cms/ui/viewers/AbstractPageViewer.java

   1 package org.argeo.cms.ui.viewers;
   2
   3 import java.security.AccessControlContext;
   4 import java.security.AccessController;
   5 import java.security.PrivilegedAction;
   6 import java.util.Observable;
   7 import java.util.Observer;
   8
   9 import javax.jcr.Node;
  10 import javax.jcr.RepositoryException;
  11 import javax.jcr.Session;
  12 import javax.security.auth.Subject;
  13
  14 import org.apache.commons.logging.Log;
  15 import org.apache.commons.logging.LogFactory;
  16 import org.argeo.cms.ui.CmsEditable;
  17 import org.argeo.cms.ui.widgets.ScrolledPage;
  18 import org.argeo.jcr.JcrException;
  19 import org.eclipse.jface.viewers.ContentViewer;
  20 import org.eclipse.jface.viewers.ISelection;
  21 import org.eclipse.jface.viewers.StructuredSelection;
  22 import org.eclipse.swt.SWT;
  23 import org.eclipse.swt.events.FocusEvent;
  24 import org.eclipse.swt.events.FocusListener;
  25 import org.eclipse.swt.events.MouseAdapter;
  26 import org.eclipse.swt.events.MouseListener;
  27 import org.eclipse.swt.widgets.Composite;
  28 import org.eclipse.swt.widgets.Control;
  29 import org.eclipse.swt.widgets.Widget;
  30 import org.xml.sax.SAXParseException;
  31
  32 /** Base class for viewers related to a page */
  33 public abstract class AbstractPageViewer extends ContentViewer implements Observer {
  34         private static final long serialVersionUID = 5438688173410341485L;
  35
  36         private final static Log log = LogFactory.getLog(AbstractPageViewer.class);
  37
  38         private final boolean readOnly;
  39         /** The basis for the layouts, typically a ScrolledPage. */
  40         private final Composite page;
  41         private final CmsEditable cmsEditable;
  42
  43         private MouseListener mouseListener;
  44         private FocusListener focusListener;
  45
  46         private EditablePart edited;
  47         private ISelection selection = StructuredSelection.EMPTY;
  48
  49         private AccessControlContext accessControlContext;
  50
  51         protected AbstractPageViewer(Section parent, int style, CmsEditable cmsEditable) {
  52                 // read only at UI level
  53                 readOnly = SWT.READ_ONLY == (style & SWT.READ_ONLY);
  54
  55                 this.cmsEditable = cmsEditable == null ? CmsEditable.NON_EDITABLE : cmsEditable;
  56                 if (this.cmsEditable instanceof Observable)
  57                         ((Observable) this.cmsEditable).addObserver(this);
  58
  59                 if (cmsEditable.canEdit()) {
  60                         mouseListener = createMouseListener();
  61                         focusListener = createFocusListener();
  62                 }
  63                 page = findPage(parent);
  64                 accessControlContext = AccessController.getContext();
  65         }
  66
  67         /**
  68          * Can be called to simplify the called to isModelInitialized() and initModel()
  69          */
  70         protected void initModelIfNeeded(Node node) {
  71                 try {
  72                         if (!isModelInitialized(node))
  73                                 if (getCmsEditable().canEdit()) {
  74                                         initModel(node);
  75                                         node.getSession().save();
  76                                 }
  77                 } catch (RepositoryException e) {
  78                         throw new JcrException("Cannot initialize model", e);
  79                 }
  80         }
  81
  82         /** Called if user can edit and model is not initialized */
  83         protected Boolean isModelInitialized(Node node) throws RepositoryException {
  84                 return true;
  85         }
  86
  87         /** Called if user can edit and model is not initialized */
  88         protected void initModel(Node node) throws RepositoryException {
  89         }
  90
  91         /** Create (retrieve) the MouseListener to use. */
  92         protected MouseListener createMouseListener() {
  93                 return new MouseAdapter() {
  94                         private static final long serialVersionUID = 1L;
  95                 };
  96         }
  97
  98         /** Create (retrieve) the FocusListener to use. */
  99         protected FocusListener createFocusListener() {
 100                 return new FocusListener() {
 101                         private static final long serialVersionUID = 1L;
 102
 103                         @Override
 104                         public void focusLost(FocusEvent event) {
 105                         }
 106
 107                         @Override
 108                         public void focusGained(FocusEvent event) {
 109                         }
 110                 };
 111         }
 112
 113         protected Composite findPage(Composite composite) {
 114                 if (composite instanceof ScrolledPage) {
 115                         return (ScrolledPage) composite;
