package at.bestsolution.efxclipse.text.editor;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.ListenerList;
import at.bestsolution.efxclipse.jface.preferences.IPreferenceStore;
import at.bestsolution.efxclipse.jface.util.IPropertyChangeListener;
import at.bestsolution.efxclipse.jface.util.PropertyChangeEvent;
/**
* Preference store that composes multiple preference stores in a
* chain and serves a preference value from the first preference store in the
* chain that contains the preference.
* <p>
* This preference store is read-only i.e. write access
* throws an {@link java.lang.UnsupportedOperationException}.</p>
*
* @since 3.0
*/
public class ChainedPreferenceStore implements IPreferenceStore {
/** Child preference stores. */
private IPreferenceStore[] fPreferenceStores;
/** Listeners on this chained preference store. */
private ListenerList fClientListeners= new ListenerList(ListenerList.IDENTITY);
/** Listeners on the child preference stores. */
private List fChildListeners= new ArrayList();
/**
* Listener on the chained preference stores. Forwards only the events
* that are visible to clients.
*/
private class PropertyChangeListener implements IPropertyChangeListener {
/** Preference store to listen too. */
private IPreferenceStore fPreferenceStore;
/**
* Initialize with the given preference store.
*
* @param preferenceStore the preference store
*/
public PropertyChangeListener(IPreferenceStore preferenceStore) {
setPreferenceStore(preferenceStore);
}
/*
* @see org.eclipse.jface.util.IPropertyChangeListener#propertyChange(org.eclipse.jface.util.PropertyChangeEvent)
*/
public void propertyChange(PropertyChangeEvent event) {
IPreferenceStore childPreferenceStore= getPreferenceStore();
handlePropertyChangeEvent(childPreferenceStore, event);
}
/**
* Registers this listener on the preference store.
*/
public void register() {
getPreferenceStore().addPropertyChangeListener(this);
}
/**
* Unregisters this listener from the preference store.
*/
public void unregister() {
getPreferenceStore().removePropertyChangeListener(this);
}
/**
* Returns the preference store.
*
* @return the preference store
*/
public IPreferenceStore getPreferenceStore() {
return fPreferenceStore;
}
/**
* Sets the preference store.
*
* @param preferenceStore the preference store to set
*/
public void setPreferenceStore(IPreferenceStore preferenceStore) {
fPreferenceStore= preferenceStore;
}
}
/**
* Sets the chained preference stores.
*
* @param preferenceStores the chained preference stores to set
*/
public ChainedPreferenceStore(IPreferenceStore[] preferenceStores) {
Assert.isTrue(preferenceStores != null && preferenceStores.length > 0);
fPreferenceStores= new IPreferenceStore[preferenceStores.length];
System.arraycopy(preferenceStores, 0, fPreferenceStores, 0, preferenceStores.length);
// Create listeners
for (int i= 0, length= fPreferenceStores.length; i < length; i++) {
PropertyChangeListener listener= new PropertyChangeListener(fPreferenceStores[i]);
fChildListeners.add(listener);
}
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#addPropertyChangeListener(org.eclipse.jface.util.IPropertyChangeListener)
*/
public void addPropertyChangeListener(IPropertyChangeListener listener) {
if (fClientListeners.size() == 0) {
registerChildListeners();
}
fClientListeners.add(listener);
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#removePropertyChangeListener(org.eclipse.jface.util.IPropertyChangeListener)
*/
public void removePropertyChangeListener(IPropertyChangeListener listener) {
fClientListeners.remove(listener);
if (fClientListeners.size() == 0) {
unregisterChildListeners();
}
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#contains(java.lang.String)
*/
public boolean contains(String name) {
return getVisibleStore(name) != null;
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#firePropertyChangeEvent(java.lang.String, java.lang.Object, java.lang.Object)
*/
public void firePropertyChangeEvent(String name, Object oldValue, Object newValue) {
firePropertyChangeEvent(new PropertyChangeEvent(this, name, oldValue, newValue));
}
/**
* Fire the given property change event.
