Java tutorial
/* * Dlrc 2, NesC development in Eclipse. * Copyright (C) 2009 DLRC * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. * * Web: http://tos-ide.ethz.ch * Mail: tos-ide@tik.ee.ethz.ch */ package tinyos.dlrc.utility.preferences; import java.util.HashMap; import java.util.HashSet; import java.util.Map; import java.util.Set; import org.eclipse.jface.preference.IPreferenceStore; import org.eclipse.jface.util.IPropertyChangeListener; /** * A map containing some preferences which can be written into an {@link IPreferenceStore} * when necessary. While this class implements {@link IPreferenceStore}, not * all methods are available. Especially setting the default values will * throw an exception.<br> * Clients can call {@link #transmit()} to transmit all the changes made in * this buffer to the underlying store.<br> * Note: {@link IPropertyChangeListener}s are not supported. * @author Benjamin Sigg */ public class BufferedPreferenceStore implements IPreferenceStore { private IPreferenceStore base; private Set<String> defaults = new HashSet<String>(); private Map<String, Entry> values = new HashMap<String, Entry>(); public BufferedPreferenceStore(IPreferenceStore base) { this.base = base; } /** * Transmits the contents of this store to the underlying {@link IPreferenceStore}. */ public void transmit() { for (Map.Entry<String, Entry> entry : values.entrySet()) { switch (entry.getValue().type) { case BOOLEAN: base.setValue(entry.getKey(), (Boolean) entry.getValue().value); break; case FLOAT: base.setValue(entry.getKey(), (Float) entry.getValue().value); break; case DOUBLE: base.setValue(entry.getKey(), (Double) entry.getValue().value); break; case INT: base.setValue(entry.getKey(), (Integer) entry.getValue().value); break; case LONG: base.setValue(entry.getKey(), (Long) entry.getValue().value); break; case STRING: base.setValue(entry.getKey(), (String) entry.getValue().value); break; } } for (String name : defaults) { base.setToDefault(name); } clear(); } public void clear() { values.clear(); defaults.clear(); } public void addPropertyChangeListener(IPropertyChangeListener listener) { // ignore } public void removePropertyChangeListener(IPropertyChangeListener listener) { // ignore } public void firePropertyChangeEvent(String name, Object oldValue, Object newValue) { // ignore } public boolean contains(String name) { return base.contains(name); } public boolean isDefault(String name) { return !values.containsKey(name) && base.isDefault(name); } public boolean needsSaving() { return false; } public boolean getDefaultBoolean(String name) { return base.getDefaultBoolean(name); } public double getDefaultDouble(String name) { return base.getDefaultDouble(name); } public float getDefaultFloat(String name) { return base.getDefaultFloat(name); } public int getDefaultInt(String name) { return base.getDefaultInt(name); } public long getDefaultLong(String name) { return base.getDefaultLong(name); } public String getDefaultString(String name) { return base.getDefaultString(name); } public void setDefault(String name, boolean value) { throw new UnsupportedOperationException(); } public void setDefault(String name, double value) { throw new UnsupportedOperationException(); } public void setDefault(String name, float value) { throw new UnsupportedOperationException(); } public void setDefault(String name, int value) { throw new UnsupportedOperationException(); } public void setDefault(String name, long value) { throw new UnsupportedOperationException(); } public void setDefault(String name, String defaultObject) { throw new UnsupportedOperationException(); } public boolean getBoolean(String name) { if (defaults.contains(name)) return base.getDefaultBoolean(name); Boolean result = (Boolean) get(name, Type.BOOLEAN); if (result != null) return result.booleanValue(); return base.getBoolean(name); } public double getDouble(String name) { if (defaults.contains(name)) return base.getDefaultDouble(name); Double result = (Double) get(name, Type.DOUBLE); if (result != null) return result.doubleValue(); return base.getDouble(name); } public float getFloat(String name) { if (defaults.contains(name)) return base.getDefaultFloat(name); Float result = (Float) get(name, Type.FLOAT); if (result != null) return result.floatValue(); return base.getFloat(name); } public int getInt(String name) { if (defaults.contains(name)) return base.getDefaultInt(name); Integer result = (Integer) get(name, Type.INT); if (result != null) return result.intValue(); return base.getInt(name); } public long getLong(String name) { if (defaults.contains(name)) return base.getDefaultLong(name); Long result = (Long) get(name, Type.LONG); if (result != null) return result.longValue(); return base.getLong(name); } public String getString(String name) { if (defaults.contains(name)) return base.getDefaultString(name); String result = (String) get(name, Type.STRING); if (result != null) return result; return base.getString(name); } private Object get(String name, Type type) { Entry result = values.get(name); if (result == null) return null; if (result.type != type) return null; return result.value; } public void setToDefault(String name) { values.remove(name); defaults.add(name); } public void putValue(String name, String value) { setValue(name, value); } public void setValue(String name, double value) { values.put(name, new Entry(Type.DOUBLE, Double.valueOf(value))); defaults.remove(name); } public void setValue(String name, float value) { values.put(name, new Entry(Type.FLOAT, Float.valueOf(value))); defaults.remove(name); } public void setValue(String name, int value) { values.put(name, new Entry(Type.INT, Integer.valueOf(value))); defaults.remove(name); } public void setValue(String name, long value) { values.put(name, new Entry(Type.LONG, Long.valueOf(value))); defaults.remove(name); } public void setValue(String name, String value) { values.put(name, new Entry(Type.STRING, value)); defaults.remove(name); } public void setValue(String name, boolean value) { values.put(name, new Entry(Type.BOOLEAN, Boolean.valueOf(value))); defaults.remove(name); } private static enum Type { DOUBLE, FLOAT, INT, LONG, STRING, BOOLEAN } private static class Entry { public Type type; public Object value; public Entry(Type type, Object value) { this.type = type; this.value = value; } } }