org.argeo.eclipse.ui/src/org/argeo/eclipse/ui/dialogs/LightweightDialog.java

   1 package org.argeo.eclipse.ui.dialogs;
   2
   3 import org.apache.commons.logging.Log;
   4 import org.apache.commons.logging.LogFactory;
   5 import org.argeo.eclipse.ui.EclipseUiException;
   6 import org.eclipse.swt.SWT;
   7 import org.eclipse.swt.events.FocusEvent;
   8 import org.eclipse.swt.events.FocusListener;
   9 import org.eclipse.swt.events.ShellAdapter;
  10 import org.eclipse.swt.events.ShellEvent;
  11 import org.eclipse.swt.graphics.Point;
  12 import org.eclipse.swt.graphics.Rectangle;
  13 import org.eclipse.swt.layout.GridData;
  14 import org.eclipse.swt.layout.GridLayout;
  15 import org.eclipse.swt.widgets.Composite;
  16 import org.eclipse.swt.widgets.Control;
  17 import org.eclipse.swt.widgets.Display;
  18 import org.eclipse.swt.widgets.Shell;
  19
  20 /** Generic lightweight dialog, not based on JFace. */
  21 public class LightweightDialog {
  22         private final static Log log = LogFactory.getLog(LightweightDialog.class);
  23
  24         // must be the same value as org.eclipse.jface.window.Window#OK
  25         public final static int OK = 0;
  26         // must be the same value as org.eclipse.jface.window.Window#CANCEL
  27         public final static int CANCEL = 1;
  28
  29         private Shell parentShell;
  30         private Shell backgroundShell;
  31         private Shell foregoundShell;
  32
  33         private Integer returnCode = null;
  34         private boolean block = true;
  35
  36         private String title;
  37
  38         /** Tries to find a display */
  39         private static Display getDisplay() {
  40                 try {
  41                         Display display = Display.getCurrent();
  42                         if (display != null)
  43                                 return display;
  44                         else
  45                                 return Display.getDefault();
  46                 } catch (Exception e) {
  47                         return Display.getCurrent();
  48                 }
  49         }
  50
  51         public LightweightDialog(Shell parentShell) {
  52                 this.parentShell = parentShell;
  53         }
  54
  55         public int open() {
  56                 if (foregoundShell != null)
  57                         throw new EclipseUiException("There is already a shell");
  58                 backgroundShell = new Shell(parentShell, SWT.ON_TOP);
  59                 backgroundShell.setFullScreen(true);
  60                 // if (parentShell != null) {
  61                 // backgroundShell.setBounds(parentShell.getBounds());
  62                 // } else
  63                 // backgroundShell.setMaximized(true);
  64                 backgroundShell.setAlpha(128);
  65                 backgroundShell.setBackground(getDisplay().getSystemColor(SWT.COLOR_BLACK));
  66                 foregoundShell = new Shell(backgroundShell, SWT.NO_TRIM | SWT.ON_TOP);
  67                 if (title != null)
  68                         setTitle(title);
  69                 foregoundShell.setLayout(new GridLayout());
  70                 foregoundShell.setSize(getInitialSize());
  71                 createDialogArea(foregoundShell);
  72                 // shell.pack();
  73                 // shell.layout();
  74
  75                 Rectangle shellBounds = parentShell != null ? parentShell.getBounds() : Display.getCurrent().getBounds();// RAP
  76                 Point dialogSize = foregoundShell.getSize();
  77                 int x = shellBounds.x + (shellBounds.width - dialogSize.x) / 2;
  78                 int y = shellBounds.y + (shellBounds.height - dialogSize.y) / 2;
  79                 foregoundShell.setLocation(x, y);
  80
  81                 foregoundShell.addShellListener(new ShellAdapter() {
  82                         private static final long serialVersionUID = -2701270481953688763L;
  83
  84                         @Override
  85                         public void shellDeactivated(ShellEvent e) {
  86                                 if (hasChildShells())
  87                                         return;
  88                                 if (returnCode == null)// not yet closed
  89                                         closeShell(CANCEL);
  90                         }
  91
  92                         @Override
  93                         public void shellClosed(ShellEvent e) {
  94                                 notifyClose();
  95                         }
  96
  97                 });
  98
  99                 backgroundShell.open();
 100                 foregoundShell.open();
 101                 // after the foreground shell has been opened
 102                 backgroundShell.addFocusListener(new FocusListener() {
 103                         private static final long serialVersionUID = 3137408447474661070L;
 104
 105                         @Override
 106                         public void focusLost(FocusEvent event) {
 107                         }
 108
 109                         @Override
 110                         public void focusGained(FocusEvent event) {
 111                                 if (hasChildShells())
 112                                         return;