*
* @param event the property change event
*/
private void firePropertyChangeEvent(PropertyChangeEvent event) {
Object[] listeners= fClientListeners.getListeners();
for (int i= 0; i < listeners.length; i++)
((IPropertyChangeListener) listeners[i]).propertyChange(event);
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#getBoolean(java.lang.String)
*/
public boolean getBoolean(String name) {
IPreferenceStore visibleStore= getVisibleStore(name);
if (visibleStore != null)
return visibleStore.getBoolean(name);
return BOOLEAN_DEFAULT_DEFAULT;
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#getDefaultBoolean(java.lang.String)
*/
public boolean getDefaultBoolean(String name) {
IPreferenceStore visibleStore= getVisibleStore(name);
if (visibleStore != null)
return visibleStore.getDefaultBoolean(name);
return BOOLEAN_DEFAULT_DEFAULT;
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#getDefaultDouble(java.lang.String)
*/
public double getDefaultDouble(String name) {
IPreferenceStore visibleStore= getVisibleStore(name);
if (visibleStore != null)
return visibleStore.getDefaultDouble(name);
return DOUBLE_DEFAULT_DEFAULT;
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#getDefaultFloat(java.lang.String)
*/
public float getDefaultFloat(String name) {
IPreferenceStore visibleStore= getVisibleStore(name);
if (visibleStore != null)
return visibleStore.getDefaultFloat(name);
return FLOAT_DEFAULT_DEFAULT;
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#getDefaultInt(java.lang.String)
*/
public int getDefaultInt(String name) {
IPreferenceStore visibleStore= getVisibleStore(name);
if (visibleStore != null)
return visibleStore.getDefaultInt(name);
return INT_DEFAULT_DEFAULT;
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#getDefaultLong(java.lang.String)
*/
public long getDefaultLong(String name) {
IPreferenceStore visibleStore= getVisibleStore(name);
if (visibleStore != null)
return visibleStore.getDefaultLong(name);
return LONG_DEFAULT_DEFAULT;
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#getDefaultString(java.lang.String)
*/
public String getDefaultString(String name) {
IPreferenceStore visibleStore= getVisibleStore(name);
if (visibleStore != null)
return visibleStore.getDefaultString(name);
return STRING_DEFAULT_DEFAULT;
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#getDouble(java.lang.String)
*/
public double getDouble(String name) {
IPreferenceStore visibleStore= getVisibleStore(name);
if (visibleStore != null)
return visibleStore.getDouble(name);
return DOUBLE_DEFAULT_DEFAULT;
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#getFloat(java.lang.String)
*/
public float getFloat(String name) {
IPreferenceStore visibleStore= getVisibleStore(name);
if (visibleStore != null)
return visibleStore.getFloat(name);
return FLOAT_DEFAULT_DEFAULT;
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#getInt(java.lang.String)
*/
public int getInt(String name) {
IPreferenceStore visibleStore= getVisibleStore(name);
if (visibleStore != null)
return visibleStore.getInt(name);
return INT_DEFAULT_DEFAULT;
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#getLong(java.lang.String)
*/
public long getLong(String name) {
IPreferenceStore visibleStore= getVisibleStore(name);
if (visibleStore != null)
return visibleStore.getLong(name);
return LONG_DEFAULT_DEFAULT;
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#getString(java.lang.String)
*/
public String getString(String name) {
IPreferenceStore visibleStore= getVisibleStore(name);
if (visibleStore != null)
return visibleStore.getString(name);
return STRING_DEFAULT_DEFAULT;
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#isDefault(java.lang.String)
*/
public boolean isDefault(String name) {
IPreferenceStore visibleStore= getVisibleStore(name);
if (visibleStore != null)
return visibleStore.isDefault(name);
return false;
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#needsSaving()
*/
public boolean needsSaving() {
throw new UnsupportedOperationException();
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#putValue(java.lang.String, java.lang.String)
*/
public void putValue(String name, String value) {
throw new UnsupportedOperationException();
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#setDefault(java.lang.String, double)
*/
public void setDefault(String name, double value) {
throw new UnsupportedOperationException();
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#setDefault(java.lang.String, float)
*/
public void setDefault(String name, float value) {
throw new UnsupportedOperationException();
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#setDefault(java.lang.String, int)
*/
public void setDefault(String name, int value) {
throw new UnsupportedOperationException();
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#setDefault(java.lang.String, long)
*/
public void setDefault(String name, long value) {
throw new UnsupportedOperationException();
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#setDefault(java.lang.String, java.lang.String)
*/
public void setDefault(String name, String defaultObject) {
throw new UnsupportedOperationException();
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#setDefault(java.lang.String, boolean)
*/
public void setDefault(String name, boolean value) {
throw new UnsupportedOperationException();
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#setToDefault(java.lang.String)
*/
public void setToDefault(String name) {
throw new UnsupportedOperationException();
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#setValue(java.lang.String, double)
*/
public void setValue(String name, double value) {
throw new UnsupportedOperationException();
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#setValue(java.lang.String, float)
*/
public void setValue(String name, float value) {
throw new UnsupportedOperationException();
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#setValue(java.lang.String, int)
*/
public void setValue(String name, int value) {
throw new UnsupportedOperationException();
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#setValue(java.lang.String, long)
*/
public void setValue(String name, long value) {
throw new UnsupportedOperationException();
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#setValue(java.lang.String, java.lang.String)
*/
public void setValue(String name, String value) {
throw new UnsupportedOperationException();
}
/*
* @see org.eclipse.jface.preference.IPreferenceStore#setValue(java.lang.String, boolean)
*/
public void setValue(String name, boolean value) {
throw new UnsupportedOperationException();
}
/**
* Handle property change event from the child listener with the given child preference store.
