org.eclipse.ui.editors/src/org/eclipse/ui/internal/texteditor/SourceViewerInformationControl.java - platform/eclipse.platform.text - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2008 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.ui.internal.texteditor;

 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.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.jface.resource.JFaceResources;

 import org.eclipse.jface.text.BadLocationException;
 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.IRegion;
 import org.eclipse.jface.text.source.SourceViewer;

 import org.eclipse.ui.internal.editors.text.EditorsPlugin;

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

 /**
  * Source viewer based implementation of <code>IInformationControl</code>.
  * Displays information in a source viewer configured with the text editor
  * preference store.
  *
  * @since 3.0
  */
 class SourceViewerInformationControl implements IInformationControl, IInformationControlExtension, IInformationControlExtension3, IInformationControlExtension5, DisposeListener {

 	/** The control's shell */
 	private Shell fShell;
 	/** The control's text widget */
 	private StyledText fText;
 	/** The symbolic font name of the text font */
 	private final String fSymbolicFontName;
 	/** The text font (do not dispose!) */
 	private Font fTextFont;
 	/** The control's source viewer */
 	private SourceViewer fViewer;
 	/** The optional status field. */
 	private Label fStatusField;
 	/** The separator for the optional status field. */
 	private Label fSeparator;
 	/** The font of the optional status text label.*/
 	private Font fStatusTextFont;
 	/** The maximal widget width. */
 	private int fMaxWidth;
 	/** The maximal widget height. */
 	private int fMaxHeight;
 	/** The horizontal scroll index. */
 	private int fHorizontalScrollPixel;


 	/**
 	 * Creates a source viewer information control with the given shell as
 	 * parent. The given shell styles are applied to the created shell. The
 	 * given styles are applied to the created styled text widget. The text
 	 * widget will be initialized with the given font. The status field will
 	 * contain the given text or be hidden.
 	 *
 	 * @param parent the parent shell
 	 * @param isResizable <code>true</code> if resizable
 	 * @param symbolicFontName the symbolic font name
 	 * @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, String symbolicFontName, String statusFieldText) {
 		GridLayout layout;
 		GridData gd;

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

 		fShell= new Shell(parent, shellStyle);
 		Display display= fShell.getDisplay();

 		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;
 			composite.setLayout(layout);
 			gd= new GridData(GridData.FILL_BOTH);
 			composite.setLayoutData(gd);
 			composite.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));
 			composite.setBackground(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND));
 		}

 		// Source viewer
 		fViewer= new SourceViewer(composite, null, textStyle);
 		fViewer.configure(new TextSourceViewerConfiguration(EditorsPlugin.getDefault().getPreferenceStore()));
 		fViewer.setEditable(false);

 		fText= fViewer.getTextWidget();
 		gd= new GridData(GridData.BEGINNING | GridData.FILL_BOTH);
 		fText.setLayoutData(gd);
 		fText.setForeground(parent.getDisplay().getSystemColor(SWT.COLOR_INFO_FOREGROUND));
 		fText.setBackground(parent.getDisplay().getSystemColor(SWT.COLOR_INFO_BACKGROUND));
 		fSymbolicFontName= symbolicFontName;
 		fTextFont= JFaceResources.getFont(symbolicFontName);
 		fText.setFont(fTextFont);

 		fText.addKeyListener(new KeyListener() {

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

 			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_VERTICAL | GridData.FILL_HORIZONTAL | GridData.HORIZONTAL_ALIGN_BEGINNING | GridData.VERTICAL_ALIGN_BEGINNING);
 			fStatusField.setLayoutData(gd2);

 			// Regarding the color see bug 41128
 			fStatusField.setForeground(display.getSystemColor(SWT.COLOR_WIDGET_DARK_SHADOW));

 			fStatusField.setBackground(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND));
 		}

 		addDisposeListener(this);
 	}

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

 		IDocument doc= new Document(content);
 		fViewer.setInput(doc);

 		// ensure that we can scroll enough
 		ensureScrollable();

 		fViewer.getTextWidget().setHorizontalPixel(fHorizontalScrollPixel);
 	}

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

 	/*
 	 * @see org.eclipse.swt.events.DisposeListener#widgetDisposed(org.eclipse.swt.events.DisposeEvent)
 	 */
 	public void widgetDisposed(DisposeEvent event) {
 		if (fStatusTextFont != null && !fStatusTextFont.isDisposed())
 			fStatusTextFont.dispose();

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

 	/*
 	 * @see org.eclipse.jface.text.IInformationControl#dispose()
 	 */
 	public final void dispose() {
 		if (fShell != null && !fShell.isDisposed())
 			fShell.dispose();
 		else
 			widgetDisposed(null);
 	}

