Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2003 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Common Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/cpl-v10.html * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package com.agynamix.platform.frontend.preferences; import java.io.InputStream; import java.io.OutputStream; import java.io.PrintStream; import java.io.PrintWriter; import java.util.ArrayList; import java.util.Enumeration; import java.util.Iterator; import java.util.Properties; import org.eclipse.core.runtime.Assert; import org.eclipse.core.runtime.ListenerList; import org.eclipse.jface.preference.IPersistentPreferenceStore; import org.eclipse.jface.preference.IPreferenceStore; import org.eclipse.jface.util.IPropertyChangeListener; import org.eclipse.jface.util.PropertyChangeEvent; import com.agynamix.platform.infra.IPreferenceConfigAdapter; /** * I used the Eclipse PreferenceStore here and modified it so that it * works together with the applications overall preference mechanism. * * @see IPreferenceStore */ public class ApplicationPreferenceStore implements IPersistentPreferenceStore { /** * List of registered listeners (element type: * <code>IPropertyChangeListener</code>). These listeners are to be * informed when the current value of a preference changes. */ private ListenerList listeners = new ListenerList(); /** * The mapping from preference name to preference value (represented as * strings). */ private Properties properties; /** * The mapping from preference name to default preference value (represented * as strings); <code>null</code> if none. */ private Properties defaultProperties; /** * Indicates whether a value as been changed by <code>setToDefault</code> * or <code>setValue</code>; initially <code>false</code>. */ private boolean dirty = false; final IPreferenceConfigAdapter configAdapter; /** * Creates an empty preference store. * <p> * Use the methods <code>load(InputStream)</code> and * <code>save(InputStream)</code> to load and store this preference store. * </p> * * @see #load(InputStream) * @see #save(OutputStream, String) */ public ApplicationPreferenceStore(IPreferenceConfigAdapter configAdapter) { this.configAdapter = configAdapter; defaultProperties = new Properties(); this.loadDefaults(configAdapter.loadDefaultProperties()); properties = new Properties(defaultProperties); this.load(configAdapter.loadProperties()); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void addPropertyChangeListener(IPropertyChangeListener listener) { listeners.add(listener); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public boolean contains(String name) { return (properties.containsKey(name) || defaultProperties.containsKey(name)); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void firePropertyChangeEvent(String name, Object oldValue, Object newValue) { final Object[] finalListeners = this.listeners.getListeners(); // Do we need to fire an event. if (finalListeners.length > 0 && (oldValue == null || !oldValue.equals(newValue))) { final PropertyChangeEvent pe = new PropertyChangeEvent(this, name, oldValue, newValue); for (int i = 0; i < finalListeners.length; ++i) { IPropertyChangeListener l = (IPropertyChangeListener) finalListeners[i]; l.propertyChange(pe); } // } // }); } } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public boolean getBoolean(String name) { return getBoolean(properties, name); } /** * Helper function: gets boolean for a given name. * * @param p * @param name * @return boolean */ private boolean getBoolean(Properties p, String name) { String value = p != null ? p.getProperty(name) : null; if (value == null) return BOOLEAN_DEFAULT_DEFAULT; if (value.equals(IPreferenceStore.TRUE)) return true; return false; } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public boolean getDefaultBoolean(String name) { return getBoolean(defaultProperties, name); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public double getDefaultDouble(String name) { return getDouble(defaultProperties, name); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public float getDefaultFloat(String name) { return getFloat(defaultProperties, name); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public int getDefaultInt(String name) { return getInt(defaultProperties, name); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public long getDefaultLong(String name) { return getLong(defaultProperties, name); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public String getDefaultString(String name) { return getString(defaultProperties, name); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public double getDouble(String name) { return getDouble(properties, name); } /** * Helper function: gets double for a given name. * * @param p * @param name * @return double */ private double getDouble(Properties p, String name) { String value = p != null ? p.getProperty(name) : null; if (value == null) return DOUBLE_DEFAULT_DEFAULT; double ival = DOUBLE_DEFAULT_DEFAULT; try { ival = new Double(value).doubleValue(); } catch (NumberFormatException e) { } return ival; } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public float getFloat(String name) { return getFloat(properties, name); } /** * Helper function: gets float for a given name. * * @param p * @param name * @return float */ private float getFloat(Properties p, String name) { String value = p != null ? p.getProperty(name) : null; if (value == null) return FLOAT_DEFAULT_DEFAULT; float ival = FLOAT_DEFAULT_DEFAULT; try { ival = new Float(value).floatValue(); } catch (NumberFormatException e) { } return ival; } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public int getInt(String name) { return getInt(properties, name); } /** * Helper function: gets int for a given name. * * @param p * @param name * @return int */ private int getInt(Properties p, String name) { String value = p != null ? p.getProperty(name) : null; if (value == null) return INT_DEFAULT_DEFAULT; int ival = 0; try { ival = Integer.parseInt(value); } catch (NumberFormatException e) { } return ival; } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public long getLong(String name) { return getLong(properties, name); } /** * Helper function: gets long for a given name. * * @param p * @param name * @return */ private long getLong(Properties p, String name) { String value = p != null ? p.getProperty(name) : null; if (value == null) return LONG_DEFAULT_DEFAULT; long ival = LONG_DEFAULT_DEFAULT; try { ival = Long.parseLong(value); } catch (NumberFormatException e) { } return ival; } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public String getString(String name) { return getString(properties, name); } /** * Helper function: gets string for a given name. * * @param p * @param