core/plugins/org.eclipse.dltk.ui/src/org/eclipse/dltk/internal/ui/text/hover/DocumentationHover.java - dltk/org.eclipse.dltk.core - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2018 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  *******************************************************************************/
 package org.eclipse.dltk.internal.ui.text.hover;

 import java.io.IOException;
 import java.io.Reader;
 import java.net.URL;

 import org.eclipse.core.runtime.PlatformObject;
 import org.eclipse.dltk.annotations.Internal;
 import org.eclipse.dltk.core.IModelElement;
 import org.eclipse.dltk.core.ModelException;
 import org.eclipse.dltk.ui.DLTKPluginImages;
 import org.eclipse.dltk.ui.DLTKUIPlugin;
 import org.eclipse.dltk.ui.PreferenceConstants;
 import org.eclipse.dltk.ui.ScriptElementImageProvider;
 import org.eclipse.dltk.ui.ScriptElementLabels;
 import org.eclipse.dltk.ui.documentation.IDocumentationResponse;
 import org.eclipse.dltk.ui.documentation.IScriptDocumentationTitleAdapter;
 import org.eclipse.dltk.ui.documentation.ScriptDocumentationAccess;
 import org.eclipse.dltk.ui.documentation.TextDocumentationResponse;
 import org.eclipse.dltk.ui.text.completion.HTMLPrinter;
 import org.eclipse.jface.action.Action;
 import org.eclipse.jface.action.ToolBarManager;
 import org.eclipse.jface.internal.text.html.BrowserInformationControl;
 import org.eclipse.jface.internal.text.html.BrowserInformationControlInput;
 import org.eclipse.jface.resource.ColorRegistry;
 import org.eclipse.jface.resource.ImageDescriptor;
 import org.eclipse.jface.resource.JFaceResources;
 import org.eclipse.jface.text.AbstractReusableInformationControlCreator;
 import org.eclipse.jface.text.DefaultInformationControl;
 import org.eclipse.jface.text.IInformationControl;
 import org.eclipse.jface.text.IInformationControlCreator;
 import org.eclipse.jface.text.IInformationControlExtension4;
 import org.eclipse.jface.text.IInformationControlExtension5;
 import org.eclipse.jface.text.IInputChangedListener;
 import org.eclipse.jface.text.ITextHoverExtension;
 import org.eclipse.jface.text.information.IInformationProviderExtension2;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.graphics.RGB;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.ui.IEditorPart;
 import org.eclipse.ui.ISharedImages;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.IWorkbenchSite;
 import org.eclipse.ui.PartInitException;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.editors.text.EditorsUI;

 /**
  * Provides documentation as hover info for Script elements and keywords.
  */
 @SuppressWarnings("restriction")
 public class DocumentationHover extends AbstractScriptEditorTextHover
 		implements IInformationProviderExtension2, ITextHoverExtension {

 	private static final long LABEL_FLAGS = ScriptElementLabels.ALL_FULLY_QUALIFIED
 			| ScriptElementLabels.M_APP_RETURNTYPE | ScriptElementLabels.F_APP_TYPE_SIGNATURE
 			| ScriptElementLabels.M_PARAMETER_TYPES | ScriptElementLabels.M_PARAMETER_NAMES
 			| ScriptElementLabels.M_EXCEPTIONS | ScriptElementLabels.F_PRE_TYPE_SIGNATURE
 			| ScriptElementLabels.M_PRE_TYPE_PARAMETERS | ScriptElementLabels.T_TYPE_PARAMETERS
 			| ScriptElementLabels.USE_RESOLVED;
 	private static final long LOCAL_VARIABLE_FLAGS = LABEL_FLAGS & ~ScriptElementLabels.F_FULLY_QUALIFIED
 			| ScriptElementLabels.F_POST_QUALIFIED;

 	/**
 	 * The hover control creator.
 	 */
 	private IInformationControlCreator fHoverControlCreator;

 	/**
 	 * The presentation control creator.
 	 */
 	private IInformationControlCreator fPresenterControlCreator;

 	/**
 	 * Action to go back to the previous input in the hover control.
 	 *
 	 * @since 4.0
 	 */
 	private static final class BackAction extends Action {
 		private final BrowserInformationControl fInfoControl;

 		public BackAction(BrowserInformationControl infoControl) {
 			fInfoControl = infoControl;
 			setText(ScriptHoverMessages.ScriptdocHover_back);
 			ISharedImages images = PlatformUI.getWorkbench().getSharedImages();
 			setImageDescriptor(images.getImageDescriptor(ISharedImages.IMG_TOOL_BACK));
 			setDisabledImageDescriptor(images.getImageDescriptor(ISharedImages.IMG_TOOL_BACK_DISABLED));

 			update();
 		}

 		@Override
 		public void run() {
 			BrowserInformationControlInput previous = (BrowserInformationControlInput) fInfoControl.getInput()
 					.getPrevious();
 			if (previous != null) {
 				fInfoControl.setInput(previous);
 			}
 		}

 		public void update() {
 			BrowserInformationControlInput current = fInfoControl.getInput();

 			if (current != null && current.getPrevious() != null) {
 				// BrowserInput previous = current.getPrevious();
 				// setToolTipText(Messages.format(
 				// JavaHoverMessages.JavadocHover_back_toElement_toolTip,
 				// BasicElementLabels.getJavaElementName(previous
 				// .getInputName())));
 				setEnabled(true);
 			} else {
 				setEnabled(false);
 			}
 			setToolTipText(ScriptHoverMessages.ScriptdocHover_back);
 		}
 	}

