Java tutorial
/*=============================================================================# # Copyright (c) 2000-2015 IBM Corporation and others. # All rights reserved. This program and the accompanying materials # are made available under the terms of the Eclipse Public License v1.0 # which accompanies this distribution, and is available at # http://www.eclipse.org/legal/epl-v10.html # # Contributors: # IBM Corporation - initial API and implementation #=============================================================================*/ package de.walware.ecommons.preferences.ui; import org.eclipse.jface.preference.IPreferenceStore; import org.eclipse.jface.preference.PreferenceStore; import org.eclipse.jface.util.IPropertyChangeListener; import org.eclipse.jface.util.PropertyChangeEvent; import de.walware.ecommons.preferences.Preference.Type; /** * An overlaying preference store. */ public class OverlayPreferenceStore implements IPreferenceStore { private class PropertyListener implements IPropertyChangeListener { /* * @see IPropertyChangeListener#propertyChange(PropertyChangeEvent) */ @Override public void propertyChange(final PropertyChangeEvent event) { final OverlayStorePreference key = findPreferenceKey(event.getProperty()); if (key != null) { propagateProperty(fParent, key, fStore); } } } private final IPreferenceStore fParent; private final IPreferenceStore fStore; private OverlayStorePreference[] fPreferenceKeys; private PropertyListener fPropertyListener; private boolean fLoaded; public OverlayPreferenceStore(final IPreferenceStore parent, final OverlayStorePreference[] PreferenceKeys) { fParent = parent; fPreferenceKeys = PreferenceKeys; fStore = new PreferenceStore(); } private OverlayStorePreference findPreferenceKey(final String key) { for (int i = 0; i < fPreferenceKeys.length; i++) { if (fPreferenceKeys[i].fKey.equals(key)) { return fPreferenceKeys[i]; } } return null; } private boolean covers(final String key) { return (findPreferenceKey(key) != null); } private void propagateProperty(final IPreferenceStore orgin, final OverlayStorePreference key, final IPreferenceStore target) { if (orgin.isDefault(key.fKey)) { if (!target.isDefault(key.fKey)) { target.setToDefault(key.fKey); } return; } final Type type = key.fType; switch (type) { case BOOLEAN: { final boolean originValue = orgin.getBoolean(key.fKey); final boolean targetValue = target.getBoolean(key.fKey); if (targetValue != originValue) { target.setValue(key.fKey, originValue); } break; } case DOUBLE: { final double originValue = orgin.getDouble(key.fKey); final double targetValue = target.getDouble(key.fKey); if (targetValue != originValue) { target.setValue(key.fKey, originValue); } break; } case FLOAT: { final float originValue = orgin.getFloat(key.fKey); final float targetValue = target.getFloat(key.fKey); if (targetValue != originValue) { target.setValue(key.fKey, originValue); } break; } case INT: { final int originValue = orgin.getInt(key.fKey); final int targetValue = target.getInt(key.fKey); if (targetValue != originValue) { target.setValue(key.fKey, originValue); } break; } case LONG: { final long originValue = orgin.getLong(key.fKey); final long targetValue = target.getLong(key.fKey); if (targetValue != originValue) { target.setValue(key.fKey, originValue); } break; } case STRING: { final String originValue = orgin.getString(key.fKey); final String targetValue = target.getString(key.fKey); if (targetValue != null && originValue != null && !targetValue.equals(originValue)) { target.setValue(key.fKey, originValue); } break; } } } public void propagate() { for (int i = 0; i < fPreferenceKeys.length; i++) { propagateProperty(fStore, fPreferenceKeys[i], fParent); } } private void loadProperty(final IPreferenceStore orgin, final OverlayStorePreference key, final IPreferenceStore target, final boolean forceInitialization) { final Type type = key.fType; switch (type) { case BOOLEAN: { if (forceInitialization) { target.setValue(key.fKey, true); } target.setValue(key.fKey, orgin.getBoolean(key.fKey)); target.setDefault(key.fKey, orgin.getDefaultBoolean(key.fKey)); break; } case DOUBLE: { if (forceInitialization) { target.setValue(key.fKey, 1.0D); } target.setValue(key.fKey, orgin.getDouble(key.fKey)); target.setDefault(key.fKey, orgin.getDefaultDouble(key.fKey)); break; } case FLOAT: { if (forceInitialization) { target.setValue(key.fKey, 1.0F); } target.setValue(key.fKey, orgin.getFloat(key.fKey)); target.setDefault(key.fKey, orgin.getDefaultFloat(key.fKey)); break; } case INT: { if (forceInitialization) { target.setValue(key.fKey, 1); } target.setValue(key.fKey, orgin.getInt(key.fKey)); target.setDefault(key.fKey, orgin.getDefaultInt(key.fKey)); break; } case LONG: { if (forceInitialization) { target.setValue(key.fKey, 1L); } target.setValue(key.fKey, orgin.getLong(key.fKey)); target.setDefault(key.fKey, orgin.getDefaultLong(key.fKey)); break; } case