Allows the user to reflectively inspect an object hierarchy
//package com.ryanm.util.swing;
import java.awt.event.MouseEvent;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Collection;
import java.util.LinkedList;
import javax.swing.JTree;
import javax.swing.ToolTipManager;
import javax.swing.event.TreeExpansionEvent;
import javax.swing.event.TreeWillExpandListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.ExpandVetoException;
import javax.swing.tree.TreePath;
/**
* Allows the user to reflectively inspect an object hierarchy
*
* @author ryanm
*/
public class ObjectInspector extends JTree
{
private boolean showInaccessibleFields = true;
private boolean showStaticFields = true;
private ObjectNode treeRoot = new ObjectNode( null, true );
private DefaultTreeModel treeModel = new DefaultTreeModel( treeRoot );
private TreeWillExpandListener expansionListener = new TreeWillExpandListener() {
@Override
public void treeWillCollapse( TreeExpansionEvent event ) throws ExpandVetoException
{
Object obj = event.getPath().getLastPathComponent();
if( obj instanceof ObjectNode )
{
ObjectNode on = ( ObjectNode ) obj;
assert !on.root;
on.expanded = false;
on.refreshValue( on.inspectedObject );
}
}
@Override
public void treeWillExpand( TreeExpansionEvent event ) throws ExpandVetoException
{
Object obj = event.getPath().getLastPathComponent();
if( obj instanceof ObjectNode )
{
ObjectNode on = ( ObjectNode ) obj;
on.expanded = true;
on.buildChildren();
on.refreshTree( on.inspectedObject );
treeModel.reload( on );
}
}
};
/**
* Builds a new {@link ObjectInspector}
*
* @param o
* The object to inspect
* @param showInaccessible
* <code>true</code> to display inaccessible fields in
* the tree, <code>false</code> to hide them
* @param showStatic
* <code>true</code> to show static fields,
* <code>false</code> to hide them
*/
public ObjectInspector( Object o, boolean showInaccessible, boolean showStatic )
{
setModel( treeModel );
showInaccessibleFields = showInaccessible;
showStaticFields = showStatic;
setEditable( false );
addTreeWillExpandListener( expansionListener );
treeRoot.refreshTree( o );
ToolTipManager.sharedInstance().registerComponent( this );
}
/**
* Inspects an object
*
* @param o
* The object to inspect
*/
public void inspect( Object o )
{
treeRoot.refreshTree( o );
}
@Override
public String getToolTipText( MouseEvent me )
{
TreePath pathForLocation = getPathForLocation( me.getX(), me.getY() );
if( pathForLocation != null )
{
Object lastPathComponent = pathForLocation.getLastPathComponent();
if( lastPathComponent instanceof ObjectNode )
{
ObjectNode on = ( ObjectNode ) lastPathComponent;
return on.tooltip;
}
}
return null;
}
private class ObjectNode extends DefaultMutableTreeNode
{
private Object inspectedObject = null;
private Field inspectedField = null;
private final boolean root;
private final boolean accessible;
private final boolean primitive;
private boolean array = false;
private boolean childrenBuilt = false;
private TreePath path;
private final DefaultMutableTreeNode dummyNode = new DefaultMutableTreeNode( "Inspecting..." );
private String tooltip;
private boolean expanded = false;
private ObjectNode( Object inspectedObject, boolean root )
{
this.root = root;
this.inspectedObject = inspectedObject;
accessible = true;
primitive = false;
if( root )
{
buildChildren();
expanded = true;
}
}
private ObjectNode( Field inspectedField )
{
root = false;
setUserObject( inspectedField.getType().getSimpleName() + " : " + inspectedField.getName() );
this.inspectedField = inspectedField;
primitive = inspectedField.getType().isPrimitive();
boolean a = false;
try
{
inspectedField.setAccessible( true );
a = true;
}
catch( SecurityException se )
{
a = false;
}
accessible = a;
if( !primitive && accessible )
{
insert( dummyNode, 0 );
}
if( !accessible )
{
setUserObject( inspectedField.getName() + " : Inaccessible" );
}
tooltip = inspectedField.getType().toString();
}
private void refreshTree( Object o )
{
if( objectTypeChanged( o ) )
{
/*
* the object class has changed, we need to change the
* tree
*/
removeAllChildren();
childrenBuilt = false;
inspectedObject = o;
if( inspectedObject != null )
{
array = o.getClass().isArray();
if( !primitive && accessible )
{
insert( dummyNode, getChildCount() );
}
if( expanded )
{
buildChildren();
}
}
else
{
childrenBuilt = true;
}
treeModel.nodeStructureChanged( this );
}
else if( array )
{ // need to check if the array length has changed
int oldCount = getChildCount();
int desiredCount = Array.getLength( o );
// may need to add or remove children
while( getChildCount() < desiredCount )
{
ObjectNode on = new ObjectNode( null, false );
insert( on, getChildCount() );
}
while( getChildCount() > desiredCount )