 	/**
 	 * Action to go forward to the next input in the hover control.
 	 *
 	 * @since 4.0
 	 */
 	private static final class ForwardAction extends Action {
 		private final BrowserInformationControl fInfoControl;

 		public ForwardAction(BrowserInformationControl infoControl) {
 			fInfoControl = infoControl;
 			setText(ScriptHoverMessages.ScriptdocHover_forward);
 			ISharedImages images = PlatformUI.getWorkbench().getSharedImages();
 			setImageDescriptor(images.getImageDescriptor(ISharedImages.IMG_TOOL_FORWARD));
 			setDisabledImageDescriptor(images.getImageDescriptor(ISharedImages.IMG_TOOL_FORWARD_DISABLED));

 			update();
 		}

 		@Override
 		public void run() {
 			BrowserInformationControlInput next = (BrowserInformationControlInput) fInfoControl.getInput().getNext();
 			if (next != null) {
 				fInfoControl.setInput(next);
 			}
 		}

 		public void update() {
 			BrowserInformationControlInput current = fInfoControl.getInput();

 			if (current != null && current.getNext() != null) {
 				// setToolTipText(Messages
 				// .format(JavaHoverMessages.JavadocHover_forward_toElement_toolTip,
 				// BasicElementLabels.getJavaElementName(current
 				// .getNext().getInputName())));
 				setEnabled(true);
 			} else {
 				setEnabled(false);
 			}
 			setToolTipText(ScriptHoverMessages.ScriptdocHover_forward);
 		}
 	}

 	/**
 	 * Action that opens the current hover input element.
 	 *
 	 * @since 4.0
 	 */
 	private static final class OpenDeclarationAction extends Action {
 		private final BrowserInformationControl fInfoControl;

 		public OpenDeclarationAction(BrowserInformationControl infoControl) {
 			fInfoControl = infoControl;
 			setText(ScriptHoverMessages.ScriptdocHover_openDeclaration);
 			DLTKPluginImages.setLocalImageDescriptors(this, "goto_input.png"); //$NON-NLS-1$ //TODO:
 																				// better
 																				// images
 		}

 		@Override
 		public void run() {
 			DocumentationBrowserInformationControlInput infoInput = (DocumentationBrowserInformationControlInput) fInfoControl
 					.getInput(); // TODO: check cast
 			fInfoControl.notifyDelayedInputChange(null);
 			fInfoControl.dispose(); // FIXME: should have protocol to hide,
 									// rather than dispose

 			try {
 				if (infoInput.getElement() instanceof IModelElement) {
 					// FIXME: add hover location to editor navigation history?
 					DLTKUIPlugin.openInEditor((IModelElement) infoInput.getElement());
 				}
 				// TODO (alex) try via IOpenDelegate
 			} catch (PartInitException | ModelException e) {
 				DLTKUIPlugin.log(e);
 			}
 		}
 	}

 	/**
 	 * Presenter control creator.
 	 *
 	 * @since 4.0
 	 */
 	public static final class PresenterControlCreator extends AbstractReusableInformationControlCreator {

 		/**
 		 * Creates a new PresenterControlCreator.
 		 *
 		 * @param site the site or <code>null</code> if none
 		 */
 		public PresenterControlCreator(IWorkbenchSite site) {
 		}

 		@Override
 		public IInformationControl doCreateInformationControl(Shell parent) {
 			if (BrowserInformationControl.isAvailable(parent)) {
 				ToolBarManager tbm = new ToolBarManager(SWT.FLAT);
 				String font = PreferenceConstants.APPEARANCE_DOCUMENTATION_FONT;
 				BrowserInformationControl iControl = new BrowserInformationControl(parent, font, tbm);

 				final BackAction backAction = new BackAction(iControl);
 				backAction.setEnabled(false);
 				tbm.add(backAction);
 				final ForwardAction forwardAction = new ForwardAction(iControl);
 				tbm.add(forwardAction);
 				forwardAction.setEnabled(false);

 				// final ShowInJavadocViewAction showInJavadocViewAction = new
 				// ShowInJavadocViewAction(
 				// iControl);
 				// tbm.add(showInJavadocViewAction);
 				final OpenDeclarationAction openDeclarationAction = new OpenDeclarationAction(iControl);
 				tbm.add(openDeclarationAction);

 				// final SimpleSelectionProvider selectionProvider = new
 				// SimpleSelectionProvider();
 				// if (fSite != null) {
 				// OpenAttachedJavadocAction openAttachedJavadocAction = new
 				// OpenAttachedJavadocAction(
 				// fSite);
 				// openAttachedJavadocAction
 				// .setSpecialSelectionProvider(selectionProvider);
 				// openAttachedJavadocAction
 				// .setImageDescriptor(DLTKPluginImages.DESC_ELCL_OPEN_BROWSER);
 				// openAttachedJavadocAction
 				// .setDisabledImageDescriptor(DLTKPluginImages.DESC_DLCL_OPEN_BROWSER);
 				// selectionProvider
 				// .addSelectionChangedListener(openAttachedJavadocAction);
 				// selectionProvider.setSelection(new StructuredSelection());
 				// tbm.add(openAttachedJavadocAction);
 				// }

 				IInputChangedListener inputChangeListener = newInput -> {
 					backAction.update();
 					forwardAction.update();
 					if (newInput == null) {
 						// selectionProvider
 						// .setSelection(new StructuredSelection());
 					} else if (newInput instanceof BrowserInformationControlInput) {
 						BrowserInformationControlInput input = (BrowserInformationControlInput) newInput;
 						Object inputElement = input.getInputElement();
 						// selectionProvider
 						// .setSelection(new StructuredSelection(
 						// inputElement));
 						boolean isJavaElementInput = inputElement instanceof IModelElement;
 						// showInJavadocViewAction
 						// .setEnabled(isJavaElementInput);
 						openDeclarationAction.setEnabled(isJavaElementInput);
 					}
 				};
 				iControl.addInputChangeListener(inputChangeListener);

 				tbm.update(true);

 				// TODO (alex) addLinkListener(iControl);
 				return iControl;

