org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/hover/SourceViewerInformationControl.java - jdt/eclipse.jdt.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2012 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
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.jdt.internal.ui.text.java.hover;

 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.StyledText;
 import org.eclipse.swt.events.DisposeEvent;
 import org.eclipse.swt.events.DisposeListener;
 import org.eclipse.swt.events.FocusListener;
 import org.eclipse.swt.events.KeyEvent;
 import org.eclipse.swt.events.KeyListener;
 import org.eclipse.swt.graphics.Color;
 import org.eclipse.swt.graphics.Font;
 import org.eclipse.swt.graphics.FontData;
 import org.eclipse.swt.graphics.GC;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.RGB;
 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.Shell;

 import org.eclipse.core.runtime.Assert;

 import org.eclipse.jface.preference.IPreferenceStore;
 import org.eclipse.jface.preference.PreferenceConverter;
 import org.eclipse.jface.resource.JFaceResources;

 import org.eclipse.jface.text.Document;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IInformationControl;
 import org.eclipse.jface.text.IInformationControlCreator;
 import org.eclipse.jface.text.IInformationControlExtension;
 import org.eclipse.jface.text.IInformationControlExtension3;
 import org.eclipse.jface.text.IInformationControlExtension5;
 import org.eclipse.jface.text.source.ISourceViewer;
 import org.eclipse.jface.text.source.SourceViewer;

 import org.eclipse.ui.texteditor.AbstractTextEditor;

 import org.eclipse.jdt.ui.JavaUI;
 import org.eclipse.jdt.ui.PreferenceConstants;
 import org.eclipse.jdt.ui.text.IJavaColorConstants;
 import org.eclipse.jdt.ui.text.IJavaPartitions;

 import org.eclipse.jdt.internal.ui.JavaPlugin;
 import org.eclipse.jdt.internal.ui.javaeditor.JavaSourceViewer;
 import org.eclipse.jdt.internal.ui.text.SimpleJavaSourceViewerConfiguration;

 /**
  * Source viewer based implementation of <code>IInformationControl</code>.
  * Displays information in a source viewer.
  *
  * @since 3.0
  */
 public class SourceViewerInformationControl implements IInformationControl, IInformationControlExtension, IInformationControlExtension3, IInformationControlExtension5, DisposeListener {

 	/** The control's shell */
 	private Shell fShell;
 	/** The control's text widget */
 	private StyledText fText;
 	/** The text font (do not dispose!) */
 	private Font fTextFont;
 	/** The control's source viewer */
 	private SourceViewer fViewer;
 	/**
 	 * The optional status field.
 	 *
 	 * @since 3.0
 	 */
 	private Label fStatusField;
 	/**
 	 * The separator for the optional status field.
 	 *
 	 * @since 3.0
 	 */
 	private Label fSeparator;
 	/**
 	 * The font of the optional status text label.
 	 *
 	 * @since 3.0
 	 */
 	private Font fStatusTextFont;
 	/**
 	 * The color of the optional status text label or <code>null</code> if none.
 	 *
 	 * @since 3.6
 	 */
 	private Color fStatusTextForegroundColor;
 	/**
 	 * The width size constraint.
 	 * @since 3.2
 	 */
 	private int fMaxWidth= SWT.DEFAULT;
 	/**
 	 * The height size constraint.
 	 * @since 3.2
 	 */
 	private int fMaxHeight= SWT.DEFAULT;
 	/**
 	 * The orientation of the shell
 	 * @since 3.4
 	 */
 	private final int fOrientation;

 	private Color fBackgroundColor;
 	private boolean fIsSystemBackgroundColor= true;


 	/**
 	 * Creates a source viewer information control with the given shell as parent. The given
 	 * styles are applied to the created styled text widget. The status field will
 	 * contain the given text or be hidden.
 	 *
 	 * @param parent the parent shell
 	 * @param isResizable <code>true</code> if resizable
 	 * @param orientation the orientation
 	 * @param statusFieldText the text to be used in the optional status field
 	 *            or <code>null</code> if the status field should be hidden
 	 */
 	public SourceViewerInformationControl(Shell parent, boolean isResizable, int orientation, String statusFieldText) {
 		Assert.isLegal(orientation == SWT.RIGHT_TO_LEFT || orientation == SWT.LEFT_TO_RIGHT || orientation == SWT.NONE);
 		fOrientation= orientation;

 		GridLayout layout;
 		GridData gd;

 		int shellStyle= SWT.TOOL | SWT.ON_TOP | orientation | (isResizable ? SWT.RESIZE : 0);
 		int textStyle= isResizable ? SWT.V_SCROLL | SWT.H_SCROLL : SWT.NONE;

 		fShell= new Shell(parent, SWT.NO_FOCUS | SWT.ON_TOP | shellStyle);
 		Display display= fShell.getDisplay();

 		initializeColors();

