org.eclipse.ui.editors/src/org/eclipse/ui/texteditor/RevisionHoverInformationControlCreator.java

/*******************************************************************************
 * Copyright (c) 2007, 2008 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.texteditor;

import org.eclipse.swt.widgets.Shell;

import org.eclipse.jface.internal.text.html.BrowserInformationControl;
import org.eclipse.jface.internal.text.html.HTMLPrinter;
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.IInformationControlExtension4;

import org.eclipse.ui.editors.text.EditorsUI;


/**
 * The revision information control creator that can show the tool tip affordance.
 *
 * @since 3.3
 */
class RevisionHoverInformationControlCreator extends AbstractReusableInformationControlCreator {

	private static final String fgStyleSheet= "/* Font definitions */\n" + //$NON-NLS-1$
	"body, h1, h2, h3, h4, h5, h6, p, table, td, caption, th, ul, ol, dl, li, dd, dt {font-family: sans-serif; font-size: 9pt }\n" + //$NON-NLS-1$
	"pre				{ font-family: monospace; font-size: 9pt }\n" + //$NON-NLS-1$
	"\n" + //$NON-NLS-1$
	"/* Margins */\n" + //$NON-NLS-1$
	"body	     { overflow: auto; margin-top: 0; margin-bottom: 4; margin-left: 3; margin-right: 0 }\n" + //$NON-NLS-1$
	"h1           { margin-top: 5; margin-bottom: 1 }	\n" + //$NON-NLS-1$
	"h2           { margin-top: 25; margin-bottom: 3 }\n" + //$NON-NLS-1$
	"h3           { margin-top: 20; margin-bottom: 3 }\n" + //$NON-NLS-1$
	"h4           { margin-top: 20; margin-bottom: 3 }\n" + //$NON-NLS-1$
	"h5           { margin-top: 0; margin-bottom: 0 }\n" + //$NON-NLS-1$
	"p            { margin-top: 10px; margin-bottom: 10px }\n" + //$NON-NLS-1$
	"pre	         { margin-left: 6 }\n" + //$NON-NLS-1$
	"ul	         { margin-top: 0; margin-bottom: 10 }\n" + //$NON-NLS-1$
	"li	         { margin-top: 0; margin-bottom: 0 } \n" + //$NON-NLS-1$
	"li p	     { margin-top: 0; margin-bottom: 0 } \n" + //$NON-NLS-1$
	"ol	         { margin-top: 0; margin-bottom: 10 }\n" + //$NON-NLS-1$
	"dl	         { margin-top: 0; margin-bottom: 10 }\n" + //$NON-NLS-1$
	"dt	         { margin-top: 0; margin-bottom: 0; font-weight: bold }\n" + //$NON-NLS-1$
	"dd	         { margin-top: 0; margin-bottom: 0 }\n" + //$NON-NLS-1$
	"\n" + //$NON-NLS-1$
	"/* Styles and colors */\n" + //$NON-NLS-1$
	"a:link	     { color: hyperlinkColor }\n" + //$NON-NLS-1$
	"a:hover	     { color: activeHyperlinkColor }\n" + //$NON-NLS-1$
	"a:visited    { text-decoration: underline }\n" + //$NON-NLS-1$
	"h4           { font-style: italic }\n" + //$NON-NLS-1$
	"strong	     { font-weight: bold }\n" + //$NON-NLS-1$
	"em	         { font-style: italic }\n" + //$NON-NLS-1$
	"var	         { font-style: italic }\n" + //$NON-NLS-1$
	"th	         { font-weight: bold }\n" + //$NON-NLS-1$
	""; //$NON-NLS-1$


	private static final class RevisionInformationControl extends BrowserInformationControl {

		public RevisionInformationControl(Shell parent, String statusFieldText) {
			super(parent, JFaceResources.DIALOG_FONT, statusFieldText);
		}

		public RevisionInformationControl(Shell parent) {
			super(parent, JFaceResources.DIALOG_FONT, true);
		}

		/**
		 * {@inheritDoc}
		 *
		 * @deprecated use {@link #setInput(Object)}
		 */
		@Deprecated
		@Override
		public void setInformation(String content) {
			content= addCSSToHTMLFragment(content);
			super.setInformation(content);
		}

		/**
		 * Adds a HTML header and CSS info if <code>html</code> is only an HTML fragment (has no
		 * &lt;html&gt; section).
		 *
		 * @param html the html / text produced by a revision
		 * @return modified html
		 */
		private String addCSSToHTMLFragment(String html) {
			int max= Math.min(100, html.length());
			if (html.substring(0, max).contains("<html>")) //$NON-NLS-1$
				// there is already a header
				return html;

			StringBuilder info= new StringBuilder(512 + html.length());
			HTMLPrinter.insertPageProlog(info, 0, fgStyleSheet);
			info.append(html);
			HTMLPrinter.addPageEpilog(info);
			return info.toString();
		}
	}


	private boolean fIsFocusable;


	public RevisionHoverInformationControlCreator(boolean isFocusable) {
		fIsFocusable= isFocusable;
	}

	@Override
	public boolean canReuse(IInformationControl control) {
		if (!super.canReuse(control))
			return false;

		if (control instanceof IInformationControlExtension4)
			((IInformationControlExtension4)control).setStatusText(EditorsUI.getTooltipAffordanceString());

		return true;
	}

	@Override
	protected IInformationControl doCreateInformationControl(Shell parent) {
		if (BrowserInformationControl.isAvailable(parent)) {
			if (fIsFocusable)
				return new RevisionInformationControl(parent);
			return new RevisionInformationControl(parent, EditorsUI.getTooltipAffordanceString());
		}

		if (fIsFocusable)
			return new DefaultInformationControl(parent, true);
		return new DefaultInformationControl(parent, EditorsUI.getTooltipAffordanceString());
	}

}