package org.eparapher.rcp.tools;
   
   import org.eclipse.swt.SWT;
   import org.eclipse.swt.custom.CLabel;
   import org.eclipse.swt.events.DisposeEvent;
   import org.eclipse.swt.events.DisposeListener;
   import org.eclipse.swt.events.MouseAdapter;
   import org.eclipse.swt.events.MouseEvent;
   import org.eclipse.swt.events.MouseListener;
  import org.eclipse.swt.graphics.GC;
  import org.eclipse.swt.graphics.Image;
  import org.eclipse.swt.widgets.Composite;
  import org.eclipse.swt.widgets.Display;
  import org.eclipse.swt.widgets.Label;
  
  import org.eclipse.jface.action.ContributionItem;
  import org.eclipse.jface.action.IAction;
  import org.eclipse.jface.action.StatusLineLayoutData;
  import org.eclipse.jface.resource.JFaceColors;
  
  /**
   * Contribution item for the status line.
   * @since 2.0
   */
  public class StatusLineContributionItem extends ContributionItem {
  
  	/**
  	 * Internal mouse listener to track double clicking the status line item.
  	 * @since 3.0
  	 */
  	private class Listener extends MouseAdapter {
  		/*
  		 * @see org.eclipse.swt.events.MouseAdapter#mouseDoubleClick(org.eclipse.swt.events.MouseEvent)
  		 */
  		public void mouseDoubleClick(MouseEvent e) {
  			if (fActionHandler != null && fActionHandler.isEnabled())
  				fActionHandler.run();
  		}
  	}
  
  	/**
  	 * Left and right margin used in CLabel.
  	 * @since 2.1
  	 */
  	private static final int INDENT= 3;
  	/**
  	 * Default number of characters that should fit into the item.
  	 * @since 3.0
  	 */
  	static final int DEFAULT_WIDTH_IN_CHARS= 14;
  	/**
  	 * Pre-computed label width hint.
  	 * @since 2.1
  	 */
  	private int fFixedWidth= -1;
  	/**
  	 * Pre-computed label height hint.
  	 * @since 3.0
  	 */
  	private int fFixedHeight= -1;
  	/** The text */
  	private String fText;
  	/** The image */
  	private Image fImage;
  	/**
  	 * The error text.
  	 * @since 3.0
  	 */
  	private String fErrorText;
  	/**
  	 * The error image.
  	 * @since 3.0
  	 */
  	private Image fErrorImage;
  	/**
  	 * The tool tip text.
  	 * @since 3.0
  	 */
  	private String fToolTipText;
  	/**
  	 * Number of characters that should fit into the item.
  	 * @since 3.0
  	 */
  	private int fWidthInChars;
  	/** The status line label widget */
  	private CLabel fLabel;
  	/**
  	 * The action handler.
  	 * @since 3.0
  	 */
  	private IAction fActionHandler;
  	/**
  	 * The mouse listener
  	 * @since 3.0
  	 */
  	private MouseListener fMouseListener;
  
  
  	/**
 	 * Creates a new item with the given id.
 	 *
 	 * @param id the item's id
 	 */
 	public StatusLineContributionItem(String id) {
 		this(id, true, DEFAULT_WIDTH_IN_CHARS);
 	}
 
 	/**
 	 * Creates a new item with the given attributes.
 	 *
 	 * @param id the item's id
 	 * @param visible the visibility of this item
 	 * @param widthInChars the width in characters
 	 * @since 3.0
 	 */
 	public StatusLineContributionItem(String id, boolean visible, int widthInChars) {
 		super(id);
 		setVisible(visible);
 		fWidthInChars= widthInChars;
 	}
 
 	/*
 	 * @see IStatusField#setText(String)
 	 */
 	public void setText(String text) {
 		fText= text;
 		updateMessageLabel();
 	}
 
 	/*
 	 * @see IStatusField#setImage(Image)
 	 */
 	public void setImage(Image image) {
 		fImage= image;
 		updateMessageLabel();
 	}
 
 	/*
 	 * @see org.eclipse.ui.texteditor.IStatusFieldExtension#setErrorText(java.lang.String)
 	 * @since 3.0
 	 */
 	public void setErrorText(String text) {
 		fErrorText= text;
 		updateMessageLabel();
 	}
 
