Java tutorial
/******************************************************************************* * Copyright (c) 2016 - 2017 Certiv Analytics 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 ******************************************************************************/ package net.certiv.fluentmark.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 { /** * Descriptor used to denote data types. */ public static final class TypeDescriptor { private TypeDescriptor() { } } 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(); /** * Data structure for the overlay key. */ public static class OverlayKey { TypeDescriptor fDescriptor; String fKey; public OverlayKey(TypeDescriptor descriptor, String key) { fDescriptor = descriptor; fKey = key; } } /* * @see IPropertyChangeListener */ private class PropertyListener implements IPropertyChangeListener { @Override public void propertyChange(PropertyChangeEvent event) { OverlayKey key = findOverlayKey(event.getProperty()); if (key != null) propagateProperty(fParent, key, fStore); } } /** The parent preference store. */ private IPreferenceStore fParent; /** This store. */ private IPreferenceStore fStore; /** The keys of this store. */ private OverlayKey[] fOverlayKeys; /** The property listener. */ private PropertyListener fPropertyListener; private boolean fLoaded; /** * Creates and returns a new overlay preference store. * * @param parent the parent preference store * @param overlayKeys the overlay keys */ public OverlayPreferenceStore(IPreferenceStore parent, OverlayKey[] overlayKeys) { fParent = parent; fOverlayKeys = overlayKeys; fStore = new PreferenceStore(); } /** * Tries to find and return the overlay key for the given preference key string. * * @param key the preference key string * @return the overlay key or <code>null</code> if none can be found */ private OverlayKey findOverlayKey(String key) { for (OverlayKey fOverlayKey : fOverlayKeys) { if (fOverlayKey.fKey.equals(key)) return fOverlayKey; } return null; } /** * Tells whether the given preference key string is covered by this overlay store. * * @param key the preference key string * @return <code>true</code> if this overlay store covers the given key */ private boolean covers(String key) { return (findOverlayKey(key) != null); } /** * Propagates the given overlay key from the origin to the target preference store. * * @param origin the source preference store * @param key the overlay key * @param target the preference store to which the key is propagated */ private void propagateProperty(IPreferenceStore origin, OverlayKey key, IPreferenceStore target) { if (origin.isDefault(key.fKey)) { if (!target.isDefault(key.fKey)) target.setToDefault(key.fKey); return; } TypeDescriptor d = key.fDescriptor; if (BOOLEAN == d) { boolean originValue = origin.getBoolean(key.fKey); boolean targetValue = target.getBoolean(key.fKey); if (targetValue != originValue) target.setValue(key.fKey, originValue); } else if (DOUBLE == d) { double originValue = origin.getDouble(key.fKey); double targetValue = target.getDouble(key.fKey); if (targetValue != originValue) target.setValue(key.fKey, originValue); } else if (FLOAT == d) { float originValue = origin.getFloat(key.fKey); float targetValue = target.getFloat(key.fKey); if (targetValue != originValue) target.setValue(key.fKey, originValue); } else if (INT == d) { int originValue = origin.getInt(key.fKey); int targetValue = target.getInt(key.fKey); if (targetValue != originValue) target.setValue(key.fKey, originValue); } else if (LONG == d) { long originValue = origin.getLong(key.fKey); long targetValue = target.getLong(key.fKey); if (targetValue != originValue) target.setValue(key.fKey, originValue); } else if (STRING == d) { String originValue = origin.getString(key.fKey); String targetValue = target.getString(key.fKey); if (targetValue != null && originValue != null && !targetValue.equals(originValue)) target.setValue(key.fKey, originValue); } } /** * Propagates all overlay keys from this store to the parent store. */ public void propagate() { for (OverlayKey fOverlayKey : fOverlayKeys) propagateProperty(fStore, fOverlayKey, fParent); } /** * Loads the given key from the origin into the target. * * @param origin the source preference store * @param key the overlay key * @param target the preference store to which the key is propagated * @param forceInitialization if <code>true</code> the value in the target gets initialized * before loading */ private void loadProperty(IPreferenceStore origin, OverlayKey key, IPreferenceStore target, boolean forceInitialization) { TypeDescriptor d = key.fDescriptor; if (BOOLEAN == d) { if (forceInitialization) target.setValue(key.fKey, true); target.setValue(key.fKey, origin.getBoolean(key.fKey)); target.setDefault(key.fKey, origin.getDefaultBoolean(key.fKey)); } else if (DOUBLE == d) { if (forceInitialization) target.setValue(key.fKey, 