* This class represents a data model for choosing a component for handing a * given {@link Intent}. The model is responsible for querying the system for * activities that can handle the given intent and order found activities * based on historical data of previous choices. The historical data is stored * in an application private file. If a client does not want to have persistent * choice history the file can be omitted, thus the activities will be ordered * based on historical usage for the current session. *
*
* For each backing history file there is a singleton instance of this class. Thus, * several clients that specify the same history file will share the same model. Note * that if multiple clients are sharing the same model they should implement semantically * equivalent functionality since setting the model intent will change the found * activities and they may be inconsistent with the functionality of some of the clients. * For example, choosing a share activity can be implemented by a single backing * model and two different views for performing the selection. If however, one of the * views is used for sharing but the other for importing, for example, then each * view should be backed by a separate model. * ** The way clients interact with this class is as follows: *
**
*
* // Get a model and set it to a couple of clients with semantically similar function.
* ActivityChooserModel dataModel =
* ActivityChooserModel.get(context, "task_specific_history_file_name.xml");
*
* ActivityChooserModelClient modelClient1 = getActivityChooserModelClient1();
* modelClient1.setActivityChooserModel(dataModel);
*
* ActivityChooserModelClient modelClient2 = getActivityChooserModelClient2();
* modelClient2.setActivityChooserModel(dataModel);
*
* // Set an intent to choose a an activity for.
* dataModel.setIntent(intent);
*
*
*
*
* Note: This class is thread safe.
*
*/
class ActivityChooserModel extends DataSetObservable {
/**
* Client that utilizes an {@link ActivityChooserModel}.
*/
public interface ActivityChooserModelClient {
/**
* Sets the {@link ActivityChooserModel}.
*
* @param dataModel The model.
*/
public void setActivityChooserModel(ActivityChooserModel dataModel);
}
/**
* Defines a sorter that is responsible for sorting the activities
* based on the provided historical choices and an intent.
*/
public interface ActivitySorter {
/**
* Sorts the activities in descending order of relevance
* based on previous history and an intent.
*
* @param intent The {@link Intent}.
* @param activities Activities to be sorted.
* @param historicalRecords Historical records.
*/
// This cannot be done by a simple comparator since an Activity weight
// is computed from history. Note that Activity implements Comparable.
public void sort(Intent intent, List activities,
List historicalRecords);
}
/**
* Listener for choosing an activity.
*/
public interface OnChooseActivityListener {
/**
* Called when an activity has been chosen. The client can decide whether
* an activity can be chosen and if so the caller of
* {@link ActivityChooserModel#chooseActivity(int)} will receive and {@link Intent}
* for launching it.
*
* Note: Modifying the intent is not permitted and
* any changes to the latter will be ignored.
*
*
* @param host The listener's host model.
* @param intent The intent for launching the chosen activity.
* @return Whether the intent is handled and should not be delivered to clients.
*
* @see ActivityChooserModel#chooseActivity(int)
*/
public boolean onChooseActivity(ActivityChooserModel host, Intent intent);
}
/**
* Flag for selecting debug mode.
*/
static final boolean DEBUG = false;
/**
* Tag used for logging.
*/
static final String LOG_TAG = ActivityChooserModel.class.getSimpleName();
/**
* The root tag in the history file.
*/
static final String TAG_HISTORICAL_RECORDS = "historical-records";
/**
* The tag for a record in the history file.
*/
static final String TAG_HISTORICAL_RECORD = "historical-record";
/**
* Attribute for the activity.
*/
static final String ATTRIBUTE_ACTIVITY = "activity";
/**
* Attribute for the choice time.
*/
static final String ATTRIBUTE_TIME = "time";
/**
* Attribute for the choice weight.
*/
static final String ATTRIBUTE_WEIGHT = "weight";
/**
* The default name of the choice history file.
*/
public static final String DEFAULT_HISTORY_FILE_NAME =
"activity_choser_model_history.xml";
/**
* The default maximal length of the choice history.
*/
public static final int DEFAULT_HISTORY_MAX_LENGTH = 50;
/**
* The amount with which to inflate a chosen activity when set as default.