 		Composite composite= fShell;
 		layout= new GridLayout(1, false);
 		layout.marginHeight= 0;
 		layout.marginWidth= 0;
 		composite.setLayout(layout);
 		gd= new GridData(GridData.FILL_HORIZONTAL);
 		composite.setLayoutData(gd);

 		if (statusFieldText != null) {
 			composite= new Composite(composite, SWT.NONE);
 			layout= new GridLayout(1, false);
 			layout.marginHeight= 0;
 			layout.marginWidth= 0;
 			layout.verticalSpacing= 1;
 			composite.setLayout(layout);
 			gd= new GridData(GridData.FILL_BOTH);
 			composite.setLayoutData(gd);
 			composite.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));
 			composite.setBackground(fBackgroundColor);
 		}

 		// Source viewer
 		IPreferenceStore store= JavaPlugin.getDefault().getCombinedPreferenceStore();
 		fViewer= new JavaSourceViewer(composite, null, null, false, textStyle, store);
 		fViewer.configure(new SimpleJavaSourceViewerConfiguration(JavaPlugin.getDefault().getJavaTextTools().getColorManager(), store, null, IJavaPartitions.JAVA_PARTITIONING, false));
 		fViewer.setEditable(false);

 		fText= fViewer.getTextWidget();
 		gd= new GridData(GridData.BEGINNING | GridData.FILL_BOTH);
 		fText.setLayoutData(gd);
 		fText.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));
 		fText.setBackground(fBackgroundColor);

 		initializeFont();

 		fText.addKeyListener(new KeyListener() {

 			@Override
 			public void keyPressed(KeyEvent e)  {
 				if (e.character == 0x1B) // ESC
 					fShell.dispose();
 			}

 			@Override
 			public void keyReleased(KeyEvent e) {}
 		});

 		// Status field
 		if (statusFieldText != null) {

 			// Horizontal separator line
 			fSeparator= new Label(composite, SWT.SEPARATOR | SWT.HORIZONTAL | SWT.LINE_DOT);
 			fSeparator.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));

 			// Status field label
 			fStatusField= new Label(composite, SWT.RIGHT);
 			fStatusField.setText(statusFieldText);
 			Font font= fStatusField.getFont();
 			FontData[] fontDatas= font.getFontData();
 			for (int i= 0; i < fontDatas.length; i++)
 				fontDatas[i].setHeight(fontDatas[i].getHeight() * 9 / 10);
 			fStatusTextFont= new Font(fStatusField.getDisplay(), fontDatas);
 			fStatusField.setFont(fStatusTextFont);
 			GridData gd2= new GridData(GridData.FILL_HORIZONTAL | GridData.VERTICAL_ALIGN_BEGINNING);
 			fStatusField.setLayoutData(gd2);

 			RGB javaDefaultColor= JavaUI.getColorManager().getColor(IJavaColorConstants.JAVA_DEFAULT).getRGB();
 			fStatusTextForegroundColor= new Color(fStatusField.getDisplay(), blend(fBackgroundColor.getRGB(), javaDefaultColor, 0.56f));
 			fStatusField.setForeground(fStatusTextForegroundColor);
 			fStatusField.setBackground(fBackgroundColor);
 		}

 		addDisposeListener(this);
 	}

 	/**
 	 * Returns an RGB that lies between the given foreground and background
 	 * colors using the given mixing factor. A <code>factor</code> of 1.0 will produce a
 	 * color equal to <code>fg</code>, while a <code>factor</code> of 0.0 will produce one
 	 * equal to <code>bg</code>.
 	 * @param bg the background color
 	 * @param fg the foreground color
 	 * @param factor the mixing factor, must be in [0,&nbsp;1]
 	 *
 	 * @return the interpolated color
 	 * @since 3.6
 	 */
 	private static RGB blend(RGB bg, RGB fg, float factor) {
 		// copy of org.eclipse.jface.internal.text.revisions.Colors#blend(..)
 		Assert.isLegal(bg != null);
 		Assert.isLegal(fg != null);
 		Assert.isLegal(factor >= 0f && factor <= 1f);

 		float complement= 1f - factor;
 		return new RGB(
 				(int) (complement * bg.red + factor * fg.red),
 				(int) (complement * bg.green + factor * fg.green),
 				(int) (complement * bg.blue + factor * fg.blue)
 		);
 	}

 	private void initializeColors() {
 		IPreferenceStore store= JavaPlugin.getDefault().getPreferenceStore();
 		RGB bgRGB;
 		if (store.getBoolean(PreferenceConstants.EDITOR_SOURCE_HOVER_BACKGROUND_COLOR_SYSTEM_DEFAULT)) {
 			bgRGB= getVisibleBackgroundColor(fShell.getDisplay());
 		} else {
 			bgRGB= PreferenceConverter.getColor(store, PreferenceConstants.EDITOR_SOURCE_HOVER_BACKGROUND_COLOR);
 		}
 		if (bgRGB != null) {
 			fBackgroundColor= new Color(fShell.getDisplay(), bgRGB);
 			fIsSystemBackgroundColor= false;
 		} else {
 			fBackgroundColor= fShell.getDisplay().getSystemColor(SWT.COLOR_INFO_BACKGROUND);
 			fIsSystemBackgroundColor= true;
 		}
 	}

