package com.appsimobile.appsii;
import android.app.Application;
import android.content.Loader;
import android.os.Bundle;
import android.support.v4.util.DebugUtils;
import android.support.v4.util.SparseArrayCompat;
import android.util.Log;
import java.io.FileDescriptor;
import java.io.PrintWriter;
import java.lang.reflect.Modifier;
/**
* Created by nmartens on 08/01/16.
*/
public class LoaderManagerImpl extends LoaderManager {
static final String TAG = "LoaderManager";
static boolean DEBUG = true;
// These are the currently active loaders. A loader is here
// from the time its load is started until it has been explicitly
// stopped or restarted by the application.
final SparseArrayCompat<LoaderInfo> mLoaders = new SparseArrayCompat<LoaderInfo>();
// These are previously run loaders. This list is maintained internally
// to avoid destroying a loader while an application is still using it.
// It allows an application to restart a loader, but continue using its
// previously run loader until the new loader's data is available.
final SparseArrayCompat<LoaderInfo> mInactiveLoaders = new SparseArrayCompat<LoaderInfo>();
final String mWho;
Application mActivity;
boolean mStarted;
boolean mRetaining;
boolean mRetainingStarted;
boolean mCreatingLoader;
public LoaderManagerImpl(String who, Application activity, boolean started) {
mWho = who;
mActivity = activity;
mStarted = started;
}
/**
* Call to initialize a particular ID with a Loader. If this ID already
* has a Loader associated with it, it is left unchanged and any previous
* callbacks replaced with the newly provided ones. If there is not currently
* a Loader for the ID, a new one is created and started.
* <p/>
* <p>This function should generally be used when a component is initializing,
* to ensure that a Loader it relies on is created. This allows it to re-use
* an existing Loader's data if there already is one, so that for example
* when an {@link android.app.Activity} is re-created after a configuration change it
* does not need to re-create its loaders.
* <p/>
* <p>Note that in the case where an existing Loader is re-used, the
* <var>args</var> given here <em>will be ignored</em> because you will
* continue using the previous Loader.
*
* @param id A unique (to this LoaderManager instance) identifier under
* which to manage the new Loader.
* @param args Optional arguments that will be propagated to
* {@link LoaderCallbacks#onCreateLoader(int, android.os.Bundle) LoaderCallbacks
* .onCreateLoader()}.
* @param callback Interface implementing management of this Loader. Required.
* Its onCreateLoader() method will be called while inside of the function to
* instantiate the Loader object.
*/
@SuppressWarnings("unchecked")
public <D> Loader<D> initLoader(int id, Bundle args, LoaderCallbacks<D> callback) {
if (mCreatingLoader) {
throw new IllegalStateException("Called while creating a loader");
}
LoaderInfo info = mLoaders.get(id);
if (DEBUG) Log.v(TAG, "initLoader in " + this + ": args=" + args);
if (info == null) {
// Loader doesn't already exist; create.
info = createAndInstallLoader(id, args, (LoaderCallbacks<Object>) callback);
if (DEBUG) Log.v(TAG, " Created new loader " + info);
} else {
if (DEBUG) Log.v(TAG, " Re-using existing loader " + info);
info.mCallbacks = (LoaderCallbacks<Object>) callback;
}
if (info.mHaveData && mStarted) {
// If the loader has already generated its data, report it now.
info.callOnLoadFinished(info.mLoader, info.mData);
}
return (Loader<D>) info.mLoader;
}
private LoaderInfo createAndInstallLoader(int id, Bundle args,
LoaderCallbacks<Object> callback) {
try {
mCreatingLoader = true;
LoaderInfo info = createLoader(id, args, callback);
installLoader(info);
return info;
} finally {
mCreatingLoader = false;
}
}
private LoaderInfo createLoader(int id, Bundle args,
LoaderCallbacks<Object> callback) {
LoaderInfo info = new LoaderInfo(id, args, callback);
Loader<Object> loader = callback.onCreateLoader(id, args);
info.mLoader = loader;
return info;
}
void installLoader(LoaderInfo info) {
mLoaders.put(info.mId, info);
if (mStarted) {
// The activity will start all existing loaders in it's onStart(),
// so only start them here if we're past that point of the activitiy's
// life cycle
info.start();
}
}
/**
* Call to re-create the Loader associated with a particular ID. If there
* is currently a Loader associated with this ID, it will be
* canceled/stopped/destroyed as appropriate. A new Loader with the given
* arguments will be created and its data delivered to you once available.
