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      1 /*
      2  * Copyright (C) 2015 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 package com.android.messaging.ui;
     17 
     18 import android.content.Context;
     19 import android.content.res.ColorStateList;
     20 import android.content.res.TypedArray;
     21 import android.graphics.Outline;
     22 import android.graphics.drawable.ColorDrawable;
     23 import android.support.v4.view.PagerAdapter;
     24 import android.support.v4.view.ViewPager;
     25 import android.util.AttributeSet;
     26 import android.util.TypedValue;
     27 import android.view.Gravity;
     28 import android.view.View;
     29 import android.view.ViewOutlineProvider;
     30 import android.widget.FrameLayout;
     31 import android.widget.HorizontalScrollView;
     32 import android.widget.LinearLayout;
     33 import android.widget.TextView;
     34 import android.widget.Toast;
     35 
     36 import com.android.messaging.Factory;
     37 import com.android.messaging.R;
     38 import com.android.messaging.util.OsUtil;
     39 
     40 /**
     41  * Lightweight implementation of ViewPager tabs. This looks similar to traditional actionBar tabs,
     42  * but allows for the view containing the tabs to be placed anywhere on screen. Text-related
     43  * attributes can also be assigned in XML - these will get propogated to the child TextViews
     44  * automatically.
     45  *
     46  * Note: this file is taken from the AOSP /packages/apps/ContactsCommon/src/com/android/contacts/
     47  * common/list/ViewPagerTabs.java. Some platform specific API calls (e.g. ViewOutlineProvider which
     48  * assumes L and above) have been modified to support down to Api Level 16.
     49  */
     50 public class ViewPagerTabs extends HorizontalScrollView implements ViewPager.OnPageChangeListener {
     51 
     52     ViewPager mPager;
     53     private ViewPagerTabStrip mTabStrip;
     54 
     55     /**
     56      * Linearlayout that will contain the TextViews serving as tabs. This is the only child
     57      * of the parent HorizontalScrollView.
     58      */
     59     final int mTextStyle;
     60     final ColorStateList mTextColor;
     61     final int mTextSize;
     62     final boolean mTextAllCaps;
     63     int mPrevSelected = -1;
     64     int mSidePadding;
     65 
     66     private static final int TAB_SIDE_PADDING_IN_DPS = 10;
     67 
     68     // TODO: This should use <declare-styleable> in the future
     69     private static final int[] ATTRS = new int[] {
     70         android.R.attr.textSize,
     71         android.R.attr.textStyle,
     72         android.R.attr.textColor,
     73         android.R.attr.textAllCaps
     74     };
     75 
     76     /**
     77      * Shows a toast with the tab description when long-clicked.
     78      */
     79     private class OnTabLongClickListener implements OnLongClickListener {
     80         final String mTabDescription;
     81 
     82         public OnTabLongClickListener(String tabDescription) {
     83             mTabDescription = tabDescription;
     84         }
     85 
     86         @Override
     87         public boolean onLongClick(View v) {
     88             final int[] screenPos = new int[2];
     89             getLocationOnScreen(screenPos);
     90 
     91             final Context context = getContext();
     92             final int width = getWidth();
     93             final int height = getHeight();
     94             final int screenWidth = context.getResources().getDisplayMetrics().widthPixels;
     95 
     96             Toast toast = Toast.makeText(context, mTabDescription, Toast.LENGTH_SHORT);
     97 
     98             // Show the toast under the tab
     99             toast.setGravity(Gravity.TOP | Gravity.CENTER_HORIZONTAL,
    100                     (screenPos[0] + width / 2) - screenWidth / 2, screenPos[1] + height);
    101 
    102             toast.show();
    103             return true;
    104         }
    105     }
    106 
    107     public ViewPagerTabs(Context context) {
    108         this(context, null);
    109     }
    110 
    111     public ViewPagerTabs(Context context, AttributeSet attrs) {
    112         this(context, attrs, 0);
    113     }
    114 
    115     public ViewPagerTabs(Context context, AttributeSet attrs, int defStyle) {
    116         super(context, attrs, defStyle);
    117         setFillViewport(true);
    118 
    119         mSidePadding = (int) (getResources().getDisplayMetrics().density * TAB_SIDE_PADDING_IN_DPS);
    120 
    121         final TypedArray a = context.obtainStyledAttributes(attrs, ATTRS);
    122         mTextSize = a.getDimensionPixelSize(0, 0);
    123         mTextStyle = a.getInt(1, 0);
    124         mTextColor = a.getColorStateList(2);