STRING: { 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)); break; } } } public void load() { for (int i = 0; i < fPreferenceKeys.length; i++) { loadProperty(fParent, fPreferenceKeys[i], fStore, true); } fLoaded = true; } public void loadDefaults() { for (int i = 0; i < fPreferenceKeys.length; i++) { setToDefault(fPreferenceKeys[i].fKey); } } public void start() { if (fPropertyListener == null) { fPropertyListener = new PropertyListener(); fParent.addPropertyChangeListener(fPropertyListener); } } public void stop() { if (fPropertyListener != null) { fParent.removePropertyChangeListener(fPropertyListener); fPropertyListener = null; } } @Override public void addPropertyChangeListener(final IPropertyChangeListener listener) { fStore.addPropertyChangeListener(listener); } @Override public void removePropertyChangeListener(final IPropertyChangeListener listener) { fStore.removePropertyChangeListener(listener); } @Override public void firePropertyChangeEvent(final String name, final Object oldValue, final Object newValue) { fStore.firePropertyChangeEvent(name, oldValue, newValue); } @Override public boolean contains(final String name) { return fStore.contains(name); } @Override public boolean getBoolean(final String name) { return fStore.getBoolean(name); } @Override public boolean getDefaultBoolean(final String name) { return fStore.getDefaultBoolean(name); } @Override public double getDefaultDouble(final String name) { return fStore.getDefaultDouble(name); } @Override public float getDefaultFloat(final String name) { return fStore.getDefaultFloat(name); } @Override public int getDefaultInt(final String name) { return fStore.getDefaultInt(name); } @Override public long getDefaultLong(final String name) { return fStore.getDefaultLong(name); } @Override public String getDefaultString(final String name) { return fStore.getDefaultString(name); } @Override public double getDouble(final String name) { return fStore.getDouble(name); } @Override public float getFloat(final String name) { return fStore.getFloat(name); } @Override public int getInt(final String name) { return fStore.getInt(name); } @Override public long getLong(final String name) { return fStore.getLong(name); } @Override public String getString(final String name) { return fStore.getString(name); } @Override public boolean isDefault(final String name) { return fStore.isDefault(name); } @Override public boolean needsSaving() { return fStore.needsSaving(); } @Override public void putValue(final String name, final String value) { if (covers(name)) { fStore.putValue(name, value); } } @Override public void setDefault(final String name, final double value) { if (covers(name)) { fStore.setDefault(name, value); } } @Override public void setDefault(final String name, final float value) { if (covers(name)) { fStore.setDefault(name, value); } } @Override public void setDefault(final String name, final int value) { if (covers(name)) { fStore.setDefault(name, value); } } @Override public void setDefault(final String name, final long value) { if (covers(name)) { fStore.setDefault(name, value); } } @Override public void setDefault(final String name, final String value) { if (covers(name)) { fStore.setDefault(name, value); } } @Override public void setDefault(final String name, final boolean value) { if (covers(name)) { fStore.setDefault(name, value); } } @Override public void setToDefault(final String name) { fStore.setToDefault(name); } @Override public void setValue(final String name, final double value) { if (covers(name)) { fStore.setValue(name, value); } } @Override public void setValue(final String name, final float value) { if (covers(name)) { fStore.setValue(name, value); } } @Override public void setValue(final String name, final int value) { if (covers(name)) { fStore.setValue(name, value); } } @Override public void setValue(final String name, final long value) { if (covers(name)) { fStore.setValue(name, value); } } @Override public void setValue(final String name, final String value) { if (covers(name)) { fStore.setValue(name, value); } } @Override public void setValue(final String name, final boolean value) { if (covers(name)) { fStore.setValue(name, value); } } /** * 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 * @since 3.0 */ public void addKeys(final OverlayStorePreference[] keys) { assert (!fLoaded); assert (keys != null); final int PreferenceKeysLength = fPreferenceKeys.length; final OverlayStorePreference[] result = new OverlayStorePreference[keys.length + PreferenceKeysLength]; for (int i = 0, length = PreferenceKeysLength; i < length; i++) { result[i] = fPreferenceKeys[i]; } for (int i = 0, length = keys.length; i < length; i++) { result[PreferenceKeysLength + i] = keys[i]; } fPreferenceKeys = result; if (fLoaded) { load(); } } }