1.0D); target.setValue(key.fKey, origin.getDouble(key.fKey)); target.setDefault(key.fKey, origin.getDefaultDouble(key.fKey)); } else if (FLOAT == d) { if (forceInitialization) target.setValue(key.fKey, 1.0F); target.setValue(key.fKey, origin.getFloat(key.fKey)); target.setDefault(key.fKey, origin.getDefaultFloat(key.fKey)); } else if (INT == d) { if (forceInitialization) target.setValue(key.fKey, 1); target.setValue(key.fKey, origin.getInt(key.fKey)); target.setDefault(key.fKey, origin.getDefaultInt(key.fKey)); } else if (LONG == d) { if (forceInitialization) target.setValue(key.fKey, 1L); target.setValue(key.fKey, origin.getLong(key.fKey)); target.setDefault(key.fKey, origin.getDefaultLong(key.fKey)); } else if (STRING == d) { if (forceInitialization) target.setValue(key.fKey, "1"); //$NON-NLS-1$ target.setValue(key.fKey, origin.getString(key.fKey)); target.setDefault(key.fKey, origin.getDefaultString(key.fKey)); } } /** * Loads the values from the parent into this store. */ public void load() { for (OverlayKey fOverlayKey : fOverlayKeys) loadProperty(fParent, fOverlayKey, fStore, true); fLoaded = true; } /** * Loads the default values. */ public void loadDefaults() { for (OverlayKey fOverlayKey : fOverlayKeys) setToDefault(fOverlayKey.fKey); } /** * Starts to listen for changes. */ public void start() { if (fPropertyListener == null) { fPropertyListener = new PropertyListener(); fParent.addPropertyChangeListener(fPropertyListener); } } /** * Stops to listen for changes. */ public void stop() { if (fPropertyListener != null) { fParent.removePropertyChangeListener(fPropertyListener); fPropertyListener = null; } } @Override public void addPropertyChangeListener(IPropertyChangeListener listener) { fStore.addPropertyChangeListener(listener); } @Override public void removePropertyChangeListener(IPropertyChangeListener listener) { fStore.removePropertyChangeListener(listener); } @Override public void firePropertyChangeEvent(String name, Object oldValue, Object newValue) { fStore.firePropertyChangeEvent(name, oldValue, newValue); } @Override public boolean contains(String name) { return fStore.contains(name); } @Override public boolean getBoolean(String name) { return fStore.getBoolean(name); } @Override public boolean getDefaultBoolean(String name) { return fStore.getDefaultBoolean(name); } @Override public double getDefaultDouble(String name) { return fStore.getDefaultDouble(name); } @Override public float getDefaultFloat(String name) { return fStore.getDefaultFloat(name); } @Override public int getDefaultInt(String name) { return fStore.getDefaultInt(name); } @Override public long getDefaultLong(String name) { return fStore.getDefaultLong(name); } @Override public String getDefaultString(String name) { return fStore.getDefaultString(name); } @Override public double getDouble(String name) { return fStore.getDouble(name); } @Override public float getFloat(String name) { return fStore.getFloat(name); } @Override public int getInt(String name) { return fStore.getInt(name); } @Override public long getLong(String name) { return fStore.getLong(name); } @Override public String getString(String name) { return fStore.getString(name); } @Override public boolean isDefault(String name) { return fStore.isDefault(name); } @Override public boolean needsSaving() { return fStore.needsSaving(); } @Override public void putValue(String name, String value) { if (covers(name)) fStore.putValue(name, value); } @Override public void setDefault(String name, double value) { if (covers(name)) fStore.setDefault(name, value); } @Override public void setDefault(String name, float value) { if (covers(name)) fStore.setDefault(name, value); } @Override public void setDefault(String name, int value) { if (covers(name)) fStore.setDefault(name, value); } @Override public void setDefault(String name, long value) { if (covers(name)) fStore.setDefault(name, value); } @Override public void setDefault(String name, String value) { if (covers(name)) fStore.setDefault(name, value); } @Override public void setDefault(String name, boolean value) { if (covers(name)) fStore.setDefault(name, value); } @Override public void setToDefault(String name) { fStore.setToDefault(name); } @Override public void setValue(String name, double value) { if (covers(name)) fStore.setValue(name, value); } @Override public void setValue(String name, float value) { if (covers(name)) fStore.setValue(name, value); } @Override public void setValue(String name, int value) { if (covers(name)) fStore.setValue(name, value); } @Override public void setValue(String name, long value) { if (covers(name)) fStore.setValue(name, value); } @Override public void setValue(String name, String value) { if (covers(name)) fStore.setValue(name, value); } @Override public void setValue(String name, 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 an array with overlay keys * @since 3.0 */ 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(); } }