comparison src/org/tmatesoft/hg/internal/LifecycleBridge.java @ 520:1ee452f31187

Experimental support for inverse direction history walking. Refactored/streamlined cancellation in HgLogCommand and down the stack
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Fri, 21 Dec 2012 21:20:26 +0100
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519:934037edbea0 520:1ee452f31187
1 /*
2 * Copyright (c) 2012 TMate Software Ltd
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; version 2 of the License.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * For information on how to redistribute this software under
14 * the terms of a license other than GNU General Public License
15 * contact TMate Software at support@hg4j.com
16 */
17 package org.tmatesoft.hg.internal;
18
19 import org.tmatesoft.hg.util.CancelSupport;
20 import org.tmatesoft.hg.util.CancelledException;
21 import org.tmatesoft.hg.util.ProgressSupport;
22
23 /**
24 * Bridge low-level life-cycle ({@link Lifecycle}) API with high-level one ({@link ProgressSupport} and {@link CancelSupport}).
25 *
26 * @author Artem Tikhomirov
27 * @author TMate Software Ltd.
28 */
29 public class LifecycleBridge implements Lifecycle {
30 private final ProgressSupport progressHelper;
31 private final CancelSupport cancelSupport;
32 // may be null unless #start() is invoked
33 private Callback receiver;
34 private CancelledException cancellation;
35
36
37 public LifecycleBridge(ProgressSupport progress, CancelSupport cancel) {
38 progressHelper = progress;
39 cancelSupport = cancel;
40 }
41
42 public void start(int count, Callback callback, Object token) {
43 receiver = callback;
44 if (progressHelper != null) {
45 progressHelper.start(count);
46 }
47 }
48
49 public void finish(Object token) {
50 if (progressHelper != null) {
51 progressHelper.done();
52 }
53 receiver = null;
54 }
55
56 // XXX SHALL work without start/finish sequence because
57 // HgLogCommand invokes ChangesetTransformer#next directly (i.e. not from
58 // inside a library's #range() or similar) to process changesets in unnatural order.
59 public void nextStep() {
60 if (progressHelper != null) {
61 progressHelper.worked(1);
62 }
63 if (cancelSupport == null) {
64 return;
65 }
66 try {
67 cancelSupport.checkCancelled();
68 } catch (CancelledException ex) {
69 if (receiver != null) {
70 receiver.stop();
71 }
72 cancellation = ex;
73 }
74 }
75
76 public void stop() {
77 if (receiver != null) {
78 receiver.stop();
79 }
80 }
81
82 /**
83 * @return <code>true</code> iff {@link CancelledException} was thrown and catched. Forced stop doesn't count
84 */
85 public boolean isCancelled() {
86 return cancellation != null;
87 }
88
89 public CancelledException getCancelOrigin() {
90 return cancellation;
91 }
92 }