1/*
2 * Copyright (C) 2018 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.setupwizardlib.view;
18
19import android.text.Selection;
20import android.text.Spannable;
21import android.text.method.LinkMovementMethod;
22import android.text.method.MovementMethod;
23import android.view.MotionEvent;
24import android.widget.TextView;
25
26/**
27 * A movement method that tracks the last result of whether touch events are handled. This is
28 * used to patch the return value of {@link TextView#onTouchEvent} so that it consumes the touch
29 * events only when the movement method says the event is consumed.
30 */
31public interface TouchableMovementMethod {
32
33    /**
34     * @return The last touch event received in {@link MovementMethod#onTouchEvent}
35     */
36    MotionEvent getLastTouchEvent();
37
38    /**
39     * @return The return value of the last {@link MovementMethod#onTouchEvent}, or whether the
40     * last touch event should be considered handled by the text view
41     */
42    boolean isLastTouchEventHandled();
43
44    /**
45     * An extension of LinkMovementMethod that tracks whether the event is handled when it is
46     * touched.
47     */
48    class TouchableLinkMovementMethod extends LinkMovementMethod
49            implements TouchableMovementMethod {
50
51        public static TouchableLinkMovementMethod getInstance() {
52            return new TouchableLinkMovementMethod();
53        }
54
55        boolean mLastEventResult = false;
56        MotionEvent mLastEvent;
57
58        @Override
59        public boolean onTouchEvent(TextView widget, Spannable buffer, MotionEvent event) {
60            mLastEvent = event;
61            boolean result = super.onTouchEvent(widget, buffer, event);
62            if (event.getAction() == MotionEvent.ACTION_DOWN) {
63                // Unfortunately, LinkMovementMethod extends ScrollMovementMethod, and it always
64                // consume the down event. So here we use the selection instead as a hint of whether
65                // the down event landed on a link.
66                mLastEventResult = Selection.getSelectionStart(buffer) != -1;
67            } else {
68                mLastEventResult = result;
69            }
70            return result;
71        }
72
73        @Override
74        public MotionEvent getLastTouchEvent() {
75            return mLastEvent;
76        }
77
78        @Override
79        public boolean isLastTouchEventHandled() {
80            return mLastEventResult;
81        }
82    }
83}
84