*/
private static final int DEFAULT_ACTIVITY_INFLATION = 5;
/**
* Default weight for a choice record.
*/
private static final float DEFAULT_HISTORICAL_RECORD_WEIGHT = 1.0f;
/**
* The extension of the history file.
*/
private static final String HISTORY_FILE_EXTENSION = ".xml";
/**
* An invalid item index.
*/
private static final int INVALID_INDEX = -1;
/**
* Lock to guard the model registry.
*/
private static final Object sRegistryLock = new Object();
/**
* This the registry for data models.
*/
private static final Map sDataModelRegistry =
new HashMap();
/**
* Lock for synchronizing on this instance.
*/
private final Object mInstanceLock = new Object();
/**
* List of activities that can handle the current intent.
*/
private final List mActivities = new ArrayList();
/**
* List with historical choice records.
*/
private final List mHistoricalRecords = new ArrayList();
/**
* Context for accessing resources.
*/
final Context mContext;
/**
* The name of the history file that backs this model.
*/
final String mHistoryFileName;
/**
* The intent for which a activity is being chosen.
*/
private Intent mIntent;
/**
* The sorter for ordering activities based on intent and past choices.
*/
private ActivitySorter mActivitySorter = new DefaultSorter();
/**
* The maximal length of the choice history.
*/
private int mHistoryMaxSize = DEFAULT_HISTORY_MAX_LENGTH;
/**
* Flag whether choice history can be read. In general many clients can
* share the same data model and {@link #readHistoricalDataIfNeeded()} may be called
* by arbitrary of them any number of times. Therefore, this class guarantees
* that the very first read succeeds and subsequent reads can be performed
* only after a call to {@link #persistHistoricalDataIfNeeded()} followed by change
* of the share records.
*/
boolean mCanReadHistoricalData = true;
/**
* Flag whether the choice history was read. This is used to enforce that
* before calling {@link #persistHistoricalDataIfNeeded()} a call to
* {@link #persistHistoricalDataIfNeeded()} has been made. This aims to avoid a
* scenario in which a choice history file exits, it is not read yet and
* it is overwritten. Note that always all historical records are read in
* full and the file is rewritten. This is necessary since we need to
* purge old records that are outside of the sliding window of past choices.
*/
private boolean mReadShareHistoryCalled = false;
/**
* Flag whether the choice records have changed. In general many clients can
* share the same data model and {@link #persistHistoricalDataIfNeeded()} may be called
* by arbitrary of them any number of times. Therefore, this class guarantees
* that choice history will be persisted only if it has changed.
*/
private boolean mHistoricalRecordsChanged = true;
/**
* Flag whether to reload the activities for the current intent.
*/
private boolean mReloadActivities = false;
/**
* Policy for controlling how the model handles chosen activities.
*/
private OnChooseActivityListener mActivityChoserModelPolicy;
/**
* Gets the data model backed by the contents of the provided file with historical data.
* Note that only one data model is backed by a given file, thus multiple calls with
* the same file name will return the same model instance. If no such instance is present
* it is created.
*
* Note: To use the default historical data file clients should explicitly
* pass as file name {@link #DEFAULT_HISTORY_FILE_NAME}. If no persistence of the choice
* history is desired clients should pass null for the file name. In such
* case a new model is returned for each invocation.
*
*
*
* Always use difference historical data files for semantically different actions.
* For example, sharing is different from importing.
*
*
* @param context Context for loading resources.
* @param historyFileName File name with choice history, null
* if the model should not be backed by a file. In this case the activities
* will be ordered only by data from the current session.
*
* @return The model.
*/
public static ActivityChooserModel get(Context context, String historyFileName) {
synchronized (sRegistryLock) {
ActivityChooserModel dataModel = sDataModelRegistry.get(historyFileName);
if (dataModel == null) {
dataModel = new ActivityChooserModel(context, historyFileName);
sDataModelRegistry.put(historyFileName, dataModel);
}
return dataModel;
}
}
/**
* Creates a new instance.
