1 /*
2  * Copyright (C) 2013 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.android.keyguard;
18 
19 import android.content.Context;
20 import android.view.MotionEvent;
21 import android.view.View;
22 import android.view.accessibility.AccessibilityManager;
23 
24 /**
25  * Hover listener that implements lift-to-activate interaction for
26  * accessibility. May be added to multiple views.
27  */
28 class LiftToActivateListener implements View.OnHoverListener {
29     /** Manager used to query accessibility enabled state. */
30     private final AccessibilityManager mAccessibilityManager;
31 
32     private boolean mCachedClickableState;
33 
LiftToActivateListener(Context context)34     public LiftToActivateListener(Context context) {
35         mAccessibilityManager = (AccessibilityManager) context.getSystemService(
36                 Context.ACCESSIBILITY_SERVICE);
37     }
38 
39     @Override
onHover(View v, MotionEvent event)40     public boolean onHover(View v, MotionEvent event) {
41         // When touch exploration is turned on, lifting a finger while
42         // inside the view bounds should perform a click action.
43         if (mAccessibilityManager.isEnabled()
44                 && mAccessibilityManager.isTouchExplorationEnabled()) {
45             switch (event.getActionMasked()) {
46                 case MotionEvent.ACTION_HOVER_ENTER:
47                     // Lift-to-type temporarily disables double-tap
48                     // activation by setting the view as not clickable.
49                     mCachedClickableState = v.isClickable();
50                     v.setClickable(false);
51                     break;
52                 case MotionEvent.ACTION_HOVER_EXIT:
53                     final int x = (int) event.getX();
54                     final int y = (int) event.getY();
55                     if ((x > v.getPaddingLeft()) && (y > v.getPaddingTop())
56                             && (x < v.getWidth() - v.getPaddingRight())
57                             && (y < v.getHeight() - v.getPaddingBottom())) {
58                         v.performClick();
59                     }
60                     v.setClickable(mCachedClickableState);
61                     break;
62             }
63         }
64 
65         // Pass the event to View.onHoverEvent() to handle accessibility.
66         v.onHoverEvent(event);
67 
68         // Consume the event so it doesn't fall through to other views.
69         return true;
70     }
71 }