 	/**
 	 * Returns <code>null</code> if {@link SWT#COLOR_INFO_BACKGROUND} is visibly distinct from the
 	 * default Java source text color. Otherwise, returns the editor background color.
 	 *
 	 * @param display the display
 	 * @return an RGB or <code>null</code>
 	 * @since 3.6.1
 	 */
 	public static RGB getVisibleBackgroundColor(Display display) {
 		float[] infoBgHSB= display.getSystemColor(SWT.COLOR_INFO_BACKGROUND).getRGB().getHSB();

 		Color javaDefaultColor= JavaUI.getColorManager().getColor(IJavaColorConstants.JAVA_DEFAULT);
 		RGB javaDefaultRGB= javaDefaultColor != null ? javaDefaultColor.getRGB() : new RGB(255, 255, 255);
 		float[] javaDefaultHSB= javaDefaultRGB.getHSB();

 		if (Math.abs(infoBgHSB[2] - javaDefaultHSB[2]) < 0.5f) {
 			// workaround for dark tooltip background color, see https://bugs.eclipse.org/309334
 			IPreferenceStore preferenceStore= JavaPlugin.getDefault().getCombinedPreferenceStore();
 			boolean useDefault= preferenceStore.getBoolean(AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND_SYSTEM_DEFAULT);
 			if (useDefault)
 				return display.getSystemColor(SWT.COLOR_LIST_BACKGROUND).getRGB();
 			return PreferenceConverter.getColor(preferenceStore, AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND);
 		}
 		return null;
 	}

 	/**
 	 * Initialize the font to the Java editor font.
 	 *
 	 * @since 3.2
 	 */
 	private void initializeFont() {
 		fTextFont= JFaceResources.getFont(PreferenceConstants.EDITOR_TEXT_FONT);
 		StyledText styledText= getViewer().getTextWidget();
 		styledText.setFont(fTextFont);
 	}

 	/*
 	 * @see org.eclipse.jface.text.IInformationControlExtension2#setInput(java.lang.Object)
 	 */
 	public void setInput(Object input) {
 		if (input instanceof String)
 			setInformation((String)input);
 		else
 			setInformation(null);
 	}

 	/*
 	 * @see IInformationControl#setInformation(String)
 	 */
 	@Override
 	public void setInformation(String content) {
 		if (content == null) {
 			fViewer.setInput(null);
 			return;
 		}

 		IDocument doc= new Document(content);
 		JavaPlugin.getDefault().getJavaTextTools().setupJavaDocumentPartitioner(doc, IJavaPartitions.JAVA_PARTITIONING);
 		fViewer.setInput(doc);
 	}

 	/*
 	 * @see IInformationControl#setVisible(boolean)
 	 */
 	@Override
 	public void setVisible(boolean visible) {
 			fShell.setVisible(visible);
 	}

 	/**
 	 * {@inheritDoc}
 	 * @since 3.0
 	 */
 	@Override
 	public void widgetDisposed(DisposeEvent event) {
 		if (fStatusTextFont != null && !fStatusTextFont.isDisposed())
 			fStatusTextFont.dispose();
 		fStatusTextFont= null;

 		if (fStatusTextForegroundColor != null && !fStatusTextForegroundColor.isDisposed())
 			fStatusTextForegroundColor.dispose();
 		fStatusTextForegroundColor= null;

 		fTextFont= null;
 		fShell= null;
 		fText= null;
 	}

 	@Override
 	public final void dispose() {
 		if (!fIsSystemBackgroundColor)
 			fBackgroundColor.dispose();
 		if (fShell != null && !fShell.isDisposed())
 			fShell.dispose();
 		else
 			widgetDisposed(null);
 	}

 	/*
 	 * @see IInformationControl#setSize(int, int)
 	 */
 	@Override
 	public void setSize(int width, int height) {
 		fShell.setSize(width, height);
 	}

 	/*
 	 * @see IInformationControl#setLocation(Point)
 	 */
 	@Override
 	public void setLocation(Point location) {
 		fShell.setLocation(location);
 	}

 	/*
 	 * @see IInformationControl#setSizeConstraints(int, int)
 	 */
 	@Override
 	public void setSizeConstraints(int maxWidth, int maxHeight) {
 		fMaxWidth= maxWidth;
 		fMaxHeight= maxHeight;
 	}

 	/*
 	 * @see IInformationControl#computeSizeHint()
 	 */
 	@Override
 	public Point computeSizeHint() {
 		// compute the preferred size
 		int x= SWT.DEFAULT;
 		int y= SWT.DEFAULT;
 		Point size= fShell.computeSize(x, y);
 		if (size.x > fMaxWidth)
 			x= fMaxWidth;
 		if (size.y > fMaxHeight)
 			y= fMaxHeight;

