package org.hamcrest.object;

import org.hamcrest.Description;
import org.hamcrest.Matcher;
import org.hamcrest.TypeSafeDiagnosingMatcher;

import java.util.EventObject;


/**
 
* Tests if the value is an event announced by a specific object.
 
*/

public class IsEventFrom extends TypeSafeDiagnosingMatcher<EventObject> {
    
private final Class<?> eventClass;
    
private final Object source;

    
public IsEventFrom(Class<?> eventClass, Object source) {
        
this.eventClass = eventClass;
        
this.source = source;
    
}

    
@Override
    
public boolean matchesSafely(EventObject item, Description mismatchDescription) {
        
if (!eventClass.isInstance(item)) {
          
mismatchDescription.appendText("item type was " + item.getClass().getName());
          
return false;
        
}
        

        
if (!eventHasSameSource(item)) {
          
mismatchDescription.appendText("source was ").appendValue(item.getSource());
          
return false;
        
}
        
return true;
    
}

    

    
private boolean eventHasSameSource(EventObject ev) {
        
return ev.getSource() == source;
    
}

    
@Override
    
public void describeTo(Description description) {
        
description.appendText("an event of type ")
                
.appendText(eventClass.getName())
                
.appendText(" from ")
                
.appendValue(source);
    
}

    
/**
     
* Creates a matcher of {@link java.util.EventObject} that matches any object
     
* derived from <var>eventClass</var> announced by <var>source</var>.
     
* For example:
     
* <pre>assertThat(myEvent, is(eventFrom(PropertyChangeEvent.class, myBean)))</pre>
     
*
 

     
* @param eventClass
     
*the class of the event to match on
     
* @param source
     
*the source of the event
     
*/

    
public static Matcher<EventObject> eventFrom(Class<? extends EventObject> eventClass, Object source) {
        
return new IsEventFrom(eventClass, source);
    
}

    
/**
     
* Creates a matcher of {@link java.util.EventObject} that matches any EventObject
     
* announced by <var>source</var>.
     
* For example:
     
* <pre>assertThat(myEvent, is(eventFrom(myBean)))</pre>
     
*
 

     
* @param source
     
*the source of the event
     
*/

    
public static Matcher<EventObject> eventFrom(Object source) {
        
return eventFrom(EventObject.class, source);
    
}
}