*
* @param context Context for loading resources.
* @param historyFileName The history XML file.
*/
private ActivityChooserModel(Context context, String historyFileName) {
mContext = context.getApplicationContext();
if (!TextUtils.isEmpty(historyFileName)
&& !historyFileName.endsWith(HISTORY_FILE_EXTENSION)) {
mHistoryFileName = historyFileName + HISTORY_FILE_EXTENSION;
} else {
mHistoryFileName = historyFileName;
}
}
/**
* Sets an intent for which to choose a activity.
*
* Note: Clients must set only semantically similar
* intents for each data model.
*
*
* @param intent The intent.
*/
public void setIntent(Intent intent) {
synchronized (mInstanceLock) {
if (mIntent == intent) {
return;
}
mIntent = intent;
mReloadActivities = true;
ensureConsistentState();
}
}
/**
* Gets the intent for which a activity is being chosen.
*
* @return The intent.
*/
public Intent getIntent() {
synchronized (mInstanceLock) {
return mIntent;
}
}
/**
* Gets the number of activities that can handle the intent.
*
* @return The activity count.
*
* @see #setIntent(Intent)
*/
public int getActivityCount() {
synchronized (mInstanceLock) {
ensureConsistentState();
return mActivities.size();
}
}
/**
* Gets an activity at a given index.
*
* @return The activity.
*
* @see ActivityResolveInfo
* @see #setIntent(Intent)
*/
public ResolveInfo getActivity(int index) {
synchronized (mInstanceLock) {
ensureConsistentState();
return mActivities.get(index).resolveInfo;
}
}
/**
* Gets the index of a the given activity.
*
* @param activity The activity index.
*
* @return The index if found, -1 otherwise.
*/
public int getActivityIndex(ResolveInfo activity) {
synchronized (mInstanceLock) {
ensureConsistentState();
List activities = mActivities;
final int activityCount = activities.size();
for (int i = 0; i < activityCount; i++) {
ActivityResolveInfo currentActivity = activities.get(i);
if (currentActivity.resolveInfo == activity) {
return i;
}
}
return INVALID_INDEX;
}
}
/**
* Chooses a activity to handle the current intent. This will result in
* adding a historical record for that action and construct intent with
* its component name set such that it can be immediately started by the
* client.
*
* Note: By calling this method the client guarantees
* that the returned intent will be started. This intent is returned to
* the client solely to let additional customization before the start.
*
*
* @return An {@link Intent} for launching the activity or null if the
* policy has consumed the intent or there is not current intent
* set via {@link #setIntent(Intent)}.
*
* @see HistoricalRecord
* @see OnChooseActivityListener
*/
public Intent chooseActivity(int index) {
synchronized (mInstanceLock) {
if (mIntent == null) {
return null;
}
ensureConsistentState();
ActivityResolveInfo chosenActivity = mActivities.get(index);
ComponentName chosenName = new ComponentName(
chosenActivity.resolveInfo.activityInfo.packageName,
chosenActivity.resolveInfo.activityInfo.name);
Intent choiceIntent = new Intent(mIntent);
choiceIntent.setComponent(chosenName);
if (mActivityChoserModelPolicy != null) {
// Do not allow the policy to change the intent.
Intent choiceIntentCopy = new Intent(choiceIntent);
final boolean handled = mActivityChoserModelPolicy.onChooseActivity(this,
choiceIntentCopy);
if (handled) {
return null;
}
}
HistoricalRecord historicalRecord = new HistoricalRecord(chosenName,
System.currentTimeMillis(), DEFAULT_HISTORICAL_RECORD_WEIGHT);
addHistoricalRecord(historicalRecord);
return choiceIntent;
}
}
/**
* Sets the listener for choosing an activity.
*
* @param listener The listener.
*/
public void setOnChooseActivityListener(OnChooseActivityListener listener) {
synchronized (mInstanceLock) {
mActivityChoserModelPolicy = listener;
}
}
/**
* Gets the default activity, The default activity is defined as the one
* with highest rank i.e. the first one in the list of activities that can
* handle the intent.