 		// recompute using the constraints if the preferred size is larger than the constraints
 		if (x != SWT.DEFAULT || y != SWT.DEFAULT)
 			size= fShell.computeSize(x, y, false);

 		return size;
 	}

 	/*
 	 * @see IInformationControl#addDisposeListener(DisposeListener)
 	 */
 	@Override
 	public void addDisposeListener(DisposeListener listener) {
 		fShell.addDisposeListener(listener);
 	}

 	/*
 	 * @see IInformationControl#removeDisposeListener(DisposeListener)
 	 */
 	@Override
 	public void removeDisposeListener(DisposeListener listener) {
 		fShell.removeDisposeListener(listener);
 	}

 	/*
 	 * @see IInformationControl#setForegroundColor(Color)
 	 */
 	@Override
 	public void setForegroundColor(Color foreground) {
 		fText.setForeground(foreground);
 	}

 	/*
 	 * @see IInformationControl#setBackgroundColor(Color)
 	 */
 	@Override
 	public void setBackgroundColor(Color background) {
 		fText.setBackground(background);
 	}

 	/*
 	 * @see IInformationControl#isFocusControl()
 	 */
 	@Override
 	public boolean isFocusControl() {
 		return fShell.getDisplay().getActiveShell() == fShell;
 	}

 	/*
 	 * @see IInformationControl#setFocus()
 	 */
 	@Override
 	public void setFocus() {
 		fShell.forceFocus();
 		fText.setFocus();
 	}

 	/*
 	 * @see IInformationControl#addFocusListener(FocusListener)
 	 */
 	@Override
 	public void addFocusListener(FocusListener listener) {
 		fText.addFocusListener(listener);
 	}

 	/*
 	 * @see IInformationControl#removeFocusListener(FocusListener)
 	 */
 	@Override
 	public void removeFocusListener(FocusListener listener) {
 		fText.removeFocusListener(listener);
 	}

 	/*
 	 * @see IInformationControlExtension#hasContents()
 	 */
 	@Override
 	public boolean hasContents() {
 		return fText.getCharCount() > 0;
 	}

 	protected ISourceViewer getViewer()  {
 		return fViewer;
 	}

 	/*
 	 * @see org.eclipse.jface.text.IInformationControlExtension3#computeTrim()
 	 * @since 3.4
 	 */
 	@Override
 	public Rectangle computeTrim() {
 		Rectangle trim= fShell.computeTrim(0, 0, 0, 0);
 		addInternalTrim(trim);
 		return trim;
 	}

 	/**
 	 * Adds the internal trimmings to the given trim of the shell.
 	 *
 	 * @param trim the shell's trim, will be updated
 	 * @since 3.4
 	 */
 	private void addInternalTrim(Rectangle trim) {
 		Rectangle textTrim= fText.computeTrim(0, 0, 0, 0);
 		trim.x+= textTrim.x;
 		trim.y+= textTrim.y;
 		trim.width+= textTrim.width;
 		trim.height+= textTrim.height;

 		if (fStatusField != null) {
 			trim.height+= fSeparator.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;
 			trim.height+= fStatusField.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;
 			trim.height+= 1; // verticalSpacing
 		}
 	}

 	/*
 	 * @see org.eclipse.jface.text.IInformationControlExtension3#getBounds()
 	 * @since 3.4
 	 */
 	@Override
 	public Rectangle getBounds() {
 		return fShell.getBounds();
 	}

 	/*
 	 * @see org.eclipse.jface.text.IInformationControlExtension3#restoresLocation()
 	 * @since 3.4
 	 */
 	@Override
 	public boolean restoresLocation() {
 		return false;
 	}

 	/*
 	 * @see org.eclipse.jface.text.IInformationControlExtension3#restoresSize()
 	 * @since 3.4
 	 */
 	@Override
 	public boolean restoresSize() {
 		return false;
 	}

 	/*
 	 * @see org.eclipse.jface.text.IInformationControlExtension5#getInformationPresenterControlCreator()
 	 * @since 3.4
 	 */
 	@Override
 	public IInformationControlCreator getInformationPresenterControlCreator() {
 		return new IInformationControlCreator() {
 			@Override
 			public IInformationControl createInformationControl(Shell parent) {
 				return new SourceViewerInformationControl(parent, true, fOrientation, null);
 			}
 		};
 	}

 	/*
 	 * @see org.eclipse.jface.text.IInformationControlExtension5#containsControl(org.eclipse.swt.widgets.Control)
 	 * @since 3.4
 	 */
 	@Override
 	public boolean containsControl(Control control) {
 		do {
 			if (control == fShell)
 				return true;
 			if (control instanceof Shell)
 				return false;
 			control= control.getParent();
 		} while (control != null);
 		return false;
 	}

 	/*
 	 * @see org.eclipse.jface.text.IInformationControlExtension5#isVisible()
 	 * @since 3.4
 	 */
 	@Override
 	public boolean isVisible() {
 		return fShell != null && !fShell.isDisposed() && fShell.isVisible();
 	}