 	/*
 	 * @see IInformationControl#setSize(int, int)
 	 */
 	public void setSize(int width, int height) {

 		if (fStatusField != null) {
 			GridData gd= (GridData)fViewer.getTextWidget().getLayoutData();
 			Point statusSize= fStatusField.computeSize(SWT.DEFAULT, SWT.DEFAULT, true);
 			Point separatorSize= fSeparator.computeSize(SWT.DEFAULT, SWT.DEFAULT, true);
 			gd.heightHint= height - statusSize.y - separatorSize.y;
 		}
 		fShell.setSize(width, height);

 		if (fStatusField != null)
 			fShell.pack(true);
 	}

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

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

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

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

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

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

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

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

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

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

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

 	/**
 	 * @param scrollIndex the new horizontal scroll index.
 	 */
 	void setHorizontalScrollPixel(int scrollIndex) {
 		scrollIndex= Math.max(0, scrollIndex);
 		fHorizontalScrollPixel= scrollIndex;
 	}

 	/**
 	 * Ensures that the control can be scrolled at least to
 	 * <code>fHorizontalScrollPixel</code> and adjusts <code>fMaxWidth</code>
 	 * accordingly.
 	 *
 	 * @since 3.3
 	 */
 	private void ensureScrollable() {
 		IDocument doc= fViewer.getDocument();
 		if (doc == null)
 			return;

 		StyledText widget= fViewer.getTextWidget();
 		if (widget == null || widget.isDisposed())
 			return;

 		int last= doc.getNumberOfLines() - 1;
 		GC gc= new GC(widget);
 		gc.setFont(widget.getFont());
 		int maxWidth= 0;
 		String content= new String();

 		try {
 			for (int i= 0; i <= last; i++) {
 				IRegion line;
 				line= doc.getLineInformation(i);
 				content= doc.get(line.getOffset(), line.getLength());
 				int width= gc.textExtent(content).x;
 				if (width > maxWidth) {
 					maxWidth= width;
 				}
 			}
 		} catch (BadLocationException e) {
 			return;
 		} finally {
 			gc.dispose();
 		}

 		// limit the size of the window to the maximum width minus scrolling,
 		// but never more than the configured max size (viewport size).
 		fMaxWidth= Math.max(0, Math.min(fMaxWidth, maxWidth - fHorizontalScrollPixel + 8));
 	}


 	/*
 	 * @see org.eclipse.jface.text.IInformationControlExtension3#computeTrim()
 	 * @since 3.4
 	 */
 	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) {
 		if (fStatusField != null) {
 			trim.height+= fSeparator.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;
 			trim.height+= fStatusField.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;
 		}
 	}

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

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

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

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

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

 	/*
 	 * @see org.eclipse.jface.text.IInformationControlExtension5#computeSizeConstraints(int, int)
 	 * @since 3.4
 	 */
 	public Point computeSizeConstraints(int widthInChars, int heightInChars) {
 		GC gc= new GC(fText);
 		gc.setFont(fTextFont);
 		int width= gc.getFontMetrics().getAverageCharWidth();
 		int height = gc.getFontMetrics().getHeight();
 		gc.dispose();

 		return new Point (widthInChars * width, heightInChars * height);
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2008 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.ui.internal.texteditor;

	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.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.jface.resource.JFaceResources;

	import org.eclipse.jface.text.BadLocationException;
	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.IRegion;
	import org.eclipse.jface.text.source.SourceViewer;

	import org.eclipse.ui.internal.editors.text.EditorsPlugin;

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

	/**
	* Source viewer based implementation of <code>IInformationControl</code>.
	* Displays information in a source viewer configured with the text editor
	* preference store.
	*
	* @since 3.0
	*/
	class SourceViewerInformationControl implements IInformationControl, IInformationControlExtension, IInformationControlExtension3, IInformationControlExtension5, DisposeListener {

	/** The control's shell */
	private Shell fShell;
	/** The control's text widget */
	private StyledText fText;
	/** The symbolic font name of the text font */
	private final String fSymbolicFontName;
	/** The text font (do not dispose!) */
	private Font fTextFont;
	/** The control's source viewer */
	private SourceViewer fViewer;
	/** The optional status field. */
	private Label fStatusField;
	/** The separator for the optional status field. */
	private Label fSeparator;
	/** The font of the optional status text label.*/
	private Font fStatusTextFont;
	/** The maximal widget width. */
	private int fMaxWidth;
	/** The maximal widget height. */
	private int fMaxHeight;
	/** The horizontal scroll index. */
	private int fHorizontalScrollPixel;


	/**
	* Creates a source viewer information control with the given shell as
	* parent. The given shell styles are applied to the created shell. The
	* given styles are applied to the created styled text widget. The text
	* widget will be initialized with the given font. The status field will
	* contain the given text or be hidden.
	*
	* @param parent the parent shell
	* @param isResizable <code>true</code> if resizable
	* @param symbolicFontName the symbolic font name
	* @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, String symbolicFontName, String statusFieldText) {
	GridLayout layout;
	GridData gd;

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

	fShell= new Shell(parent, shellStyle);
	Display display= fShell.getDisplay();

	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;
	composite.setLayout(layout);
	gd= new GridData(GridData.FILL_BOTH);
	composite.setLayoutData(gd);
	composite.setForeground(display.getSystemColor(SWT.COLOR_INFO_FOREGROUND));
	composite.setBackground(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND));
	}