{
remove( getChildCount() - 1 );
}
if( oldCount != desiredCount )
{
treeModel.nodeStructureChanged( this );
}
assert getChildCount() == desiredCount;
}
inspectedObject = o;
if( !root && getChildCount() == 0 )
{
expanded = false;
}
if( expanded && getChildCount() > 0 )
{
int index = 0;
for( Object child : children )
{
assert child != dummyNode;
ObjectNode on = ( ObjectNode ) child;
if( array )
{
on.refreshTree( Array.get( inspectedObject, index ) );
}
else if( on.accessible )
{
try
{
on.refreshTree( on.inspectedField.get( inspectedObject ) );
}
catch( IllegalArgumentException e )
{
e.printStackTrace();
}
catch( IllegalAccessException e )
{
e.printStackTrace();
}
}
index++;
}
}
refreshValue( o );
}
/**
* Updates the value of this node
*
* @param o
*/
private void refreshValue( Object o )
{
StringBuilder buff = new StringBuilder();
if( inspectedField != null )
{
buff.append( inspectedField.getName() );
buff.append( " : " );
buff.append( inspectedField.getType().getSimpleName() );
}
else
{
assert inspectedField == null;
if( o != null )
{
buff.append( o.getClass().getSimpleName() );
}
else
{
buff.append( "null" );
}
}
if( primitive )
{
buff.append( " : " );
buff.append( o );
}
else if( !expanded )
{
buff.append( " : " );
buff.append( buildString( o ) );
}
setUserObject( buff.toString() );
if( path != null )
{
path = new TreePath( getPath() );
}
if( path == null )
{
path = new TreePath( getPath() );
}
treeModel.valueForPathChanged( path, getUserObject() );
if( o != null )
{
if( !primitive )
{
tooltip = o.getClass().getName();
}
else
{
tooltip = inspectedField.getType().getName();
}
}
else
{
tooltip = "null";
}
}
/**
* Determines if the object type has changed
*
* @param o
* the new object
* @return <code>true</code> if the tree needs to be changed,
* false otherwise
*/
private boolean objectTypeChanged( Object o )
{
if( inspectedObject == null && o == null )
{
return false;
}
else if( inspectedObject == null != ( o == null ) )
{
return true;
}
else if( inspectedObject != null && o != null
&& !inspectedObject.getClass().equals( o.getClass() ) )
{
return true;
}
return false;
}
private void buildChildren()
{
if( !childrenBuilt )
{
if( children != null && children.contains( dummyNode ) )
{
remove( dummyNode );
}
if( inspectedObject != null )
{
if( array )
{
for( int i = 0; i < Array.getLength( inspectedObject ); i++ )
{
ObjectNode on = new ObjectNode( inspectedObject, false );
insert( on, getChildCount() );
}
}
else
{
Collection<Field> fields = new LinkedList<Field>();
getFields( fields, inspectedObject.getClass() );
for( Field f : fields )
{
ObjectNode on = new ObjectNode( f );
if( ( showInaccessibleFields || on.accessible )
&& ( showStaticFields || !Modifier.isStatic( f.getModifiers() ) ) )
{
insert( on, getChildCount() );
}
}
}
treeModel.nodeStructureChanged( this );
}
else
{
setUserObject( "null" );
}
childrenBuilt = true;
}
}
}
/**
* Recurses up the inheritance chain and collects all the fields
*
* @param fields
* The collection of fields found so far
* @param c
* The class to get fields from
*/
private static void getFields( Collection<Field> fields, Class c )
{
for( Field f : c.getDeclaredFields() )
{
fields.add( f );
}
if( c.getSuperclass() != null )
{
getFields( fields, c.getSuperclass() );
}
}
/**
* Attempts to build a nicer looking string than the basic
* {@link Object}.toString()
*
* @param o
* The object to build from
* @return A descriptive string
*/
private static String buildString( Object o )
{
if( o == null )
{
return "null";
}
// first see if there is a version of toString more specific
// than that supplied by Object...
try
{
Method m = o.getClass().getMethod( "toString" );
if( !m.getDeclaringClass().equals( Object.class ) )
{
return o.toString();
}
}
catch( SecurityException e )
{
}
catch( NoSuchMethodException e )
{
}
// then see if it is an array...
if( o.getClass().isArray() )
{
StringBuilder buff = new StringBuilder( " [ " );
for( int i = 0; i < Array.getLength( o ); i++ )
{
/*
* this could recurse infinitely, but only if the user is
* trying to be malicious, like so - Object[] array = new
* Object[ 1 ]; array[ 0 ] = array; - which, I'm sure
* we'll agree, is and odd thing to do. I say let the
* StackOverflowException catch it.
*/
buff.append( buildString( Array.get( o, i ) ) );
buff.append( ", " );
}
if( Array.getLength( o ) > 0 )
{
buff.delete( buff.length() - 2, buff.length() );
}
buff.append( " ]" );
return buff.toString();
}
return getObjectPosition( o );
}
/**
* Returns a String of an object's position in memory
*
* @param o
* @return The object's memory position
*/
private static String getObjectPosition( Object o )
{
String s = o.toString();
s = s.substring( s.lastIndexOf( "@" ) );
return s;
}
}