 			}
 			return new DefaultInformationControl(parent, true);
 		}
 	}

 	@Override
 	public IInformationControlCreator getInformationPresenterControlCreator() {
 		if (fPresenterControlCreator == null) {
 			fPresenterControlCreator = new PresenterControlCreator(getSite());
 		}
 		return fPresenterControlCreator;
 	}

 	private IWorkbenchSite getSite() {
 		IEditorPart editor = getEditor();
 		if (editor == null) {
 			IWorkbenchPage page = DLTKUIPlugin.getActivePage();
 			if (page != null)
 				editor = page.getActiveEditor();
 		}
 		if (editor != null)
 			return editor.getSite();

 		return null;
 	}

 	/**
 	 * Hover control creator.
 	 *
 	 * @since 4.0
 	 */
 	public static final class HoverControlCreator extends AbstractReusableInformationControlCreator {
 		/**
 		 * The information presenter control creator.
 		 */
 		private final IInformationControlCreator fInformationPresenterControlCreator;

 		/**
 		 * <code>true</code> to use the additional info affordance, <code>false</code>
 		 * to use the hover affordance.
 		 */
 		private final boolean fAdditionalInfoAffordance;

 		/**
 		 * @param informationPresenterControlCreator control creator for enriched hover
 		 */
 		public HoverControlCreator(IInformationControlCreator informationPresenterControlCreator) {
 			this(informationPresenterControlCreator, false);
 		}

 		/**
 		 * @param informationPresenterControlCreator control creator for enriched hover
 		 * @param additionalInfoAffordance           <code>true</code> to use the
 		 *                                           additional info affordance,
 		 *                                           <code>false</code> to use the hover
 		 *                                           affordance
 		 */
 		public HoverControlCreator(IInformationControlCreator informationPresenterControlCreator,
 				boolean additionalInfoAffordance) {
 			fInformationPresenterControlCreator = informationPresenterControlCreator;
 			fAdditionalInfoAffordance = additionalInfoAffordance;
 		}

 		/**
 		 * @see AbstractReusableInformationControlCreator#doCreateInformationControl(Shell)
 		 */
 		@Override
 		public IInformationControl doCreateInformationControl(Shell parent) {
 			String tooltipAffordanceString = fAdditionalInfoAffordance
 					? DLTKUIPlugin.getAdditionalInfoAffordanceString()
 					: EditorsUI.getTooltipAffordanceString();
 			if (BrowserInformationControl.isAvailable(parent)) {
 				String font = PreferenceConstants.APPEARANCE_DOCUMENTATION_FONT;
 				BrowserInformationControl iControl = new BrowserInformationControl(parent, font,
 						tooltipAffordanceString) {
 					/**
 					 * @see IInformationControlExtension5#getInformationPresenterControlCreator()
 					 */
 					@Override
 					public IInformationControlCreator getInformationPresenterControlCreator() {
 						return fInformationPresenterControlCreator;
 					}
 				};
 				// TODO (alex) addLinkListener(iControl);
 				return iControl;
 			}
 			return new DefaultInformationControl(parent, tooltipAffordanceString);
 		}

 		/**
 		 * @see AbstractReusableInformationControlCreator#canReuse(IInformationControl)
 		 */
 		@Override
 		public boolean canReuse(IInformationControl control) {
 			if (!super.canReuse(control))
 				return false;

 			if (control instanceof IInformationControlExtension4) {
 				String tooltipAffordanceString = fAdditionalInfoAffordance
 						? DLTKUIPlugin.getAdditionalInfoAffordanceString()
 						: EditorsUI.getTooltipAffordanceString();
 				((IInformationControlExtension4) control).setStatusText(tooltipAffordanceString);
 			}

 			return true;
 		}
 	}

 	@Override
 	public IInformationControlCreator getHoverControlCreator() {
 		if (fHoverControlCreator == null)
 			fHoverControlCreator = new HoverControlCreator(getInformationPresenterControlCreator());
 		return fHoverControlCreator;
 	}

 	@Override
 	protected String getHoverInfo(String nature, Object[] result) {
 		StringBuffer buffer = new StringBuffer();
 		int nResults = result.length;
 		if (nResults == 0)
 			return null;

 		boolean hasContents = false;
 		if (nResults > 1) {
 			HTMLPrinter.addSmallHeader(buffer,
 					getInfoText(result[0], titleAdapter.getTitle(result[0]), titleAdapter.getImage(result[0])));
 			HTMLPrinter.addParagraph(buffer, "<hr>"); //$NON-NLS-1$
 			for (int i = 0; i < result.length; i++) {
 				Object element = result[i];
 				Reader reader = ScriptDocumentationAccess.getHTMLContentReader(nature, element, true, true);
 				if (reader == null) {
 					continue;
 				}
 				if (hasContents) {
 					HTMLPrinter.addParagraph(buffer, "<hr>"); //$NON-NLS-1$
 				}
 				HTMLPrinter.addParagraph(buffer, reader);
 				hasContents = true;
 			}
 		} else {
 			Object element = result[0];
 			IDocumentationResponse response = ScriptDocumentationAccess.getDocumentation(nature, element, titleAdapter);
 			// Provide hint why there's no doc
 			if (response == null) {
 				response = new TextDocumentationResponse(element, titleAdapter.getTitle(element),
 						titleAdapter.getImage(element), ScriptHoverMessages.ScriptdocHover_noAttachedInformation);
 			}
 			try {
 				HTMLPrinter.addSmallHeader(buffer, getInfoText(element, response.getTitle(), response.getImage()));
 				HTMLPrinter.addParagraph(buffer, response.getReader());
 				hasContents = true;
 			} catch (IOException e) {
 				return null;
 			}
 			/*
 			 * else if (curr.getElementType() == IModelElement.LOCAL_VARIABLE ||
 			 * curr.getElementType() == IModelElement.TYPE_PARAMETER) {
 			 * HTMLPrinter.addSmallHeader(buffer, getInfoText(curr)); hasContents= true; }
 			 */
 		}
 		if (!hasContents)
 			return null;
 		if (buffer.length() > 0) {
 			ColorRegistry registry = JFaceResources.getColorRegistry();
 			RGB fgRGB = registry.getRGB("org.eclipse.dltk.ui.documentation.foregroundColor"); //$NON-NLS-1$
 			RGB bgRGB = registry.getRGB("org.eclipse.dltk.ui.documentation.backgroundColor"); //$NON-NLS-1$
 			HTMLPrinter.insertPageProlog(buffer, 0, bgRGB, fgRGB, getStyleSheet());
 			HTMLPrinter.addPageEpilog(buffer);
 			return buffer.toString();
 		}
 		return null;
 	}

