-
Notifications
You must be signed in to change notification settings - Fork 13
/
SubjectFragment.java
310 lines (260 loc) · 10.3 KB
/
SubjectFragment.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
/*
* Copyright (C) 2014 Murray Cumming
*
* This file is part of android-galaxyzoo.
*
* android-galaxyzoo is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* android-galaxyzoo is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with android-galaxyzoo. If not, see <http://www.gnu.org/licenses/>.
*/
package com.murrayc.galaxyzoo.app;
import android.app.Activity;
import android.content.Context;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.LoaderManager;
import android.support.v4.content.CursorLoader;
import android.support.v4.content.Loader;
import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import com.murrayc.galaxyzoo.app.provider.Item;
import com.murrayc.galaxyzoo.app.provider.ItemsContentProvider;
import java.lang.ref.WeakReference;
/**
* A fragment representing a single subject.
* This fragment is either contained in a {@link ListActivity}
* in two-pane mode (on tablets) or a {@link ClassifyActivity}
* on handsets.
*/
public class SubjectFragment extends ItemFragment
implements LoaderManager.LoaderCallbacks<Cursor> {
private static final int URL_LOADER = 0;
private static final String ARG_INVERTED = "inverted";
// We have to hard-code the indices - we can't use getColumnIndex because the Cursor
// (actually a SQliteDatabase cursor returned
// from our ContentProvider) only knows about the underlying SQLite database column names,
// not our ContentProvider's column names. That seems like a design error in the Android API.
//TODO: Use org.apache.commons.lang.ArrayUtils.indexOf() instead?
/* private static final int COLUMN_INDEX_ID = 0; */
private static final int COLUMN_INDEX_LOCATION_STANDARD_URI = 1;
private static final int COLUMN_INDEX_LOCATION_STANDARD_DOWNLOADED = 2;
private static final int COLUMN_INDEX_LOCATION_INVERTED_URI = 3;
private static final int COLUMN_INDEX_LOCATION_INVERTED_DOWNLOADED = 4;
private final String[] mColumns = {Item.Columns._ID,
Item.Columns.LOCATION_STANDARD_URI, Item.Columns.LOCATION_STANDARD_DOWNLOADED,
Item.Columns.LOCATION_INVERTED_URI, Item.Columns.LOCATION_INVERTED_DOWNLOADED};
private Cursor mCursor;
private View mRootView;
private ImageView mImageView;
private boolean mInverted = false;
/**
* Mandatory empty constructor for the fragment manager to instantiate the
* fragment (e.g. upon screen orientation changes).
*/
public SubjectFragment() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (savedInstanceState != null) {
setInverted(savedInstanceState.getBoolean(ARG_INVERTED));
}
setHasOptionsMenu(true);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
mRootView = inflater.inflate(R.layout.fragment_subject, container, false);
assert mRootView != null;
mImageView = (ImageView) mRootView.findViewById(R.id.imageView);
if (mImageView == null) {
Log.error("mImageView is null.");
}
//Make the image invert when clicked,
//like in the web UI:
mImageView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
doInvert();
}
});
setHasOptionsMenu(true);
update();
return mRootView;
}
@Override
public void onSaveInstanceState(final Bundle outState) {
//Save extra state to be used later by onCreate().
outState.putBoolean(ARG_INVERTED, getInverted());
//TODO: Allow use of ARG_INVERTED in the intent's arguments too?
//For instance, see QuestionFragment.onSaveInstanceState().
super.onSaveInstanceState(outState);
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
// Inflate the menu items for use in the action bar
inflater.inflate(R.menu.actionbar_menu_subject, menu);
super.onCreateOptionsMenu(menu, inflater);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// handle item selection
switch (item.getItemId()) {
case R.id.option_menu_item_invert:
doInvert();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
private void doInvert() {
setInverted(!getInverted());
showImage();
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
}
@Override
public void onDetach() {
super.onDetach();
}
public void update() {
final Activity activity = getActivity();
if (activity == null)
return;
//If the item is the next ID, then wait for the parent (ClassifyFragment) fragment
//to discover the real ID, after which it will update this fragment with the real ID.
