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 */
16package com.android.contacts.common.list;
17
18import android.content.Context;
19import android.content.res.ColorStateList;
20import android.content.res.TypedArray;
21import android.graphics.Outline;
22import android.support.v4.view.PagerAdapter;
23import android.support.v4.view.ViewPager;
24import android.util.AttributeSet;
25import android.util.TypedValue;
26import android.view.Gravity;
27import android.view.View;
28import android.view.ViewOutlineProvider;
29import android.widget.FrameLayout;
30import android.widget.HorizontalScrollView;
31import android.widget.LinearLayout;
32import android.widget.TextView;
33import android.widget.Toast;
34
35import com.android.contacts.common.R;
36
37/**
38 * Lightweight implementation of ViewPager tabs. This looks similar to traditional actionBar tabs,
39 * but allows for the view containing the tabs to be placed anywhere on screen. Text-related
40 * attributes can also be assigned in XML - these will get propogated to the child TextViews
41 * automatically.
42 */
43public class ViewPagerTabs extends HorizontalScrollView implements ViewPager.OnPageChangeListener {
44
45    ViewPager mPager;
46    private ViewPagerTabStrip mTabStrip;
47
48    /**
49     * Linearlayout that will contain the TextViews serving as tabs. This is the only child
50     * of the parent HorizontalScrollView.
51     */
52    final int mTextStyle;
53    final ColorStateList mTextColor;
54    final int mTextSize;
55    final boolean mTextAllCaps;
56    int mPrevSelected = -1;
57    int mSidePadding;
58
59    private int[] mTabIcons;
60
61    private static final ViewOutlineProvider VIEW_BOUNDS_OUTLINE_PROVIDER =
62            new ViewOutlineProvider() {
63        @Override
64        public void getOutline(View view, Outline outline) {
65            outline.setRect(0, 0, view.getWidth(), view.getHeight());
66        }
67    };
68
69    private static final int TAB_SIDE_PADDING_IN_DPS = 10;
70
71    // TODO: This should use <declare-styleable> in the future
72    private static final int[] ATTRS = new int[] {
73        android.R.attr.textSize,
74        android.R.attr.textStyle,
75        android.R.attr.textColor,
76        android.R.attr.textAllCaps
77    };
78
79    /**
80     * Simulates actionbar tab behavior by showing a toast with the tab title when long clicked.
81     */
82    private class OnTabLongClickListener implements OnLongClickListener {
83        final int mPosition;
84
85        public OnTabLongClickListener(int position) {
86            mPosition = position;
87        }
88
89        @Override
90        public boolean onLongClick(View v) {
91            final int[] screenPos = new int[2];
92            getLocationOnScreen(screenPos);
93
94            final Context context = getContext();
95            final int width = getWidth();
96            final int height = getHeight();
97            final int screenWidth = context.getResources().getDisplayMetrics().widthPixels;
98
99            Toast toast = Toast.makeText(context, mPager.getAdapter().getPageTitle(mPosition),
100                    Toast.LENGTH_SHORT);
101
102            // Show the toast under the tab
103            toast.setGravity(Gravity.TOP | Gravity.CENTER_HORIZONTAL,
104                    (screenPos[0] + width / 2) - screenWidth / 2, screenPos[1] + height);
105
106            toast.show();
107            return true;
108        }
109    }
110
111    public ViewPagerTabs(Context context) {
112        this(context, null);
113    }
114
115    public ViewPagerTabs(Context context, AttributeSet attrs) {
116        this(context, attrs, 0);
117    }
118
119    public ViewPagerTabs(Context context, AttributeSet attrs, int defStyle) {
120        super(context, attrs, defStyle);
121        setFillViewport(true);
122
123        mSidePadding = (int) (getResources().getDisplayMetrics().density * TAB_SIDE_PADDING_IN_DPS);
124
125        final TypedArray a = context.obtainStyledAttributes(attrs, ATTRS);
126        mTextSize = a.getDimensionPixelSize(0, 0);
127        mTextStyle = a.getInt(1, 0);
128        mTextColor = a.getColorStateList(2);
129        mTextAllCaps = a.getBoolean(3, false);
130
131        mTabStrip = new ViewPagerTabStrip(context);
132        addView(mTabStrip,