 	private String getInfoText(Object element, String title, ImageDescriptor image) {
 		String imageName = null;
 		if (image != null) {
 			final URL imageURL = DLTKUIPlugin.getDefault().getImagesOnFSRegistry().getImageURL(image);
 			if (imageURL != null) {
 				imageName = imageURL.toExternalForm();
 			}
 		}
 		StringBuffer buf = new StringBuffer();
 		addImageAndLabel(buf, element, imageName, 16, 16,
 				org.eclipse.jface.internal.text.html.HTMLPrinter.convertToHTMLContent(title), 20, 2);
 		return buf.toString();
 	}

 	private static void addImageAndLabel(StringBuffer buf, Object element, String imageSrcPath, int imageWidth,
 			int imageHeight, String label, int labelLeft, int labelTop) {
 		buf.append("<div style='word-wrap: break-word; position: relative; "); //$NON-NLS-1$

 		if (imageSrcPath != null) {
 			buf.append("margin-left: ").append(labelLeft).append("px; "); //$NON-NLS-1$ //$NON-NLS-2$
 			buf.append("padding-top: ").append(labelTop).append("px; "); //$NON-NLS-1$ //$NON-NLS-2$
 		}

 		buf.append("'>"); //$NON-NLS-1$
 		if (imageSrcPath != null) {
 			// if (element != null) {
 			// try {
 			// String uri = JavaElementLinks.createURI(
 			// JavaElementLinks.OPEN_LINK_SCHEME, element);
 			// buf.append("<a href='").append(uri).append("'>");
 			// //$NON-NLS-1$//$NON-NLS-2$
 			// } catch (URISyntaxException e) {
 			// element = null; // no link
 			// }
 			// }
 			StringBuffer imageStyle = new StringBuffer("border:none; position: absolute; "); //$NON-NLS-1$
 			imageStyle.append("width: ").append(imageWidth).append("px; "); //$NON-NLS-1$ //$NON-NLS-2$
 			imageStyle.append("height: ").append(imageHeight).append("px; "); //$NON-NLS-1$ //$NON-NLS-2$
 			imageStyle.append("left: ").append(-labelLeft - 1).append("px; "); //$NON-NLS-1$ //$NON-NLS-2$

 			// hack for broken transparent PNG support in IE 6, see
 			// https://bugs.eclipse.org/bugs/show_bug.cgi?id=223900 :
 			buf.append("<!--[if lte IE 6]><![if gte IE 5.5]>\n"); //$NON-NLS-1$
 			String tooltip = element == null ? "" //$NON-NLS-1$
 					: "alt='" //$NON-NLS-1$
 							+ ScriptHoverMessages.ScriptdocHover_openDeclaration + "' "; //$NON-NLS-1$
 			buf.append("<span ").append(tooltip).append("style=\"") //$NON-NLS-1$ //$NON-NLS-2$
 					.append(imageStyle).append("filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='") //$NON-NLS-1$
 					.append(imageSrcPath).append("')\"></span>\n"); //$NON-NLS-1$
 			buf.append("<![endif]><![endif]-->\n"); //$NON-NLS-1$

 			buf.append("<!--[if !IE]>-->\n"); //$NON-NLS-1$
 			buf.append("<img ").append(tooltip).append("style='") //$NON-NLS-1$ //$NON-NLS-2$
 					.append(imageStyle).append("' src='").append(imageSrcPath) //$NON-NLS-1$
 					.append("'/>\n"); //$NON-NLS-1$
 			buf.append("<!--<![endif]-->\n"); //$NON-NLS-1$
 			buf.append("<!--[if gte IE 7]>\n"); //$NON-NLS-1$
 			buf.append("<img ").append(tooltip).append("style='") //$NON-NLS-1$ //$NON-NLS-2$
 					.append(imageStyle).append("' src='").append(imageSrcPath) //$NON-NLS-1$
 					.append("'/>\n"); //$NON-NLS-1$
 			buf.append("<![endif]-->\n"); //$NON-NLS-1$
 			// if (element != null) {
 			// buf.append("</a>"); //$NON-NLS-1$
 			// }
 		}

 		buf.append(label);
 		buf.append("</div>"); //$NON-NLS-1$
 	}

 	@Override
 	protected String getHoverInfo(String nature, String content) {
 		try {
 			Reader reader = ScriptDocumentationAccess.getKeywordDocumentation(nature, getEditorInputModelElement(),
 					content);
 			if (reader != null) {
 				StringBuffer buffer = new StringBuffer();
 				HTMLPrinter.addParagraph(buffer, reader);
 				if (buffer.length() > 0) {
 					ColorRegistry registry = JFaceResources.getColorRegistry();
 					RGB fgRGB = registry.getRGB("org.eclipse.dltk.ui.documentation.foregroundColor"); //$NON-NLS-1$
 					RGB bgRGB = registry.getRGB("org.eclipse.dltk.ui.documentation.backgroundColor"); //$NON-NLS-1$
 					HTMLPrinter.insertPageProlog(buffer, 0, bgRGB, fgRGB, getStyleSheet());
 					HTMLPrinter.addPageEpilog(buffer);
 					return buffer.toString();
 				}
 			}
 		} catch (ModelException ex) {
 			// TODO: log
 		}
 		return null;
 	}

 	private static final ScriptDocumentationTitleAdapter titleAdapter = new ScriptDocumentationTitleAdapter();

 	@Internal
 	static class ScriptDocumentationTitleAdapter extends PlatformObject implements IScriptDocumentationTitleAdapter {

 		private ScriptElementImageProvider fImageProvider;

 		@Override
 		public String getTitle(Object element) {
 			if (element instanceof IModelElement) {
 				IModelElement member = (IModelElement) element;
 				long flags = member.getElementType() == IModelElement.LOCAL_VARIABLE ? LOCAL_VARIABLE_FLAGS
 						: LABEL_FLAGS;
 				String label = ScriptElementLabels.getDefault().getElementLabel(member, flags);
 				return label;
 			}
 			return null;
 		}

