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