 	/*
 	 * @see org.eclipse.ui.texteditor.IStatusFieldExtension#setErrorImage(org.eclipse.swt.graphics.Image)
 	 * @since 3.0
 	 */
 	public void setErrorImage(Image image) {
 		fErrorImage= image;
 		updateMessageLabel();
 	}
 
 	/*
 	 * @see org.eclipse.ui.texteditor.IStatusFieldExtension#setToolTipText(java.lang.String)
 	 * @since 3.0
 	 */
 	public void setToolTipText(String string) {
 		fToolTipText= string;
 		updateMessageLabel();
 	}
 
 	/*
 	 * @see IContributionItem#fill(Composite)
 	 */
 	public void fill(Composite parent) {
 
 		Label sep= new Label(parent, SWT.SEPARATOR);
 		fLabel= new CLabel(parent, SWT.SHADOW_NONE);
 
 		fLabel.addDisposeListener(new DisposeListener() {
 			public void widgetDisposed(DisposeEvent e) {
 				fMouseListener= null;
 			}
 		});
 		if (fActionHandler != null) {
 			fMouseListener= new Listener();
 			fLabel.addMouseListener(fMouseListener);
 		}
 
 		StatusLineLayoutData data= new StatusLineLayoutData();
 		data.widthHint= getWidthHint(parent);
 		fLabel.setLayoutData(data);
 
 		data= new StatusLineLayoutData();
 		data.heightHint= getHeightHint(parent);
 		sep.setLayoutData(data);
 
 		updateMessageLabel();
 	}
 
 	public void setActionHandler(IAction actionHandler) {
 		if (fActionHandler != null && actionHandler == null && fMouseListener != null) {
 			if (!fLabel.isDisposed())
 				fLabel.removeMouseListener(fMouseListener);
 			fMouseListener= null;
 		}
 
 		fActionHandler= actionHandler;
 
 		if (fLabel != null && !fLabel.isDisposed() && fMouseListener == null && fActionHandler != null) {
 			fMouseListener= new Listener();
 			fLabel.addMouseListener(fMouseListener);
 		}
 	}
 
 	/**
 	 * Returns the width hint for this label.
 	 *
 	 * @param control the root control of this label
 	 * @return the width hint for this label
 	 * @since 2.1
 	 */
 	private int getWidthHint(Composite control) {
 		if (fFixedWidth < 0) {
 			GC gc= new GC(control);
 			gc.setFont(control.getFont());
 			fFixedWidth= gc.getFontMetrics().getAverageCharWidth() * fWidthInChars;
 			fFixedWidth += INDENT * 2;
 			gc.dispose();
 		}
 		return fFixedWidth;
 	}
 
 	/**
 	 * Returns the height hint for this label.
 	 *
 	 * @param control the root control of this label
 	 * @return the height hint for this label
 	 * @since 3.0
 	 */
 	private int getHeightHint(Composite control) {
 		if (fFixedHeight < 0) {
 			GC gc= new GC(control);
 			gc.setFont(control.getFont());
 			fFixedHeight= gc.getFontMetrics().getHeight();
 			gc.dispose();
 		}
 		return fFixedHeight;
 	}
 
 	/**
 	 * Updates the message label widget.
 	 *
 	 * @since 3.0
 	 */
 	private void updateMessageLabel() {
 		if (fLabel != null && !fLabel.isDisposed()) {
 			Display display= fLabel.getDisplay();
 			if ((fErrorText != null && fErrorText.length() > 0) || fErrorImage != null) {
 				fLabel.setForeground(JFaceColors.getErrorText(display));
 				fLabel.setText(fErrorText);
 				fLabel.setImage(fErrorImage);
 				if (fToolTipText != null)
 					fLabel.setToolTipText(fToolTipText);
 				else if (fErrorText.length() > fWidthInChars)
 					fLabel.setToolTipText(fErrorText);
 				else
 					fLabel.setToolTipText(null);
 			}
 			else {
 				fLabel.setForeground(display.getSystemColor(SWT.COLOR_WIDGET_FOREGROUND));
 				fLabel.setText(fText);
 				fLabel.setImage(fImage);
 				if (fToolTipText != null)
 					fLabel.setToolTipText(fToolTipText);
 				else if (fText != null && fText.length() > fWidthInChars)
 					fLabel.setToolTipText(fText);
 				else
 					fLabel.setToolTipText(null);
 			}
 		}
 	}
 }