org.spearce.jgit/src/org/spearce/jgit/lib/ProgressMonitor.java

   1 /*
   2  *  Copyright (C) 2007  Robin Rosenberg
   3  *
   4  *  This library is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU General Public
   6  *  License, version 2, as published by the Free Software Foundation.
   7  *
   8  *  This library 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 GNU
  11  *  General Public License for more details.
  12  *
  13  *  You should have received a copy of the GNU General Public
  14  *  License along with this library; if not, write to the Free Software
  15  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301
  16  */
  17 package org.spearce.jgit.lib;
  18
  19 /** A progress reporting interface. */
  20 public interface ProgressMonitor {
  21         /** Constant indicating the total work units cannot be predicted. */
  22         public static final int UNKNOWN = 0;
  23
  24         /**
  25          * Advise the monitor of the total number of subtasks.
  26          * <p>
  27          * This should be invoked at most once per progress monitor interface.
  28          *
  29          * @param totalTasks
  30          *            the total number of tasks the caller will need to complete
  31          *            their processing.
  32          */
  33         void start(int totalTasks);
  34
  35         /**
  36          * Begin processing a single task.
  37          *
  38          * @param title
  39          *            title to describe the task. Callers should publish these as
  40          *            stable string constants that implementations could match
  41          *            against for translation support.
  42          * @param totalWork
  43          *            total number of work units the application will perform;
  44          *            {@link #UNKNOWN} if it cannot be predicted in advance.
  45          */
  46         void beginTask(String title, int totalWork);
  47
  48         /**
  49          * Denote that some work units have been completed.
  50          * <p>
  51          * This is an incremental update; if invoked once per work unit the correct
  52          * value for our argument is <code>1</code>, to indicate a single unit of
  53          * work has been finished by the caller.
  54          *
  55          * @param completed
  56          *            the number of work units completed since the last call.
  57          */
  58         void update(int completed);
  59
  60         /** Finish the current task, so the next can begin. */
  61         void endTask();
  62
  63         /**
  64          * Check for user task cancellation.
  65          *
  66          * @return true if the user asked the process to stop working.
  67          */
  68         boolean isCancelled();
  69 }