Java tutorial
/* * Copyright (C) 2012 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.manning.androidhacks.hack040; import android.os.Bundle; import android.support.v4.app.Fragment; import android.view.LayoutInflater; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import android.widget.ImageView; import com.manning.androidhacks.hack040.util.ImageWorker; import com.manning.androidhacks.hack040.util.Utils; /** * This fragment will populate the children of the ViewPager from * {@link ImageDetailActivity}. */ public class ImageDetailFragment extends Fragment { private static final String IMAGE_DATA_EXTRA = "resId"; private int mImageNum; private ImageView mImageView; private ImageWorker mImageWorker; /** * Factory method to generate a new instance of the fragment given an image * number. * * @param imageNum * The image number within the parent adapter to load * @return A new instance of ImageDetailFragment with imageNum extras */ public static ImageDetailFragment newInstance(int imageNum) { final ImageDetailFragment f = new ImageDetailFragment(); final Bundle args = new Bundle(); args.putInt(IMAGE_DATA_EXTRA, imageNum); f.setArguments(args); return f; } /** * Empty constructor as per the Fragment documentation */ public ImageDetailFragment() { } /** * Populate image number from extra, use the convenience factory method * {@link ImageDetailFragment#newInstance(int)} to create this fragment. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mImageNum = getArguments() != null ? getArguments().getInt(IMAGE_DATA_EXTRA) : -1; } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // Inflate and locate the main ImageView final View v = inflater.inflate(R.layout.image_detail_fragment, container, false); mImageView = (ImageView) v.findViewById(R.id.imageView); return v; } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); // Use the parent activity to load the image asynchronously into the // ImageView (so a single // cache can be used over all pages in the ViewPager if (ImageDetailActivity.class.isInstance(getActivity())) { mImageWorker = ((ImageDetailActivity) getActivity()).getImageWorker(); mImageWorker.loadImage(mImageNum, mImageView); } // Pass clicks on the ImageView to the parent activity to handle if (OnClickListener.class.isInstance(getActivity()) && Utils.hasActionBar()) { mImageView.setOnClickListener((OnClickListener) getActivity()); } } /** * Cancels the asynchronous work taking place on the ImageView, called by the * adapter backing the ViewPager when the child is destroyed. */ public void cancelWork() { ImageWorker.cancelWork(mImageView); mImageView.setImageDrawable(null); mImageView = null; } }