/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.print;
import android.annotation.NonNull;
import android.annotation.Nullable;
import android.content.Context;
import android.content.pm.ParceledListSlice;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.os.RemoteException;
import android.util.ArrayMap;
import android.util.Log;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
/**
* @hide
*/
public final class PrinterDiscoverySession {
private static final String LOG_TAG ="PrinterDiscoverySession";
private static final int MSG_PRINTERS_ADDED = 1;
private static final int MSG_PRINTERS_REMOVED = 2;
private final LinkedHashMap<PrinterId, PrinterInfo> mPrinters =
new LinkedHashMap<PrinterId, PrinterInfo>();
private final IPrintManager mPrintManager;
private final int mUserId;
private final Handler mHandler;
private IPrinterDiscoveryObserver mObserver;
private OnPrintersChangeListener mListener;
private boolean mIsPrinterDiscoveryStarted;
public static interface OnPrintersChangeListener {
public void onPrintersChanged();
}
PrinterDiscoverySession(IPrintManager printManager, Context context, int userId) {
mPrintManager = printManager;
mUserId = userId;
mHandler = new SessionHandler(context.getMainLooper());
mObserver = new PrinterDiscoveryObserver(this);
try {
mPrintManager.createPrinterDiscoverySession(mObserver, mUserId);
} catch (RemoteException re) {
Log.e(LOG_TAG, "Error creating printer discovery session", re);
}
}
public final void startPrinterDiscovery(@Nullable List<PrinterId> priorityList) {
if (isDestroyed()) {
Log.w(LOG_TAG, "Ignoring start printers discovery - session destroyed");
return;
}
if (!mIsPrinterDiscoveryStarted) {
mIsPrinterDiscoveryStarted = true;
try {
mPrintManager.startPrinterDiscovery(mObserver, priorityList, mUserId);
} catch (RemoteException re) {
Log.e(LOG_TAG, "Error starting printer discovery", re);
}
}
}
public final void stopPrinterDiscovery() {
if (isDestroyed()) {
Log.w(LOG_TAG, "Ignoring stop printers discovery - session destroyed");
return;
}
if (mIsPrinterDiscoveryStarted) {
mIsPrinterDiscoveryStarted = false;
try {
mPrintManager.stopPrinterDiscovery(mObserver, mUserId);
} catch (RemoteException re) {
Log.e(LOG_TAG, "Error stopping printer discovery", re);
}
}
}
public final void startPrinterStateTracking(@NonNull PrinterId printerId) {
if (isDestroyed()) {
Log.w(LOG_TAG, "Ignoring start printer state tracking - session destroyed");
return;
}
try {
mPrintManager.startPrinterStateTracking(printerId, mUserId);
} catch (RemoteException re) {
Log.e(LOG_TAG, "Error starting printer state tracking", re);
}
}
public final void stopPrinterStateTracking(@NonNull PrinterId printerId) {
if (isDestroyed()) {
Log.w(LOG_TAG, "Ignoring stop printer state tracking - session destroyed");
return;
}
try {
mPrintManager.stopPrinterStateTracking(printerId, mUserId);
} catch (RemoteException re) {
Log.e(LOG_TAG, "Error stopping printer state tracking", re);
}
}
public final void validatePrinters(List<PrinterId> printerIds) {
if (isDestroyed()) {
Log.w(LOG_TAG, "Ignoring validate printers - session destroyed");
return;
}
try {
mPrintManager.validatePrinters(printerIds, mUserId);
} catch (RemoteException re) {
Log.e(LOG_TAG, "Error validating printers", re);
}
}
public final void destroy() {
if (isDestroyed()) {
Log.w(LOG_TAG, "Ignoring destroy - session destroyed");
}
destroyNoCheck();
}
public final List<PrinterInfo> getPrinters() {
if (isDestroyed()) {
Log.w(LOG_TAG, "Ignoring get printers - session destroyed");
return Collections.emptyList();
}
return new ArrayList<PrinterInfo>(mPrinters.values());
}
public final boolean isDestroyed() {
throwIfNotCalledOnMainThread();
return isDestroyedNoCheck();
}
public final boolean isPrinterDiscoveryStarted() {
throwIfNotCalledOnMainThread();
return mIsPrinterDiscoveryStarted;
}
public final void setOnPrintersChangeListener(OnPrintersChangeListener listener) {
throwIfNotCalledOnMainThread();
mListener = listener;
}
@Override
protected final void finalize() throws Throwable {
if (!isDestroyedNoCheck()) {
Log.e(LOG_TAG, "Destroying leaked printer discovery session");
destroyNoCheck();
}
super.finalize();
}
private boolean isDestroyedNoCheck() {
return (mObserver == null);
}
private void destroyNoCheck() {
stopPrinterDiscovery();
try {
mPrintManager.destroyPrinterDiscoverySession(mObserver, mUserId);
} catch (RemoteException re) {
Log.e(LOG_TAG, "Error destroying printer discovery session", re);
} finally {
mObserver = null;
mPrinters.clear();
}
}
private void handlePrintersAdded(List<PrinterInfo> addedPrinters) {
if (isDestroyed()) {
return;
}
// No old printers - do not bother keeping their position.
