/*******************************************************************************
* Copyright (c) 2000, 2009 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.search.internal.ui.util;
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.core.runtime.Assert;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.layout.PixelConverter;
import org.eclipse.jface.resource.JFaceResources;
/**
* Utility class to simplify access to some SWT resources.
*/
public class SWTUtil {
/**
* Returns the standard display to be used. The method first checks, if
* the thread calling this method has an associated disaply. If so, this
* display is returned. Otherwise the method returns the default display.
* @return Returns the standard display to be used.
*/
public static Display getStandardDisplay() {
Display 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</code> is returned.
*
* @param widget The widget to get the shell for
* @return the shell for the given widget
*/
public static Shell getShell(Widget widget) {
if (widget instanceof Control)
return ((Control)widget).getShell();
if (widget instanceof Caret)
return ((Caret)widget).getParent().getShell();
if (widget instanceof DragSource)
return ((DragSource)widget).getControl().getShell();
if (widget instanceof DropTarget)
return ((DropTarget)widget).getControl().getShell();
if (widget instanceof Menu)
return ((Menu)widget).getParent().getShell();
if (widget instanceof ScrollBar)
return ((ScrollBar)widget).getParent().getShell();
return null;
}
/**
* Returns a width hint for a button control.
* @param button The button to calculate the width for
* @return The width of the button
*/
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</code>.
*
* @param button the button for which to set the dimension hint
*/
public static void setButtonDimensionHint(Button button) {
Assert.isNotNull(button);
Object gd= button.getLayoutData();
if (gd instanceof GridData) {
((GridData)gd).widthHint= getButtonWidthHint(button);
((GridData)gd).horizontalAlignment = GridData.FILL;
}
}
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;
}
}
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