svtools/source/misc/filechangedchecker.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9
  10 #include <sal/config.h>
  11 #include <sal/log.hxx>
  12 #include <osl/file.hxx>
  13
  14 #include <svtools/filechangedchecker.hxx>
  15 #include <vcl/timer.hxx>
  16
  17 FileChangedChecker::FileChangedChecker(const OUString& rFilename,
  18         const ::std::function<void ()>& rCallback)
  19     : mTimer("SVTools FileChangedChecker Timer")
  20     , mFileName(rFilename)
  21     , mLastModTime()
  22     , mpCallback(rCallback)
  23 {
  24     // Get the curren last file modified Status
  25     getCurrentModTime(mLastModTime);
  26
  27     // associate the callback function for the Timer
  28     mTimer.SetInvokeHandler(LINK(this, FileChangedChecker, TimerHandler));
  29
  30     // set timer interval
  31     mTimer.SetTimeout(100);
  32
  33     // start the timer
  34     resetTimer();
  35 }
  36
  37 void FileChangedChecker::resetTimer()
  38 {
  39     // Start the Idle if it's not active
  40     if(!mTimer.IsActive())
  41         mTimer.Start();
  42
  43     // Set lowest Priority
  44     mTimer.SetPriority(TaskPriority::LOWEST);
  45 }
  46
  47 bool FileChangedChecker::getCurrentModTime(TimeValue& o_rValue) const
  48 {
  49     // Need a Directory item to fetch file status
  50     osl::DirectoryItem aItem;
  51     if (osl::FileBase::E_None != osl::DirectoryItem::get(mFileName, aItem))
  52         return false;
  53
  54     // Retrieve the status - we are only interested in last File
  55     // Modified time
  56     osl::FileStatus aStatus( osl_FileStatus_Mask_ModifyTime );
  57     if (osl::FileBase::E_None != aItem.getFileStatus(aStatus))
  58         return false;
  59
  60     o_rValue = aStatus.getModifyTime();
  61     return true;
  62 }
  63
  64 bool FileChangedChecker::hasFileChanged()
  65 {
  66     // Get the current file Status
  67     TimeValue newTime={0,0};
  68     if( !getCurrentModTime(newTime) )
  69         return true; // well. hard to answer correctly here ...
  70
  71     // Check if the seconds time stamp has any difference
  72     // If so, then our file has changed meanwhile
  73     if( newTime.Seconds != mLastModTime.Seconds ||
  74         newTime.Nanosec != mLastModTime.Nanosec )
  75     {
  76         // Since the file has changed, set the new status as the file status and
  77         // return True
  78         mLastModTime = newTime ;
  79
  80         return true;
  81     }
  82     else
  83         return false;
  84 }
  85
  86 IMPL_LINK_NOARG(FileChangedChecker, TimerHandler, Timer *, void)
  87 {
  88     // If the file has changed, then update the graphic in the doc
  89     SAL_INFO("svtools", "Timeout Called");
  90     if(hasFileChanged())
  91     {
  92         SAL_INFO("svtools", "File modified");
  93         mpCallback();
  94     }
  95
  96     // Reset the Timer in any case
  97     resetTimer();
  98 }
  99
 100 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */