Java tutorial
/* * Copyright (c) 2011, the Dart project authors. * * Licensed under the Eclipse Public License v1.0 (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.eclipse.org/legal/epl-v10.html * * 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.google.dart.tools.ui.internal.preferences; import org.eclipse.core.runtime.Assert; import org.eclipse.jface.preference.IPreferenceStore; import org.eclipse.jface.preference.PreferenceStore; import org.eclipse.jface.util.IPropertyChangeListener; import org.eclipse.jface.util.PropertyChangeEvent; /** * An overlaying preference store. */ public class OverlayPreferenceStore implements IPreferenceStore { public static class OverlayKey { TypeDescriptor fDescriptor; String fKey; public OverlayKey(TypeDescriptor descriptor, String key) { fDescriptor = descriptor; fKey = key; } } public static final class TypeDescriptor { private TypeDescriptor() { } } private class PropertyListener implements IPropertyChangeListener { /* * @see IPropertyChangeListener#propertyChange(PropertyChangeEvent) */ @Override public void propertyChange(PropertyChangeEvent event) { OverlayKey key = findOverlayKey(event.getProperty()); if (key != null) { propagateProperty(fParent, key, fStore); } } } public static final TypeDescriptor BOOLEAN = new TypeDescriptor(); public static final TypeDescriptor DOUBLE = new TypeDescriptor(); public static final TypeDescriptor FLOAT = new TypeDescriptor(); public static final TypeDescriptor INT = new TypeDescriptor(); public static final TypeDescriptor LONG = new TypeDescriptor(); public static final TypeDescriptor STRING = new TypeDescriptor(); private IPreferenceStore fParent; private IPreferenceStore fStore; private OverlayKey[] fOverlayKeys; private PropertyListener fPropertyListener; private boolean fLoaded; public OverlayPreferenceStore(IPreferenceStore parent, OverlayKey[] overlayKeys) { fParent = parent; fOverlayKeys = overlayKeys; fStore = new PreferenceStore(); } /** * The keys to add to the list of overlay keys. * <p> * Note: This method must be called before {@link #load()} is called. * </p> * * @param keys */ public void addKeys(OverlayKey[] keys) { Assert.isTrue(!fLoaded); Assert.isNotNull(keys); int overlayKeysLength = fOverlayKeys.length; OverlayKey[] result = new OverlayKey[keys.length + overlayKeysLength]; for (int i = 0, length = overlayKeysLength; i < length; i++) { result[i] = fOverlayKeys[i]; } for (int i = 0, length = keys.length; i < length; i++) { result[overlayKeysLength + i] = keys[i]; } fOverlayKeys = result; if (fLoaded) { load(); } } /* * @see IPreferenceStore#addPropertyChangeListener(IPropertyChangeListener) */ @Override public void addPropertyChangeListener(IPropertyChangeListener listener) { fStore.addPropertyChangeListener(listener); } /* * @see IPreferenceStore#contains(String) */ @Override public boolean contains(String name) { return fStore.contains(name); } /* * @see IPreferenceStore#firePropertyChangeEvent(String, Object, Object) */ @Override public void firePropertyChangeEvent(String name, Object oldValue, Object newValue) { fStore.firePropertyChangeEvent(name, oldValue, newValue); } /* * @see IPreferenceStore#getBoolean(String) */ @Override public boolean getBoolean(String name) { return fStore.getBoolean(name); } /* * @see IPreferenceStore#getDefaultBoolean(String) */ @Override public boolean getDefaultBoolean(String name) { return fStore.getDefaultBoolean(name); } /* * @see IPreferenceStore#getDefaultDouble(String) */ @Override public double getDefaultDouble(String name) { return fStore.getDefaultDouble(name); } /* * @see IPreferenceStore#getDefaultFloat(String) */ @Override public float getDefaultFloat(String name) { return fStore.getDefaultFloat(name); } /* * @see IPreferenceStore#getDefaultInt(String) */ @Override public