*
* @return The default activity, null id not activities.
*
* @see #getActivity(int)
*/
public ResolveInfo getDefaultActivity() {
synchronized (mInstanceLock) {
ensureConsistentState();
if (!mActivities.isEmpty()) {
return mActivities.get(0).resolveInfo;
}
}
return null;
}
/**
* Sets the default activity. The default activity is set by adding a
* historical record with weight high enough that this activity will
* become the highest ranked. Such a strategy guarantees that the default
* will eventually change if not used. Also the weight of the record for
* setting a default is inflated with a constant amount to guarantee that
* it will stay as default for awhile.
*
* @param index The index of the activity to set as default.
*/
public void setDefaultActivity(int index) {
synchronized (mInstanceLock) {
ensureConsistentState();
ActivityResolveInfo newDefaultActivity = mActivities.get(index);
ActivityResolveInfo oldDefaultActivity = mActivities.get(0);
final float weight;
if (oldDefaultActivity != null) {
// Add a record with weight enough to boost the chosen at the top.
weight = oldDefaultActivity.weight - newDefaultActivity.weight
+ DEFAULT_ACTIVITY_INFLATION;
} else {
weight = DEFAULT_HISTORICAL_RECORD_WEIGHT;
}
ComponentName defaultName = new ComponentName(
newDefaultActivity.resolveInfo.activityInfo.packageName,
newDefaultActivity.resolveInfo.activityInfo.name);
HistoricalRecord historicalRecord = new HistoricalRecord(defaultName,
System.currentTimeMillis(), weight);
addHistoricalRecord(historicalRecord);
}
}
/**
* Persists the history data to the backing file if the latter
* was provided. Calling this method before a call to {@link #readHistoricalDataIfNeeded()}
* throws an exception. Calling this method more than one without choosing an
* activity has not effect.
*
* @throws IllegalStateException If this method is called before a call to
* {@link #readHistoricalDataIfNeeded()}.
*/
private void persistHistoricalDataIfNeeded() {
if (!mReadShareHistoryCalled) {
throw new IllegalStateException("No preceding call to #readHistoricalData");
}
if (!mHistoricalRecordsChanged) {
return;
}
mHistoricalRecordsChanged = false;
if (!TextUtils.isEmpty(mHistoryFileName)) {
AsyncTaskCompat.executeParallel(new PersistHistoryAsyncTask(),
new ArrayList(mHistoricalRecords), mHistoryFileName);
}
}
/**
* Sets the sorter for ordering activities based on historical data and an intent.
*
* @param activitySorter The sorter.
*
* @see ActivitySorter
*/
public void setActivitySorter(ActivitySorter activitySorter) {
synchronized (mInstanceLock) {
if (mActivitySorter == activitySorter) {
return;
}
mActivitySorter = activitySorter;
if (sortActivitiesIfNeeded()) {
notifyChanged();
}
}
}
/**
* Sets the maximal size of the historical data. Defaults to
* {@link #DEFAULT_HISTORY_MAX_LENGTH}
*
* Note: Setting this property will immediately
* enforce the specified max history size by dropping enough old
* historical records to enforce the desired size. Thus, any
* records that exceed the history size will be discarded and
* irreversibly lost.
*
*
* @param historyMaxSize The max history size.
*/
public void setHistoryMaxSize(int historyMaxSize) {
synchronized (mInstanceLock) {
if (mHistoryMaxSize == historyMaxSize) {
return;
}
mHistoryMaxSize = historyMaxSize;
pruneExcessiveHistoricalRecordsIfNeeded();
if (sortActivitiesIfNeeded()) {
notifyChanged();
}
}
}
/**
* Gets the history max size.
*
* @return The history max size.
*/
public int getHistoryMaxSize() {
synchronized (mInstanceLock) {
return mHistoryMaxSize;
}
}
/**
* Gets the history size.
*
* @return The history size.
*/
public int getHistorySize() {
synchronized (mInstanceLock) {
ensureConsistentState();
return mHistoricalRecords.size();
}
}
/**
* Ensures the model is in a consistent state which is the
* activities for the current intent have been loaded, the
* most recent history has been read, and the activities
* are sorted.
