basicdirectorymodel.java

java1.6众多例子参考

                    sort(acceptsList);
        
                    Vector newDirectories = new Vector(50);
                    Vector newFiles = new Vector();
                    // run through list grabbing directories in chunks of ten
                    for(int i = 0; i < acceptsList.size(); i++) {
                        File f = (File) acceptsList.elementAt(i);
                        boolean isTraversable = filechooser.isTraversable(f);
                        if (isTraversable) {
                            newDirectories.addElement(f);
                        } else if (!isTraversable && filechooser.isFileSelectionEnabled()) {
                            newFiles.addElement(f);
                        }
                        if(isInterrupted()) {
                            return null;
                        }
                    }
        
                    Vector newFileCache = new Vector(newDirectories);
                    newFileCache.addAll(newFiles);
        
                    int newSize = newFileCache.size();
                    int oldSize = fileCache.size();
        
                    if (newSize > oldSize) {
                        //see if interval is added
                        int start = oldSize;
                        int end = newSize;
                        for (int i = 0; i < oldSize; i++) {
                            if (!newFileCache.get(i).equals(fileCache.get(i))) {
                                start = i;
                                for (int j = i; j < newSize; j++) {
                                    if (newFileCache.get(j).equals(fileCache.get(i))) {
                                        end = j;
                                        break;
                                    }
                                }
                                break;
                            }
                        }
                        if (start >= 0 && end > start
                            && newFileCache.subList(end, newSize).equals(fileCache.subList(start, oldSize))) {
                            if(isInterrupted()) {
                                return null;
                            }
                            invokeLater(new DoChangeContents(newFileCache.subList(start, end), start, null, 0, fid));
                            newFileCache = null;
                        }
                    } else if (newSize < oldSize) {
                        //see if interval is removed
                        int start = -1;
                        int end = -1;
                        for (int i = 0; i < newSize; i++) {
                            if (!newFileCache.get(i).equals(fileCache.get(i))) {
                                start = i;
                                end = i + oldSize - newSize;
                                break;
                            }
                        }
                        if (start >= 0 && end > start
                            && fileCache.subList(end, oldSize).equals(newFileCache.subList(start, newSize))) {
                            if(isInterrupted()) {
                                return null;
                            }
                            invokeLater(new DoChangeContents(null, 0, new Vector(fileCache.subList(start, end)),
                                                             start, fid));
                            newFileCache = null;
                        }
                    }
                    if (newFileCache != null && !fileCache.equals(newFileCache)) {
                        if (isInterrupted()) {
                            cancelRunnables(runnables);
                        }
                        invokeLater(new DoChangeContents(newFileCache, 0, fileCache, 0, fid));
                    }
                    return null;
                }
            });
        }


        public void cancelRunnables(Vector runnables) {
            for(int i = 0; i < runnables.size(); i++) {
                ((DoChangeContents)runnables.elementAt(i)).cancel();
            }
        }

         public void cancelRunnables() {
            cancelRunnables(runnables);
        }
   }


    /**
     * Adds a PropertyChangeListener to the listener list. The listener is
     * registered for all bound properties of this class.
     * <p>
     * If <code>listener</code> is <code>null</code>,
     * no exception is thrown and no action is performed.
     *
     * @param    listener  the property change listener to be added
     *
     * @see #removePropertyChangeListener
     * @see #getPropertyChangeListeners
     *
     * @since 1.6
     */
    public void addPropertyChangeListener(PropertyChangeListener listener) {
        if (changeSupport == null) {
            changeSupport = new PropertyChangeSupport(this);
        }
        changeSupport.addPropertyChangeListener(listener);
    }

    /**
     * Removes a PropertyChangeListener from the listener list.
     * <p>
     * If listener is null, no exception is thrown and no action is performed.
     *
     * @param listener the PropertyChangeListener to be removed
     *
     * @see #addPropertyChangeListener
     * @see #getPropertyChangeListeners
     *
     * @since 1.6
     */
    public void removePropertyChangeListener(PropertyChangeListener listener) {
        if (changeSupport != null) {
            changeSupport.removePropertyChangeListener(listener);
        }
    }

    /**
     * Returns an array of all the property change listeners
     * registered on this component.
     *
     * @return all of this component's <code>PropertyChangeListener</code>s
     *         or an empty array if no property change
     *         listeners are currently registered
     *
     * @see      #addPropertyChangeListener
     * @see      #removePropertyChangeListener
     * @see      java.beans.PropertyChangeSupport#getPropertyChangeListeners
     *
     * @since 1.6
     */
    public PropertyChangeListener[] getPropertyChangeListeners() {
        if (changeSupport == null) {
            return new PropertyChangeListener[0];
        }
        return changeSupport.getPropertyChangeListeners();
    }

    /**
     * Support for reporting bound property changes for boolean properties. 
     * This method can be called when a bound property has changed and it will
     * send the appropriate PropertyChangeEvent to any registered
     * PropertyChangeListeners.
     *
     * @param propertyName the property whose value has changed
     * @param oldValue the property's previous value
     * @param newValue the property's new value
     *
     * @since 1.6
     */
    protected void firePropertyChange(String propertyName,
                                      Object oldValue, Object newValue) {
        if (changeSupport != null) {
            changeSupport.firePropertyChange(propertyName,
                                             oldValue, newValue);
        }
    }


    /**
     * Set the busy state for the model. The model is considered
     * busy when it is running a separate (interruptable)
     * thread in order to load the contents of a directory.
     */
    private synchronized void setBusy(final boolean busy, int fid) {
        if (fid == fetchID) {
            boolean oldValue = this.busy;
            this.busy = busy;

            if (changeSupport != null && busy != oldValue) {
                SwingUtilities.invokeLater(new Runnable() {
                    public void run() {
                        firePropertyChange("busy", !busy, busy);
                    }
                });
            }
        }
    }


    class DoChangeContents implements Runnable {
        private List addFiles;
        private List remFiles;
        private boolean doFire = true;
        private int fid;
        private int addStart = 0;
        private int remStart = 0;
        private int change;

        public DoChangeContents(List addFiles, int addStart, List remFiles, int remStart, int fid) {
            this.addFiles = addFiles;
            this.addStart = addStart;
            this.remFiles = remFiles;
            this.remStart = remStart;
            this.fid = fid;
        }

        synchronized void cancel() {
                doFire = false;
        }

        public synchronized void run() {
            if (fetchID == fid && doFire) {
                int remSize = (remFiles == null) ? 0 : remFiles.size();
                int addSize = (addFiles == null) ? 0 : addFiles.size();
                synchronized(fileCache) {
                    if (remSize > 0) {
                        fileCache.removeAll(remFiles);
                    }
                    if (addSize > 0) {
                        fileCache.addAll(addStart, addFiles);
                    }
                    files = null;
                    directories = null;
                }
                if (remSize > 0 && addSize == 0) {
                    fireIntervalRemoved(BasicDirectoryModel.this, remStart, remStart + remSize - 1);
                } else if (addSize > 0 && remSize == 0 && fileCache.size() > addSize) {
                    fireIntervalAdded(BasicDirectoryModel.this, addStart, addStart + addSize - 1);
                } else {
                    fireContentsChanged();
                }
            }
        }
    }
}