if (mPrinters.isEmpty()) {
final int printerCount = addedPrinters.size();
for (int i = 0; i < printerCount; i++) {
PrinterInfo printer = addedPrinters.get(i);
mPrinters.put(printer.getId(), printer);
}
notifyOnPrintersChanged();
return;
}
// Add the printers to a map.
ArrayMap<PrinterId, PrinterInfo> addedPrintersMap =
new ArrayMap<PrinterId, PrinterInfo>();
final int printerCount = addedPrinters.size();
for (int i = 0; i < printerCount; i++) {
PrinterInfo printer = addedPrinters.get(i);
addedPrintersMap.put(printer.getId(), printer);
}
// Update printers we already have.
for (PrinterId oldPrinterId : mPrinters.keySet()) {
PrinterInfo updatedPrinter = addedPrintersMap.remove(oldPrinterId);
if (updatedPrinter != null) {
mPrinters.put(oldPrinterId, updatedPrinter);
}
}
// Add the new printers, i.e. what is left.
mPrinters.putAll(addedPrintersMap);
// Announce the change.
notifyOnPrintersChanged();
}
private void handlePrintersRemoved(List<PrinterId> printerIds) {
if (isDestroyed()) {
return;
}
boolean printersChanged = false;
final int removedPrinterIdCount = printerIds.size();
for (int i = 0; i < removedPrinterIdCount; i++) {
PrinterId removedPrinterId = printerIds.get(i);
if (mPrinters.remove(removedPrinterId) != null) {
printersChanged = true;
}
}
if (printersChanged) {
notifyOnPrintersChanged();
}
}
private void notifyOnPrintersChanged() {
if (mListener != null) {
mListener.onPrintersChanged();
}
}
private static void throwIfNotCalledOnMainThread() {
if (!Looper.getMainLooper().isCurrentThread()) {
throw new IllegalAccessError("must be called from the main thread");
}
}
private final class SessionHandler extends Handler {
public SessionHandler(Looper looper) {
super(looper, null, false);
}
@Override
@SuppressWarnings("unchecked")
public void handleMessage(Message message) {
switch (message.what) {
case MSG_PRINTERS_ADDED: {
List<PrinterInfo> printers = (List<PrinterInfo>) message.obj;
handlePrintersAdded(printers);
} break;
case MSG_PRINTERS_REMOVED: {
List<PrinterId> printerIds = (List<PrinterId>) message.obj;
handlePrintersRemoved(printerIds);
} break;
}
}
}
public static final class PrinterDiscoveryObserver extends IPrinterDiscoveryObserver.Stub {
private final WeakReference<PrinterDiscoverySession> mWeakSession;
public PrinterDiscoveryObserver(PrinterDiscoverySession session) {
mWeakSession = new WeakReference<PrinterDiscoverySession>(session);
}
@Override
@SuppressWarnings("rawtypes")
public void onPrintersAdded(ParceledListSlice printers) {
PrinterDiscoverySession session = mWeakSession.get();
if (session != null) {
session.mHandler.obtainMessage(MSG_PRINTERS_ADDED,
printers.getList()).sendToTarget();
}
}
@Override
@SuppressWarnings("rawtypes")
public void onPrintersRemoved(ParceledListSlice printerIds) {
PrinterDiscoverySession session = mWeakSession.get();
if (session != null) {
session.mHandler.obtainMessage(MSG_PRINTERS_REMOVED,
printerIds.getList()).sendToTarget();
}
}
}
}