.add(
	new HandlerContributionItem(new CommandContributionItemParameter(
	serviceLocator, null, NAVIGATE_FORWARD_COMMAND_ID, HandlerContributionItem.STYLE_PUSH),
	handlers.get(NAVIGATE_FORWARD_COMMAND_ID) ));

	toolBarManager.add(new Separator());
	toolBarManager.add(new SimpleContributionItem(
	"Show in R Help View", "V",
	RUI.getImageDescriptor(RUI.IMG_OBJ_R_HELP_SEARCH), null ) {
	@Override
	protected void execute() throws ExecutionException {
	if (UIAccess.isOkToUse(RHelpInfoControl.this.infoBrowser)) {
	try {
	final String urlString= RHelpInfoControl.this.infoBrowser.getUrl();
	final IWorkbenchPage page= UIAccess.getActiveWorkbenchPage(true);
	final RHelpView view= (RHelpView) page.showView(RUI.R_HELP_VIEW_ID);
	final URI browseUrl= RCore.getRHelpHttpService().toHttpUrl(urlString,
	null, RHelpHttpService.BROWSE_TARGET );
	if (browseUrl != null) {
	view.openUrl(browseUrl, null);
	}
	else {
	view.openUrl(urlString, null);
	}
	}
	catch (final Exception e) {}
	}
	}
	});
	}


	@Override
	public Browser getBrowser() {
	return this.infoBrowser;
	}

	@Override
	public void showMessage(final IStatus status) {
	}

	@Override
	public void changing(final LocationEvent event) {
	if (event.location.startsWith("http://")) { //$NON-NLS-1$
	try {
	if (RCore.getRHelpHttpService().isDynamicUrl(new URI(event.location))) {
	return;
	}
	}
	catch (final Exception e) {}
	}
	if (event.location.equals("about:blank")) { //$NON-NLS-1$
	return;
	}
	event.doit= false;
	}

	@Override
	public void changed(final LocationEvent event) {
	if (!event.top) {
	return;
	}
	final String url= this.infoBrowser.getUrl();
	final Object obj= RCore.getRHelpHttpService().getContentOfUrl(url);
	updateTitle(obj, this.browserTitle);
	}

	@Override
	public void changed(final ProgressEvent event) {
	this.handlerCollection.update(null);
	}

	@Override
	public void completed(final ProgressEvent event) {
	this.loadingCompleted= true;
	this.handlerCollection.update(null);
	}

	@Override
	public void changed(final TitleEvent event) {
	String title= event.title;
	if (title == null) {
	title= ""; //$NON-NLS-1$
	}
	else if (title.startsWith("http://")) { //$NON-NLS-1$
	final int idx= title.lastIndexOf('/');
	if (idx >= 0) {
	title= title.substring(idx+1);
	}
	}
	this.browserTitle= title;
	}

	@Override
	public void open(final WindowEvent event) {
	event.required= true;
	}


	@Override
	public void setBackgroundColor(final Color background) {
	super.setBackgroundColor(background);
	this.contentComposite.setBackground(background);
	this.infoBrowser.setBackground(background);
	}

	@Override
	public void setForegroundColor(final Color foreground) {
	super.setForegroundColor(foreground);
	this.contentComposite.setForeground(foreground);
	this.titleText.setForeground(foreground);
	this.infoBrowser.setForeground(foreground);
	}

	@Override
	public void setSize(final int width, final int height) {
	this.infoBrowser.setRedraw(false); // avoid flickering
	try {
	super.setSize(width, height);
	}
	finally {
	this.infoBrowser.setRedraw(true);
	}
	}


	@Override
	public Rectangle computeTrim() {
	final Rectangle trim= super.computeTrim();

	final Rectangle textTrim= this.infoBrowser.computeTrim(0, 0, 0, 0);
	if ((this.mode & MODE_FOCUS) != 0 && textTrim.width == 0) {
	if (gScrollBarSize == null) {
	final Text text= new Text(this.contentComposite, SWT.MULTI \| SWT.V_SCROLL \| SWT.H_SCROLL \| SWT.BORDER);
	gScrollBarSize= new Point(
	text.getVerticalBar().getSize().x,
	text.getHorizontalBar().getSize().y);
	text.dispose();
	}
	textTrim.x= 0;
	textTrim.y= 0;
	textTrim.width= gScrollBarSize.x;
	textTrim.height= gScrollBarSize.y;
	}
	trim.x+= textTrim.x;
	trim.y+= textTrim.y;
	trim.width+= textTrim.width;
	trim.height+= textTrim.height;

	return trim;
	}

	@Override
	public Point computeSizeHint() {
	updateInput();
	final Point sizeConstraints= getSizeConstraints();
	final Rectangle trim= computeTrim();

	this.titleText.setFont(JFaceResources.getDialogFont());
	final PixelConverter converter= new PixelConverter(this.titleText);
	int widthHint= converter.convertWidthInCharsToPixels(60);
	final GC gc= new GC(this.contentComposite);
	gc.setFont(JFaceResources.getTextFont());
	widthHint= Math.max(widthHint, gc.getFontMetrics().getAverageCharWidth() * 60);
	gc.dispose();