 	/*
 	 * @see org.eclipse.jface.text.IInformationControlExtension5#computeSizeConstraints(int, int)
 	 */
 	@Override
 	public Point computeSizeConstraints(int widthInChars, int heightInChars) {
 		GC gc= new GC(fText);
 		gc.setFont(fTextFont);
 		int width= gc.getFontMetrics().getAverageCharWidth();
 		int height= fText.getLineHeight(); //https://bugs.eclipse.org/bugs/show_bug.cgi?id=377109
 		gc.dispose();

 		return new Point(widthInChars * width, heightInChars * height);
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2012 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
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.jdt.internal.ui.text.java.hover;

	import org.eclipse.swt.SWT;
	import org.eclipse.swt.custom.StyledText;
	import org.eclipse.swt.events.DisposeEvent;
	import org.eclipse.swt.events.DisposeListener;
	import org.eclipse.swt.events.FocusListener;
	import org.eclipse.swt.events.KeyEvent;
	import org.eclipse.swt.events.KeyListener;
	import org.eclipse.swt.graphics.Color;
	import org.eclipse.swt.graphics.Font;
	import org.eclipse.swt.graphics.FontData;
	import org.eclipse.swt.graphics.GC;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.graphics.RGB;
	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.Shell;

	import org.eclipse.core.runtime.Assert;

	import org.eclipse.jface.preference.IPreferenceStore;
	import org.eclipse.jface.preference.PreferenceConverter;
	import org.eclipse.jface.resource.JFaceResources;

	import org.eclipse.jface.text.Document;
	import org.eclipse.jface.text.IDocument;
	import org.eclipse.jface.text.IInformationControl;
	import org.eclipse.jface.text.IInformationControlCreator;
	import org.eclipse.jface.text.IInformationControlExtension;
	import org.eclipse.jface.text.IInformationControlExtension3;
	import org.eclipse.jface.text.IInformationControlExtension5;
	import org.eclipse.jface.text.source.ISourceViewer;
	import org.eclipse.jface.text.source.SourceViewer;

	import org.eclipse.ui.texteditor.AbstractTextEditor;

	import org.eclipse.jdt.ui.JavaUI;
	import org.eclipse.jdt.ui.PreferenceConstants;
	import org.eclipse.jdt.ui.text.IJavaColorConstants;
	import org.eclipse.jdt.ui.text.IJavaPartitions;

	import org.eclipse.jdt.internal.ui.JavaPlugin;
	import org.eclipse.jdt.internal.ui.javaeditor.JavaSourceViewer;
	import org.eclipse.jdt.internal.ui.text.SimpleJavaSourceViewerConfiguration;

	/**
	* Source viewer based implementation of <code>IInformationControl</code>.
	* Displays information in a source viewer.
	*
	* @since 3.0
	*/
	public class SourceViewerInformationControl implements IInformationControl, IInformationControlExtension, IInformationControlExtension3, IInformationControlExtension5, DisposeListener {

	/** The control's shell */
	private Shell fShell;
	/** The control's text widget */
	private StyledText fText;
	/** The text font (do not dispose!) */
	private Font fTextFont;
	/** The control's source viewer */
	private SourceViewer fViewer;
	/**
	* The optional status field.
	*
	* @since 3.0
	*/
	private Label fStatusField;
	/**
	* The separator for the optional status field.
	*
	* @since 3.0
	*/
	private Label fSeparator;
	/**
	* The font of the optional status text label.
	*
	* @since 3.0
	*/
	private Font fStatusTextFont;
	/**
	* The color of the optional status text label or <code>null</code> if none.
	*
	* @since 3.6
	*/
	private Color fStatusTextForegroundColor;
	/**
	* The width size constraint.
	* @since 3.2
	*/
	private int fMaxWidth= SWT.DEFAULT;
	/**
	* The height size constraint.
	* @since 3.2
	*/
	private int fMaxHeight= SWT.DEFAULT;
	/**
	* The orientation of the shell
	* @since 3.4
	*/
	private final int fOrientation;

	private Color fBackgroundColor;
	private boolean fIsSystemBackgroundColor= true;


	/**
	* Creates a source viewer information control with the given shell as parent. The given
	* styles are applied to the created styled text widget. The status field will
	* contain the given text or be hidden.
	*
	* @param parent the parent shell
	* @param isResizable <code>true</code> if resizable
	* @param orientation the orientation
	* @param statusFieldText the text to be used in the optional status field
	* or <code>null</code> if the status field should be hidden
	*/
	public SourceViewerInformationControl(Shell parent, boolean isResizable, int orientation, String statusFieldText) {
	Assert.isLegal(orientation == SWT.RIGHT_TO_LEFT \|\| orientation == SWT.LEFT_TO_RIGHT \|\| orientation == SWT.NONE);
	fOrientation= orientation;

