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 <utility>
  16 #include <vcl/timer.hxx>
  17
  18 FileChangedChecker::FileChangedChecker(OUString aFilename,
  19         ::std::function<void ()> aCallback)
  20     : mTimer("SVTools FileChangedChecker Timer")
  21     , mFileName(std::move(aFilename))
  22     , mLastModTime()
  23     , mpCallback(std::move(aCallback))
  24 {
  25     // Get the current last file modified Status
  26     getCurrentModTime(mLastModTime);
  27
  28     // associate the callback function for the Timer
  29     mTimer.SetInvokeHandler(LINK(this, FileChangedChecker, TimerHandler));
  30
  31     // set timer interval
  32     mTimer.SetTimeout(100);
  33
  34     // start the timer
  35     resetTimer();
  36 }
  37
  38 FileChangedChecker::FileChangedChecker(OUString aFilename)
  39     : mTimer("")
  40     , mFileName(std::move(aFilename))
  41     , mLastModTime()
  42     , mpCallback(nullptr)
  43 {
  44     // Get the current last file modified Status
  45     getCurrentModTime(mLastModTime);
  46 }
  47
  48 void FileChangedChecker::resetTimer()
  49 {
  50     if (mpCallback == nullptr)
  51         return;
  52
  53     // Start the Idle if it's not active
  54     if (!mTimer.IsActive())
  55         mTimer.Start();
  56
  57     // Set lowest Priority
  58     mTimer.SetPriority(TaskPriority::LOWEST);
  59 }
  60
  61 bool FileChangedChecker::getCurrentModTime(TimeValue& o_rValue) const
  62 {
  63     // Need a Directory item to fetch file status
  64     osl::DirectoryItem aItem;
  65     if (osl::FileBase::E_None != osl::DirectoryItem::get(mFileName, aItem))
  66         return false;
  67
  68     // Retrieve the status - we are only interested in last File
  69     // Modified time
  70     osl::FileStatus aStatus( osl_FileStatus_Mask_ModifyTime );
  71     if (osl::FileBase::E_None != aItem.getFileStatus(aStatus))
  72         return false;
  73
  74     o_rValue = aStatus.getModifyTime();
  75     return true;
  76 }
  77
  78 bool FileChangedChecker::hasFileChanged(bool bUpdate)
  79 {
  80     // Get the current file Status
  81     TimeValue newTime={0,0};
  82     if( !getCurrentModTime(newTime) )
  83         return true; // well. hard to answer correctly here ...
  84
  85     // Check if the seconds time stamp has any difference
  86     // If so, then our file has changed meanwhile
  87     if( newTime.Seconds != mLastModTime.Seconds ||
  88         newTime.Nanosec != mLastModTime.Nanosec )
  89     {
  90         // Since the file has changed, set the new status as the file status and
  91         // return True
  92         if(bUpdate)
  93             mLastModTime = newTime ;
  94
  95         return true;
  96     }
  97     else
  98         return false;
  99 }
 100
 101 IMPL_LINK_NOARG(FileChangedChecker, TimerHandler, Timer *, void)
 102 {
 103     // If the file has changed, then update the graphic in the doc
 104     SAL_INFO("svtools", "Timeout Called");
 105     if(hasFileChanged())
 106     {
 107         SAL_INFO("svtools", "File modified");
 108         mpCallback();
 109     }
 110
 111     // Reset the Timer in any case
 112     resetTimer();
 113 }
 114
 115 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */