1 /* 2 * Copyright (C) 2016 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.example.android.support.design.widget; 18 19 import android.os.Bundle; 20 import android.view.Gravity; 21 import android.view.View; 22 import android.view.ViewGroup; 23 import android.widget.RadioButton; 24 import android.widget.RadioGroup; 25 import android.widget.TextView; 26 27 import androidx.appcompat.app.AppCompatActivity; 28 import androidx.appcompat.widget.Toolbar; 29 import androidx.core.widget.TextViewCompat; 30 import androidx.viewpager.widget.PagerAdapter; 31 import androidx.viewpager.widget.ViewPager; 32 33 import com.example.android.support.design.Cheeses; 34 import com.example.android.support.design.R; 35 import com.google.android.material.tabs.TabLayout; 36 37 import java.util.ArrayList; 38 39 /** 40 * This demonstrates idiomatic usage of TabLayout with a ViewPager 41 */ 42 public class TabLayoutPreselectedUsage extends AppCompatActivity { 43 44 private TabLayout mTabLayout; 45 private ViewPager mViewPager; 46 private CheesePagerAdapter mPagerAdapter; 47 48 @Override 49 protected void onCreate(Bundle savedInstanceState) { 50 super.onCreate(savedInstanceState); 51 setContentView(R.layout.design_tabs_viewpager); 52 53 // Retrieve the Toolbar from our content view, and set it as the action bar 54 Toolbar toolbar = findViewById(R.id.toolbar); 55 setSupportActionBar(toolbar); 56 getSupportActionBar().setDisplayHomeAsUpEnabled(true); 57 58 mTabLayout = findViewById(R.id.tabs); 59 mViewPager = findViewById(R.id.tabs_viewpager); 60 61 findViewById(R.id.buttons).setVisibility(View.GONE); 62 63 mPagerAdapter = new CheesePagerAdapter(); 64 for (int i = 0; i < 5; i++) { 65 mPagerAdapter.addTab(Cheeses.sCheeseStrings[i]); 66 } 67 mViewPager.setAdapter(mPagerAdapter); 68 mViewPager.setCurrentItem(2, false); 69 70 mTabLayout.setupWithViewPager(mViewPager); 71 72 setupRadioGroup(); 73 } 74 75 private void setupRadioGroup() { 76 // Setup the initially checked item 77 switch (mTabLayout.getTabMode()) { 78 case TabLayout.MODE_SCROLLABLE: 79 ((RadioButton) findViewById(R.id.rb_tab_scrollable)).setChecked(true); 80 break; 81 case TabLayout.MODE_FIXED: 82 ((RadioButton) findViewById(R.id.rb_tab_fixed)).setChecked(true); 83 break; 84 } 85 86 RadioGroup rg = findViewById(R.id.radiogroup_tab_mode); 87 rg.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() { 88 @Override 89 public void onCheckedChanged(RadioGroup radioGroup, int id) { 90 switch (id) { 91 case R.id.rb_tab_fixed: 92 mTabLayout.setTabMode(TabLayout.MODE_FIXED); 93 break; 94 case R.id.rb_tab_scrollable: 95 mTabLayout.setTabMode(TabLayout.MODE_SCROLLABLE); 96 break; 97 } 98 } 99 }); 100 101 // Setup the initially checked item 102 switch (mTabLayout.getTabGravity()) { 103 case TabLayout.GRAVITY_CENTER: 104 ((RadioButton) findViewById(R.id.rb_tab_g_center)).setChecked(true); 105 break; 106 case TabLayout.GRAVITY_FILL: 107 ((RadioButton) findViewById(R.id.rb_tab_g_fill)).setChecked(true); 108 break; 109 } 110 111 rg = findViewById(R.id.radiogroup_tab_gravity); 112 rg.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() { 113 @Override 114 public void onCheckedChanged(RadioGroup radioGroup, int id) { 115 switch (id) { 116 case R.id.rb_tab_g_center: 117 mTabLayout.setTabGravity(TabLayout.GRAVITY_CENTER); 118 break; 119 case R.id.rb_tab_g_fill: 120 mTabLayout.setTabGravity(TabLayout.GRAVITY_FILL); 121 break; 122 } 123 } 124 }); 125 } 126 127 private static class CheesePagerAdapter extends PagerAdapter { 128 private final ArrayList<CharSequence> mCheeses = new ArrayList<>(); 129 130 public void addTab(String title) { 131 mCheeses.add(title); 132 notifyDataSetChanged(); 133 } 134 135 @Override 136 public int getCount() { 137 return mCheeses.size(); 138 } 139 140 @Override 141 public int getItemPosition(Object object) { 142 final Item item = (Item) object; 143 final int index = mCheeses.indexOf(item.cheese); 144 return index >= 0 ? index : POSITION_NONE; 145 } 146 147 @Override 148 public Object instantiateItem(ViewGroup container, int position) { 149 final TextView tv = new TextView(container.getContext()); 150 tv.setText(getPageTitle(position)); 151 tv.setGravity(Gravity.CENTER); 152 TextViewCompat.setTextAppearance(tv, R.style.TextAppearance_AppCompat_Title); 153 container.addView(tv, ViewGroup.LayoutParams.MATCH_PARENT, 154 ViewGroup.LayoutParams.MATCH_PARENT); 155 156 Item item = new Item(); 157 item.cheese = mCheeses.get(position); 158 item.view = tv; 159 return item; 160 } 161 162 @Override 163 public boolean isViewFromObject(View view, Object object) { 164 final Item item = (Item) object; 165 return item.view == view; 166 } 167 168 @Override 169 public CharSequence getPageTitle(int position) { 170 return mCheeses.get(position); 171 } 172 173 @Override 174 public void destroyItem(ViewGroup container, int position, Object object) { 175 final Item item = (Item) object; 176 container.removeView(item.view); 177 } 178 179 private static class Item { 180 TextView view; 181 CharSequence cheese; 182 } 183 } 184 185 } 186