	GridLayout layout;
	GridData gd;

	int shellStyle= SWT.TOOL \| SWT.ON_TOP \| orientation \| (isResizable ? SWT.RESIZE : 0);
	int textStyle= isResizable ? SWT.V_SCROLL \| SWT.H_SCROLL : SWT.NONE;

	fShell= new Shell(parent, SWT.NO_FOCUS \| SWT.ON_TOP \| shellStyle);
	Display display= fShell.getDisplay();

	initializeColors();

	Composite composite= fShell;
	layout= new GridLayout(1, false);
	layout.marginHeight= 0;
	layout.marginWidth= 0;
	composite.setLayout(layout);
	gd= new GridData(GridData.FILL_HORIZONTAL);
	composite.setLayoutData(gd);

	if (statusFieldText != null) {
	composite= new Composite(composite, SWT.NONE);
	layout= new GridLayout(1, false);
	layout.marginHeight= 0;
	layout.marginWidth= 0;
	layout.verticalSpacing= 1;
	composite.setLayout(layout);
	gd= new GridData(GridData.FILL_BOTH);
	composite.setLayoutData(gd);
	composite.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));
	composite.setBackground(fBackgroundColor);
	}

	// Source viewer
	IPreferenceStore store= JavaPlugin.getDefault().getCombinedPreferenceStore();
	fViewer= new JavaSourceViewer(composite, null, null, false, textStyle, store);
	fViewer.configure(new SimpleJavaSourceViewerConfiguration(JavaPlugin.getDefault().getJavaTextTools().getColorManager(), store, null, IJavaPartitions.JAVA_PARTITIONING, false));
	fViewer.setEditable(false);

	fText= fViewer.getTextWidget();
	gd= new GridData(GridData.BEGINNING \| GridData.FILL_BOTH);
	fText.setLayoutData(gd);
	fText.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));
	fText.setBackground(fBackgroundColor);

	initializeFont();

	fText.addKeyListener(new KeyListener() {

	@Override
	public void keyPressed(KeyEvent e) {
	if (e.character == 0x1B) // ESC
	fShell.dispose();
	}

	@Override
	public void keyReleased(KeyEvent e) {}
	});

	// Status field
	if (statusFieldText != null) {

	// Horizontal separator line
	fSeparator= new Label(composite, SWT.SEPARATOR \| SWT.HORIZONTAL \| SWT.LINE_DOT);
	fSeparator.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));

	// Status field label
	fStatusField= new Label(composite, SWT.RIGHT);
	fStatusField.setText(statusFieldText);
	Font font= fStatusField.getFont();
	FontData[] fontDatas= font.getFontData();
	for (int i= 0; i < fontDatas.length; i++)
	fontDatas[i].setHeight(fontDatas[i].getHeight() * 9 / 10);
	fStatusTextFont= new Font(fStatusField.getDisplay(), fontDatas);
	fStatusField.setFont(fStatusTextFont);
	GridData gd2= new GridData(GridData.FILL_HORIZONTAL \| GridData.VERTICAL_ALIGN_BEGINNING);
	fStatusField.setLayoutData(gd2);

	RGB javaDefaultColor= JavaUI.getColorManager().getColor(IJavaColorConstants.JAVA_DEFAULT).getRGB();
	fStatusTextForegroundColor= new Color(fStatusField.getDisplay(), blend(fBackgroundColor.getRGB(), javaDefaultColor, 0.56f));
	fStatusField.setForeground(fStatusTextForegroundColor);
	fStatusField.setBackground(fBackgroundColor);
	}

	addDisposeListener(this);
	}

	/**
	* Returns an RGB that lies between the given foreground and background
	* colors using the given mixing factor. A <code>factor</code> of 1.0 will produce a
	* color equal to <code>fg</code>, while a <code>factor</code> of 0.0 will produce one
	* equal to <code>bg</code>.
	* @param bg the background color
	* @param fg the foreground color
	* @param factor the mixing factor, must be in [0, 1]
	*
	* @return the interpolated color
	* @since 3.6
	*/
	private static RGB blend(RGB bg, RGB fg, float factor) {
	// copy of org.eclipse.jface.internal.text.revisions.Colors#blend(..)
	Assert.isLegal(bg != null);
	Assert.isLegal(fg != null);
	Assert.isLegal(factor >= 0f && factor <= 1f);

	float complement= 1f - factor;
	return new RGB(
	(int) (complement * bg.red + factor * fg.red),
	(int) (complement * bg.green + factor * fg.green),
	(int) (complement * bg.blue + factor * fg.blue)
	);
	}

	private void initializeColors() {
	IPreferenceStore store= JavaPlugin.getDefault().getPreferenceStore();
	RGB bgRGB;
	if (store.getBoolean(PreferenceConstants.EDITOR_SOURCE_HOVER_BACKGROUND_COLOR_SYSTEM_DEFAULT)) {
	bgRGB= getVisibleBackgroundColor(fShell.getDisplay());
	} else {
	bgRGB= PreferenceConverter.getColor(store, PreferenceConstants.EDITOR_SOURCE_HOVER_BACKGROUND_COLOR);
	}
	if (bgRGB != null) {
	fBackgroundColor= new Color(fShell.getDisplay(), bgRGB);
	fIsSystemBackgroundColor= false;
	} else {
	fBackgroundColor= fShell.getDisplay().getSystemColor(SWT.COLOR_INFO_BACKGROUND);
	fIsSystemBackgroundColor= true;
	}
	}

