LightweightDialog.java

   1 /*
   2  * Copyright (C) 2007-2012 Argeo GmbH
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *         http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package org.argeo.eclipse.ui.dialogs;
  17
  18 import org.apache.commons.logging.Log;
  19 import org.apache.commons.logging.LogFactory;
  20 import org.argeo.eclipse.ui.EclipseUiException;
  21 import org.eclipse.swt.SWT;
  22 import org.eclipse.swt.events.FocusEvent;
  23 import org.eclipse.swt.events.FocusListener;
  24 import org.eclipse.swt.events.ShellAdapter;
  25 import org.eclipse.swt.events.ShellEvent;
  26 import org.eclipse.swt.graphics.Point;
  27 import org.eclipse.swt.graphics.Rectangle;
  28 import org.eclipse.swt.layout.GridData;
  29 import org.eclipse.swt.layout.GridLayout;
  30 import org.eclipse.swt.widgets.Composite;
  31 import org.eclipse.swt.widgets.Control;
  32 import org.eclipse.swt.widgets.Display;
  33 import org.eclipse.swt.widgets.Shell;
  34
  35 /** Generic lightweight dialog, not based on JFace. */
  36 public class LightweightDialog {
  37         private final static Log log = LogFactory.getLog(LightweightDialog.class);
  38
  39         // must be the same value as org.eclipse.jface.window.Window#OK
  40         public final static int OK = 0;
  41         // must be the same value as org.eclipse.jface.window.Window#CANCEL
  42         public final static int CANCEL = 1;
  43
  44         private Shell parentShell;
  45         private Shell backgroundShell;
  46         private Shell foregoundShell;
  47
  48         private Integer returnCode = null;
  49         private boolean block = true;
  50
  51         private String title;
  52
  53         /** Tries to find a display */
  54         private static Display getDisplay() {
  55                 try {
  56                         Display display = Display.getCurrent();
  57                         if (display != null)
  58                                 return display;
  59                         else
  60                                 return Display.getDefault();
  61                 } catch (Exception e) {
  62                         return Display.getCurrent();
  63                 }
  64         }
  65
  66         public LightweightDialog(Shell parentShell) {
  67                 this.parentShell = parentShell;
  68         }
  69
  70         public int open() {
  71                 if (foregoundShell != null)
  72                         throw new EclipseUiException("There is already a shell");
  73                 backgroundShell = new Shell(parentShell, SWT.DIALOG_TRIM | SWT.ON_TOP);
  74                 backgroundShell.setFullScreen(true);
  75                 // backgroundShell.setMaximized(true);
  76                 backgroundShell.setAlpha(128);
  77                 backgroundShell.setBackground(getDisplay().getSystemColor(SWT.COLOR_BLACK));
  78                 foregoundShell = new Shell(backgroundShell, SWT.NO_TRIM | SWT.ON_TOP);
  79                 if (title != null)
  80                         setTitle(title);
  81                 foregoundShell.setLayout(new GridLayout());
  82                 foregoundShell.setSize(getInitialSize());
  83                 createDialogArea(foregoundShell);
  84                 // shell.pack();
  85                 // shell.layout();
  86
  87                 Rectangle shellBounds = Display.getCurrent().getBounds();// RAP
  88                 Point dialogSize = foregoundShell.getSize();
  89                 int x = shellBounds.x + (shellBounds.width - dialogSize.x) / 2;
  90                 int y = shellBounds.y + (shellBounds.height - dialogSize.y) / 2;
  91                 foregoundShell.setLocation(x, y);
  92
  93                 foregoundShell.addShellListener(new ShellAdapter() {
  94                         private static final long serialVersionUID = -2701270481953688763L;
  95
  96                         @Override
  97                         public void shellDeactivated(ShellEvent e) {
  98                                 if (returnCode == null)// not yet closed
  99                                         closeShell(CANCEL);
 100                         }
 101
 102                         @Override
 103                         public void shellClosed(ShellEvent e) {
 104                                 notifyClose();
 105                         }
 106
 107                 });
 108
 109                 backgroundShell.open();
 110                 foregoundShell.open();
 111                 // after the foreground shell has been opened
 112                 backgroundShell.addFocusListener(new FocusListener() {
 113                         private static final long serialVersionUID = 3137408447474661070L;
 114
 115                         @Override
 116                         public void focusLost(FocusEvent event) {
