• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1/*
2 * Copyright (c) 2023-2023 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 *     http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16import Vector from '@ohos.util.Vector';
17import { Log, PrinterCapability } from '@ohos/common';
18import CheckEmptyUtils from '@ohos/common';
19import type { PrintServiceAdapter } from '../PrintServiceAdapter';
20import type DiscoveredPrinter from '../discovery/DiscoveredPrinter';
21import type { Backend } from '../ipp/Backend';
22import type uri from '@ohos.uri';
23
24const TAG = 'CapabilitiesCache';
25
26export class CapabilitiesCache {
27  private readonly mPrintServiceAdapter: PrintServiceAdapter;
28  private readonly mBackend: Backend;
29  private readonly requestVector: Vector<Request> = new Vector<Request>();
30  private currentRequest: Request;
31
32  constructor(printServiceAdapter: PrintServiceAdapter) {
33    this.mPrintServiceAdapter = printServiceAdapter;
34    this.mBackend = this.mPrintServiceAdapter.backend;
35  }
36
37  /**
38   * request printer caps
39   *
40   * @param printer
41   * @param onLocalPrinterCapabilities
42   */
43  public async requestCapabilities(printer: DiscoveredPrinter, onLocalPrinterCapabilities: OnLocalPrinterCapabilities): Promise<void> {
44    if (CheckEmptyUtils.isEmpty<DiscoveredPrinter>(printer)) {
45      Log.error(TAG, 'printer is empty');
46      return;
47    }
48    if (CheckEmptyUtils.isEmpty<uri.URI>(printer.getUri())) {
49      Log.error(TAG, 'uri is empty');
50      return;
51    }
52    let uri = printer.getUri();
53    Log.debug(TAG, 'caps not in cache, request from printer');
54    let request = new Request(this.mBackend, uri, printer.getDeviceName(), onLocalPrinterCapabilities);
55    this.requestVector.add(request);
56    this.startNextRequest();
57  }
58
59  private startNextRequest(): void {
60    Log.debug(TAG, 'startNextRequest enter');
61    if (this.requestVector.length === 0) {
62      Log.error(TAG, 'no active request in requestVector');
63      return;
64    }
65    if (this.currentRequest !== undefined) {
66      Log.error(TAG, 'a active request is running, requestVector len: ' + this.requestVector.length);
67      return;
68    }
69    this.currentRequest = this.requestVector.removeByIndex(0);
70    if (CheckEmptyUtils.isEmpty<Request>(this.currentRequest)) {
71      Log.error(TAG, 'currentRequest is empty');
72      return;
73    }
74    this.currentRequest.start(() => {
75      Log.info(TAG, 'Previous request complete, start next request');
76      this.currentRequest = undefined;
77      this.startNextRequest();
78    });
79  }
80
81  public close(): void {
82    Log.info(TAG, 'close');
83  }
84}
85
86class Request {
87  constructor(private backend: Backend, private uri: uri.URI, private printerName: string, private capsCallback: OnLocalPrinterCapabilities) {
88    this.backend = backend;
89    this.uri = uri;
90    this.printerName = printerName;
91    this.capsCallback = capsCallback;
92  }
93
94  public start(requestCallback: () => void): void {
95    this.backend.getCapabilities(this.uri, this.printerName, this.capsCallback, requestCallback);
96  }
97}
98
99
100/**
101 * Callback for receiving capabilities
102 */
103export interface OnLocalPrinterCapabilities {
104
105  /**
106  * Called when capabilities are retrieved
107  *
108  * @param capabilities PrinterCapability
109  */
110  onCapabilities(capabilities: PrinterCapability): void;
111
112}