* <p/>
* <p>This function does some throttling of Loaders. If too many Loaders
* have been created for the given ID but not yet generated their data,
* new calls to this function will create and return a new Loader but not
* actually start it until some previous loaders have completed.
* <p/>
* <p>After calling this function, any previous Loaders associated with
* this ID will be considered invalid, and you will receive no further
* data updates from them.
*
* @param id A unique (to this LoaderManager instance) identifier under
* which to manage the new Loader.
* @param args Optional arguments that will be propagated to
* {@link LoaderCallbacks#onCreateLoader(int, Bundle) LoaderCallbacks
* .onCreateLoader()}.
* @param callback Interface implementing management of this Loader. Required.
* Its onCreateLoader() method will be called while inside of the function to
* instantiate the Loader object.
*/
@SuppressWarnings("unchecked")
public <D> Loader<D> restartLoader(int id, Bundle args, LoaderCallbacks<D> callback) {
if (mCreatingLoader) {
throw new IllegalStateException("Called while creating a loader");
}
LoaderInfo info = mLoaders.get(id);
if (DEBUG) Log.v(TAG, "restartLoader in " + this + ": args=" + args);
if (info != null) {
LoaderInfo inactive = mInactiveLoaders.get(id);
if (inactive != null) {
if (info.mHaveData) {
// This loader now has data... we are probably being
// called from within onLoadComplete, where we haven't
// yet destroyed the last inactive loader. So just do
// that now.
if (DEBUG) Log.v(TAG, " Removing last inactive loader: " + info);
inactive.mDeliveredData = false;
inactive.destroy();
info.mLoader.abandon();
mInactiveLoaders.put(id, info);
} else {
// We already have an inactive loader for this ID that we are
// waiting for! What to do, what to do...
if (!info.mStarted) {
// The current Loader has not been started... we thus
// have no reason to keep it around, so bam, slam,
// thank-you-ma'am.
if (DEBUG) Log.v(TAG, " Current loader is stopped; replacing");
mLoaders.put(id, null);
info.destroy();
} else {
// Now we have three active loaders... we'll queue
// up this request to be processed once one of the other loaders
// finishes.
if (info.mPendingLoader != null) {
if (DEBUG) {
Log.v(TAG, " Removing pending loader: " + info.mPendingLoader);
}
info.mPendingLoader.destroy();
info.mPendingLoader = null;
}
if (DEBUG) Log.v(TAG, " Enqueuing as new pending loader");
info.mPendingLoader = createLoader(id, args,
(LoaderCallbacks<Object>) callback);
return (Loader<D>) info.mPendingLoader.mLoader;
}
}
} else {
// Keep track of the previous instance of this loader so we can destroy
// it when the new one completes.
if (DEBUG) Log.v(TAG, " Making last loader inactive: " + info);
info.mLoader.abandon();
mInactiveLoaders.put(id, info);
}
}
info = createAndInstallLoader(id, args, (LoaderCallbacks<Object>) callback);
return (Loader<D>) info.mLoader;
}
/**
* Rip down, tear apart, shred to pieces a current Loader ID. After returning
* from this function, any Loader objects associated with this ID are
* destroyed. Any data associated with them is destroyed. You better not
* be using it when you do this.
*
* @param id Identifier of the Loader to be destroyed.
*/
public void destroyLoader(int id) {
if (mCreatingLoader) {
throw new IllegalStateException("Called while creating a loader");
}
if (DEBUG) Log.v(TAG, "destroyLoader in " + this + " of " + id);
int idx = mLoaders.indexOfKey(id);
if (idx >= 0) {
LoaderInfo info = mLoaders.valueAt(idx);
mLoaders.removeAt(idx);
info.destroy();
}
idx = mInactiveLoaders.indexOfKey(id);
if (idx >= 0) {
LoaderInfo info = mInactiveLoaders.valueAt(idx);
mInactiveLoaders.removeAt(idx);
info.destroy();
}
}
/**
* Return the most recent Loader object associated with the
* given ID.