 		@Override
 		public ImageDescriptor getImage(Object element) {
 			if (element instanceof IModelElement) {
 				final IModelElement modelElement = (IModelElement) element;
 				if (fImageProvider == null) {
 					fImageProvider = new ScriptElementImageProvider();
 				}
 				return fImageProvider.getScriptImageDescriptor(modelElement,
 						ScriptElementImageProvider.OVERLAY_ICONS | ScriptElementImageProvider.SMALL_ICONS);
 			}
 			return null;
 		}
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2018 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	*******************************************************************************/
	package org.eclipse.dltk.internal.ui.text.hover;

	import java.io.IOException;
	import java.io.Reader;
	import java.net.URL;

	import org.eclipse.core.runtime.PlatformObject;
	import org.eclipse.dltk.annotations.Internal;
	import org.eclipse.dltk.core.IModelElement;
	import org.eclipse.dltk.core.ModelException;
	import org.eclipse.dltk.ui.DLTKPluginImages;
	import org.eclipse.dltk.ui.DLTKUIPlugin;
	import org.eclipse.dltk.ui.PreferenceConstants;
	import org.eclipse.dltk.ui.ScriptElementImageProvider;
	import org.eclipse.dltk.ui.ScriptElementLabels;
	import org.eclipse.dltk.ui.documentation.IDocumentationResponse;
	import org.eclipse.dltk.ui.documentation.IScriptDocumentationTitleAdapter;
	import org.eclipse.dltk.ui.documentation.ScriptDocumentationAccess;
	import org.eclipse.dltk.ui.documentation.TextDocumentationResponse;
	import org.eclipse.dltk.ui.text.completion.HTMLPrinter;
	import org.eclipse.jface.action.Action;
	import org.eclipse.jface.action.ToolBarManager;
	import org.eclipse.jface.internal.text.html.BrowserInformationControl;
	import org.eclipse.jface.internal.text.html.BrowserInformationControlInput;
	import org.eclipse.jface.resource.ColorRegistry;
	import org.eclipse.jface.resource.ImageDescriptor;
	import org.eclipse.jface.resource.JFaceResources;
	import org.eclipse.jface.text.AbstractReusableInformationControlCreator;
	import org.eclipse.jface.text.DefaultInformationControl;
	import org.eclipse.jface.text.IInformationControl;
	import org.eclipse.jface.text.IInformationControlCreator;
	import org.eclipse.jface.text.IInformationControlExtension4;
	import org.eclipse.jface.text.IInformationControlExtension5;
	import org.eclipse.jface.text.IInputChangedListener;
	import org.eclipse.jface.text.ITextHoverExtension;
	import org.eclipse.jface.text.information.IInformationProviderExtension2;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.graphics.RGB;
	import org.eclipse.swt.widgets.Shell;
	import org.eclipse.ui.IEditorPart;
	import org.eclipse.ui.ISharedImages;
	import org.eclipse.ui.IWorkbenchPage;
	import org.eclipse.ui.IWorkbenchSite;
	import org.eclipse.ui.PartInitException;
	import org.eclipse.ui.PlatformUI;
	import org.eclipse.ui.editors.text.EditorsUI;

	/**
	* Provides documentation as hover info for Script elements and keywords.
	*/
	@SuppressWarnings("restriction")
	public class DocumentationHover extends AbstractScriptEditorTextHover
	implements IInformationProviderExtension2, ITextHoverExtension {

	private static final long LABEL_FLAGS = ScriptElementLabels.ALL_FULLY_QUALIFIED
	\| ScriptElementLabels.M_APP_RETURNTYPE \| ScriptElementLabels.F_APP_TYPE_SIGNATURE
	\| ScriptElementLabels.M_PARAMETER_TYPES \| ScriptElementLabels.M_PARAMETER_NAMES
	\| ScriptElementLabels.M_EXCEPTIONS \| ScriptElementLabels.F_PRE_TYPE_SIGNATURE
	\| ScriptElementLabels.M_PRE_TYPE_PARAMETERS \| ScriptElementLabels.T_TYPE_PARAMETERS
	\| ScriptElementLabels.USE_RESOLVED;
	private static final long LOCAL_VARIABLE_FLAGS = LABEL_FLAGS & ~ScriptElementLabels.F_FULLY_QUALIFIED
	\| ScriptElementLabels.F_POST_QUALIFIED;

	/**
	* The hover control creator.
	*/
	private IInformationControlCreator fHoverControlCreator;

	/**
	* The presentation control creator.
	*/
	private IInformationControlCreator fPresenterControlCreator;

	/**
	* Action to go back to the previous input in the hover control.
	*
	* @since 4.0
	*/
	private static final class BackAction extends Action {
	private final BrowserInformationControl fInfoControl;

	public BackAction(BrowserInformationControl infoControl) {
	fInfoControl = infoControl;
	setText(ScriptHoverMessages.ScriptdocHover_back);
	ISharedImages images = PlatformUI.getWorkbench().getSharedImages();
	setImageDescriptor(images.getImageDescriptor(ISharedImages.IMG_TOOL_BACK));
	setDisabledImageDescriptor(images.getImageDescriptor(ISharedImages.IMG_TOOL_BACK_DISABLED));

	update();
	}

	@Override
	public void run() {
	BrowserInformationControlInput previous = (BrowserInformationControlInput) fInfoControl.getInput()
	.getPrevious();
	if (previous != null) {
	fInfoControl.setInput(previous);
	}
	}

	public void update() {
	BrowserInformationControlInput current = fInfoControl.getInput();

	if (current != null && current.getPrevious() != null) {
	// BrowserInput previous = current.getPrevious();
	// setToolTipText(Messages.format(
	// JavaHoverMessages.JavadocHover_back_toElement_toolTip,
	// BasicElementLabels.getJavaElementName(previous
	// .getInputName())));
	setEnabled(true);
	} else {
	setEnabled(false);
	}
	setToolTipText(ScriptHoverMessages.ScriptdocHover_back);
	}
	}

