/*==========================================================================*\
| $Id: SWTUtil.java,v 1.2 2010/12/06 21:08:41 aallowat Exp $
|*-------------------------------------------------------------------------*|
| Copyright (C) 2006-2009 Virginia Tech
|
| This file is part of Web-CAT Eclipse Plugins.
|
| Web-CAT is free software; you can redistribute it and/or modify
| it under the terms of the GNU General Public License as published by
| the Free Software Foundation; either version 2 of the License, or
| (at your option) any later version.
|
| Web-CAT is distributed in the hope that it will be useful,
| but WITHOUT ANY WARRANTY; without even the implied warranty of
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
| GNU General Public License for more details.
|
| You should have received a copy of the GNU General Public License along
| with Web-CAT; if not, see <http://www.gnu.org/licenses/>.
\*==========================================================================*/
package org.webcat.eclipse.submitter.ui;
import org.eclipse.swt.SWT;
import org.eclipse.swt.dnd.DragSource;
import org.eclipse.swt.dnd.DropTarget;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Caret;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.ScrollBar;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.Widget;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.resource.JFaceResources;
//--------------------------------------------------------------------------
/**
* A utility class used to simplify access to some SWT resources. This code is
* adapted from code in the SWT source.
*
* @author Tony Allevato (Virginia Tech Computer Science)
* @author latest changes by: $Author: aallowat $
* @version $Revision: 1.2 $ $Date: 2010/12/06 21:08:41 $
*/
public class SWTUtil
{
// ----------------------------------------------------------
/**
* Returns the standard display to be used. The method first checks, if
* the thread calling this method has an associated dispaly. If so, this
* display is returned. Otherwise the method returns the default display.
*
* @return the standard display
*/
public static Display getStandardDisplay()
{
Display display = Display.getCurrent();
if (display == null)
{
display = Display.getDefault();
}
return display;
}
// ----------------------------------------------------------
/**
* Returns the shell for the given widget. If the widget doesn't represent a
* SWT object that manage a shell, {@code null} is returned.
*
* @param widget the widget
* @return the shell for the given widget
*/
public static Shell getShell(Widget widget)
{
if (widget instanceof Control)
{
return ((Control) widget).getShell();
}
else if (widget instanceof Caret)
{
return ((Caret) widget).getParent().getShell();
}
else if (widget instanceof DragSource)
{
return ((DragSource) widget).getControl().getShell();
}
else if (widget instanceof DropTarget)
{
return ((DropTarget) widget).getControl().getShell();
}
else if (widget instanceof Menu)
{
return ((Menu) widget).getParent().getShell();
}
else if (widget instanceof ScrollBar)
{
return ((ScrollBar) widget).getParent().getShell();
}
else
{
return null;
}
}
// ----------------------------------------------------------
/**
* Returns a width hint for a button control.
*
* @param button the button
* @return a width hint
*/
public static int getButtonWidthHint(Button button)
{
button.setFont(JFaceResources.getDialogFont());
PixelConverter converter = new PixelConverter(button);
int widthHint = converter.convertHorizontalDLUsToPixels(
IDialogConstants.BUTTON_WIDTH);
return Math.max(widthHint, button.computeSize(
SWT.DEFAULT, SWT.DEFAULT, true).x);
}
// ----------------------------------------------------------
/**
* Sets width and height hint for the button control. <b>Note:</b> This is
* a NOP if the button's layout data is not an instance of
* {@code GridData}.
*
* @param button the button for which to set the dimension hint
*/
public static void setButtonDimensionHint(Button button)
{
assert button != null;
Object gd = button.getLayoutData();
if (gd instanceof GridData)
{
((GridData) gd).widthHint = getButtonWidthHint(button);
((GridData) gd).horizontalAlignment = GridData.FILL;
}
}
// ----------------------------------------------------------
/**
* Returns an estimate of the height in pixels of a table with the
* specified number of rows.
*
* @param table the Table whose height should be calculated
* @param rows the number of rows that should be used to estimate the
* height of the table
* @return the estimated height of the table, in pixels
*/
public static int getTableHeightHint(Table table, int rows)
{
if (table.getFont().equals(JFaceResources.getDefaultFont()))
{
table.setFont(JFaceResources.getDialogFont());
}
int result = table.getItemHeight() * rows + table.getHeaderHeight();
if (table.getLinesVisible())
{
result += table.getGridLineWidth() * (rows - 1);
}
return result;
}
}