	/**
	* Returns <code>null</code> if {@link SWT#COLOR_INFO_BACKGROUND} is visibly distinct from the
	* default Java source text color. Otherwise, returns the editor background color.
	*
	* @param display the display
	* @return an RGB or <code>null</code>
	* @since 3.6.1
	*/
	public static RGB getVisibleBackgroundColor(Display display) {
	float[] infoBgHSB= display.getSystemColor(SWT.COLOR_INFO_BACKGROUND).getRGB().getHSB();

	Color javaDefaultColor= JavaUI.getColorManager().getColor(IJavaColorConstants.JAVA_DEFAULT);
	RGB javaDefaultRGB= javaDefaultColor != null ? javaDefaultColor.getRGB() : new RGB(255, 255, 255);
	float[] javaDefaultHSB= javaDefaultRGB.getHSB();

	if (Math.abs(infoBgHSB[2] - javaDefaultHSB[2]) < 0.5f) {
	// workaround for dark tooltip background color, see https://bugs.eclipse.org/309334
	IPreferenceStore preferenceStore= JavaPlugin.getDefault().getCombinedPreferenceStore();
	boolean useDefault= preferenceStore.getBoolean(AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND_SYSTEM_DEFAULT);
	if (useDefault)
	return display.getSystemColor(SWT.COLOR_LIST_BACKGROUND).getRGB();
	return PreferenceConverter.getColor(preferenceStore, AbstractTextEditor.PREFERENCE_COLOR_BACKGROUND);
	}
	return null;
	}

	/**
	* Initialize the font to the Java editor font.
	*
	* @since 3.2
	*/
	private void initializeFont() {
	fTextFont= JFaceResources.getFont(PreferenceConstants.EDITOR_TEXT_FONT);
	StyledText styledText= getViewer().getTextWidget();
	styledText.setFont(fTextFont);
	}

	/*
	* @see org.eclipse.jface.text.IInformationControlExtension2#setInput(java.lang.Object)
	*/
	public void setInput(Object input) {
	if (input instanceof String)
	setInformation((String)input);
	else
	setInformation(null);
	}

	/*
	* @see IInformationControl#setInformation(String)
	*/
	@Override
	public void setInformation(String content) {
	if (content == null) {
	fViewer.setInput(null);
	return;
	}

	IDocument doc= new Document(content);
	JavaPlugin.getDefault().getJavaTextTools().setupJavaDocumentPartitioner(doc, IJavaPartitions.JAVA_PARTITIONING);
	fViewer.setInput(doc);
	}

	/*
	* @see IInformationControl#setVisible(boolean)
	*/
	@Override
	public void setVisible(boolean visible) {
	fShell.setVisible(visible);
	}

	/**
	* {@inheritDoc}
	* @since 3.0
	*/
	@Override
	public void widgetDisposed(DisposeEvent event) {
	if (fStatusTextFont != null && !fStatusTextFont.isDisposed())
	fStatusTextFont.dispose();
	fStatusTextFont= null;

	if (fStatusTextForegroundColor != null && !fStatusTextForegroundColor.isDisposed())
	fStatusTextForegroundColor.dispose();
	fStatusTextForegroundColor= null;

	fTextFont= null;
	fShell= null;
	fText= null;
	}

	@Override
	public final void dispose() {
	if (!fIsSystemBackgroundColor)
	fBackgroundColor.dispose();
	if (fShell != null && !fShell.isDisposed())
	fShell.dispose();
	else
	widgetDisposed(null);
	}

	/*
	* @see IInformationControl#setSize(int, int)
	*/
	@Override
	public void setSize(int width, int height) {
	fShell.setSize(width, height);
	}

	/*
	* @see IInformationControl#setLocation(Point)
	*/
	@Override
	public void setLocation(Point location) {
	fShell.setLocation(location);
	}

	/*
	* @see IInformationControl#setSizeConstraints(int, int)
	*/
	@Override
	public void setSizeConstraints(int maxWidth, int maxHeight) {
	fMaxWidth= maxWidth;
	fMaxHeight= maxHeight;
	}

	/*
	* @see IInformationControl#computeSizeHint()
	*/
	@Override
	public Point computeSizeHint() {
	// compute the preferred size
	int x= SWT.DEFAULT;
	int y= SWT.DEFAULT;
	Point size= fShell.computeSize(x, y);
	if (size.x > fMaxWidth)
	x= fMaxWidth;
	if (size.y > fMaxHeight)
	y= fMaxHeight;