int getDefaultInt(String name) { return fStore.getDefaultInt(name); } /* * @see IPreferenceStore#getDefaultLong(String) */ @Override public long getDefaultLong(String name) { return fStore.getDefaultLong(name); } /* * @see IPreferenceStore#getDefaultString(String) */ @Override public String getDefaultString(String name) { return fStore.getDefaultString(name); } /* * @see IPreferenceStore#getDouble(String) */ @Override public double getDouble(String name) { return fStore.getDouble(name); } /* * @see IPreferenceStore#getFloat(String) */ @Override public float getFloat(String name) { return fStore.getFloat(name); } /* * @see IPreferenceStore#getInt(String) */ @Override public int getInt(String name) { return fStore.getInt(name); } /* * @see IPreferenceStore#getLong(String) */ @Override public long getLong(String name) { return fStore.getLong(name); } /* * @see IPreferenceStore#getString(String) */ @Override public String getString(String name) { return fStore.getString(name); } /* * @see IPreferenceStore#isDefault(String) */ @Override public boolean isDefault(String name) { return fStore.isDefault(name); } public void load() { for (int i = 0; i < fOverlayKeys.length; i++) { loadProperty(fParent, fOverlayKeys[i], fStore, true); } fLoaded = true; } public void loadDefaults() { for (int i = 0; i < fOverlayKeys.length; i++) { setToDefault(fOverlayKeys[i].fKey); } } /* * @see IPreferenceStore#needsSaving() */ @Override public boolean needsSaving() { return fStore.needsSaving(); } public void propagate() { for (int i = 0; i < fOverlayKeys.length; i++) { propagateProperty(fStore, fOverlayKeys[i], fParent); } } /* * @see IPreferenceStore#putValue(String, String) */ @Override public void putValue(String name, String value) { if (covers(name)) { fStore.putValue(name, value); } } /* * @see IPreferenceStore#removePropertyChangeListener(IPropertyChangeListener) */ @Override public void removePropertyChangeListener(IPropertyChangeListener listener) { fStore.removePropertyChangeListener(listener); } /* * @see IPreferenceStore#setDefault(String, boolean) */ @Override public void setDefault(String name, boolean value) { if (covers(name)) { fStore.setDefault(name, value); } } /* * @see IPreferenceStore#setDefault(String, double) */ @Override public void setDefault(String name, double value) { if (covers(name)) { fStore.setDefault(name, value); } } /* * @see IPreferenceStore#setDefault(String, float) */ @Override public void setDefault(String name, float value) { if (covers(name)) { fStore.setDefault(name, value); } } /* * @see IPreferenceStore#setDefault(String, int) */ @Override public void setDefault(String name, int value) { if (covers(name)) { fStore.setDefault(name, value); } } /* * @see IPreferenceStore#setDefault(String, long) */ @Override public void setDefault(String name, long value) { if (covers(name)) { fStore.setDefault(name, value); } } /* * @see IPreferenceStore#setDefault(String, String) */ @Override public void setDefault(String name, String value) { if (covers(name)) { fStore.setDefault(name, value); } } /* * @see IPreferenceStore#setToDefault(String) */ @Override public void setToDefault(String name) { fStore.setToDefault(name); } /* * @see IPreferenceStore#setValue(String, boolean) */ @Override public void setValue(String name, boolean value) { if (covers(name)) { fStore.setValue(name, value); } } /* * @see IPreferenceStore#setValue(String, double) */ @Override public void setValue(String name, double value) { if (covers(name)) { fStore.setValue(name, value); } } /* * @see IPreferenceStore#setValue(String, float) */ @Override public void setValue(String name, float value) { if (covers(name)) { fStore.setValue(name, value); } } /* * @see IPreferenceStore#setValue(String, int) */ @Override public void setValue(String name, int