	/**
	* Action to go forward to the next input in the hover control.
	*
	* @since 4.0
	*/
	private static final class ForwardAction extends Action {
	private final BrowserInformationControl fInfoControl;

	public ForwardAction(BrowserInformationControl infoControl) {
	fInfoControl = infoControl;
	setText(ScriptHoverMessages.ScriptdocHover_forward);
	ISharedImages images = PlatformUI.getWorkbench().getSharedImages();
	setImageDescriptor(images.getImageDescriptor(ISharedImages.IMG_TOOL_FORWARD));
	setDisabledImageDescriptor(images.getImageDescriptor(ISharedImages.IMG_TOOL_FORWARD_DISABLED));

	update();
	}

	@Override
	public void run() {
	BrowserInformationControlInput next = (BrowserInformationControlInput) fInfoControl.getInput().getNext();
	if (next != null) {
	fInfoControl.setInput(next);
	}
	}

	public void update() {
	BrowserInformationControlInput current = fInfoControl.getInput();

	if (current != null && current.getNext() != null) {
	// setToolTipText(Messages
	// .format(JavaHoverMessages.JavadocHover_forward_toElement_toolTip,
	// BasicElementLabels.getJavaElementName(current
	// .getNext().getInputName())));
	setEnabled(true);
	} else {
	setEnabled(false);
	}
	setToolTipText(ScriptHoverMessages.ScriptdocHover_forward);
	}
	}

	/**
	* Action that opens the current hover input element.
	*
	* @since 4.0
	*/
	private static final class OpenDeclarationAction extends Action {
	private final BrowserInformationControl fInfoControl;

	public OpenDeclarationAction(BrowserInformationControl infoControl) {
	fInfoControl = infoControl;
	setText(ScriptHoverMessages.ScriptdocHover_openDeclaration);
	DLTKPluginImages.setLocalImageDescriptors(this, "goto_input.png"); //$NON-NLS-1$ //TODO:
	// better
	// images
	}

	@Override
	public void run() {
	DocumentationBrowserInformationControlInput infoInput = (DocumentationBrowserInformationControlInput) fInfoControl
	.getInput(); // TODO: check cast
	fInfoControl.notifyDelayedInputChange(null);
	fInfoControl.dispose(); // FIXME: should have protocol to hide,
	// rather than dispose

	try {
	if (infoInput.getElement() instanceof IModelElement) {
	// FIXME: add hover location to editor navigation history?
	DLTKUIPlugin.openInEditor((IModelElement) infoInput.getElement());
	}
	// TODO (alex) try via IOpenDelegate
	} catch (PartInitException \| ModelException e) {
	DLTKUIPlugin.log(e);
	}
	}
	}

	/**
	* Presenter control creator.
	*
	* @since 4.0
	*/
	public static final class PresenterControlCreator extends AbstractReusableInformationControlCreator {

	/**
	* Creates a new PresenterControlCreator.
	*
	* @param site the site or <code>null</code> if none
	*/
	public PresenterControlCreator(IWorkbenchSite site) {
	}

	@Override
	public IInformationControl doCreateInformationControl(Shell parent) {
	if (BrowserInformationControl.isAvailable(parent)) {
	ToolBarManager tbm = new ToolBarManager(SWT.FLAT);
	String font = PreferenceConstants.APPEARANCE_DOCUMENTATION_FONT;
	BrowserInformationControl iControl = new BrowserInformationControl(parent, font, tbm);

	final BackAction backAction = new BackAction(iControl);
	backAction.setEnabled(false);
	tbm.add(backAction);
	final ForwardAction forwardAction = new ForwardAction(iControl);
	tbm.add(forwardAction);
	forwardAction.setEnabled(false);

	// final ShowInJavadocViewAction showInJavadocViewAction = new
	// ShowInJavadocViewAction(
	// iControl);
	// tbm.add(showInJavadocViewAction);
	final OpenDeclarationAction openDeclarationAction = new OpenDeclarationAction(iControl);
	tbm.add(openDeclarationAction);

	// final SimpleSelectionProvider selectionProvider = new
	// SimpleSelectionProvider();
	// if (fSite != null) {
	// OpenAttachedJavadocAction openAttachedJavadocAction = new
	// OpenAttachedJavadocAction(
	// fSite);
	// openAttachedJavadocAction
	// .setSpecialSelectionProvider(selectionProvider);
	// openAttachedJavadocAction
	// .setImageDescriptor(DLTKPluginImages.DESC_ELCL_OPEN_BROWSER);
	// openAttachedJavadocAction
	// .setDisabledImageDescriptor(DLTKPluginImages.DESC_DLCL_OPEN_BROWSER);
	// selectionProvider
	// .addSelectionChangedListener(openAttachedJavadocAction);
	// selectionProvider.setSelection(new StructuredSelection());
	// tbm.add(openAttachedJavadocAction);
	// }

	IInputChangedListener inputChangeListener = newInput -> {
	backAction.update();
	forwardAction.update();
	if (newInput == null) {
	// selectionProvider
	// .setSelection(new StructuredSelection());
	} else if (newInput instanceof BrowserInformationControlInput) {
	BrowserInformationControlInput input = (BrowserInformationControlInput) newInput;
	Object inputElement = input.getInputElement();
	// selectionProvider
	// .setSelection(new StructuredSelection(
	// inputElement));
	boolean isJavaElementInput = inputElement instanceof IModelElement;
	// showInJavadocViewAction
	// .setEnabled(isJavaElementInput);
	openDeclarationAction.setEnabled(isJavaElementInput);
	}
	};
	iControl.addInputChangeListener(inputChangeListener);

	tbm.update(true);

	// TODO (alex) addLinkListener(iControl);
	return iControl;