*/
@SuppressWarnings("unchecked")
public <D> Loader<D> getLoader(int id) {
if (mCreatingLoader) {
throw new IllegalStateException("Called while creating a loader");
}
LoaderInfo loaderInfo = mLoaders.get(id);
if (loaderInfo != null) {
if (loaderInfo.mPendingLoader != null) {
return (Loader<D>) loaderInfo.mPendingLoader.mLoader;
}
return (Loader<D>) loaderInfo.mLoader;
}
return null;
}
@Override
public void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) {
if (mLoaders.size() > 0) {
writer.print(prefix);
writer.println("Active Loaders:");
String innerPrefix = prefix + " ";
for (int i = 0; i < mLoaders.size(); i++) {
LoaderInfo li = mLoaders.valueAt(i);
writer.print(prefix);
writer.print(" #");
writer.print(mLoaders.keyAt(i));
writer.print(": ");
writer.println(li.toString());
li.dump(innerPrefix, fd, writer, args);
}
}
if (mInactiveLoaders.size() > 0) {
writer.print(prefix);
writer.println("Inactive Loaders:");
String innerPrefix = prefix + " ";
for (int i = 0; i < mInactiveLoaders.size(); i++) {
LoaderInfo li = mInactiveLoaders.valueAt(i);
writer.print(prefix);
writer.print(" #");
writer.print(mInactiveLoaders.keyAt(i));
writer.print(": ");
writer.println(li.toString());
li.dump(innerPrefix, fd, writer, args);
}
}
}
@Override
public boolean hasRunningLoaders() {
boolean loadersRunning = false;
final int count = mLoaders.size();
for (int i = 0; i < count; i++) {
final LoaderInfo li = mLoaders.valueAt(i);
loadersRunning |= li.mStarted && !li.mDeliveredData;
}
return loadersRunning;
}
public boolean isStarted() {
return mStarted;
}
void doStart() {
if (DEBUG) Log.v(TAG, "Starting in " + this);
if (mStarted) {
RuntimeException e = new RuntimeException("here");
e.fillInStackTrace();
Log.w(TAG, "Called doStart when already started: " + this, e);
return;
}
mStarted = true;
// Call out to sub classes so they can start their loaders
// Let the existing loaders know that we want to be notified when a load is complete
for (int i = mLoaders.size() - 1; i >= 0; i--) {
mLoaders.valueAt(i).start();
}
// added by me
doReportStart();
}
void doReportStart() {
for (int i = mLoaders.size() - 1; i >= 0; i--) {
mLoaders.valueAt(i).reportStart();
}
}
void doStop() {
if (DEBUG) Log.v(TAG, "Stopping in " + this);
if (!mStarted) {
RuntimeException e = new RuntimeException("here");
e.fillInStackTrace();
Log.w(TAG, "Called doStop when not started: " + this, e);
return;
}
for (int i = mLoaders.size() - 1; i >= 0; i--) {
mLoaders.valueAt(i).stop();
}
mStarted = false;
// added by me
doReportNextStart();
}
void doReportNextStart() {
for (int i = mLoaders.size() - 1; i >= 0; i--) {
mLoaders.valueAt(i).mReportNextStart = true;
}
}
void doRetain() {
if (DEBUG) Log.v(TAG, "Retaining in " + this);
if (!mStarted) {
RuntimeException e = new RuntimeException("here");
e.fillInStackTrace();
Log.w(TAG, "Called doRetain when not started: " + this, e);
return;
}
mRetaining = true;
mStarted = false;
for (int i = mLoaders.size() - 1; i >= 0; i--) {
mLoaders.valueAt(i).retain();
}
}
void finishRetain() {
if (mRetaining) {
