ParseApplication/ExternalLibs/Parse-SDK-Android/Parse/src/main/java/com/parse/ParseTraverser.java

140 lines
3.7 KiB
Java

/*
* Copyright (c) 2015-present, Parse, LLC.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*/
package com.parse;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.IdentityHashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
/**
* Subclass ParseTraverser to make an function to be run recursively on every object pointed to on
* the given object.
*/
/** package */ abstract class ParseTraverser {
// Whether to recurse into ParseObjects that are seen.
private boolean traverseParseObjects;
// Whether to call visit with the object passed in.
private boolean yieldRoot;
/**
* Creates a new ParseTraverser.
*/
public ParseTraverser() {
traverseParseObjects = false;
yieldRoot = false;
}
/**
* Override this method to implement your own functionality.
* @return true if you want the Traverser to continue. false if you want it to cancel.
*/
protected abstract boolean visit(Object object);
/**
* Internal implementation of traverse.
*/
private void traverseInternal(Object root, boolean yieldRoot, IdentityHashMap<Object, Object> seen) {
if (root == null || seen.containsKey(root)) {
return;
}
if (yieldRoot) {
if (!visit(root)) {
return;
}
}
seen.put(root, root);
if (root instanceof JSONObject) {
JSONObject json = (JSONObject) root;
Iterator<String> keys = json.keys();
while (keys.hasNext()) {
String key = keys.next();
try {
traverseInternal(json.get(key), true, seen);
} catch (JSONException e) {
// This should never happen.
throw new RuntimeException(e);
}
}
} else if (root instanceof JSONArray) {
JSONArray array = (JSONArray) root;
for (int i = 0; i < array.length(); ++i) {
try {
traverseInternal(array.get(i), true, seen);
} catch (JSONException e) {
// This should never happen.
throw new RuntimeException(e);
}
}
} else if (root instanceof Map) {
Map<?, ?> map = (Map<?, ?>) root;
for (Object value : map.values()) {
traverseInternal(value, true, seen);
}
} else if (root instanceof List) {
List<?> list = (List<?>) root;
for (Object value : list) {
traverseInternal(value, true, seen);
}
} else if (root instanceof ParseObject) {
if (traverseParseObjects) {
ParseObject object = (ParseObject) root;
for (String key : object.keySet()) {
traverseInternal(object.get(key), true, seen);
}
}
} else if (root instanceof ParseACL) {
ParseACL acl = (ParseACL) root;
ParseUser user = acl.getUnresolvedUser();
if (user != null && user.isCurrentUser()) {
traverseInternal(user, true, seen);
}
}
}
/**
* Sets whether to recurse into ParseObjects that are seen.
* @return this to enable chaining.
*/
public ParseTraverser setTraverseParseObjects(boolean newValue) {
traverseParseObjects = newValue;
return this;
}
/**
* Sets whether to call visit with the object passed in.
* @return this to enable chaining.
*/
public ParseTraverser setYieldRoot(boolean newValue) {
yieldRoot = newValue;
return this;
}
/**
* Causes the traverser to traverse all objects pointed to by root, recursively.
*/
public void traverse(Object root) {
IdentityHashMap<Object, Object> seen = new IdentityHashMap<>();
traverseInternal(root, yieldRoot, seen);
}
}