	}
	return new DefaultInformationControl(parent, true);
	}
	}

	@Override
	public IInformationControlCreator getInformationPresenterControlCreator() {
	if (fPresenterControlCreator == null) {
	fPresenterControlCreator = new PresenterControlCreator(getSite());
	}
	return fPresenterControlCreator;
	}

	private IWorkbenchSite getSite() {
	IEditorPart editor = getEditor();
	if (editor == null) {
	IWorkbenchPage page = DLTKUIPlugin.getActivePage();
	if (page != null)
	editor = page.getActiveEditor();
	}
	if (editor != null)
	return editor.getSite();

	return null;
	}

	/**
	* Hover control creator.
	*
	* @since 4.0
	*/
	public static final class HoverControlCreator extends AbstractReusableInformationControlCreator {
	/**
	* The information presenter control creator.
	*/
	private final IInformationControlCreator fInformationPresenterControlCreator;

	/**
	* <code>true</code> to use the additional info affordance, <code>false</code>
	* to use the hover affordance.
	*/
	private final boolean fAdditionalInfoAffordance;

	/**
	* @param informationPresenterControlCreator control creator for enriched hover
	*/
	public HoverControlCreator(IInformationControlCreator informationPresenterControlCreator) {
	this(informationPresenterControlCreator, false);
	}

	/**
	* @param informationPresenterControlCreator control creator for enriched hover
	* @param additionalInfoAffordance <code>true</code> to use the
	* additional info affordance,
	* <code>false</code> to use the hover
	* affordance
	*/
	public HoverControlCreator(IInformationControlCreator informationPresenterControlCreator,
	boolean additionalInfoAffordance) {
	fInformationPresenterControlCreator = informationPresenterControlCreator;
	fAdditionalInfoAffordance = additionalInfoAffordance;
	}

	/**
	* @see AbstractReusableInformationControlCreator#doCreateInformationControl(Shell)
	*/
	@Override
	public IInformationControl doCreateInformationControl(Shell parent) {
	String tooltipAffordanceString = fAdditionalInfoAffordance
	? DLTKUIPlugin.getAdditionalInfoAffordanceString()
	: EditorsUI.getTooltipAffordanceString();
	if (BrowserInformationControl.isAvailable(parent)) {
	String font = PreferenceConstants.APPEARANCE_DOCUMENTATION_FONT;
	BrowserInformationControl iControl = new BrowserInformationControl(parent, font,
	tooltipAffordanceString) {
	/**
	* @see IInformationControlExtension5#getInformationPresenterControlCreator()
	*/
	@Override
	public IInformationControlCreator getInformationPresenterControlCreator() {
	return fInformationPresenterControlCreator;
	}
	};
	// TODO (alex) addLinkListener(iControl);
	return iControl;
	}
	return new DefaultInformationControl(parent, tooltipAffordanceString);
	}

	/**
	* @see AbstractReusableInformationControlCreator#canReuse(IInformationControl)
	*/
	@Override
	public boolean canReuse(IInformationControl control) {
	if (!super.canReuse(control))
	return false;

	if (control instanceof IInformationControlExtension4) {
	String tooltipAffordanceString = fAdditionalInfoAffordance
	? DLTKUIPlugin.getAdditionalInfoAffordanceString()
	: EditorsUI.getTooltipAffordanceString();
	((IInformationControlExtension4) control).setStatusText(tooltipAffordanceString);
	}

	return true;
	}
	}

	@Override
	public IInformationControlCreator getHoverControlCreator() {
	if (fHoverControlCreator == null)
	fHoverControlCreator = new HoverControlCreator(getInformationPresenterControlCreator());
	return fHoverControlCreator;
	}

	@Override
	protected String getHoverInfo(String nature, Object[] result) {
	StringBuffer buffer = new StringBuffer();
	int nResults = result.length;
	if (nResults == 0)
	return null;

	boolean hasContents = false;
	if (nResults > 1) {
	HTMLPrinter.addSmallHeader(buffer,
	getInfoText(result[0], titleAdapter.getTitle(result[0]), titleAdapter.getImage(result[0])));
	HTMLPrinter.addParagraph(buffer, "<hr>"); //$NON-NLS-1$
	for (int i = 0; i < result.length; i++) {
	Object element = result[i];
	Reader reader = ScriptDocumentationAccess.getHTMLContentReader(nature, element, true, true);
	if (reader == null) {
	continue;
	}
	if (hasContents) {
	HTMLPrinter.addParagraph(buffer, "<hr>"); //$NON-NLS-1$
	}
	HTMLPrinter.addParagraph(buffer, reader);
	hasContents = true;
	}
	} else {
	Object element = result[0];
	IDocumentationResponse response = ScriptDocumentationAccess.getDocumentation(nature, element, titleAdapter);
	// Provide hint why there's no doc
	if (response == null) {
	response = new TextDocumentationResponse(element, titleAdapter.getTitle(element),
	titleAdapter.getImage(element), ScriptHoverMessages.ScriptdocHover_noAttachedInformation);
	}
	try {
	HTMLPrinter.addSmallHeader(buffer, getInfoText(element, response.getTitle(), response.getImage()));
	HTMLPrinter.addParagraph(buffer, response.getReader());
	hasContents = true;
	} catch (IOException e) {
	return null;
	}
	/*
	* else if (curr.getElementType() == IModelElement.LOCAL_VARIABLE \|\|
	* curr.getElementType() == IModelElement.TYPE_PARAMETER) {
	* HTMLPrinter.addSmallHeader(buffer, getInfoText(curr)); hasContents= true; }
	*/
	}
	if (!hasContents)
	return null;
	if (buffer.length() > 0) {
	ColorRegistry registry = JFaceResources.getColorRegistry();
	RGB fgRGB = registry.getRGB("org.eclipse.dltk.ui.documentation.foregroundColor"); //$NON-NLS-1$
	RGB bgRGB = registry.getRGB("org.eclipse.dltk.ui.documentation.backgroundColor"); //$NON-NLS-1$
	HTMLPrinter.insertPageProlog(buffer, 0, bgRGB, fgRGB, getStyleSheet());
	HTMLPrinter.addPageEpilog(buffer);
	return buffer.toString();
	}
	return null;
	}

