1/*
2 * Copyright (C) 2011 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 */
16package com.android.browser;
17
18import android.os.SystemClock;
19import android.view.MotionEvent;
20import android.view.View;
21import android.view.View.OnTouchListener;
22import android.view.ViewConfiguration;
23import android.webkit.WebView;
24
25import com.android.browser.BrowserWebView.OnScrollChangedListener;
26
27/**
28 * Helper class to manage when to show the URL bar based off of touch
29 * input, and when to begin the hide timer.
30 */
31public class UrlBarAutoShowManager implements OnTouchListener,
32        OnScrollChangedListener {
33
34    private static float V_TRIGGER_ANGLE = .9f;
35    private static long SCROLL_TIMEOUT_DURATION = 150;
36    private static long IGNORE_INTERVAL = 250;
37
38    private BrowserWebView mTarget;
39    private BaseUi mUi;
40
41    private int mSlop;
42
43    private float mStartTouchX;
44    private float mStartTouchY;
45    private boolean mIsTracking;
46    private boolean mHasTriggered;
47    private long mLastScrollTime;
48    private long mTriggeredTime;
49    private boolean mIsScrolling;
50
51    public UrlBarAutoShowManager(BaseUi ui) {
52        mUi = ui;
53        ViewConfiguration config = ViewConfiguration.get(mUi.getActivity());
54        mSlop = config.getScaledTouchSlop() * 2;
55    }
56
57    public void setTarget(BrowserWebView v) {
58        if (mTarget == v) return;
59
60        if (mTarget != null) {
61            mTarget.setOnTouchListener(null);
62            mTarget.setOnScrollChangedListener(null);
63        }
64        mTarget = v;
65        if (mTarget != null) {
66            mTarget.setOnTouchListener(this);
67            mTarget.setOnScrollChangedListener(this);
68        }
69    }
70
71    @Override
72    public void onScrollChanged(int l, int t, int oldl, int oldt) {
73        mLastScrollTime = SystemClock.uptimeMillis();
74        mIsScrolling = true;
75        if (t != 0) {
76            // If it is showing, extend it
77            if (mUi.isTitleBarShowing()) {
78                long remaining = mLastScrollTime - mTriggeredTime;
79                remaining = Math.max(BaseUi.HIDE_TITLEBAR_DELAY - remaining,
80                        SCROLL_TIMEOUT_DURATION);
81                mUi.showTitleBarForDuration(remaining);
82            }
83        } else {
84            mUi.suggestHideTitleBar();
85        }
86    }
87
88    void stopTracking() {
89        if (mIsTracking) {
90            mIsTracking = false;
91            mIsScrolling = false;
92            if (mUi.isTitleBarShowing()) {
93                mUi.showTitleBarForDuration();
94            }
95        }
96    }
97
98    @Override
99    public boolean onTouch(View v, MotionEvent event) {
100        if (event.getPointerCount() > 1) {
101            stopTracking();
102        }
103        switch (event.getAction()) {
104        case MotionEvent.ACTION_DOWN:
105            if (!mIsTracking && event.getPointerCount() == 1) {
106                long sinceLastScroll =
107                        SystemClock.uptimeMillis() - mLastScrollTime;
108                if (sinceLastScroll < IGNORE_INTERVAL) {
109                    break;
110                }
111                mStartTouchY = event.getY();
112                mStartTouchX = event.getX();
113                mIsTracking = true;
114                mHasTriggered = false;
115            }
116            break;
117        case MotionEvent.ACTION_MOVE:
118            if (mIsTracking && !mHasTriggered) {
119                WebView web = (WebView) v;
120                float dy = event.getY() - mStartTouchY;
121                float ady = Math.abs(dy);
122                float adx = Math.abs(event.getX() - mStartTouchX);
123                if (ady > mSlop) {
124                    mHasTriggered = true;
125                    float angle = (float) Math.atan2(ady, adx);
126                    if (dy > mSlop && angle > V_TRIGGER_ANGLE
127                            && !mUi.isTitleBarShowing()
128                            && (web.getVisibleTitleHeight() == 0
129                            || (!mIsScrolling && web.getScrollY() > 0))) {
130                        mTriggeredTime = SystemClock.uptimeMillis();
131                        mUi.showTitleBar();
132                    }
133                }
134            }
135            break;
136        case MotionEvent.ACTION_CANCEL:
137        case MotionEvent.ACTION_UP:
138            stopTracking();
139            break;
140        }
141        return false;
142    }
143
144}
145