 116                 } else {
 117                         if (composite.getParent() == null)
 118                                 return composite;
 119                         return findPage(composite.getParent());
 120                 }
 121         }
 122
 123         public void layoutPage() {
 124                 if (page != null)
 125                         page.layout(true, true);
 126         }
 127
 128         protected void showControl(Control control) {
 129                 if (page != null && (page instanceof ScrolledPage))
 130                         ((ScrolledPage) page).showControl(control);
 131         }
 132
 133         @Override
 134         public void update(Observable o, Object arg) {
 135                 if (o == cmsEditable)
 136                         editingStateChanged(cmsEditable);
 137         }
 138
 139         /** To be overridden in order to provide the actual refresh */
 140         protected void refresh(Control control) throws RepositoryException {
 141         }
 142
 143         /** To be overridden.Save the edited part. */
 144         protected void save(EditablePart part) throws RepositoryException {
 145         }
 146
 147         /** Prepare the edited part */
 148         protected void prepare(EditablePart part, Object caretPosition) {
 149         }
 150
 151         /** Notified when the editing state changed. Does nothing, to be overridden */
 152         protected void editingStateChanged(CmsEditable cmsEditable) {
 153         }
 154
 155         @Override
 156         public void refresh() {
 157                 // TODO check actual context in order to notice a discrepancy
 158                 Subject viewerSubject = getViewerSubject();
 159                 Subject.doAs(viewerSubject, (PrivilegedAction<Void>) () -> {
 160                         try {
 161                                 if (cmsEditable.canEdit() && !readOnly)
 162                                         mouseListener = createMouseListener();
 163                                 else
 164                                         mouseListener = null;
 165                                 refresh(getControl());
 166                                 // layout(getControl());
 167                                 layoutPage();
 168                         } catch (RepositoryException e) {
 169                                 throw new JcrException("Cannot refresh", e);
 170                         }
 171                         return null;
 172                 });
 173         }
 174
 175         @Override
 176         public void setSelection(ISelection selection, boolean reveal) {
 177                 this.selection = selection;
 178         }
 179
 180         protected void updateContent(EditablePart part) throws RepositoryException {
 181         }
 182
 183         // LOW LEVEL EDITION
 184         protected void edit(EditablePart part, Object caretPosition) {
 185                 try {
 186                         if (edited == part)
 187                                 return;
 188
 189                         if (edited != null && edited != part) {
 190                                 EditablePart previouslyEdited = edited;
 191                                 try {
 192                                         stopEditing(true);
 193                                 } catch (Exception e) {
 194                                         notifyEditionException(e);
 195                                         edit(previouslyEdited, caretPosition);
 196                                         return;
 197                                 }
 198                         }
 199
 200                         part.startEditing();
 201                         edited = part;
 202                         updateContent(part);
 203                         prepare(part, caretPosition);
 204                         edited.getControl().addFocusListener(new FocusListener() {
 205                                 private static final long serialVersionUID = 6883521812717097017L;
 206
 207                                 @Override
 208                                 public void focusLost(FocusEvent event) {
 209                                         stopEditing(true);
 210                                 }
 211
 212                                 @Override
 213                                 public void focusGained(FocusEvent event) {
 214                                 }
 215                         });
 216
 217                         layout(part.getControl());
 218                         showControl(part.getControl());
 219                 } catch (RepositoryException e) {
 220                         throw new JcrException("Cannot edit " + part, e);
 221                 }
 222         }
 223
 224         protected void stopEditing(Boolean save) {
 225                 if (edited instanceof Widget && ((Widget) edited).isDisposed()) {
 226                         edited = null;
