base/runtime/org.argeo.util/src/main/java/org/argeo/ArgeoMonitor.java

   1 package org.argeo;
   2
   3 /**
   4  * Simple monitor abstraction. Inspired by Eclipse IProgressMOnitor, but without
   5  * dependency to it.
   6  */
   7 public interface ArgeoMonitor {
   8         /**
   9          * Constant indicating an unknown amount of work.
  10          */
  11         public final static int UNKNOWN = -1;
  12
  13         /**
  14          * Notifies that the main task is beginning. This must only be called once
  15          * on a given progress monitor instance.
  16          *
  17          * @param name
  18          *            the name (or description) of the main task
  19          * @param totalWork
  20          *            the total number of work units into which the main task is
  21          *            been subdivided. If the value is <code>UNKNOWN</code> the
  22          *            implementation is free to indicate progress in a way which
  23          *            doesn't require the total number of work units in advance.
  24          */
  25         public void beginTask(String name, int totalWork);
  26
  27         /**
  28          * Notifies that the work is done; that is, either the main task is
  29          * completed or the user canceled it. This method may be called more than
  30          * once (implementations should be prepared to handle this case).
  31          */
  32         public void done();
  33
  34         /**
  35          * Returns whether cancelation of current operation has been requested.
  36          * Long-running operations should poll to see if cancelation has been
  37          * requested.
  38          *
  39          * @return <code>true</code> if cancellation has been requested, and
  40          *         <code>false</code> otherwise
  41          * @see #setCanceled(boolean)
  42          */
  43         public boolean isCanceled();
  44
  45         /**
  46          * Sets the cancel state to the given value.
  47          *
  48          * @param value
  49          *            <code>true</code> indicates that cancelation has been
  50          *            requested (but not necessarily acknowledged);
  51          *            <code>false</code> clears this flag
  52          * @see #isCanceled()
  53          */
  54         public void setCanceled(boolean value);
  55
  56         /**
  57          * Sets the task name to the given value. This method is used to restore the
  58          * task label after a nested operation was executed. Normally there is no
  59          * need for clients to call this method.
  60          *
  61          * @param name
  62          *            the name (or description) of the main task
  63          * @see #beginTask(java.lang.String, int)
  64          */
  65         public void setTaskName(String name);
  66
  67         /**
  68          * Notifies that a subtask of the main task is beginning. Subtasks are
  69          * optional; the main task might not have subtasks.
  70          *
  71          * @param name
  72          *            the name (or description) of the subtask
  73          */
  74         public void subTask(String name);
  75
  76         /**
  77          * Notifies that a given number of work unit of the main task has been
  78          * completed. Note that this amount represents an installment, as opposed to
  79          * a cumulative amount of work done to date.
  80          *
  81          * @param work
  82          *            a non-negative number of work units just completed
  83          */
  84         public void worked(int work);
  85
  86 }