value) { if (covers(name)) { fStore.setValue(name, value); } } /* * @see IPreferenceStore#setValue(String, long) */ @Override public void setValue(String name, long value) { if (covers(name)) { fStore.setValue(name, value); } } /* * @see IPreferenceStore#setValue(String, String) */ @Override public void setValue(String name, String value) { if (covers(name)) { fStore.setValue(name, value); } } public void start() { if (fPropertyListener == null) { fPropertyListener = new PropertyListener(); fParent.addPropertyChangeListener(fPropertyListener); } } public void stop() { if (fPropertyListener != null) { fParent.removePropertyChangeListener(fPropertyListener); fPropertyListener = null; } } private boolean covers(String key) { return (findOverlayKey(key) != null); } private OverlayKey findOverlayKey(String key) { for (int i = 0; i < fOverlayKeys.length; i++) { if (fOverlayKeys[i].fKey.equals(key)) { return fOverlayKeys[i]; } } return null; } private void loadProperty(IPreferenceStore orgin, OverlayKey key, IPreferenceStore target, boolean forceInitialization) { TypeDescriptor d = key.fDescriptor; if (BOOLEAN == d) { if (forceInitialization) { target.setValue(key.fKey, true); } target.setValue(key.fKey, orgin.getBoolean(key.fKey)); target.setDefault(key.fKey, orgin.getDefaultBoolean(key.fKey)); } else if (DOUBLE == d) { if (forceInitialization) { target.setValue(key.fKey, 1.0D); } target.setValue(key.fKey, orgin.getDouble(key.fKey)); target.setDefault(key.fKey, orgin.getDefaultDouble(key.fKey)); } else if (FLOAT == d) { if (forceInitialization) { target.setValue(key.fKey, 1.0F); } target.setValue(key.fKey, orgin.getFloat(key.fKey)); target.setDefault(key.fKey, orgin.getDefaultFloat(key.fKey)); } else if (INT == d) { if (forceInitialization) { target.setValue(key.fKey, 1); } target.setValue(key.fKey, orgin.getInt(key.fKey)); target.setDefault(key.fKey, orgin.getDefaultInt(key.fKey)); } else if (LONG == d) { if (forceInitialization) { target.setValue(key.fKey, 1L); } target.setValue(key.fKey, orgin.getLong(key.fKey)); target.setDefault(key.fKey, orgin.getDefaultLong(key.fKey)); } else if (STRING == d) { if (forceInitialization) { target.setValue(key.fKey, "1"); //$NON-NLS-1$ } target.setValue(key.fKey, orgin.getString(key.fKey)); target.setDefault(key.fKey, orgin.getDefaultString(key.fKey)); } } private void propagateProperty(IPreferenceStore orgin, OverlayKey key, IPreferenceStore target) { if (orgin.isDefault(key.fKey)) { if (!target.isDefault(key.fKey)) { target.setToDefault(key.fKey); } return; } TypeDescriptor d = key.fDescriptor; if (BOOLEAN == d) { boolean originValue = orgin.getBoolean(key.fKey); boolean targetValue = target.getBoolean(key.fKey); if (targetValue != originValue) { target.setValue(key.fKey, originValue); } } else if (DOUBLE == d) { double originValue = orgin.getDouble(key.fKey); double targetValue = target.getDouble(key.fKey); if (targetValue != originValue) { target.setValue(key.fKey, originValue); } } else if (FLOAT == d) { float originValue = orgin.getFloat(key.fKey); float targetValue = target.getFloat(key.fKey); if (targetValue != originValue) { target.setValue(key.fKey, originValue); } } else if (INT == d) { int originValue = orgin.getInt(key.fKey); int targetValue = target.getInt(key.fKey); if (targetValue != originValue) { target.setValue(key.fKey, originValue); } } else if (LONG == d) { long originValue = orgin.getLong(key.fKey); long targetValue = target.getLong(key.fKey); if (targetValue != originValue) { target.setValue(key.fKey, originValue); } } else if (STRING == d) { String originValue = orgin.getString(key.fKey); String targetValue = target.getString(key.fKey); if (targetValue != null && originValue != null && !targetValue.equals(originValue)) { target.setValue(key.fKey, originValue); } } } }