net.sourceforge.phpeclipse.ui/src/net/sourceforge/phpdt/internal/ui/util/SWTUtil.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2004 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v10.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package net.sourceforge.phpdt.internal.ui.util;
  12
  13 import org.eclipse.jface.dialogs.IDialogConstants;
  14 import org.eclipse.jface.resource.JFaceResources;
  15 import org.eclipse.jface.util.Assert;
  16 import org.eclipse.swt.SWT;
  17 import org.eclipse.swt.dnd.DragSource;
  18 import org.eclipse.swt.dnd.DropTarget;
  19 import org.eclipse.swt.layout.GridData;
  20 import org.eclipse.swt.widgets.Button;
  21 import org.eclipse.swt.widgets.Caret;
  22 import org.eclipse.swt.widgets.Control;
  23 import org.eclipse.swt.widgets.Display;
  24 import org.eclipse.swt.widgets.Menu;
  25 import org.eclipse.swt.widgets.ScrollBar;
  26 import org.eclipse.swt.widgets.Shell;
  27 import org.eclipse.swt.widgets.Table;
  28 import org.eclipse.swt.widgets.Widget;
  29
  30 /**
  31  * Utility class to simplify access to some SWT resources.
  32  */
  33 public class SWTUtil {
  34
  35         /**
  36          * Returns the standard display to be used. The method first checks, if the
  37          * thread calling this method has an associated disaply. If so, this display
  38          * is returned. Otherwise the method returns the default display.
  39          */
  40         public static Display getStandardDisplay() {
  41                 Display display;
  42                 display = Display.getCurrent();
  43                 if (display == null)
  44                         display = Display.getDefault();
  45                 return display;
  46         }
  47
  48         /**
  49          * Returns the shell for the given widget. If the widget doesn't represent a
  50          * SWT object that manage a shell, <code>null</code> is returned.
  51          *
  52          * @return the shell for the given widget
  53          */
  54         public static Shell getShell(Widget widget) {
  55                 if (widget instanceof Control)
  56                         return ((Control) widget).getShell();
  57                 if (widget instanceof Caret)
  58                         return ((Caret) widget).getParent().getShell();
  59                 if (widget instanceof DragSource)
  60                         return ((DragSource) widget).getControl().getShell();
  61                 if (widget instanceof DropTarget)
  62                         return ((DropTarget) widget).getControl().getShell();
  63                 if (widget instanceof Menu)
  64                         return ((Menu) widget).getParent().getShell();
  65                 if (widget instanceof ScrollBar)
  66                         return ((ScrollBar) widget).getParent().getShell();
  67
  68                 return null;
  69         }
  70
  71         /**
  72          * Returns a width hint for a button control.
  73          */
  74         public static int getButtonWidthHint(Button button) {
  75                 button.setFont(JFaceResources.getDialogFont());
  76                 PixelConverter converter = new PixelConverter(button);
  77                 int widthHint = converter
  78                                 .convertHorizontalDLUsToPixels(IDialogConstants.BUTTON_WIDTH);
  79                 return Math.max(widthHint, button.computeSize(SWT.DEFAULT, SWT.DEFAULT,
  80                                 true).x);
  81         }
  82
  83         /**
  84          * Returns a height hint for a button control.
  85          */
  86         public static int getButtonHeightHint(Button button) {
  87                 button.setFont(JFaceResources.getDialogFont());
  88                 PixelConverter converter = new PixelConverter(button);
  89                 return converter
  90                                 .convertVerticalDLUsToPixels(IDialogConstants.BUTTON_HEIGHT);
  91         }
  92
  93         /**
  94          * Sets width and height hint for the button control. <b>Note:</b> This is
  95          * a NOP if the button's layout data is not an instance of
  96          * <code>GridData</code>.
  97          *
  98          * @param button
  99          *            the button for which to set the dimension hint
 100          */
 101         public static void setButtonDimensionHint(Button button) {
 102                 Assert.isNotNull(button);
 103                 Object gd = button.getLayoutData();
 104                 if (gd instanceof GridData) {
 105                         ((GridData) gd).heightHint = getButtonHeightHint(button);
 106                         ((GridData) gd).widthHint = getButtonWidthHint(button);
 107                         ((GridData) gd).horizontalAlignment = GridData.FILL;
 108                 }
 109         }
 110
 111         public static int getTableHeightHint(Table table, int rows) {
 112                 if (table.getFont().equals(JFaceResources.getDefaultFont()))
 113                         table.setFont(JFaceResources.getDialogFont());
 114                 int result = table.getItemHeight() * rows + table.getHeaderHeight();
 115                 if (table.getLinesVisible())
 116                         result += table.getGridLineWidth() * (rows - 1);
 117                 return result;
 118         }
 119
 120 }