Java tutorial
/* 50AH-code ========= 50 Android Hacks (http://manning.com/sessa/) book source code Copyright (c) 2012 Manning Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ /* * 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.annotation.SuppressLint; import android.app.ActionBar; import android.content.Intent; import android.os.Bundle; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentActivity; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentStatePagerAdapter; import android.support.v4.view.ViewPager; import android.util.DisplayMetrics; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import android.view.WindowManager.LayoutParams; import android.widget.Toast; import com.manning.androidhacks.hack040.provider.Images; import com.manning.androidhacks.hack040.util.ImageCache; import com.manning.androidhacks.hack040.util.ImageFetcher; import com.manning.androidhacks.hack040.util.ImageResizer; import com.manning.androidhacks.hack040.util.ImageWorker; import com.manning.androidhacks.hack040.util.Utils; public class ImageDetailActivity extends FragmentActivity implements OnClickListener { private static final String IMAGE_CACHE_DIR = "images"; public static final String EXTRA_IMAGE = "extra_image"; private ImagePagerAdapter mAdapter; private ImageResizer mImageWorker; private ViewPager mPager; @SuppressLint("NewApi") @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.image_detail_pager); // Fetch screen height and width, to use as our max size when loading images // as this // activity runs full screen final DisplayMetrics displaymetrics = new DisplayMetrics(); getWindowManager().getDefaultDisplay().getMetrics(displaymetrics); final int height = displaymetrics.heightPixels; final int width = displaymetrics.widthPixels; final int longest = height > width ? height : width; // The ImageWorker takes care of loading images into our ImageView children // asynchronously mImageWorker = new ImageFetcher(this, longest); mImageWorker.setAdapter(Images.imageWorkerUrlsAdapter); mImageWorker.setImageCache(ImageCache.findOrCreateCache(this, IMAGE_CACHE_DIR)); mImageWorker.setImageFadeIn(false); // Set up ViewPager and backing adapter mAdapter = new ImagePagerAdapter(getSupportFragmentManager(), mImageWorker.getAdapter().getSize()); mPager = (ViewPager) findViewById(R.id.pager); mPager.setAdapter(mAdapter); mPager.setPageMargin((int) getResources().getDimension(R.dimen.image_detail_pager_margin)); // Set up activity to go full screen getWindow().addFlags(LayoutParams.FLAG_FULLSCREEN); // Enable some additional newer visibility and ActionBar features to create // a more immersive // photo viewing experience if (Utils.hasActionBar()) { final ActionBar actionBar = getActionBar(); // Enable "up" navigation on ActionBar icon and hide title text actionBar.setDisplayHomeAsUpEnabled(true); actionBar.setDisplayShowTitleEnabled(false); // Start low profile mode and hide ActionBar mPager.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE); actionBar.hide(); // Hide and show the ActionBar as the visibility changes mPager.setOnSystemUiVisibilityChangeListener(new View.OnSystemUiVisibilityChangeListener() { @Override public void onSystemUiVisibilityChange(int vis) { if ((vis & View.SYSTEM_UI_FLAG_LOW_PROFILE) != 0) { actionBar.hide(); } else { actionBar.show(); } } }); } // Set the current item based on the extra passed in to this activity final int extraCurrentItem = getIntent().getIntExtra(EXTRA_IMAGE, -1); if (extraCurrentItem != -1) { mPager.setCurrentItem(extraCurrentItem); } } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case android.R.id.home: // Home or "up" navigation final Intent intent = new Intent(this, ImageGridActivity.class); intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); startActivity(intent); return true; case R.id.clear_cache: final ImageCache cache = mImageWorker.getImageCache(); if (cache != null) { mImageWorker.getImageCache().clearCaches(); // DiskLruCache.clearCache(this, ImageFetcher.HTTP_CACHE_DIR); Toast.makeText(this, R.string.clear_cache_complete, Toast.LENGTH_SHORT).show(); } return true; } return super.onOptionsItemSelected(item); } @Override public boolean onCreateOptionsMenu(Menu menu) { MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.main_menu, menu); return true; } /** * Called by the ViewPager child fragments to load images via the one * ImageWorker * * @return */ public ImageWorker getImageWorker() { return mImageWorker; } /** * The main adapter that backs the ViewPager. A subclass of * FragmentStatePagerAdapter as there could be a large number of items in the * ViewPager and we don't want to retain them all in memory at once but * create/destroy them on the fly. */ private class ImagePagerAdapter extends FragmentStatePagerAdapter { private final int mSize; public ImagePagerAdapter(FragmentManager fm, int size) { super(fm); mSize = size; } @Override public int getCount() { return mSize; } @Override public Fragment getItem(int position) { return ImageDetailFragment.newInstance(position); } @Override public void destroyItem(ViewGroup container, int position, Object object) { final ImageDetailFragment fragment = (ImageDetailFragment) object; // As the item gets destroyed we try and cancel any existing work. fragment.cancelWork(); super.destroyItem(container, position, object); } } /** * Set on the ImageView in the ViewPager children fragments, to enable/disable * low profile mode when the ImageView is touched. */ @SuppressLint("NewApi") @Override public void onClick(View v) { final int vis = mPager.getSystemUiVisibility(); if ((vis & View.SYSTEM_UI_FLAG_LOW_PROFILE) != 0) { mPager.setSystemUiVisibility(View.SYSTEM_UI_FLAG_VISIBLE); } else { mPager.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE); } } }