if (DEBUG) Log.v(TAG, "Finished Retaining in " + this);
mRetaining = false;
for (int i = mLoaders.size() - 1; i >= 0; i--) {
mLoaders.valueAt(i).finishRetain();
}
}
}
void doDestroy() {
if (!mRetaining) {
if (DEBUG) Log.v(TAG, "Destroying Active in " + this);
for (int i = mLoaders.size() - 1; i >= 0; i--) {
mLoaders.valueAt(i).destroy();
}
mLoaders.clear();
}
if (DEBUG) Log.v(TAG, "Destroying Inactive in " + this);
for (int i = mInactiveLoaders.size() - 1; i >= 0; i--) {
mInactiveLoaders.valueAt(i).destroy();
}
mInactiveLoaders.clear();
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder(128);
sb.append("LoaderManager{");
sb.append(Integer.toHexString(System.identityHashCode(this)));
sb.append(" in ");
DebugUtils.buildShortClassTag(mActivity, sb);
sb.append("}}");
return sb.toString();
}
final class LoaderInfo implements Loader.OnLoadCompleteListener<Object> {
final int mId;
final Bundle mArgs;
LoaderCallbacks<Object> mCallbacks;
Loader<Object> mLoader;
boolean mHaveData;
boolean mDeliveredData;
Object mData;
boolean mStarted;
boolean mRetaining;
boolean mRetainingStarted;
boolean mReportNextStart;
boolean mDestroyed;
boolean mListenerRegistered;
LoaderInfo mPendingLoader;
public LoaderInfo(int id, Bundle args, LoaderCallbacks<Object> callbacks) {
mId = id;
mArgs = args;
mCallbacks = callbacks;
}
void start() {
if (mRetaining && mRetainingStarted) {
// Our owner is started, but we were being retained from a
// previous instance in the started state... so there is really
// nothing to do here, since the loaders are still started.
mStarted = true;
return;
}
if (mStarted) {
// If loader already started, don't restart.
return;
}
mStarted = true;
if (DEBUG) Log.v(TAG, " Starting: " + this);
if (mLoader == null && mCallbacks != null) {
mLoader = mCallbacks.onCreateLoader(mId, mArgs);
}
if (mLoader != null) {
if (mLoader.getClass().isMemberClass()
&& !Modifier.isStatic(mLoader.getClass().getModifiers())) {
throw new IllegalArgumentException(
"Object returned from onCreateLoader must not be a non-static inner " +
"member class: "
+ mLoader);
}
if (!mListenerRegistered) {
mLoader.registerListener(mId, this);
mListenerRegistered = true;
}
mLoader.startLoading();
}
}
void retain() {
if (DEBUG) Log.v(TAG, " Retaining: " + this);
mRetaining = true;
mRetainingStarted = mStarted;
mStarted = false;
mCallbacks = null;
}
void finishRetain() {
if (mRetaining) {
if (DEBUG) Log.v(TAG, " Finished Retaining: " + this);
mRetaining = false;
if (mStarted != mRetainingStarted) {
if (!mStarted) {
// This loader was retained in a started state, but
// at the end of retaining everything our owner is
// no longer started... so make it stop.
stop();
}
}
}
if (mStarted && mHaveData && !mReportNextStart) {
// This loader has retained its data, either completely across
// a configuration change or just whatever the last data set
// was after being restarted from a stop, and now at the point of
// finishing the retain we find we remain started, have
// our data, and the owner has a new callback... so
// let's deliver the data now.