	final int heightHint= this.titleText.getLineHeight() * 12;

	final int widthMax= ((sizeConstraints != null && sizeConstraints.x != SWT.DEFAULT) ?
	sizeConstraints.x : widthHint+100) - trim.width;
	final int heightMax= ((sizeConstraints != null && sizeConstraints.y != SWT.DEFAULT) ?
	sizeConstraints.y : this.titleText.getLineHeight()*12) - trim.height;

	final Point size= new Point(widthHint, heightHint);
	size.y+= LayoutUtils.defaultVSpacing();
	size.x= Math.max(Math.min(size.x, widthMax), 200) + trim.width;
	size.y= Math.max(Math.min(size.y, heightMax), 100) + trim.height;
	return size;
	}

	@Override
	public Point computeSizeConstraints(final int widthInChars, final int heightInChars) {
	final int width= LayoutUtils.hintWidth(this.titleText, JFaceResources.DIALOG_FONT, widthInChars);
	final int lineHeight= this.titleText.getLineHeight();

	return new Point(width, lineHeight * heightInChars + LayoutUtils.defaultVSpacing());
	}

	@Override
	public void setVisible(final boolean visible) {
	if (visible) {
	this.hide= false;
	updateInput();
	waitCompleted();
	if (this.hide \|\| !UIAccess.isOkToUse(getShell())) {
	return;
	}

	if (this.layoutWorkaround) {
	this.contentComposite.layout(true, true);
	this.layoutWorkaround= false;
	}

	if (Platform.WS_WIN32.equals(SWT.getPlatform())) {
	getShell().moveAbove(null);
	}
	}
	else {
	this.hide= true;
	}
	super.setVisible(visible);
	}

	private void waitCompleted() {
	final Display display= Display.getCurrent();
	display.timerExec(200, new Runnable() {
	@Override
	public void run() {
	RHelpInfoControl.this.loadingCompleted= true;
	}
	});
	while (!this.loadingCompleted) {
	// Drive the event loop to process the events required to load the browser widget's contents:
	if (!display.readAndDispatch()) {
	display.sleep();
	}
	}
	}

	@Override
	public void setFocus() {
	this.infoBrowser.setFocus();
	}

	private void updateInput() {
	if (this.infoBrowser == null \|\| !this.inputChanged) {
	return;
	}
	if (this.labelProvider == null) {
	this.labelProvider= new RHelpLabelProvider(RHelpLabelProvider.WITH_TITLE \| RHelpLabelProvider.WITH_QUALIFIER \| RHelpLabelProvider.HEADER);
	}
	this.loadingCompleted= false;
	this.inputChanged= false;
	this.browserTitle= null;
	updateTitle(this.input.helpObject, null);
	if (this.input != null && this.input.httpUrl != null) {
	URI url= this.input.httpUrl;
	if ((this.mode & MODE_FOCUS) == 0) { // disable scrollbars
	try {
	url= new URI(url.toString() +
	'?' + RHelpUIServlet.STYLE_PARAM + '=' + RHelpUIServlet.HOVER_STYLE );
	}
	catch (final URISyntaxException e) {}
	}
	this.infoBrowser.setUrl(url.toString());
	}
	else {
	this.infoBrowser.setUrl("about:blank"); //$NON-NLS-1$
	}
	if ((this.mode & MODE_FOCUS) == 0) {
	setStatusText((this.input.getControl() != null
	&& this.input.getControl().isFocusControl() ) ?
	InformationDispatchHandler.getAffordanceString(this.mode) : "" ); //$NON-NLS-1$
	}
	}

	private void updateTitle(final Object helpObject, final String alt) {
	if (helpObject != null) {
	final Image image= this.labelProvider.getImage(helpObject);
	this.titleImage.setImage((image != null) ? image : SharedUIResources.getImages().get(SharedUIResources.PLACEHOLDER_IMAGE_ID));
	final StyledString styleString= this.labelProvider.getStyledText(helpObject);
	this.titleText.setText(styleString.getString());
	this.titleText.setStyleRanges(styleString.getStyleRanges());
	}
	else {
	this.titleImage.setImage(SharedUIResources.getImages().get(SharedUIResources.PLACEHOLDER_IMAGE_ID));
	this.titleText.setText((alt != null) ? alt : ""); //$NON-NLS-1$
	}
	}


	@Override
	public IInformationControlCreator getInformationPresenterControlCreator() {
	// enriched mode
	return new RHelpInfoHoverCreator(this.mode \| MODE_FOCUS);
	}

	@Override
	public void propertyChange(final PropertyChangeEvent event) {
	final String property= event.getProperty();
	if (property.equals(PREF_DETAIL_PANE_FONT) \|\| property.equals(JFaceResources.DEFAULT_FONT)) {
	dispose();
	}
	}

	@Override
	public void dispose() {
	JFaceResources.getFontRegistry().removeListener(this);
	this.handlerCollection.dispose();
	super.dispose();
	}

	}