//Otherwise, we will quickly ask for two next items at almost the same time,
//resulting in a longer wait for the first item (at first app start) to be ready.
if(!TextUtils.equals(getItemId(), ItemsContentProvider.URI_PART_ITEM_ID_NEXT)) {
/*
* Initializes the CursorLoader. The URL_LOADER value is eventually passed
* to onCreateLoader().
* We use restartLoader(), instead of initLoader(),
* so we can refresh this fragment to show a different subject,
* even when using the same query ("next") to do that.
*/
getLoaderManager().restartLoader(URL_LOADER, null, this);
}
}
private void updateFromCursor() {
if (mCursor == null) {
Log.error("mCursor is null.");
return;
}
if (mCursor.getCount() <= 0) { //In case the query returned no rows.
Log.error("SubjectFragment.updateFromCursor(): The ContentProvider query returned no rows.");
//Wipe the image instead of keeping whatever might be showing already:
mImageView.setImageDrawable(null);
UiUtils.warnAboutMissingNetwork(getActivity());
return;
}
mCursor.moveToFirst(); //There should only be one anyway.
//Look at each group in the layout:
if (mRootView == null) {
Log.error("SubjectFragment.updateFromCursor(): mRootView is null.");
return;
}
showImage();
}
private void showImage() {
final Activity activity = getActivity();
if (activity == null)
return;
//Avoid a crash in the unusual case that the ContentProvider
//didn't provide an item.
if (mCursor.getCount() < 1 || mCursor.getColumnCount() < 1) {
return;
}
//Avoid a crash in the unusual case that the ContentProvider
//didn't provide an item.
if (mCursor.getCount() < 1 || mCursor.getColumnCount() < 1) {
return;
}
final boolean inverted = getInverted();
String imageUriStr = null;
if (inverted) {
if (mCursor.getInt(COLUMN_INDEX_LOCATION_INVERTED_DOWNLOADED) == 1) {
imageUriStr = mCursor.getString(COLUMN_INDEX_LOCATION_INVERTED_URI);
}
} else {
if (mCursor.getInt(COLUMN_INDEX_LOCATION_STANDARD_DOWNLOADED) == 1) {
imageUriStr = mCursor.getString(COLUMN_INDEX_LOCATION_STANDARD_URI);
}
}
if (!TextUtils.isEmpty(imageUriStr)) {
final UiUtils.ShowImageFromContentProviderTask task = new UiUtils.ShowImageFromContentProviderTask(mImageView, activity) {
@Override
protected void onPostExecute(final Bitmap bitmap) {
super.onPostExecute(bitmap);
if (bitmap == null) {
//Something was wrong with the (cached) image,
//so just abandon this whole item.
//That seems safer and simpler than trying to recover just one of the 3 images.
SubjectFragment.this.abandonItem();
}
}
};
task.execute(imageUriStr);
}
}
private boolean getInverted() {
return mInverted;
}
void setInverted(boolean inverted) {
mInverted = inverted;
}
@Override
public Loader<Cursor> onCreateLoader(int loaderId, Bundle bundle) {
if (loaderId != URL_LOADER) {
return null;
}
final String itemId = getItemId();
if (TextUtils.isEmpty(itemId)) {
return null;
}
final Activity activity = getActivity();
final Uri.Builder builder = Item.CONTENT_URI.buildUpon();
builder.appendPath(itemId);
return new CursorLoader(
activity,
builder.build(),
mColumns,
null, // No where clause, return all records. We already specify just one via the itemId in the URI
null, // No where clause, therefore no where column values.
null // Use the default sort order.
);
}
@Override
public void onLoadFinished(Loader<Cursor> cursorLoader, Cursor cursor) {
mCursor = cursor;
updateFromCursor();
}
@Override
public void onLoaderReset(Loader<Cursor> cursorLoader) {
/*
* Clears out our reference to the Cursor.
* This prevents memory leaks.
*/
mCursor = null;
}
}