*/
private void ensureConsistentState() {
boolean stateChanged = loadActivitiesIfNeeded();
stateChanged |= readHistoricalDataIfNeeded();
pruneExcessiveHistoricalRecordsIfNeeded();
if (stateChanged) {
sortActivitiesIfNeeded();
notifyChanged();
}
}
/**
* Sorts the activities if necessary which is if there is a
* sorter, there are some activities to sort, and there is some
* historical data.
*
* @return Whether sorting was performed.
*/
private boolean sortActivitiesIfNeeded() {
if (mActivitySorter != null && mIntent != null
&& !mActivities.isEmpty() && !mHistoricalRecords.isEmpty()) {
mActivitySorter.sort(mIntent, mActivities,
Collections.unmodifiableList(mHistoricalRecords));
return true;
}
return false;
}
/**
* Loads the activities for the current intent if needed which is
* if they are not already loaded for the current intent.
*
* @return Whether loading was performed.
*/
private boolean loadActivitiesIfNeeded() {
if (mReloadActivities && mIntent != null) {
mReloadActivities = false;
mActivities.clear();
List resolveInfos = mContext.getPackageManager()
.queryIntentActivities(mIntent, 0);
final int resolveInfoCount = resolveInfos.size();
for (int i = 0; i < resolveInfoCount; i++) {
ResolveInfo resolveInfo = resolveInfos.get(i);
mActivities.add(new ActivityResolveInfo(resolveInfo));
}
return true;
}
return false;
}
/**
* Reads the historical data if necessary which is it has
* changed, there is a history file, and there is not persist
* in progress.
*
* @return Whether reading was performed.
*/
private boolean readHistoricalDataIfNeeded() {
if (mCanReadHistoricalData && mHistoricalRecordsChanged &&
!TextUtils.isEmpty(mHistoryFileName)) {
mCanReadHistoricalData = false;
mReadShareHistoryCalled = true;
readHistoricalDataImpl();
return true;
}
return false;
}
/**
* Adds a historical record.
*
* @param historicalRecord The record to add.
* @return True if the record was added.
*/
private boolean addHistoricalRecord(HistoricalRecord historicalRecord) {
final boolean added = mHistoricalRecords.add(historicalRecord);
if (added) {
mHistoricalRecordsChanged = true;
pruneExcessiveHistoricalRecordsIfNeeded();
persistHistoricalDataIfNeeded();
sortActivitiesIfNeeded();
notifyChanged();
}
return added;
}
/**
* Prunes older excessive records to guarantee maxHistorySize.
*/
private void pruneExcessiveHistoricalRecordsIfNeeded() {
final int pruneCount = mHistoricalRecords.size() - mHistoryMaxSize;
if (pruneCount <= 0) {
return;
}
mHistoricalRecordsChanged = true;
for (int i = 0; i < pruneCount; i++) {
HistoricalRecord prunedRecord = mHistoricalRecords.remove(0);
if (DEBUG) {
Log.i(LOG_TAG, "Pruned: " + prunedRecord);
}
}
}
/**
* Represents a record in the history.
*/
public final static class HistoricalRecord {
/**
* The activity name.
*/
public final ComponentName activity;
/**
* The choice time.
*/
public final long time;
/**
* The record weight.
*/
public final float weight;
/**
* Creates a new instance.
*
* @param activityName The activity component name flattened to string.
* @param time The time the activity was chosen.
* @param weight The weight of the record.
*/
public HistoricalRecord(String activityName, long time, float weight) {
this(ComponentName.unflattenFromString(activityName), time, weight);
}
/**
* Creates a new instance.
*
* @param activityName The activity name.
* @param time The time the activity was chosen.
* @param weight The weight of the record.