name * @return */ private String getString(Properties p, String name) { String value = p != null ? p.getProperty(name) : null; if (value == null) return STRING_DEFAULT_DEFAULT; return value; } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public boolean isDefault(String name) { return (!properties.containsKey(name) && defaultProperties.containsKey(name)); } /** * Prints the contents of this preference store to the given print stream. * * @param out * the print stream */ public void list(PrintStream out) { properties.list(out); } /** * Prints the contents of this preference store to the given print writer. * * @param out * the print writer */ public void list(PrintWriter out) { properties.list(out); } protected void load(Properties in) { for (Iterator it = in.keySet().iterator(); it.hasNext();) { String key = (String) it.next(); properties.setProperty(key, in.getProperty(key)); } dirty = false; } protected void loadDefaults(Properties in) { for (Iterator it = in.keySet().iterator(); it.hasNext();) { String key = (String) it.next(); defaultProperties.setProperty(key, in.getProperty(key)); } } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public boolean needsSaving() { return dirty; } /** * Returns an enumeration of all preferences known to this store which have * current values other than their default value. * * @return an array of preference names */ public String[] preferenceNames() { ArrayList list = new ArrayList(); Enumeration names = properties.propertyNames(); while (names.hasMoreElements()) { list.add(names.nextElement()); } return (String[]) list.toArray(new String[list.size()]); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void putValue(String name, String value) { String oldValue = getString(name); if (oldValue == null || !oldValue.equals(value)) { setValue(properties, name, value); dirty = true; } } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void removePropertyChangeListener(IPropertyChangeListener listener) { listeners.remove(listener); } /** * Saves the non-default-valued preferences known to this preference store * to the file from which they were originally loaded. */ public void save() { configAdapter.saveProperties(properties); dirty = false; } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void setDefault(String name, double value) { setValue(defaultProperties, name, value); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void setDefault(String name, float value) { setValue(defaultProperties, name, value); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void setDefault(String name, int value) { setValue(defaultProperties, name, value); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void setDefault(String name, long value) { setValue(defaultProperties, name, value); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void setDefault(String name, String value) { setValue(defaultProperties, name, value); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void setDefault(String name, boolean value) { setValue(defaultProperties, name, value); } /** * Sets the name of the file used when loading and storing this preference * store. * <p> * Afterward, the methods <code>load()</code> and <code>save()</code> * can be used to load and store this preference store. * </p> * * @param name * the file name * @see #load() * @see #save() */ public void setFilename(String name) { } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void setToDefault(String name) { Object oldValue = properties.get(name); properties.remove(name); dirty = true; Object newValue = null; if (defaultProperties != null) newValue = defaultProperties.get(name); firePropertyChangeEvent(name, oldValue, newValue); } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void setValue(String name, double value) { double oldValue = getDouble(name); if (oldValue != value) { setValue(properties, name, value); dirty = true; firePropertyChangeEvent(name, new Double(oldValue), new Double(value)); } } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void setValue(String name, float value) { float oldValue = getFloat(name); if (oldValue != value) { setValue(properties, name, value); dirty = true; firePropertyChangeEvent(name, new Float(oldValue), new Float(value)); } } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void setValue(String name, int value) { int oldValue = getInt(name); if (oldValue != value) { setValue(properties, name, value); dirty = true; firePropertyChangeEvent(name, new Integer(oldValue), new Integer(value)); } } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void setValue(String name, long value) { long oldValue = getLong(name); if (oldValue != value) { setValue(properties, name, value); dirty = true; firePropertyChangeEvent(name, new Long(oldValue), new Long(value)); } } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void setValue(String name, String value) { String oldValue = getString(name); if (oldValue == null || !oldValue.equals(value)) { setValue(properties, name, value); dirty = true; firePropertyChangeEvent(name, oldValue, value); } } /* * (non-Javadoc) Method declared on IPreferenceStore. */ public void setValue(String name, boolean value) { boolean oldValue = getBoolean(name); if (oldValue != value) { setValue(properties, name, value); dirty = true; firePropertyChangeEvent(name, Boolean.valueOf(oldValue), Boolean.valueOf(value)); } } /** * Helper method: sets value for a given name. * * @param p * @param name * @param value */ private void setValue(Properties p, String name, double value) { Assert.isTrue(p != null); p.put(name, Double.toString(value)); } /** * Helper method: sets value for a given name. * * @param p * @param name * @param value */ private void setValue(Properties p, String name, float value) { Assert.isTrue(p != null); p.put(name, Float.toString(value)); } /** * Helper method: sets value for a given name. * * @param p * @param name * @param value */ private void setValue(Properties p, String name, int value) { Assert.isTrue(p != null); p.put(name, Integer.toString(value)); } /** * Helper method: sets the value for a given name. * * @param p * @param name * @param value */ private void setValue(Properties p, String name, long value) { Assert.isTrue(p != null); p.put(name, Long.toString(value)); } /** * Helper method: sets the value for a given name. * * @param p * @param name * @param value */ private void setValue(Properties p, String name, String value) { Assert.isTrue(p != null && value != null); p.put(name, value); } /** * Helper method: sets the value for a given name. * * @param p * @param name * @param value */ private void setValue(Properties p, String name, boolean value) { Assert.isTrue(p != null); p.put(name, value == true ? IPreferenceStore.TRUE : IPreferenceStore.FALSE); } }