Alexander Lucas | 97842ff | 2014-03-07 14:56:55 -0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2012 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.displayingbitmaps.ui; |
| 18 | |
| 19 | import android.annotation.TargetApi; |
| 20 | import android.app.ActionBar; |
| 21 | import android.os.Build.VERSION_CODES; |
| 22 | import android.os.Bundle; |
| 23 | import android.support.v4.app.Fragment; |
| 24 | import android.support.v4.app.FragmentActivity; |
| 25 | import android.support.v4.app.FragmentManager; |
| 26 | import android.support.v4.app.FragmentStatePagerAdapter; |
| 27 | import android.support.v4.app.NavUtils; |
| 28 | import android.support.v4.view.ViewPager; |
| 29 | import android.util.DisplayMetrics; |
| 30 | import android.view.Menu; |
| 31 | import android.view.MenuItem; |
| 32 | import android.view.View; |
| 33 | import android.view.View.OnClickListener; |
| 34 | import android.view.WindowManager.LayoutParams; |
| 35 | import android.widget.Toast; |
| 36 | |
| 37 | import com.example.android.displayingbitmaps.BuildConfig; |
| 38 | import com.example.android.displayingbitmaps.R; |
| 39 | import com.example.android.displayingbitmaps.provider.Images; |
| 40 | import com.example.android.displayingbitmaps.util.ImageCache; |
| 41 | import com.example.android.displayingbitmaps.util.ImageFetcher; |
| 42 | import com.example.android.displayingbitmaps.util.Utils; |
| 43 | |
| 44 | public class ImageDetailActivity extends FragmentActivity implements OnClickListener { |
| 45 | private static final String IMAGE_CACHE_DIR = "images"; |
| 46 | public static final String EXTRA_IMAGE = "extra_image"; |
| 47 | |
| 48 | private ImagePagerAdapter mAdapter; |
| 49 | private ImageFetcher mImageFetcher; |
| 50 | private ViewPager mPager; |
| 51 | |
| 52 | @TargetApi(VERSION_CODES.HONEYCOMB) |
| 53 | @Override |
| 54 | public void onCreate(Bundle savedInstanceState) { |
| 55 | if (BuildConfig.DEBUG) { |
| 56 | Utils.enableStrictMode(); |
| 57 | } |
| 58 | super.onCreate(savedInstanceState); |
| 59 | setContentView(R.layout.image_detail_pager); |
| 60 | |
| 61 | // Fetch screen height and width, to use as our max size when loading images as this |
| 62 | // activity runs full screen |
| 63 | final DisplayMetrics displayMetrics = new DisplayMetrics(); |
| 64 | getWindowManager().getDefaultDisplay().getMetrics(displayMetrics); |
| 65 | final int height = displayMetrics.heightPixels; |
| 66 | final int width = displayMetrics.widthPixels; |
| 67 | |
| 68 | // For this sample we'll use half of the longest width to resize our images. As the |
| 69 | // image scaling ensures the image is larger than this, we should be left with a |
| 70 | // resolution that is appropriate for both portrait and landscape. For best image quality |
| 71 | // we shouldn't divide by 2, but this will use more memory and require a larger memory |
| 72 | // cache. |
| 73 | final int longest = (height > width ? height : width) / 2; |
| 74 | |
| 75 | ImageCache.ImageCacheParams cacheParams = |
| 76 | new ImageCache.ImageCacheParams(this, IMAGE_CACHE_DIR); |
| 77 | cacheParams.setMemCacheSizePercent(0.25f); // Set memory cache to 25% of app memory |
| 78 | |
| 79 | // The ImageFetcher takes care of loading images into our ImageView children asynchronously |
| 80 | mImageFetcher = new ImageFetcher(this, longest); |
| 81 | mImageFetcher.addImageCache(getSupportFragmentManager(), cacheParams); |
| 82 | mImageFetcher.setImageFadeIn(false); |
| 83 | |
| 84 | // Set up ViewPager and backing adapter |
| 85 | mAdapter = new ImagePagerAdapter(getSupportFragmentManager(), Images.imageUrls.length); |
| 86 | mPager = (ViewPager) findViewById(R.id.pager); |
| 87 | mPager.setAdapter(mAdapter); |
| 88 | mPager.setPageMargin((int) getResources().getDimension(R.dimen.horizontal_page_margin)); |
| 89 | mPager.setOffscreenPageLimit(2); |
| 90 | |
| 91 | // Set up activity to go full screen |
| 92 | getWindow().addFlags(LayoutParams.FLAG_FULLSCREEN); |
| 93 | |
| 94 | // Enable some additional newer visibility and ActionBar features to create a more |