 227                         return;
 228                 }
 229
 230                 assert edited != null;
 231                 if (edited == null) {
 232                         if (log.isTraceEnabled())
 233                                 log.warn("Told to stop editing while not editing anything");
 234                         return;
 235                 }
 236
 237                 try {
 238                         if (save)
 239                                 save(edited);
 240
 241                         edited.stopEditing();
 242                         EditablePart editablePart = edited;
 243                         Control control = ((EditablePart) edited).getControl();
 244                         edited = null;
 245                         // TODO make edited state management more robust
 246                         updateContent(editablePart);
 247                         layout(control);
 248                 } catch (RepositoryException e) {
 249                         throw new JcrException("Cannot stop editing", e);
 250                 } finally {
 251                         edited = null;
 252                 }
 253         }
 254
 255         // METHODS AVAILABLE TO EXTENDING CLASSES
 256         protected void saveEdit() {
 257                 if (edited != null)
 258                         stopEditing(true);
 259         }
 260
 261         protected void cancelEdit() {
 262                 if (edited != null)
 263                         stopEditing(false);
 264         }
 265
 266         /** Layout this controls from the related base page. */
 267         public void layout(Control... controls) {
 268                 page.layout(controls);
 269         }
 270
 271         /**
 272          * Find the first {@link EditablePart} in the parents hierarchy of this control
 273          */
 274         protected EditablePart findDataParent(Control parent) {
 275                 if (parent instanceof EditablePart) {
 276                         return (EditablePart) parent;
 277                 }
 278                 if (parent.getParent() != null)
 279                         return findDataParent(parent.getParent());
 280                 else
 281                         throw new IllegalStateException("No data parent found");
 282         }
 283
 284         // UTILITIES
 285         /** Check whether the edited part is in a proper state */
 286         protected void checkEdited() {
 287                 if (edited == null || (edited instanceof Widget) && ((Widget) edited).isDisposed())
 288                         throw new IllegalStateException("Edited should not be null or disposed at this stage");
 289         }
 290
 291         /** Persist all changes. */
 292         protected void persistChanges(Session session) throws RepositoryException {
 293                 session.save();
 294                 session.refresh(false);
 295                 // TODO notify that changes have been persisted
 296         }
 297
 298         /** Convenience method using a Node in order to save the underlying session. */
 299         protected void persistChanges(Node anyNode) throws RepositoryException {
 300                 persistChanges(anyNode.getSession());
 301         }
 302
 303         /** Notify edition exception */
 304         protected void notifyEditionException(Throwable e) {
 305                 Throwable eToLog = e;
 306                 if (e instanceof IllegalArgumentException)
 307                         if (e.getCause() instanceof SAXParseException)
 308                                 eToLog = e.getCause();
 309                 log.error(eToLog.getMessage(), eToLog);
 310 //              if (log.isTraceEnabled())
 311 //                      log.trace("Full stack of " + eToLog.getMessage(), e);
 312                 // TODO Light error notification popup
 313         }
 314
 315         protected Subject getViewerSubject() {
 316                 Subject res = null;
 317                 if (accessControlContext != null) {
 318                         res = Subject.getSubject(accessControlContext);
 319                 }
 320                 if (res == null)
 321                         throw new IllegalStateException("No subject associated with this viewer");
 322                 return res;
 323         }
 324
 325         // GETTERS / SETTERS
 326         public boolean isReadOnly() {
 327                 return readOnly;
 328         }
 329
 330         protected EditablePart getEdited() {
 331                 return edited;
 332         }
 333
 334         public MouseListener getMouseListener() {
 335                 return mouseListener;
 336         }
 337
 338         public FocusListener getFocusListener() {
 339                 return focusListener;
 340         }
 341
 342         public CmsEditable getCmsEditable() {
 343                 return cmsEditable;
 344         }
 345
 346         @Override
 347         public ISelection getSelection() {
 348                 return selection;
 349         }
 350 }