public Drawable getCachedPreview(int contentRowID) {
if (LOG)
Log.v(TAG, "getCachedPreview(" + contentRowID + ") mPreviewStatus=" + mAllPreviewStatus);
initTask();
registerObserver();
if (mAllPreviewStatus == TYPE_NEED_LOAD) {
loadPreviewStatus();
}
if (mAllPreviewStatus == TYPE_LOADED_NO_PREVIEW) {
return mDefaultDrawable;
}
//
MyDrawable cachedDrawable = null;
synchronized (sCachedPreview) {
cachedDrawable = sCachedPreview.get(contentRowID);
}
// when sdcard exists, load or reload the preview
if (mMounted && (cachedDrawable == null || cachedDrawable.type == TYPE_NEED_LOAD)) {
// add priority
prioritySeed++;
synchronized (mTaskQueue) {
// check is processing or not
// current request is not in queue.
boolean isProcessing = false;
if (currentRequest != null) {
synchronized (currentRequest) {
if (currentRequest.rowId == contentRowID) {
isProcessing = true;
}
}
}
if (LOG) Log.v(TAG, "getCachedPreview() isProcessing=" + isProcessing);
if (!isProcessing) {
// check is in request queue or not.
TaskParams oldRequest = null;
for (TaskParams one : mTaskQueue) {
if (one.rowId == contentRowID) {
oldRequest = one;
break;
}
}
if (LOG) Log.i(TAG, "getCachedPreview() oldRequest=" + oldRequest);
if (oldRequest == null) { // not in cache and not in request
MyDrawable temp = new MyDrawable(null, TYPE_NEED_LOAD);
synchronized (sCachedPreview) {
cachedDrawable = sCachedPreview.get(contentRowID);
if (cachedDrawable == null) {
sCachedPreview.put(contentRowID, temp);
}
cachedDrawable = temp;
}
TaskParams task = new TaskParams(contentRowID, mListener, -prioritySeed);
mTaskQueue.add(task);
mTaskHandler.sendEmptyMessage(TASK_REQUEST_NEW);
} else { // not in cache, but in request
oldRequest.priority = -prioritySeed; // just update priority
if (mTaskQueue.remove(oldRequest)) {
mTaskQueue.add(oldRequest); // re-order the queue
}
}
} else {
// do nothing
}
}
if (LOG) Log.v(TAG, "getCachedPreview() async load the drawable for " + contentRowID);
}
Drawable result = null;
if (cachedDrawable == null || cachedDrawable.type != TYPE_LOADED_HAS_PREVIEW) {
result = mDefaultDrawable;
} else {
result = cachedDrawable.drawable;
}
if (LOG)
Log.v(
TAG,
"getCachedPreview() mPreviewStatus="
+ mAllPreviewStatus
+ ", cachedDrawable="
+ cachedDrawable
+ ", return "
+ result);
return result;
}
/*package*/ static class CachedPreview extends Handler {
private final HashMap<Integer, MyDrawable> sCachedPreview = new HashMap<Integer, MyDrawable>();
private Context mContext;
private ContentResolver mCr;
private BitmapDrawable mDefaultDrawable;
private boolean mIsSGMode;
private Uri mUri;
private int mUsage;
private boolean mMounted;
private int mAllPreviewStatus = TYPE_NEED_LOAD;
private Boolean mRegisted = false;
private MyContentObserver mContentObserver;
private MyBroadcastReceiver mSdCardReceiver;
private int mIconWidth;
private int mIconHeight;
private DrawableStateListener mListener;
// asyc request media for fast the calling thread
private Handler mTaskHandler;
private static Looper sLooper;
// priority queue for async request
private static final PriorityQueue<TaskParams> mTaskQueue =
new PriorityQueue<TaskParams>(10, TaskParams.getComparator());
private static final int TASK_REQUEST_DONE = 1;
private static final int TASK_REQUEST_NEW = 2;
public CachedPreview(
Context context,
BitmapDrawable defaultDrawable,
boolean isSGMode,
int usage,
DrawableStateListener listener) {
mContext = context;
mCr = mContext.getContentResolver();
mDefaultDrawable = defaultDrawable;
Bitmap icon = mDefaultDrawable.getBitmap();
mIconWidth = icon.getWidth();
mIconHeight = icon.getHeight();
mUsage = usage;
mIsSGMode = isSGMode;
if (mIsSGMode) {
mUri = MBBMSStore.SG.PreviewData.CONTENT_URI;
} else {
mUri = MBBMSStore.ESG.Media.CONTENT_URI;
}
mListener = listener;
if (LOG) Log.v(TAG, "CachedPreview(" + isSGMode + ", " + usage + ")");
}
private void registerObserver() {
// Here I register the ContentObserver and BroadcasetReceiver.