	private String getInfoText(Object element, String title, ImageDescriptor image) {
	String imageName = null;
	if (image != null) {
	final URL imageURL = DLTKUIPlugin.getDefault().getImagesOnFSRegistry().getImageURL(image);
	if (imageURL != null) {
	imageName = imageURL.toExternalForm();
	}
	}
	StringBuffer buf = new StringBuffer();
	addImageAndLabel(buf, element, imageName, 16, 16,
	org.eclipse.jface.internal.text.html.HTMLPrinter.convertToHTMLContent(title), 20, 2);
	return buf.toString();
	}

	private static void addImageAndLabel(StringBuffer buf, Object element, String imageSrcPath, int imageWidth,
	int imageHeight, String label, int labelLeft, int labelTop) {
	buf.append("<div style='word-wrap: break-word; position: relative; "); //$NON-NLS-1$

	if (imageSrcPath != null) {
	buf.append("margin-left: ").append(labelLeft).append("px; "); //$NON-NLS-1$ //$NON-NLS-2$
	buf.append("padding-top: ").append(labelTop).append("px; "); //$NON-NLS-1$ //$NON-NLS-2$
	}

	buf.append("'>"); //$NON-NLS-1$
	if (imageSrcPath != null) {
	// if (element != null) {
	// try {
	// String uri = JavaElementLinks.createURI(
	// JavaElementLinks.OPEN_LINK_SCHEME, element);
	// buf.append("<a href='").append(uri).append("'>");
	// //$NON-NLS-1$//$NON-NLS-2$
	// } catch (URISyntaxException e) {
	// element = null; // no link
	// }
	// }
	StringBuffer imageStyle = new StringBuffer("border:none; position: absolute; "); //$NON-NLS-1$
	imageStyle.append("width: ").append(imageWidth).append("px; "); //$NON-NLS-1$ //$NON-NLS-2$
	imageStyle.append("height: ").append(imageHeight).append("px; "); //$NON-NLS-1$ //$NON-NLS-2$
	imageStyle.append("left: ").append(-labelLeft - 1).append("px; "); //$NON-NLS-1$ //$NON-NLS-2$

	// hack for broken transparent PNG support in IE 6, see
	// https://bugs.eclipse.org/bugs/show_bug.cgi?id=223900 :
	buf.append("<!--[if lte IE 6]><![if gte IE 5.5]>\n"); //$NON-NLS-1$
	String tooltip = element == null ? "" //$NON-NLS-1$
	: "alt='" //$NON-NLS-1$
	+ ScriptHoverMessages.ScriptdocHover_openDeclaration + "' "; //$NON-NLS-1$
	buf.append("<span ").append(tooltip).append("style=\"") //$NON-NLS-1$ //$NON-NLS-2$
	.append(imageStyle).append("filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='") //$NON-NLS-1$
	.append(imageSrcPath).append("')\"></span>\n"); //$NON-NLS-1$
	buf.append("<![endif]><![endif]-->\n"); //$NON-NLS-1$

	buf.append("<!--[if !IE]>-->\n"); //$NON-NLS-1$
	buf.append("<img ").append(tooltip).append("style='") //$NON-NLS-1$ //$NON-NLS-2$
	.append(imageStyle).append("' src='").append(imageSrcPath) //$NON-NLS-1$
	.append("'/>\n"); //$NON-NLS-1$
	buf.append("<!--<![endif]-->\n"); //$NON-NLS-1$
	buf.append("<!--[if gte IE 7]>\n"); //$NON-NLS-1$
	buf.append("<img ").append(tooltip).append("style='") //$NON-NLS-1$ //$NON-NLS-2$
	.append(imageStyle).append("' src='").append(imageSrcPath) //$NON-NLS-1$
	.append("'/>\n"); //$NON-NLS-1$
	buf.append("<![endif]-->\n"); //$NON-NLS-1$
	// if (element != null) {
	// buf.append("</a>"); //$NON-NLS-1$
	// }
	}

	buf.append(label);
	buf.append("</div>"); //$NON-NLS-1$
	}

	@Override
	protected String getHoverInfo(String nature, String content) {
	try {
	Reader reader = ScriptDocumentationAccess.getKeywordDocumentation(nature, getEditorInputModelElement(),
	content);
	if (reader != null) {
	StringBuffer buffer = new StringBuffer();
	HTMLPrinter.addParagraph(buffer, reader);
	if (buffer.length() > 0) {
	ColorRegistry registry = JFaceResources.getColorRegistry();
	RGB fgRGB = registry.getRGB("org.eclipse.dltk.ui.documentation.foregroundColor"); //$NON-NLS-1$
	RGB bgRGB = registry.getRGB("org.eclipse.dltk.ui.documentation.backgroundColor"); //$NON-NLS-1$
	HTMLPrinter.insertPageProlog(buffer, 0, bgRGB, fgRGB, getStyleSheet());
	HTMLPrinter.addPageEpilog(buffer);
	return buffer.toString();
	}
	}
	} catch (ModelException ex) {
	// TODO: log
	}
	return null;
	}

	private static final ScriptDocumentationTitleAdapter titleAdapter = new ScriptDocumentationTitleAdapter();

	@Internal
	static class ScriptDocumentationTitleAdapter extends PlatformObject implements IScriptDocumentationTitleAdapter {

	private ScriptElementImageProvider fImageProvider;

	@Override
	public String getTitle(Object element) {
	if (element instanceof IModelElement) {
	IModelElement member = (IModelElement) element;
	long flags = member.getElementType() == IModelElement.LOCAL_VARIABLE ? LOCAL_VARIABLE_FLAGS
	: LABEL_FLAGS;
	String label = ScriptElementLabels.getDefault().getElementLabel(member, flags);
	return label;
	}
	return null;
	}

	@Override
	public ImageDescriptor getImage(Object element) {
	if (element instanceof IModelElement) {
	final IModelElement modelElement = (IModelElement) element;
	if (fImageProvider == null) {
	fImageProvider = new ScriptElementImageProvider();
	}
	return fImageProvider.getScriptImageDescriptor(modelElement,
	ScriptElementImageProvider.OVERLAY_ICONS \| ScriptElementImageProvider.SMALL_ICONS);
	}
	return null;
	}
	}
	}