TextInfoCompatUtils.java revision fc137f35c8d7b03676475fbdeabdf82f89782419 
1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.inputmethod.compat;
18
19import android.view.textservice.TextInfo;
20
21import com.android.inputmethod.annotations.UsedForTesting;
22
23import java.lang.reflect.Constructor;
24import java.lang.reflect.Method;
25
26@UsedForTesting
27public final class TextInfoCompatUtils {
28    // Note that TextInfo.getCharSequence() is supposed to be available in API level 21 and later.
29    private static final Method TEXT_INFO_GET_CHAR_SEQUENCE =
30            CompatUtils.getMethod(TextInfo.class, "getCharSequence");
31    private static final Constructor<?> TEXT_INFO_CONSTRUCTOR_FOR_CHAR_SEQUENCE =
32            CompatUtils.getConstructor(TextInfo.class, CharSequence.class, int.class, int.class,
33                    int.class, int.class);
34
35    @UsedForTesting
36    public static boolean isCharSequenceSupported() {
37        return TEXT_INFO_GET_CHAR_SEQUENCE != null &&
38                TEXT_INFO_CONSTRUCTOR_FOR_CHAR_SEQUENCE != null;
39    }
40
41    @UsedForTesting
42    public static TextInfo newInstance(CharSequence charSequence, int start, int end, int cookie,
43            int sequenceNumber) {
44        if (TEXT_INFO_CONSTRUCTOR_FOR_CHAR_SEQUENCE != null) {
45            return (TextInfo) CompatUtils.newInstance(TEXT_INFO_CONSTRUCTOR_FOR_CHAR_SEQUENCE,
46                    charSequence, start, end, cookie, sequenceNumber);
47        }
48        return new TextInfo(charSequence.subSequence(start, end).toString(), cookie,
49                sequenceNumber);
50    }
51
52    /**
53     * Returns the result of {@link TextInfo#getCharSequence()} when available. Otherwise returns
54     * the result of {@link TextInfo#getText()} as fall back.
55     * @param textInfo the instance for which {@link TextInfo#getCharSequence()} or
56     * {@link TextInfo#getText()} is called.
57     * @return the result of {@link TextInfo#getCharSequence()} when available. Otherwise returns
58     * the result of {@link TextInfo#getText()} as fall back. If {@code textInfo} is {@code null},
59     * returns {@code null}.
60     */
61    @UsedForTesting
62    public static CharSequence getCharSequenceOrString(final TextInfo textInfo) {
63        final CharSequence defaultValue = (textInfo == null ? null : textInfo.getText());
64        return (CharSequence) CompatUtils.invoke(textInfo, defaultValue,
65                TEXT_INFO_GET_CHAR_SEQUENCE);
66    }
67}
68