	// recompute using the constraints if the preferred size is larger than the constraints
	if (x != SWT.DEFAULT \|\| y != SWT.DEFAULT)
	size= fShell.computeSize(x, y, false);

	return size;
	}

	/*
	* @see IInformationControl#addDisposeListener(DisposeListener)
	*/
	@Override
	public void addDisposeListener(DisposeListener listener) {
	fShell.addDisposeListener(listener);
	}

	/*
	* @see IInformationControl#removeDisposeListener(DisposeListener)
	*/
	@Override
	public void removeDisposeListener(DisposeListener listener) {
	fShell.removeDisposeListener(listener);
	}

	/*
	* @see IInformationControl#setForegroundColor(Color)
	*/
	@Override
	public void setForegroundColor(Color foreground) {
	fText.setForeground(foreground);
	}

	/*
	* @see IInformationControl#setBackgroundColor(Color)
	*/
	@Override
	public void setBackgroundColor(Color background) {
	fText.setBackground(background);
	}

	/*
	* @see IInformationControl#isFocusControl()
	*/
	@Override
	public boolean isFocusControl() {
	return fShell.getDisplay().getActiveShell() == fShell;
	}

	/*
	* @see IInformationControl#setFocus()
	*/
	@Override
	public void setFocus() {
	fShell.forceFocus();
	fText.setFocus();
	}

	/*
	* @see IInformationControl#addFocusListener(FocusListener)
	*/
	@Override
	public void addFocusListener(FocusListener listener) {
	fText.addFocusListener(listener);
	}

	/*
	* @see IInformationControl#removeFocusListener(FocusListener)
	*/
	@Override
	public void removeFocusListener(FocusListener listener) {
	fText.removeFocusListener(listener);
	}

	/*
	* @see IInformationControlExtension#hasContents()
	*/
	@Override
	public boolean hasContents() {
	return fText.getCharCount() > 0;
	}

	protected ISourceViewer getViewer() {
	return fViewer;
	}

	/*
	* @see org.eclipse.jface.text.IInformationControlExtension3#computeTrim()
	* @since 3.4
	*/
	@Override
	public Rectangle computeTrim() {
	Rectangle trim= fShell.computeTrim(0, 0, 0, 0);
	addInternalTrim(trim);
	return trim;
	}

	/**
	* Adds the internal trimmings to the given trim of the shell.
	*
	* @param trim the shell's trim, will be updated
	* @since 3.4
	*/
	private void addInternalTrim(Rectangle trim) {
	Rectangle textTrim= fText.computeTrim(0, 0, 0, 0);
	trim.x+= textTrim.x;
	trim.y+= textTrim.y;
	trim.width+= textTrim.width;
	trim.height+= textTrim.height;

	if (fStatusField != null) {
	trim.height+= fSeparator.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;
	trim.height+= fStatusField.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;
	trim.height+= 1; // verticalSpacing
	}
	}

	/*
	* @see org.eclipse.jface.text.IInformationControlExtension3#getBounds()
	* @since 3.4
	*/
	@Override
	public Rectangle getBounds() {
	return fShell.getBounds();
	}

	/*
	* @see org.eclipse.jface.text.IInformationControlExtension3#restoresLocation()
	* @since 3.4
	*/
	@Override
	public boolean restoresLocation() {
	return false;
	}

	/*
	* @see org.eclipse.jface.text.IInformationControlExtension3#restoresSize()
	* @since 3.4
	*/
	@Override
	public boolean restoresSize() {
	return false;
	}

	/*
	* @see org.eclipse.jface.text.IInformationControlExtension5#getInformationPresenterControlCreator()
	* @since 3.4
	*/
	@Override
	public IInformationControlCreator getInformationPresenterControlCreator() {
	return new IInformationControlCreator() {
	@Override
	public IInformationControl createInformationControl(Shell parent) {
	return new SourceViewerInformationControl(parent, true, fOrientation, null);
	}
	};
	}

	/*
	* @see org.eclipse.jface.text.IInformationControlExtension5#containsControl(org.eclipse.swt.widgets.Control)
	* @since 3.4
	*/
	@Override
	public boolean containsControl(Control control) {
	do {
	if (control == fShell)
	return true;
	if (control instanceof Shell)
	return false;
	control= control.getParent();
	} while (control != null);
	return false;
	}

	/*
	* @see org.eclipse.jface.text.IInformationControlExtension5#isVisible()
	* @since 3.4
	*/
	@Override
	public boolean isVisible() {
	return fShell != null && !fShell.isDisposed() && fShell.isVisible();
	}

	/*
	* @see org.eclipse.jface.text.IInformationControlExtension5#computeSizeConstraints(int, int)
	*/
	@Override
	public Point computeSizeConstraints(int widthInChars, int heightInChars) {
	GC gc= new GC(fText);
	gc.setFont(fTextFont);
	int width= gc.getFontMetrics().getAverageCharWidth();
	int height= fText.getLineHeight(); //https://bugs.eclipse.org/bugs/show_bug.cgi?id=377109
	gc.dispose();

	return new Point(widthInChars * width, heightInChars * height);
	}
	}