*/
public HistoricalRecord(ComponentName activityName, long time, float weight) {
this.activity = activityName;
this.time = time;
this.weight = weight;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((activity == null) ? 0 : activity.hashCode());
result = prime * result + (int) (time ^ (time >>> 32));
result = prime * result + Float.floatToIntBits(weight);
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
HistoricalRecord other = (HistoricalRecord) obj;
if (activity == null) {
if (other.activity != null) {
return false;
}
} else if (!activity.equals(other.activity)) {
return false;
}
if (time != other.time) {
return false;
}
if (Float.floatToIntBits(weight) != Float.floatToIntBits(other.weight)) {
return false;
}
return true;
}
@Override
public String toString() {
StringBuilder builder = new StringBuilder();
builder.append("[");
builder.append("; activity:").append(activity);
builder.append("; time:").append(time);
builder.append("; weight:").append(new BigDecimal(weight));
builder.append("]");
return builder.toString();
}
}
/**
* Represents an activity.
*/
public final class ActivityResolveInfo implements Comparable {
/**
* The {@link ResolveInfo} of the activity.
*/
public final ResolveInfo resolveInfo;
/**
* Weight of the activity. Useful for sorting.
*/
public float weight;
/**
* Creates a new instance.
*
* @param resolveInfo activity {@link ResolveInfo}.
*/
public ActivityResolveInfo(ResolveInfo resolveInfo) {
this.resolveInfo = resolveInfo;
}
@Override
public int hashCode() {
return 31 + Float.floatToIntBits(weight);
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
ActivityResolveInfo other = (ActivityResolveInfo) obj;
if (Float.floatToIntBits(weight) != Float.floatToIntBits(other.weight)) {
return false;
}
return true;
}
public int compareTo(ActivityResolveInfo another) {
return Float.floatToIntBits(another.weight) - Float.floatToIntBits(weight);
}
@Override
public String toString() {
StringBuilder builder = new StringBuilder();
builder.append("[");
builder.append("resolveInfo:").append(resolveInfo.toString());
builder.append("; weight:").append(new BigDecimal(weight));
builder.append("]");
return builder.toString();
}
}
/**
* Default activity sorter implementation.
*/
private final class DefaultSorter implements ActivitySorter {
private static final float WEIGHT_DECAY_COEFFICIENT = 0.95f;
private final Map mPackageNameToActivityMap =
new HashMap();
DefaultSorter() {
}
public void sort(Intent intent, List activities,
List historicalRecords) {
Map componentNameToActivityMap =
mPackageNameToActivityMap;
componentNameToActivityMap.clear();
final int activityCount = activities.size();
for (int i = 0; i < activityCount; i++) {
ActivityResolveInfo activity = activities.get(i);
activity.weight = 0.0f;
ComponentName componentName = new ComponentName(
activity.resolveInfo.activityInfo.packageName,
activity.resolveInfo.activityInfo.name);
componentNameToActivityMap.put(componentName, activity);
}
final int lastShareIndex = historicalRecords.size() - 1;
float nextRecordWeight = 1;
for (int i = lastShareIndex; i >= 0; i--) {
HistoricalRecord historicalRecord = historicalRecords.get(i);
ComponentName componentName = historicalRecord.activity;
ActivityResolveInfo activity = componentNameToActivityMap.get(componentName);
if (activity != null) {
activity.weight += historicalRecord.weight * nextRecordWeight;
nextRecordWeight = nextRecordWeight * WEIGHT_DECAY_COEFFICIENT;
}
}
Collections.sort(activities);
if (DEBUG) {
for (int i = 0; i < activityCount; i++) {
Log.i(LOG_TAG, "Sorted: " + activities.get(i));
}
}
}
}
private void readHistoricalDataImpl() {
FileInputStream fis = null;
try {
fis = mContext.openFileInput(mHistoryFileName);