// These can check the database's update and sdcard's state.
// So, when there's no sdcard or database has no preview infos,
// getCachedPreview() will be faster.
synchronized (mRegisted) {
if (!mRegisted) {
mContentObserver = new MyContentObserver(null);
mSdCardReceiver = new MyBroadcastReceiver();
mCr.registerContentObserver(mUri, true, mContentObserver);
IntentFilter filter1 = new IntentFilter(Intent.ACTION_MEDIA_EJECT);
filter1.addDataScheme("file");
mContext.registerReceiver(mSdCardReceiver, filter1);
IntentFilter filter2 = new IntentFilter(Intent.ACTION_MEDIA_MOUNTED);
filter2.addDataScheme("file");
mContext.registerReceiver(mSdCardReceiver, filter2);
mRegisted = true;
mMounted = isExternalStorageReady();
if (LOG) Log.v(TAG, "registerObserver() regist observers! mMounted=" + mMounted);
}
}
if (LOG) Log.v(TAG, "registerObserver() mRegisted=" + mRegisted + ", mMounted=" + mMounted);
}
@Override
public void handleMessage(Message msg) {
if (LOG) Log.v(TAG, "mCallingHandler.handleMessage(" + msg + ")");
if (msg.what == TASK_REQUEST_DONE && (msg.obj instanceof TaskParams)) {
TaskParams result = (TaskParams) msg.obj;
if (result.listener != null) {
result.listener.onChanged(result.rowId, result.drawable);
}
}
}
private boolean initTask;
private long prioritySeed;
private TaskParams currentRequest;
private void initTask() {
if (LOG) Log.v(TAG, "initTask() initTask=" + initTask + ", prioritySeed=" + prioritySeed);
if (initTask) return;
prioritySeed = 0;
synchronized (CachedPreview.class) {
if (sLooper == null) {
HandlerThread t =
new HandlerThread(
"cached-preview-thread", android.os.Process.THREAD_PRIORITY_BACKGROUND);
t.start();
sLooper = t.getLooper();
}
}
mTaskHandler =
new Handler(sLooper) {
@Override
public void handleMessage(Message msg) {
if (LOG) Log.v(TAG, "mTaskHandler.handleMessage(" + msg + ")");
if (msg.what == TASK_REQUEST_NEW) {
synchronized (mTaskQueue) {
currentRequest = mTaskQueue.poll();
}
if (currentRequest == null) {
Log.w(TAG, "wrong request, has request but no task params.");
return;
}
// recheck the drawable is exists or not.
