org.argeo.util/src/org/argeo/ArgeoMonitor.java

   1 /*
   2  * Copyright (C) 2007-2012 Argeo GmbH
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *         http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package org.argeo;
  17
  18 /**
  19  * Simple monitor abstraction. Inspired by Eclipse IProgressMOnitor, but without
  20  * dependency to it.
  21  */
  22 public interface ArgeoMonitor {
  23         /**
  24          * Constant indicating an unknown amount of work.
  25          */
  26         public final static int UNKNOWN = -1;
  27
  28         /**
  29          * Notifies that the main task is beginning. This must only be called once
  30          * on a given progress monitor instance.
  31          *
  32          * @param name
  33          *            the name (or description) of the main task
  34          * @param totalWork
  35          *            the total number of work units into which the main task is
  36          *            been subdivided. If the value is <code>UNKNOWN</code> the
  37          *            implementation is free to indicate progress in a way which
  38          *            doesn't require the total number of work units in advance.
  39          */
  40         public void beginTask(String name, int totalWork);
  41
  42         /**
  43          * Notifies that the work is done; that is, either the main task is
  44          * completed or the user canceled it. This method may be called more than
  45          * once (implementations should be prepared to handle this case).
  46          */
  47         public void done();
  48
  49         /**
  50          * Returns whether cancelation of current operation has been requested.
  51          * Long-running operations should poll to see if cancelation has been
  52          * requested.
  53          *
  54          * @return <code>true</code> if cancellation has been requested, and
  55          *         <code>false</code> otherwise
  56          * @see #setCanceled(boolean)
  57          */
  58         public boolean isCanceled();
  59
  60         /**
  61          * Sets the cancel state to the given value.
  62          *
  63          * @param value
  64          *            <code>true</code> indicates that cancelation has been
  65          *            requested (but not necessarily acknowledged);
  66          *            <code>false</code> clears this flag
  67          * @see #isCanceled()
  68          */
  69         public void setCanceled(boolean value);
  70
  71         /**
  72          * Sets the task name to the given value. This method is used to restore the
  73          * task label after a nested operation was executed. Normally there is no
  74          * need for clients to call this method.
  75          *
  76          * @param name
  77          *            the name (or description) of the main task
  78          * @see #beginTask(java.lang.String, int)
  79          */
  80         public void setTaskName(String name);
  81
  82         /**
  83          * Notifies that a subtask of the main task is beginning. Subtasks are
  84          * optional; the main task might not have subtasks.
  85          *
  86          * @param name
  87          *            the name (or description) of the subtask
  88          */
  89         public void subTask(String name);
  90
  91         /**
  92          * Notifies that a given number of work unit of the main task has been
  93          * completed. Note that this amount represents an installment, as opposed to
  94          * a cumulative amount of work done to date.
  95          *
  96          * @param work
  97          *            a non-negative number of work units just completed
  98          */
  99         public void worked(int work);
 100
 101 }