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 17 package com.example.android.pdfrendererbasic; 18 19 import android.app.Activity; 20 import android.os.Bundle; 21 import android.view.LayoutInflater; 22 import android.view.View; 23 import android.view.ViewGroup; 24 import android.widget.Button; 25 import android.widget.ImageView; 26 27 import androidx.annotation.NonNull; 28 import androidx.fragment.app.Fragment; 29 import androidx.lifecycle.LifecycleOwner; 30 import androidx.lifecycle.ViewModelProviders; 31 32 /** 33 * This fragment has a big {@link ImageView} that shows PDF pages, and 2 34 * {@link android.widget.Button}s to move between pages. 35 */ 36 public class PdfRendererBasicFragment extends Fragment { 37 38 private PdfRendererBasicViewModel mViewModel; 39 40 private final View.OnClickListener mOnClickListener = (view) -> { 41 switch (view.getId()) { 42 case R.id.previous: 43 if (mViewModel != null) { 44 mViewModel.showPrevious(); 45 } 46 break; 47 case R.id.next: 48 if (mViewModel != null) { 49 mViewModel.showNext(); 50 } 51 break; 52 } 53 }; 54 55 @Override onCreateView(@onNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)56 public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, 57 Bundle savedInstanceState) { 58 return inflater.inflate(R.layout.pdf_renderer_basic_fragment, container, false); 59 } 60 61 @Override onViewCreated(@onNull View view, Bundle savedInstanceState)62 public void onViewCreated(@NonNull View view, Bundle savedInstanceState) { 63 // View references. 64 final ImageView image = view.findViewById(R.id.image); 65 final Button buttonPrevious = view.findViewById(R.id.previous); 66 final Button buttonNext = view.findViewById(R.id.next); 67 68 // Bind data. 69 mViewModel = ViewModelProviders.of(this).get(PdfRendererBasicViewModel.class); 70 final LifecycleOwner viewLifecycleOwner = getViewLifecycleOwner(); 71 mViewModel.getPageInfo().observe(viewLifecycleOwner, pageInfo -> { 72 if (pageInfo == null) { 73 return; 74 } 75 final Activity activity = getActivity(); 76 if (activity != null) { 77 activity.setTitle(getString(R.string.app_name_with_index, 78 pageInfo.index + 1, pageInfo.count)); 79 } 80 }); 81 mViewModel.getPageBitmap().observe(viewLifecycleOwner, image::setImageBitmap); 82 mViewModel.getPreviousEnabled().observe(viewLifecycleOwner, buttonPrevious::setEnabled); 83 mViewModel.getNextEnabled().observe(viewLifecycleOwner, buttonNext::setEnabled); 84 85 // Bind events. 86 buttonPrevious.setOnClickListener(mOnClickListener); 87 buttonNext.setOnClickListener(mOnClickListener); 88 } 89 90 } 91