 113                                 if (returnCode == null)// not yet closed
 114                                         closeShell(CANCEL);
 115                         }
 116                 });
 117
 118                 if (block) {
 119                         try {
 120                                 runEventLoop(foregoundShell);
 121                         } catch (ThreadDeath t) {
 122                                 returnCode = CANCEL;
 123                                 if (log.isTraceEnabled())
 124                                         log.error("Thread death, canceling dialog", t);
 125                         } catch (Throwable t) {
 126                                 returnCode = CANCEL;
 127                                 log.error("Cannot open blocking lightweight dialog", t);
 128                         }
 129                 }
 130                 if (returnCode == null)
 131                         returnCode = OK;
 132                 return returnCode;
 133         }
 134
 135         private boolean hasChildShells() {
 136                 if (foregoundShell == null)
 137                         return false;
 138                 return foregoundShell.getShells().length != 0;
 139         }
 140
 141         // public synchronized int openAndWait() {
 142         // open();
 143         // while (returnCode == null)
 144         // try {
 145         // wait(100);
 146         // } catch (InterruptedException e) {
 147         // // silent
 148         // }
 149         // return returnCode;
 150         // }
 151
 152         private synchronized void notifyClose() {
 153                 if (returnCode == null)
 154                         returnCode = CANCEL;
 155                 notifyAll();
 156         }
 157
 158         protected void closeShell(int returnCode) {
 159                 this.returnCode = returnCode;
 160                 if (CANCEL == returnCode)
 161                         onCancel();
 162                 if (foregoundShell != null && !foregoundShell.isDisposed()) {
 163                         foregoundShell.close();
 164                         foregoundShell.dispose();
 165                         foregoundShell = null;
 166                 }
 167
 168                 if (backgroundShell != null && !backgroundShell.isDisposed()) {
 169                         backgroundShell.close();
 170                         backgroundShell.dispose();
 171                 }
 172         }
 173
 174         protected Point getInitialSize() {
 175                 // if (exception != null)
 176                 // return new Point(800, 600);
 177                 // else
 178                 return new Point(600, 400);
 179         }
 180
 181         protected Control createDialogArea(Composite parent) {
 182                 Composite dialogarea = new Composite(parent, SWT.NONE);
 183                 dialogarea.setLayout(new GridLayout());
 184                 dialogarea.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
 185                 return dialogarea;
 186         }
 187
 188         protected Shell getBackgroundShell() {
 189                 return backgroundShell;
 190         }
 191
 192         protected Shell getForegoundShell() {
 193                 return foregoundShell;
 194         }
 195
 196         public void setBlockOnOpen(boolean shouldBlock) {
 197                 block = shouldBlock;
 198         }
 199
 200         public void pack() {
 201                 foregoundShell.pack();
 202         }
 203
 204         private void runEventLoop(Shell loopShell) {
 205                 Display display;
 206                 if (foregoundShell == null) {
 207                         display = Display.getCurrent();
 208                 } else {
 209                         display = loopShell.getDisplay();
 210                 }
 211
 212                 while (loopShell != null && !loopShell.isDisposed()) {
 213                         try {
 214                                 if (!display.readAndDispatch()) {
 215                                         display.sleep();
 216                                 }
 217                         } catch (Throwable e) {
 218                                 handleException(e);
 219                         }
 220                 }
 221                 if (!display.isDisposed())
 222                         display.update();
 223         }
 224
 225         protected void handleException(Throwable t) {
 226                 if (t instanceof ThreadDeath) {
 227                         // Don't catch ThreadDeath as this is a normal occurrence when
 228                         // the thread dies
 229                         throw (ThreadDeath) t;
 230                 }
 231                 // Try to keep running.
 232                 t.printStackTrace();
 233         }
 234
 235         /** @return false, if the dialog should not be closed. */
 236         protected boolean onCancel() {
 237                 return true;
 238         }
 239
 240         public void setTitle(String title) {
 241                 this.title = title;
 242                 if (title != null && getForegoundShell() != null)
 243                         getForegoundShell().setText(title);
 244         }
 245
 246         public Integer getReturnCode() {
 247                 return returnCode;
 248         }
 249
 250 }