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