callOnLoadFinished(mLoader, mData);
}
}
void stop() {
if (DEBUG) Log.v(TAG, " Stopping: " + this);
mStarted = false;
if (!mRetaining) {
if (mLoader != null && mListenerRegistered) {
// Let the loader know we're done with it
mListenerRegistered = false;
mLoader.unregisterListener(this);
mLoader.stopLoading();
}
}
}
void callOnLoadFinished(Loader<Object> loader, Object data) {
if (mCallbacks != null) {
if (DEBUG) {
Log.v(TAG, " onLoadFinished in " + loader + ": "
+ loader.dataToString(data));
}
mCallbacks.onLoadFinished(loader, data);
mDeliveredData = true;
}
}
void reportStart() {
if (mStarted) {
if (mReportNextStart) {
mReportNextStart = false;
if (mHaveData) {
callOnLoadFinished(mLoader, mData);
}
}
}
}
void destroy() {
if (DEBUG) Log.v(TAG, " Destroying: " + this);
mDestroyed = true;
boolean needReset = mDeliveredData;
mDeliveredData = false;
if (mCallbacks != null && mLoader != null && mHaveData && needReset) {
if (DEBUG) Log.v(TAG, " Reseting: " + this);
mCallbacks.onLoaderReset(mLoader);
}
mCallbacks = null;
mData = null;
mHaveData = false;
if (mLoader != null) {
if (mListenerRegistered) {
mListenerRegistered = false;
mLoader.unregisterListener(this);
}
mLoader.reset();
}
if (mPendingLoader != null) {
mPendingLoader.destroy();
}
}
@Override
public void onLoadComplete(Loader<Object> loader, Object data) {
if (DEBUG) Log.v(TAG, "onLoadComplete: " + this);
if (mDestroyed) {
if (DEBUG) Log.v(TAG, " Ignoring load complete -- destroyed");
return;
}
if (mLoaders.get(mId) != this) {
// This data is not coming from the current active loader.
// We don't care about it.
if (DEBUG) Log.v(TAG, " Ignoring load complete -- not active");
return;
}
LoaderInfo pending = mPendingLoader;
if (pending != null) {
// There is a new request pending and we were just
// waiting for the old one to complete before starting
// it. So now it is time, switch over to the new loader.
if (DEBUG) Log.v(TAG, " Switching to pending loader: " + pending);
mPendingLoader = null;
mLoaders.put(mId, null);
destroy();
installLoader(pending);
return;
}
// Notify of the new data so the app can switch out the old data before
// we try to destroy it.
if (mData != data || !mHaveData) {
mData = data;
mHaveData = true;
if (mStarted) {
callOnLoadFinished(loader, data);
}
}
//if (DEBUG) Log.v(TAG, " onLoadFinished returned: " + this);
// We have now given the application the new loader with its
// loaded data, so it should have stopped using the previous
// loader. If there is a previous loader on the inactive list,
// clean it up.
LoaderInfo info = mInactiveLoaders.get(mId);
if (info != null && info != this) {
info.mDeliveredData = false;
info.destroy();
mInactiveLoaders.remove(mId);
}
}
public void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) {
writer.print(prefix);
writer.print("mId=");
writer.print(mId);
writer.print(" mArgs=");
writer.println(mArgs);
writer.print(prefix);
writer.print("mCallbacks=");
writer.println(mCallbacks);
writer.print(prefix);
writer.print("mLoader=");
writer.println(mLoader);
if (mLoader != null) {
mLoader.dump(prefix + " ", fd, writer, args);
}
if (mHaveData || mDeliveredData) {
writer.print(prefix);
writer.print("mHaveData=");
writer.print(mHaveData);
writer.print(" mDeliveredData=");
writer.println(mDeliveredData);
writer.print(prefix);
writer.print("mData=");
writer.println(mData);
}
writer.print(prefix);
writer.print("mStarted=");
writer.print(mStarted);
writer.print(" mReportNextStart=");
writer.print(mReportNextStart);
writer.print(" mDestroyed=");
writer.println(mDestroyed);
writer.print(prefix);
writer.print("mRetaining=");
writer.print(mRetaining);
writer.print(" mRetainingStarted=");
writer.print(mRetainingStarted);
writer.print(" mListenerRegistered=");
writer.println(mListenerRegistered);
if (mPendingLoader != null) {
writer.print(prefix);
writer.println("Pending Loader ");
writer.print(mPendingLoader);
writer.println(":");
mPendingLoader.dump(prefix + " ", fd, writer, args);
}
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder(64);
sb.append("LoaderInfo{");
sb.append(Integer.toHexString(System.identityHashCode(this)));
sb.append(" #");
sb.append(mId);
sb.append(" : ");
DebugUtils.buildShortClassTag(mLoader, sb);
sb.append("}}");
return sb.toString();
}
}
}