int contentRowID = currentRequest.rowId;
MyDrawable cachedDrawable = null;
synchronized (sCachedPreview) {
cachedDrawable = sCachedPreview.get(contentRowID);
}
if (cachedDrawable == null) {
Log.w(TAG, "cached drawable was delete. may for clear.");
return;
}
// when sdcard exists, load or reload the preview
if (mMounted && cachedDrawable.type == TYPE_NEED_LOAD) {
Bitmap tempBitmap = getPreview(contentRowID);
if (tempBitmap != null) {
tempBitmap =
Bitmap.createScaledBitmap(tempBitmap, mIconWidth, mIconHeight, true);
cachedDrawable.set(new FastBitmapDrawable(tempBitmap), TYPE_LOADED_HAS_PREVIEW);
} else {
cachedDrawable.set(null, TYPE_LOADED_NO_PREVIEW);
}
}
currentRequest.drawable = cachedDrawable;
Message done = CachedPreview.this.obtainMessage(TASK_REQUEST_DONE);
done.obj = currentRequest;
done.sendToTarget();
if (LOG) Log.v(TAG, "mTaskHandler.handleMessage() send done. " + currentRequest);
}
}
};
initTask = true;
}
private void clearTask() {
if (LOG) Log.v(TAG, "clearTask() initTask=" + initTask);
if (initTask) {
prioritySeed = 0;
removeMessages(TASK_REQUEST_DONE);
synchronized (mTaskQueue) {
mTaskQueue.clear();
}
mTaskHandler.removeMessages(TASK_REQUEST_NEW);
mTaskHandler = null;
}
initTask = false;
}
public Drawable getCachedPreview(int contentRowID) {
if (LOG)
Log.v(TAG, "getCachedPreview(" + contentRowID + ") mPreviewStatus=" + mAllPreviewStatus);
initTask();
registerObserver();
if (mAllPreviewStatus == TYPE_NEED_LOAD) {
loadPreviewStatus();
}
if (mAllPreviewStatus == TYPE_LOADED_NO_PREVIEW) {
return mDefaultDrawable;
}
//
MyDrawable cachedDrawable = null;
synchronized (sCachedPreview) {
cachedDrawable = sCachedPreview.get(contentRowID);
}
// when sdcard exists, load or reload the preview
if (mMounted && (cachedDrawable == null || cachedDrawable.type == TYPE_NEED_LOAD)) {
// add priority
prioritySeed++;
synchronized (mTaskQueue) {
// check is processing or not
// current request is not in queue.
boolean isProcessing = false;
if (currentRequest != null) {
synchronized (currentRequest) {
if (currentRequest.rowId == contentRowID) {
isProcessing = true;
}
}
}
if (LOG) Log.v(TAG, "getCachedPreview() isProcessing=" + isProcessing);
if (!isProcessing) {
// check is in request queue or not.
TaskParams oldRequest = null;
for (TaskParams one : mTaskQueue) {
if (one.rowId == contentRowID) {
oldRequest = one;
break;
}
}
if (LOG) Log.i(TAG, "getCachedPreview() oldRequest=" + oldRequest);
if (oldRequest == null) { // not in cache and not in request
MyDrawable temp = new MyDrawable(null, TYPE_NEED_LOAD);
synchronized (sCachedPreview) {
cachedDrawable = sCachedPreview.get(contentRowID);
if (cachedDrawable == null) {
sCachedPreview.put(contentRowID, temp);
}
cachedDrawable = temp;
}
TaskParams task = new TaskParams(contentRowID, mListener, -prioritySeed);
mTaskQueue.add(task);
mTaskHandler.sendEmptyMessage(TASK_REQUEST_NEW);
} else { // not in cache, but in request
oldRequest.priority = -prioritySeed; // just update priority
if (mTaskQueue.remove(oldRequest)) {
mTaskQueue.add(oldRequest); // re-order the queue
}
}
} else {
// do nothing
}
}
if (LOG) Log.v(TAG, "getCachedPreview() async load the drawable for " + contentRowID);
}
Drawable result = null;
if (cachedDrawable == null || cachedDrawable.type != TYPE_LOADED_HAS_PREVIEW) {
result = mDefaultDrawable;
} else {
result = cachedDrawable.drawable;
}
if (LOG)
Log.v(
TAG,
"getCachedPreview() mPreviewStatus="
+ mAllPreviewStatus
+ ", cachedDrawable="
+ cachedDrawable
+ ", return "
+ result);
return result;
}
private Bitmap getPreview(int contentRowID) {
Bitmap bitmap = null;
if (mIsSGMode) {
bitmap = MBBMSStore.SG.ContentPreviewData.getPreviewBitmap(mCr, contentRowID, mUsage, null);
} else {
bitmap = MBBMSStore.ESG.ContentMedia.getMediaBitmap(mCr, contentRowID, mUsage, null);
}
if (LOG) Log.v(TAG, "getPreview() bitmap=" + bitmap);
return bitmap;
}
public void clearCachedPreview() {
synchronized (mRegisted) {
if (mRegisted) {
mCr.unregisterContentObserver(mContentObserver);
mContentObserver = null;
mContext.unregisterReceiver(mSdCardReceiver);
mSdCardReceiver = null;
mAllPreviewStatus = TYPE_NEED_LOAD;
mRegisted = false;
}
}
synchronized (sCachedPreview) {
sCachedPreview.clear();
}
clearTask();
}
private void loadPreviewStatus() {
Cursor cursor = null;
try {
cursor = mCr.query(mUri, new String[] {"count(*)"}, null, null, null);
if (cursor != null && cursor.moveToFirst()) {
int count = cursor.getInt(0);
if (count > 0) {
mAllPreviewStatus = TYPE_LOADED_HAS_PREVIEW;
} else {
mAllPreviewStatus = TYPE_LOADED_NO_PREVIEW;
}
}
} catch (Exception e) {
e.printStackTrace();
// ignore it.