    125         mTextAllCaps = a.getBoolean(3, false);
    126 
    127         mTabStrip = new ViewPagerTabStrip(context);
    128         addView(mTabStrip,
    129                 new FrameLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT));
    130         a.recycle();
    131 
    132         // enable shadow casting from view bounds
    133         if (OsUtil.isAtLeastL()) {
    134             setOutlineProvider(new ViewOutlineProvider() {
    135                 @Override
    136                 public void getOutline(View view, Outline outline) {
    137                     outline.setRect(0, 0, view.getWidth(), view.getHeight());
    138                 }
    139             });
    140         }
    141     }
    142 
    143     public void setViewPager(ViewPager viewPager) {
    144         mPager = viewPager;
    145         addTabs(mPager.getAdapter());
    146     }
    147 
    148     private void addTabs(PagerAdapter adapter) {
    149         mTabStrip.removeAllViews();
    150 
    151         final int count = adapter.getCount();
    152         for (int i = 0; i < count; i++) {
    153             addTab(adapter.getPageTitle(i), i);
    154         }
    155     }
    156 
    157     private void addTab(CharSequence tabTitle, final int position) {
    158         final TextView textView = new TextView(getContext());
    159         textView.setText(tabTitle);
    160         textView.setBackgroundResource(R.drawable.contact_picker_tab_background_selector);
    161         textView.setGravity(Gravity.CENTER);
    162         textView.setOnClickListener(new OnClickListener() {
    163             @Override
    164             public void onClick(View v) {
    165                 mPager.setCurrentItem(getRtlPosition(position));
    166             }
    167         });
    168 
    169         // Assign various text appearance related attributes to child views.
    170         if (mTextStyle > 0) {
    171             textView.setTypeface(textView.getTypeface(), mTextStyle);
    172         }
    173         if (mTextSize > 0) {
    174             textView.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTextSize);
    175         }
    176         if (mTextColor != null) {
    177             textView.setTextColor(mTextColor);
    178         }
    179         textView.setAllCaps(mTextAllCaps);
    180         textView.setPadding(mSidePadding, 0, mSidePadding, 0);
    181         mTabStrip.addView(textView, new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT,
    182                 LayoutParams.MATCH_PARENT, 1));
    183         // Default to the first child being selected
    184         if (position == 0) {
    185             mPrevSelected = 0;
    186             textView.setSelected(true);
    187         }
    188     }
    189 
    190     @Override
    191     public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
    192         position = getRtlPosition(position);
    193         int tabStripChildCount = mTabStrip.getChildCount();
    194         if ((tabStripChildCount == 0) || (position < 0) || (position >= tabStripChildCount)) {
    195             return;
    196         }
    197 
    198         mTabStrip.onPageScrolled(position, positionOffset, positionOffsetPixels);
    199     }
    200 
    201     @Override
    202     public void onPageSelected(int position) {
    203         position = getRtlPosition(position);
    204         int tabStripChildCount = mTabStrip.getChildCount();
    205         if ((tabStripChildCount == 0) || (position < 0) || (position >= tabStripChildCount)) {
    206             return;
    207         }
    208 
    209         if (mPrevSelected >= 0 && mPrevSelected < tabStripChildCount) {
    210             mTabStrip.getChildAt(mPrevSelected).setSelected(false);
    211         }
    212         final View selectedChild = mTabStrip.getChildAt(position);
    213         selectedChild.setSelected(true);
    214 
    215         // Update scroll position
    216         final int scrollPos = selectedChild.getLeft() - (getWidth() - selectedChild.getWidth()) / 2;
    217         smoothScrollTo(scrollPos, 0);
    218         mPrevSelected = position;
    219     }
    220 
    221     @Override
    222     public void onPageScrollStateChanged(int state) {
    223     }
    224 
    225     private int getRtlPosition(int position) {
    226         if (OsUtil.isAtLeastJB_MR2() && Factory.get().getApplicationContext().getResources()
    227                 .getConfiguration().getLayoutDirection() == View.LAYOUT_DIRECTION_RTL) {
    228             return mTabStrip.getChildCount() - 1 - position;
    229         }
    230         return position;
    231     }
    232 
    233     public int getSelectedItemPosition() {
    234         return mPrevSelected;
    235     }
    236 }
    237