	// Source viewer
	fViewer= new SourceViewer(composite, null, textStyle);
	fViewer.configure(new TextSourceViewerConfiguration(EditorsPlugin.getDefault().getPreferenceStore()));
	fViewer.setEditable(false);

	fText= fViewer.getTextWidget();
	gd= new GridData(GridData.BEGINNING \| GridData.FILL_BOTH);
	fText.setLayoutData(gd);
	fText.setForeground(parent.getDisplay().getSystemColor(SWT.COLOR_INFO_FOREGROUND));
	fText.setBackground(parent.getDisplay().getSystemColor(SWT.COLOR_INFO_BACKGROUND));
	fSymbolicFontName= symbolicFontName;
	fTextFont= JFaceResources.getFont(symbolicFontName);
	fText.setFont(fTextFont);

	fText.addKeyListener(new KeyListener() {

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

	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_VERTICAL \| GridData.FILL_HORIZONTAL \| GridData.HORIZONTAL_ALIGN_BEGINNING \| GridData.VERTICAL_ALIGN_BEGINNING);
	fStatusField.setLayoutData(gd2);

	// Regarding the color see bug 41128
	fStatusField.setForeground(display.getSystemColor(SWT.COLOR_WIDGET_DARK_SHADOW));

	fStatusField.setBackground(display.getSystemColor(SWT.COLOR_INFO_BACKGROUND));
	}

	addDisposeListener(this);
	}

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

	IDocument doc= new Document(content);
	fViewer.setInput(doc);

	// ensure that we can scroll enough
	ensureScrollable();

	fViewer.getTextWidget().setHorizontalPixel(fHorizontalScrollPixel);
	}

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

	/*
	* @see org.eclipse.swt.events.DisposeListener#widgetDisposed(org.eclipse.swt.events.DisposeEvent)
	*/
	public void widgetDisposed(DisposeEvent event) {
	if (fStatusTextFont != null && !fStatusTextFont.isDisposed())
	fStatusTextFont.dispose();

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

	/*
	* @see org.eclipse.jface.text.IInformationControl#dispose()
	*/
	public final void dispose() {
	if (fShell != null && !fShell.isDisposed())
	fShell.dispose();
	else
	widgetDisposed(null);
	}

	/*
	* @see IInformationControl#setSize(int, int)
	*/
	public void setSize(int width, int height) {

	if (fStatusField != null) {
	GridData gd= (GridData)fViewer.getTextWidget().getLayoutData();
	Point statusSize= fStatusField.computeSize(SWT.DEFAULT, SWT.DEFAULT, true);
	Point separatorSize= fSeparator.computeSize(SWT.DEFAULT, SWT.DEFAULT, true);
	gd.heightHint= height - statusSize.y - separatorSize.y;
	}
	fShell.setSize(width, height);

	if (fStatusField != null)
	fShell.pack(true);
	}

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

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

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

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

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

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

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

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

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

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

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

	/**
	* @param scrollIndex the new horizontal scroll index.
	*/
	void setHorizontalScrollPixel(int scrollIndex) {
	scrollIndex= Math.max(0, scrollIndex);
	fHorizontalScrollPixel= scrollIndex;
	}

	/**
	* Ensures that the control can be scrolled at least to
	* <code>fHorizontalScrollPixel</code> and adjusts <code>fMaxWidth</code>
	* accordingly.
	*
	* @since 3.3
	*/
	private void ensureScrollable() {
	IDocument doc= fViewer.getDocument();
	if (doc == null)
	return;

	StyledText widget= fViewer.getTextWidget();
	if (widget == null \|\| widget.isDisposed())
	return;

	int last= doc.getNumberOfLines() - 1;
	GC gc= new GC(widget);
	gc.setFont(widget.getFont());
	int maxWidth= 0;
	String content= new String();

	try {
	for (int i= 0; i <= last; i++) {
	IRegion line;
	line= doc.getLineInformation(i);
	content= doc.get(line.getOffset(), line.getLength());
	int width= gc.textExtent(content).x;
	if (width > maxWidth) {
	maxWidth= width;
	}
	}
	} catch (BadLocationException e) {
	return;
	} finally {
	gc.dispose();
	}

	// limit the size of the window to the maximum width minus scrolling,
	// but never more than the configured max size (viewport size).
	fMaxWidth= Math.max(0, Math.min(fMaxWidth, maxWidth - fHorizontalScrollPixel + 8));
	}


	/*
	* @see org.eclipse.jface.text.IInformationControlExtension3#computeTrim()
	* @since 3.4
	*/
	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) {
	if (fStatusField != null) {
	trim.height+= fSeparator.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;
	trim.height+= fStatusField.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;
	}
	}

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

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

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

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

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

	/*
	* @see org.eclipse.jface.text.IInformationControlExtension5#computeSizeConstraints(int, int)
	* @since 3.4
	*/
	public Point computeSizeConstraints(int widthInChars, int heightInChars) {
	GC gc= new GC(fText);
	gc.setFont(fTextFont);
	int width= gc.getFontMetrics().getAverageCharWidth();
	int height = gc.getFontMetrics().getHeight();
	gc.dispose();

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