org.argeo.cms.ui/src/org/argeo/cms/viewers/AbstractPageViewer.java

   1 package org.argeo.cms.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.CmsException;
  17 import org.argeo.cms.ui.CmsEditable;
  18 import org.argeo.cms.widgets.ScrolledPage;
  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 (Exception e) {
  78                         throw new CmsException("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         @Override
 124         public void update(Observable o, Object arg) {
 125                 if (o == cmsEditable)
 126                         editingStateChanged(cmsEditable);
 127         }
 128
 129         /** To be overridden in order to provide the actual refresh */
 130         protected void refresh(Control control) throws RepositoryException {
 131         }
 132
 133         /** To be overridden.Save the edited part. */
 134         protected void save(EditablePart part) throws RepositoryException {
 135         }
 136
 137         /** Prepare the edited part */
 138         protected void prepare(EditablePart part, Object caretPosition) {
 139         }
 140
 141         /** Notified when the editing state changed. Does nothing, to be overridden */
 142         protected void editingStateChanged(CmsEditable cmsEditable) {
 143         }
 144
 145         @Override
 146         public void refresh() {
 147                 // TODO check actual context in order to notice a discrepancy
 148                 Subject viewerSubject = getViewerSubject();
 149                 Subject.doAs(viewerSubject, (PrivilegedAction<Void>) () -> {
 150                         try {
 151                                 if (cmsEditable.canEdit() && !readOnly)
 152                                         mouseListener = createMouseListener();
 153                                 else
 154                                         mouseListener = null;
 155                                 refresh(getControl());
 156                                 layout(getControl());
 157                         } catch (RepositoryException e) {
 158                                 throw new CmsException("Cannot refresh", e);
 159                         }
 160                         return null;
 161                 });
 162         }
 163
 164         @Override
 165         public void setSelection(ISelection selection, boolean reveal) {
 166                 this.selection = selection;
 167         }
 168
 169         protected void updateContent(EditablePart part) throws RepositoryException {
 170         }
 171
 172         // LOW LEVEL EDITION
 173         protected void edit(EditablePart part, Object caretPosition) {
 174                 try {
 175                         if (edited == part)
 176                                 return;
 177
 178                         if (edited != null && edited != part) {
 179                                 EditablePart previouslyEdited = edited;
 180                                 try {
 181                                         stopEditing(true);
 182                                 } catch (Exception e) {
 183                                         notifyEditionException(e);
 184                                         edit(previouslyEdited, caretPosition);
 185                                         return;
 186                                 }
 187                         }
 188
 189                         part.startEditing();
 190                         updateContent(part);
 191                         prepare(part, caretPosition);
 192                         edited = part;
 193                         layout(part.getControl());
 194                 } catch (RepositoryException e) {
 195                         throw new CmsException("Cannot edit " + part, e);
 196                 }
 197         }
 198
 199         private void stopEditing(Boolean save) throws RepositoryException {
 200                 if (edited instanceof Widget && ((Widget) edited).isDisposed()) {
 201                         edited = null;
 202                         return;
 203                 }
 204
 205                 assert edited != null;
 206                 if (edited == null) {
 207                         if (log.isTraceEnabled())
 208                                 log.warn("Told to stop editing while not editing anything");
 209                         return;
 210                 }
 211
 212                 if (save)
 213                         save(edited);
 214
 215                 edited.stopEditing();
 216                 updateContent(edited);
 217                 layout(((EditablePart) edited).getControl());
 218                 edited = null;
 219         }
 220
 221         // METHODS AVAILABLE TO EXTENDING CLASSES
 222         protected void saveEdit() {
 223                 try {
 224                         if (edited != null)
 225                                 stopEditing(true);
 226                 } catch (RepositoryException e) {
 227                         throw new CmsException("Cannot stop editing", e);
 228                 }
 229         }
 230
 231         protected void cancelEdit() {
 232                 try {
 233                         if (edited != null)
 234                                 stopEditing(false);
 235                 } catch (RepositoryException e) {
 236                         throw new CmsException("Cannot cancel editing", e);
 237                 }
 238         }
 239
 240         /** Layout this controls from the related base page. */
 241         public void layout(Control... controls) {
 242                 page.layout(controls);
 243         }
 244
 245         /**
 246          * Find the first {@link EditablePart} in the parents hierarchy of this control
 247          */
 248         protected EditablePart findDataParent(Control parent) {
 249                 if (parent instanceof EditablePart) {
 250                         return (EditablePart) parent;
 251                 }
 252                 if (parent.getParent() != null)
 253                         return findDataParent(parent.getParent());
 254                 else
 255                         throw new CmsException("No data parent found");
 256         }
 257
 258         // UTILITIES
 259         /** Check whether the edited part is in a proper state */
 260         protected void checkEdited() {
 261                 if (edited == null || (edited instanceof Widget) && ((Widget) edited).isDisposed())
 262                         throw new CmsException("Edited should not be null or disposed at this stage");
 263         }
 264
 265         /** Persist all changes. */
 266         protected void persistChanges(Session session) throws RepositoryException {
 267                 session.save();
 268                 session.refresh(false);
 269                 // TODO notify that changes have been persisted
 270         }
 271
 272         /** Convenience method using a Node in order to save the underlying session. */
 273         protected void persistChanges(Node anyNode) throws RepositoryException {
 274                 persistChanges(anyNode.getSession());
 275         }
 276
 277         /** Notify edition exception */
 278         protected void notifyEditionException(Throwable e) {
 279                 Throwable eToLog = e;
 280                 if (e instanceof IllegalArgumentException)
 281                         if (e.getCause() instanceof SAXParseException)
 282                                 eToLog = e.getCause();
 283                 log.error(eToLog.getMessage());
 284                 if (log.isTraceEnabled())
 285                         log.trace("Full stack of " + eToLog.getMessage(), e);
 286                 // TODO Light error notification popup
 287         }
 288
 289         protected Subject getViewerSubject() {
 290                 Subject res = null;
 291                 if (accessControlContext != null) {
 292                         res = Subject.getSubject(accessControlContext);
 293                 }
 294                 if (res == null)
 295                         throw new CmsException("No subject associated with this viewer");
 296                 return res;
 297         }
 298
 299         // GETTERS / SETTERS
 300         public boolean isReadOnly() {
 301                 return readOnly;
 302         }
 303
 304         protected EditablePart getEdited() {
 305                 return edited;
 306         }
 307
 308         public MouseListener getMouseListener() {
 309                 return mouseListener;
 310         }
 311
 312         public FocusListener getFocusListener() {
 313                 return focusListener;
 314         }
 315
 316         public CmsEditable getCmsEditable() {
 317                 return cmsEditable;
 318         }
 319
 320         @Override
 321         public ISelection getSelection() {
 322                 return selection;
 323         }
 324 }