} catch (FileNotFoundException fnfe) {
if (DEBUG) {
Log.i(LOG_TAG, "Could not open historical records file: " + mHistoryFileName);
}
return;
}
try {
XmlPullParser parser = Xml.newPullParser();
parser.setInput(fis, "UTF-8");
int type = XmlPullParser.START_DOCUMENT;
while (type != XmlPullParser.END_DOCUMENT && type != XmlPullParser.START_TAG) {
type = parser.next();
}
if (!TAG_HISTORICAL_RECORDS.equals(parser.getName())) {
throw new XmlPullParserException("Share records file does not start with "
+ TAG_HISTORICAL_RECORDS + " tag.");
}
List historicalRecords = mHistoricalRecords;
historicalRecords.clear();
while (true) {
type = parser.next();
if (type == XmlPullParser.END_DOCUMENT) {
break;
}
if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) {
continue;
}
String nodeName = parser.getName();
if (!TAG_HISTORICAL_RECORD.equals(nodeName)) {
throw new XmlPullParserException("Share records file not well-formed.");
}
String activity = parser.getAttributeValue(null, ATTRIBUTE_ACTIVITY);
final long time =
Long.parseLong(parser.getAttributeValue(null, ATTRIBUTE_TIME));
final float weight =
Float.parseFloat(parser.getAttributeValue(null, ATTRIBUTE_WEIGHT));
HistoricalRecord readRecord = new HistoricalRecord(activity, time, weight);
historicalRecords.add(readRecord);
if (DEBUG) {
Log.i(LOG_TAG, "Read " + readRecord.toString());
}
}
if (DEBUG) {
Log.i(LOG_TAG, "Read " + historicalRecords.size() + " historical records.");
}
} catch (XmlPullParserException xppe) {
Log.e(LOG_TAG, "Error reading historical recrod file: " + mHistoryFileName, xppe);
} catch (IOException ioe) {
Log.e(LOG_TAG, "Error reading historical recrod file: " + mHistoryFileName, ioe);
} finally {
if (fis != null) {
try {
fis.close();
} catch (IOException ioe) {
/* ignore */
}
}
}
}
/**
* Command for persisting the historical records to a file off the UI thread.
*/
private final class PersistHistoryAsyncTask extends AsyncTask {
PersistHistoryAsyncTask() {
}
@Override
@SuppressWarnings("unchecked")
public Void doInBackground(Object... args) {
List historicalRecords = (List) args[0];
String historyFileName = (String) args[1];
FileOutputStream fos = null;
try {
fos = mContext.openFileOutput(historyFileName, Context.MODE_PRIVATE);
} catch (FileNotFoundException fnfe) {
Log.e(LOG_TAG, "Error writing historical record file: " + historyFileName, fnfe);
return null;
}
XmlSerializer serializer = Xml.newSerializer();
try {
serializer.setOutput(fos, null);
serializer.startDocument("UTF-8", true);
serializer.startTag(null, TAG_HISTORICAL_RECORDS);
final int recordCount = historicalRecords.size();
for (int i = 0; i < recordCount; i++) {
HistoricalRecord record = historicalRecords.remove(0);
serializer.startTag(null, TAG_HISTORICAL_RECORD);
serializer.attribute(null, ATTRIBUTE_ACTIVITY,
record.activity.flattenToString());
serializer.attribute(null, ATTRIBUTE_TIME, String.valueOf(record.time));
serializer.attribute(null, ATTRIBUTE_WEIGHT, String.valueOf(record.weight));
serializer.endTag(null, TAG_HISTORICAL_RECORD);
if (DEBUG) {
Log.i(LOG_TAG, "Wrote " + record.toString());
}
}
serializer.endTag(null, TAG_HISTORICAL_RECORDS);
serializer.endDocument();
if (DEBUG) {
Log.i(LOG_TAG, "Wrote " + recordCount + " historical records.");
}
} catch (IllegalArgumentException iae) {
Log.e(LOG_TAG, "Error writing historical record file: " + mHistoryFileName, iae);
} catch (IllegalStateException ise) {
Log.e(LOG_TAG, "Error writing historical record file: " + mHistoryFileName, ise);
} catch (IOException ioe) {
Log.e(LOG_TAG, "Error writing historical record file: " + mHistoryFileName, ioe);
} finally {
mCanReadHistoricalData = true;
if (fos != null) {
try {
fos.close();
} catch (IOException e) {
/* ignore */
}
}
}
return null;
}
}
}