com.drgarbage.bytecodevisualizer.editors.EclipsePreferencesAdapter.java Source code

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Here is the source code for com.drgarbage.bytecodevisualizer.editors.EclipsePreferencesAdapter.java

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/**
 * Copyright (c) 2008-2012, Dr. Garbage Community
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.drgarbage.bytecodevisualizer.editors;

import org.eclipse.core.runtime.ListenerList;
import org.eclipse.core.runtime.preferences.IEclipsePreferences;
import org.eclipse.core.runtime.preferences.IScopeContext;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.swt.widgets.Display;
import org.osgi.service.prefs.BackingStoreException;

/**
 * Adapts an options {@link IEclipsePreferences} to {@link org.eclipse.jface.preference.IPreferenceStore}.
 * <p>
 * This preference store is read-only i.e. write access
 * throws an {@link java.lang.UnsupportedOperationException}.
 * </p>
 *
 * @since 3.1
 */
public final class EclipsePreferencesAdapter implements IPreferenceStore {

    /**
     * Preference change listener. Listens for events preferences
     * fires a {@link org.eclipse.jface.util.PropertyChangeEvent}
     * on this adapter with arguments from the received event.
     */
    private class PreferenceChangeListener implements IEclipsePreferences.IPreferenceChangeListener {

        /**
         * {@inheritDoc}
         */
        public void preferenceChange(final IEclipsePreferences.PreferenceChangeEvent event) {
            if (Display.getCurrent() == null) {
                Display.getDefault().asyncExec(new Runnable() {
                    public void run() {
                        firePropertyChangeEvent(event.getKey(), event.getOldValue(), event.getNewValue());
                    }
                });
            } else {
                firePropertyChangeEvent(event.getKey(), event.getOldValue(), event.getNewValue());
            }
        }
    }

    /** wrapped node */
    private final IScopeContext fContext;

    /** Listener on the node */
    private IEclipsePreferences.IPreferenceChangeListener fListener = new PreferenceChangeListener();

    /** Listeners on on this adapter */
    private ListenerList fListeners = new ListenerList(org.eclipse.core.runtime.ListenerList.IDENTITY);
    private final String fQualifier;

    /**
     * Initialize with the node to wrap
     *
     * @param context The context to access
     */
    public EclipsePreferencesAdapter(IScopeContext context, String qualifier) {
        fContext = context;
        fQualifier = qualifier;
    }

    /**
     * {@inheritDoc}
     */
    public void addPropertyChangeListener(IPropertyChangeListener listener) {
        if (fListeners.size() == 0)
            getNode().addPreferenceChangeListener(fListener);
        fListeners.add(listener);
    }

    /**
     * {@inheritDoc}
     */
    public boolean contains(String name) {
        return getNode().get(name, null) != null;
    }

    /**
     * {@inheritDoc}
     */
    public void firePropertyChangeEvent(String name, Object oldValue, Object newValue) {
        PropertyChangeEvent event = new PropertyChangeEvent(this, name, oldValue, newValue);
        Object[] listeners = fListeners.getListeners();
        for (int i = 0; i < listeners.length; i++)
            ((IPropertyChangeListener) listeners[i]).propertyChange(event);
    }

    /**
     * {@inheritDoc}
     */
    public boolean getBoolean(String name) {
        return getNode().getBoolean(name, BOOLEAN_DEFAULT_DEFAULT);
    }

    /**
     * {@inheritDoc}
     */
    public boolean getDefaultBoolean(String name) {
        return BOOLEAN_DEFAULT_DEFAULT;
    }

    /**
     * {@inheritDoc}
     */
    public double getDefaultDouble(String name) {
        return DOUBLE_DEFAULT_DEFAULT;
    }

    /**
     * {@inheritDoc}
     */
    public float getDefaultFloat(String name) {
        return FLOAT_DEFAULT_DEFAULT;
    }

    /**
     * {@inheritDoc}
     */
    public int getDefaultInt(String name) {
        return INT_DEFAULT_DEFAULT;
    }

    /**
     * {@inheritDoc}
     */
    public long getDefaultLong(String name) {
        return LONG_DEFAULT_DEFAULT;
    }

    /**
     * {@inheritDoc}
     */
    public String getDefaultString(String name) {
        return STRING_DEFAULT_DEFAULT;
    }

    /**
     * {@inheritDoc}
     */
    public double getDouble(String name) {
        return getNode().getDouble(name, DOUBLE_DEFAULT_DEFAULT);
    }

    /**
     * {@inheritDoc}
     */
    public float getFloat(String name) {
        return getNode().getFloat(name, FLOAT_DEFAULT_DEFAULT);
    }

    /**
     * {@inheritDoc}
     */
    public int getInt(String name) {
        return getNode().getInt(name, INT_DEFAULT_DEFAULT);
    }

    /**
     * {@inheritDoc}
     */
    public long getLong(String name) {
        return getNode().getLong(name, LONG_DEFAULT_DEFAULT);
    }

    private IEclipsePreferences getNode() {
        return fContext.getNode(fQualifier);
    }

    /**
     * {@inheritDoc}
     */
    public String getString(String name) {
        return getNode().get(name, STRING_DEFAULT_DEFAULT);
    }

    /**
     * {@inheritDoc}
     */
    public boolean isDefault(String name) {
        return false;
    }

    /**
     * {@inheritDoc}
     */
    public boolean needsSaving() {
        try {
            return getNode().keys().length > 0;
        } catch (BackingStoreException e) {
            // ignore
        }
        return true;
    }

    /**
     * {@inheritDoc}
     */
    public void putValue(String name, String value) {
        throw new UnsupportedOperationException();
    }

    /**
     * {@inheritDoc}
     */
    public void removePropertyChangeListener(IPropertyChangeListener listener) {
        fListeners.remove(listener);
        if (fListeners.size() == 0) {
            getNode().removePreferenceChangeListener(fListener);
        }
    }

    /**
     * {@inheritDoc}
     */
    public void setDefault(String name, boolean value) {
        throw new UnsupportedOperationException();
    }

    /**
     * {@inheritDoc}
     */
    public void setDefault(String name, double value) {
        throw new UnsupportedOperationException();
    }

    /**
     * {@inheritDoc}
     */
    public void setDefault(String name, float value) {
        throw new UnsupportedOperationException();
    }

    /**
     * {@inheritDoc}
     */
    public void setDefault(String name, int value) {
        throw new UnsupportedOperationException();
    }

    /**
     * {@inheritDoc}
     */
    public void setDefault(String name, long value) {
        throw new UnsupportedOperationException();
    }

    /**
     * {@inheritDoc}
     */
    public void setDefault(String name, String defaultObject) {
        throw new UnsupportedOperationException();
    }

    /**
     * {@inheritDoc}
     */
    public void setToDefault(String name) {
        throw new UnsupportedOperationException();
    }

    /**
     * {@inheritDoc}
     */
    public void setValue(String name, boolean value) {
        throw new UnsupportedOperationException();
    }

    /**
     * {@inheritDoc}
     */
    public void setValue(String name, double value) {
        throw new UnsupportedOperationException();
    }

    /**
     * {@inheritDoc}
     */
    public void setValue(String name, float value) {
        throw new UnsupportedOperationException();
    }

    /**
     * {@inheritDoc}
     */
    public void setValue(String name, int value) {
        throw new UnsupportedOperationException();
    }

    /**
     * {@inheritDoc}
     */
    public void setValue(String name, long value) {
        throw new UnsupportedOperationException();
    }

    /**
     * {@inheritDoc}
     */
    public void setValue(String name, String value) {
        throw new UnsupportedOperationException();
    }

}