| 95 | // immersive photo viewing experience |
| 96 | if (Utils.hasHoneycomb()) { |
| 97 | final ActionBar actionBar = getActionBar(); |
| 98 | |
| 99 | // Hide title text and set home as up |
| 100 | actionBar.setDisplayShowTitleEnabled(false); |
| 101 | actionBar.setDisplayHomeAsUpEnabled(true); |
| 102 | |
| 103 | // Hide and show the ActionBar as the visibility changes |
| 104 | mPager.setOnSystemUiVisibilityChangeListener( |
| 105 | new View.OnSystemUiVisibilityChangeListener() { |
| 106 | @Override |
| 107 | public void onSystemUiVisibilityChange(int vis) { |
| 108 | if ((vis & View.SYSTEM_UI_FLAG_LOW_PROFILE) != 0) { |
| 109 | actionBar.hide(); |
| 110 | } else { |
| 111 | actionBar.show(); |
| 112 | } |
| 113 | } |
| 114 | }); |
| 115 | |
| 116 | // Start low profile mode and hide ActionBar |
| 117 | mPager.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE); |
| 118 | actionBar.hide(); |
| 119 | } |
| 120 | |
| 121 | // Set the current item based on the extra passed in to this activity |
| 122 | final int extraCurrentItem = getIntent().getIntExtra(EXTRA_IMAGE, -1); |
| 123 | if (extraCurrentItem != -1) { |
| 124 | mPager.setCurrentItem(extraCurrentItem); |
| 125 | } |
| 126 | } |
| 127 | |
| 128 | @Override |
| 129 | public void onResume() { |
| 130 | super.onResume(); |
| 131 | mImageFetcher.setExitTasksEarly(false); |
| 132 | } |
| 133 | |
| 134 | @Override |
| 135 | protected void onPause() { |
| 136 | super.onPause(); |
| 137 | mImageFetcher.setExitTasksEarly(true); |
| 138 | mImageFetcher.flushCache(); |
| 139 | } |
| 140 | |
| 141 | @Override |
| 142 | protected void onDestroy() { |
| 143 | super.onDestroy(); |
| 144 | mImageFetcher.closeCache(); |
| 145 | } |
| 146 | |
| 147 | @Override |
| 148 | public boolean onOptionsItemSelected(MenuItem item) { |
| 149 | switch (item.getItemId()) { |
| 150 | case android.R.id.home: |
| 151 | NavUtils.navigateUpFromSameTask(this); |
| 152 | return true; |
| 153 | case R.id.clear_cache: |
| 154 | mImageFetcher.clearCache(); |
| 155 | Toast.makeText( |
| 156 | this, R.string.clear_cache_complete_toast,Toast.LENGTH_SHORT).show(); |
| 157 | return true; |
| 158 | } |
| 159 | return super.onOptionsItemSelected(item); |
| 160 | } |
| 161 | |
| 162 | @Override |
| 163 | public boolean onCreateOptionsMenu(Menu menu) { |
| 164 | getMenuInflater().inflate(R.menu.main_menu, menu); |
| 165 | return true; |
| 166 | } |
| 167 | |
| 168 | /** |
| 169 | * Called by the ViewPager child fragments to load images via the one ImageFetcher |
| 170 | */ |
| 171 | public ImageFetcher getImageFetcher() { |
| 172 | return mImageFetcher; |
| 173 | } |
| 174 | |
| 175 | /** |
| 176 | * The main adapter that backs the ViewPager. A subclass of FragmentStatePagerAdapter as there |
| 177 | * could be a large number of items in the ViewPager and we don't want to retain them all in |
| 178 | * memory at once but create/destroy them on the fly. |
| 179 | */ |
| 180 | private class ImagePagerAdapter extends FragmentStatePagerAdapter { |
| 181 | private final int mSize; |
| 182 | |
| 183 | public ImagePagerAdapter(FragmentManager fm, int size) { |
| 184 | super(fm); |
| 185 | mSize = size; |
| 186 | } |
| 187 | |
| 188 | @Override |
| 189 | public int getCount() { |
| 190 | return mSize; |
| 191 | } |
| 192 | |
| 193 | @Override |
| 194 | public Fragment getItem(int position) { |
| 195 | return ImageDetailFragment.newInstance(Images.imageUrls[position]); |
| 196 | } |
| 197 | } |
| 198 | |
| 199 | /** |
| 200 | * Set on the ImageView in the ViewPager children fragments, to enable/disable low profile mode |
| 201 | * when the ImageView is touched. |
| 202 | */ |
| 203 | @TargetApi(VERSION_CODES.HONEYCOMB) |
| 204 | @Override |
| 205 | public void onClick(View v) { |
| 206 | final int vis = mPager.getSystemUiVisibility(); |
| 207 | if ((vis & View.SYSTEM_UI_FLAG_LOW_PROFILE) != 0) { |
| 208 | mPager.setSystemUiVisibility(View.SYSTEM_UI_FLAG_VISIBLE); |
| 209 | } else { |
| 210 | mPager.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE); |
| 211 | } |
| 212 | } |
| 213 | } |