49 lines
1.8 KiB
Java
49 lines
1.8 KiB
Java
/*
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* Copyright (c) 2015-present, Parse, LLC.
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* All rights reserved.
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*
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* This source code is licensed under the BSD-style license found in the
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* LICENSE file in the root directory of this source tree. An additional grant
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* of patent rights can be found in the PATENTS file in the same directory.
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*/
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package com.parse;
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/**
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* A {@code CountCallback} is used to run code after a {@link ParseQuery} is used to count objects
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* matching a query in a background thread.
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* <p/>
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* The easiest way to use a {@code CountCallback} is through an anonymous inner class. Override the
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* {@code done} function to specify what the callback should do after the count is complete.
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* The {@code done} function will be run in the UI thread, while the count happens in a
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* background thread. This ensures that the UI does not freeze while the fetch happens.
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* <p/>
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* For example, this sample code counts objects of class {@code "MyClass"}. It calls a
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* different function depending on whether the count succeeded or not.
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* <p/>
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* <pre>
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* ParseQuery<ParseObject> query = ParseQuery.getQuery("MyClass");
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* query.countInBackground(new CountCallback() {
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* public void done(int count, ParseException e) {
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* if (e == null) {
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* objectsWereCountedSuccessfully(count);
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* } else {
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* objectCountingFailed();
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* }
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* }
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* });
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* </pre>
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*/
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// FYI, this does not extend ParseCallback2 since the first param is `int`, which can't be used
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// in a generic.
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public interface CountCallback {
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/**
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* Override this function with the code you want to run after the count is complete.
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*
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* @param count
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* The number of objects matching the query, or -1 if it failed.
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* @param e
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* The exception raised by the count, or null if it succeeded.
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*/
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void done(int count, ParseException e);
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}
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