133                new FrameLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT));
134        a.recycle();
135
136        // enable shadow casting from view bounds
137        setOutlineProvider(VIEW_BOUNDS_OUTLINE_PROVIDER);
138    }
139
140    public void setViewPager(ViewPager viewPager) {
141        mPager = viewPager;
142        addTabs(mPager.getAdapter());
143    }
144
145    public void setTabIcons(int [] tabIcons) {
146        mTabIcons = tabIcons;
147    }
148
149    private void addTabs(PagerAdapter adapter) {
150        mTabStrip.removeAllViews();
151
152        final int count = adapter.getCount();
153        for (int i = 0; i < count; i++) {
154            addTab(adapter.getPageTitle(i), i);
155        }
156    }
157
158    private void addTab(CharSequence tabTitle, final int position) {
159        View tabView;
160        if (mTabIcons != null && position < mTabIcons.length) {
161            View iconView = new View(getContext());
162            iconView.setBackgroundResource(mTabIcons[position]);
163            iconView.setContentDescription(tabTitle);
164
165            tabView = iconView;
166        } else {
167            final TextView textView = new TextView(getContext());
168            textView.setText(tabTitle);
169            textView.setBackgroundResource(R.drawable.view_pager_tab_background);
170
171            // Assign various text appearance related attributes to child views.
172            if (mTextStyle > 0) {
173                textView.setTypeface(textView.getTypeface(), mTextStyle);
174            }
175            if (mTextSize > 0) {
176                textView.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTextSize);
177            }
178            if (mTextColor != null) {
179                textView.setTextColor(mTextColor);
180            }
181            textView.setAllCaps(mTextAllCaps);
182            textView.setGravity(Gravity.CENTER);
183
184            tabView = textView;
185        }
186
187        tabView.setOnClickListener(new OnClickListener() {
188            @Override
189            public void onClick(View v) {
190                mPager.setCurrentItem(getRtlPosition(position));
191            }
192        });
193
194        tabView.setOnLongClickListener(new OnTabLongClickListener(position));
195
196        tabView.setPadding(mSidePadding, 0, mSidePadding, 0);
197        mTabStrip.addView(tabView, new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,
198                LayoutParams.MATCH_PARENT, 1));
199
200        // Default to the first child being selected
201        if (position == 0) {
202            mPrevSelected = 0;
203            tabView.setSelected(true);
204        }
205    }
206
207    @Override
208    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
209        position = getRtlPosition(position);
210        int tabStripChildCount = mTabStrip.getChildCount();
211        if ((tabStripChildCount == 0) || (position < 0) || (position >= tabStripChildCount)) {
212            return;
213        }
214
215        mTabStrip.onPageScrolled(position, positionOffset, positionOffsetPixels);
216    }
217
218    @Override
219    public void onPageSelected(int position) {
220        position = getRtlPosition(position);
221        int tabStripChildCount = mTabStrip.getChildCount();
222        if ((tabStripChildCount == 0) || (position < 0) || (position >= tabStripChildCount)) {
223            return;
224        }
225
226        if (mPrevSelected >= 0 && mPrevSelected < tabStripChildCount) {
227            mTabStrip.getChildAt(mPrevSelected).setSelected(false);
228        }
229        final View selectedChild = mTabStrip.getChildAt(position);
230        selectedChild.setSelected(true);
231
232        // Update scroll position
233        final int scrollPos = selectedChild.getLeft() - (getWidth() - selectedChild.getWidth()) / 2;
234        smoothScrollTo(scrollPos, 0);
235        mPrevSelected = position;
236    }
237
238    @Override
239    public void onPageScrollStateChanged(int state) {
240    }
241
242    private int getRtlPosition(int position) {
243        if (getLayoutDirection() == View.LAYOUT_DIRECTION_RTL) {
244            return mTabStrip.getChildCount() - 1 - position;
245        }
246        return position;
247    }
248}
249
250