*
* @param childPreferenceStore the child preference store
* @param event the event
*/
private void handlePropertyChangeEvent(IPreferenceStore childPreferenceStore, PropertyChangeEvent event) {
String property= event.getProperty();
Object oldValue= event.getOldValue();
Object newValue= event.getNewValue();
IPreferenceStore visibleStore= getVisibleStore(property);
/*
* Assume that the property is there but has no default value (its owner relies on the default-default value)
* see https://bugs.eclipse.org/bugs/show_bug.cgi?id=52827
*/
if (visibleStore == null && newValue != null)
visibleStore= childPreferenceStore;
if (visibleStore == null) {
// no visible store
if (oldValue != null)
// removal in child, last in chain -> removal in this chained preference store
firePropertyChangeEvent(event);
} else if (visibleStore == childPreferenceStore) {
// event from visible store
if (oldValue != null) {
// change in child, visible store -> change in this chained preference store
firePropertyChangeEvent(event);
} else {
// insertion in child
IPreferenceStore oldVisibleStore= null;
int i= 0;
int length= fPreferenceStores.length;
while (i < length && fPreferenceStores[i++] != visibleStore) {
// do nothing
}
while (oldVisibleStore == null && i < length) {
if (fPreferenceStores[i].contains(property))
oldVisibleStore= fPreferenceStores[i];
i++;
}
if (oldVisibleStore == null) {
// insertion in child, first in chain -> insertion in this chained preference store
firePropertyChangeEvent(event);
} else {
// insertion in child, not first in chain
oldValue= getOtherValue(property, oldVisibleStore, newValue);
if (!oldValue.equals(newValue))
// insertion in child, different old value -> change in this chained preference store
firePropertyChangeEvent(property, oldValue, newValue);
// else: insertion in child, same old value -> no change in this chained preference store
}
}
} else {
// event from other than the visible store
boolean eventBeforeVisibleStore= false;
for (int i= 0, length= fPreferenceStores.length; i < length; i++) {
IPreferenceStore store= fPreferenceStores[i];
if (store == visibleStore)
break;
if (store == childPreferenceStore) {
eventBeforeVisibleStore= true;
break;
}
}
if (eventBeforeVisibleStore) {
// removal in child, before visible store
/*
* The original event's new value can be non-null (removed assertion).
* see https://bugs.eclipse.org/bugs/show_bug.cgi?id=69419
*/
newValue= getOtherValue(property, visibleStore, oldValue);
if (!newValue.equals(oldValue))
// removal in child, before visible store, different old value -> change in this chained preference store
firePropertyChangeEvent(property, oldValue, newValue);
// else: removal in child, before visible store, same old value -> no change in this chained preference store
}
// else: event behind visible store -> no change in this chained preference store
}
}
/**
* Returns an object of the same dynamic type as <code>thisValue</code>, the returned object
* encapsulates the value of the <code>property</code> from the preference <code>store</code>.
*
* @param property the name of the considered property
* @param store the preference store
* @param thisValue the given value
* @return the other value
*/
private Object getOtherValue(String property, IPreferenceStore store, Object thisValue) {
if (thisValue instanceof Boolean)
return store.getBoolean(property) ? Boolean.TRUE : Boolean.FALSE;
else if (thisValue instanceof Double)
return new Double(store.getDouble(property));
else if (thisValue instanceof Float)
return new Float(store.getFloat(property));
else if (thisValue instanceof Integer)
return new Integer(store.getInt(property));
else if (thisValue instanceof Long)
return new Long(store.getLong(property));
else if (thisValue instanceof String)
return store.getString(property);
return store.getString(property);
}
/**
* Returns the preference store from which the given property's value
* is visible.
*
* @param property the name of the property
* @return the preference store from which the property's value is visible,
* <code>null</code> if the property is unknown
*/
private IPreferenceStore getVisibleStore(String property) {
IPreferenceStore visibleStore= null;
for (int i= 0, length= fPreferenceStores.length; i < length && visibleStore == null; i++) {
IPreferenceStore store= fPreferenceStores[i];
if (store.contains(property))
visibleStore= store;
}
return visibleStore;
}
/**
* Register the child listeners on the child preference stores.
*/
private void registerChildListeners() {
Iterator iter= fChildListeners.iterator();
while (iter.hasNext()) {
PropertyChangeListener listener= (PropertyChangeListener) iter.next();
listener.register();
}
}
/**
* Unregister the child listeners from the child preference stores.
*/
private void unregisterChildListeners() {
Iterator iter= fChildListeners.iterator();
while (iter.hasNext()) {
PropertyChangeListener listener= (PropertyChangeListener) iter.next();
listener.unregister();
}
}
}