 117                         }
 118
 119                         @Override
 120                         public void focusGained(FocusEvent event) {
 121                                 if (returnCode == null)// not yet closed
 122                                         closeShell(CANCEL);
 123                         }
 124                 });
 125
 126                 if (block) {
 127                         try {
 128                                 runEventLoop(foregoundShell);
 129                         } catch (Throwable t) {
 130                                 log.error("Cannot open blocking lightweight dialog", t);
 131                         }
 132                 }
 133                 if (returnCode == null)
 134                         returnCode = OK;
 135                 return returnCode;
 136         }
 137
 138         // public synchronized int openAndWait() {
 139         // open();
 140         // while (returnCode == null)
 141         // try {
 142         // wait(100);
 143         // } catch (InterruptedException e) {
 144         // // silent
 145         // }
 146         // return returnCode;
 147         // }
 148
 149         private synchronized void notifyClose() {
 150                 if (returnCode == null)
 151                         returnCode = CANCEL;
 152                 notifyAll();
 153         }
 154
 155         protected void closeShell(int returnCode) {
 156                 this.returnCode = returnCode;
 157                 if (CANCEL == returnCode)
 158                         onCancel();
 159                 if (foregoundShell != null && !foregoundShell.isDisposed()) {
 160                         foregoundShell.close();
 161                         foregoundShell.dispose();
 162                         foregoundShell = null;
 163                 }
 164
 165                 if (backgroundShell != null && !backgroundShell.isDisposed()) {
 166                         backgroundShell.close();
 167                         backgroundShell.dispose();
 168                 }
 169         }
 170
 171         protected Point getInitialSize() {
 172                 // if (exception != null)
 173                 // return new Point(800, 600);
 174                 // else
 175                 return new Point(600, 400);
 176         }
 177
 178         protected Control createDialogArea(Composite parent) {
 179                 Composite dialogarea = new Composite(parent, SWT.NONE);
 180                 dialogarea.setLayout(new GridLayout());
 181                 dialogarea.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
 182                 return dialogarea;
 183         }
 184
 185         protected Shell getBackgroundShell() {
 186                 return backgroundShell;
 187         }
 188
 189         protected Shell getForegoundShell() {
 190                 return foregoundShell;
 191         }
 192
 193         public void setBlockOnOpen(boolean shouldBlock) {
 194                 block = shouldBlock;
 195         }
 196
 197         public void pack() {
 198                 foregoundShell.pack();
 199         }
 200
 201         private void runEventLoop(Shell loopShell) {
 202                 Display display;
 203                 if (foregoundShell == null) {
 204                         display = Display.getCurrent();
 205                 } else {
 206                         display = loopShell.getDisplay();
 207                 }
 208
 209                 while (loopShell != null && !loopShell.isDisposed()) {
 210                         try {
 211                                 if (!display.readAndDispatch()) {
 212                                         display.sleep();
 213                                 }
 214                         } catch (Throwable e) {
 215                                 handleException(e);
 216                         }
 217                 }
 218                 if (!display.isDisposed())
 219                         display.update();
 220         }
 221
 222         protected void handleException(Throwable t) {
 223                 if (t instanceof ThreadDeath) {
 224                         // Don't catch ThreadDeath as this is a normal occurrence when
 225                         // the thread dies
 226                         throw (ThreadDeath) t;
 227                 }
 228                 // Try to keep running.
 229                 t.printStackTrace();
 230         }
 231
 232         /** @return false, if the dialog should not be closed. */
 233         protected boolean onCancel() {
 234                 return true;
 235         }
 236
 237         public void setTitle(String title) {
 238                 this.title = title;
 239                 if (title != null && getForegoundShell() != null)
 240                         getForegoundShell().setText(title);
 241         }
 242
 243 }