} finally {
if (cursor != null) {
cursor.close();
}
}
if (LOG) Log.v(TAG, "loadPreviewStatus() mPreviewStatus=" + mAllPreviewStatus);
}
private class MyContentObserver extends ContentObserver {
public MyContentObserver(Handler handler) {
super(handler);
}
@Override
public void onChange(boolean selfChange) {
if (LOG) Log.v(TAG, "mContentObserver.onChange(" + selfChange + ")");
if (mAllPreviewStatus != TYPE_NEED_LOAD) {
// we do not delete drawable until we refresh the whole SG or ESG info
// which is be operated in MainScreen Activity.
// So here do not need to consider delete case.
Set<Integer> keys = sCachedPreview.keySet();
for (Integer key : keys) {
MyDrawable drawable = sCachedPreview.get(key);
if (drawable.type == TYPE_LOADED_NO_PREVIEW) {
drawable.type = TYPE_NEED_LOAD;
}
}
mAllPreviewStatus = TYPE_NEED_LOAD;
}
}
}
private class MyBroadcastReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
String path = intent.getData().getPath();
// only observe sdcard with default path: "/mnt/sdcard"
String externalPath = Environment.getExternalStorageDirectory().getPath();
if (Intent.ACTION_MEDIA_EJECT.equals(action) && externalPath.equalsIgnoreCase(path)) {
mMounted = false;
} else if (Intent.ACTION_MEDIA_MOUNTED.equals(action)
&& externalPath.equalsIgnoreCase(path)) {
mMounted = true;
}
if (LOG) Log.v(TAG, "onReceive(" + intent + ") mMounted=" + mMounted);
}
};
/*package*/ static final int TYPE_NEED_LOAD = 0;
/*package*/ static final int TYPE_LOADED_NO_PREVIEW = 1;
/*package*/ static final int TYPE_LOADED_HAS_PREVIEW = 2;
/*package*/ class MyDrawable {
int type;
Drawable drawable;
public MyDrawable(Drawable idrawable, int itype) {
type = itype;
drawable = idrawable;
}
public void set(Drawable idrawable, int itype) {
type = itype;
drawable = idrawable;
}
@Override
public String toString() {
return new StringBuilder()
.append("MyDrawable(type=")
.append(type)
.append(", drawable=")
.append(drawable)
.append(")")
.toString();
}
}
public interface DrawableStateListener {
public void onChanged(int rowId, MyDrawable drawable);
}
public static class TaskParams {
int rowId;
MyDrawable drawable;
DrawableStateListener listener;
long priority;
public TaskParams(int rowId, DrawableStateListener listener, long priority) {
this.rowId = rowId;
this.listener = listener;
this.priority = priority;
}
@Override
public String toString() {
return new StringBuilder()
.append("TaskInput(rowId=")
.append(rowId)
.append(", listener=")
.append(listener)
.append(", drawable=")
.append(drawable)
.append(")")
.toString();
}
static Comparator<TaskParams> getComparator() {
return new Comparator<TaskParams>() {
public int compare(TaskParams r1, TaskParams r2) {
if (r1.priority != r2.priority) {
return (r1.priority < r2.priority) ? -1 : 1;
}
return 0;
}
};
}
}
}