| /* |
| * Copyright (C) 2016 The Android Open Source Project |
| * Copyright (C) 2016 Mopria Alliance, Inc. |
| * |
| * 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 com.android.bips; |
| |
| import android.print.PrintJobId; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** Manages a job queue, ensuring only one job is printed at a time */ |
| class JobQueue { |
| private final List<LocalPrintJob> mJobs = new ArrayList<>(); |
| private LocalPrintJob mCurrent; |
| |
| /** Queue a print job for printing at the next available opportunity */ |
| void print(LocalPrintJob job) { |
| mJobs.add(job); |
| startNextJob(); |
| } |
| |
| /** Cancel a previously queued job */ |
| void cancel(PrintJobId id) { |
| // If a job hasn't started, kill it instantly. |
| for (LocalPrintJob job : mJobs) { |
| if (job.getPrintJobId().equals(id)) { |
| mJobs.remove(job); |
| job.getPrintJob().cancel(); |
| return; |
| } |
| } |
| |
| if (mCurrent.getPrintJobId().equals(id)) { |
| mCurrent.cancel(); |
| } |
| } |
| |
| /** Launch the next job if possible */ |
| private void startNextJob() { |
| if (mJobs.isEmpty() || mCurrent != null) return; |
| |
| mCurrent = mJobs.remove(0); |
| mCurrent.start(job -> { |
| mCurrent = null; |
| startNextJob(); |
| }); |
| } |
| } |