messageviewer/editorwatcher.cpp

   1 /*
   2     Copyright (c) 2007 Volker Krause <vkrause@kde.org>
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  17 */
  18
  19 #include <config-messageviewer.h>
  20 #include "editorwatcher.h"
  21 #include "autoqpointer.h"
  22
  23 #include <kdebug.h>
  24 #include <klocale.h>
  25 #include <kmessagebox.h>
  26 #include <kopenwithdialog.h>
  27 #include <kprocess.h>
  28 #include <kmimetypetrader.h>
  29 #include <krun.h>
  30
  31 #include <qsocketnotifier.h>
  32
  33 #include <cassert>
  34
  35 // inotify stuff taken from kdelibs/kio/kio/kdirwatch.cpp
  36 #ifdef HAVE_SYS_INOTIFY_H
  37 #include <unistd.h>
  38 #include <fcntl.h>
  39 #include <sys/inotify.h>
  40 #include <sys/ioctl.h>
  41 #endif
  42
  43 namespace MessageViewer {
  44 EditorWatcher::EditorWatcher( const KUrl & url, const QString &mimeType, bool openWith,
  45                               QObject * parent, QWidget *parentWidget ) :
  46     QObject( parent ),
  47     mUrl( url ),
  48     mMimeType( mimeType ),
  49     mOpenWith( openWith ),
  50     mEditor( 0 ),
  51     mParentWidget( parentWidget ),
  52     mHaveInotify( false ),
  53     mFileOpen( false ),
  54     mEditorRunning( false ),
  55     mFileModified( true ), // assume the worst unless we know better
  56     mDone( false )
  57 {
  58   assert( mUrl.isLocalFile() );
  59   mTimer.setSingleShot( true );
  60   connect( &mTimer, SIGNAL(timeout()), SLOT(checkEditDone()) );
  61 }
  62
  63 bool EditorWatcher::start()
  64 {
  65   // find an editor
  66   KUrl::List list;
  67   list.append( mUrl );
  68   KService::Ptr offer = KMimeTypeTrader::self()->preferredService( mMimeType, "Application" );
  69   if ( mOpenWith || !offer ) {
  70 #ifndef Q_OS_WINCE
  71     AutoQPointer<KOpenWithDialog> dlg( new KOpenWithDialog( list, i18n("Edit with:"),
  72                                                             QString(), mParentWidget ) );
  73     int dlgrc = dlg->exec();
  74     if ( dlgrc && dlg ) {
  75       offer = dlg->service();
  76     }
  77     if ( !dlgrc || !offer )
  78 #endif
  79       return false;
  80   }
  81
  82 #ifdef HAVE_SYS_INOTIFY_H
  83   // monitor file
  84   mInotifyFd = inotify_init();
  85   if ( mInotifyFd > 0 ) {
  86     mInotifyWatch = inotify_add_watch( mInotifyFd, mUrl.path().toLatin1(), IN_CLOSE | IN_OPEN | IN_MODIFY );
  87     if ( mInotifyWatch >= 0 ) {
  88       QSocketNotifier *sn = new QSocketNotifier( mInotifyFd, QSocketNotifier::Read, this );
  89       connect( sn, SIGNAL(activated(int)), SLOT(inotifyEvent()) );
  90       mHaveInotify = true;
  91       mFileModified = false;
  92     }
  93   } else {
  94     kWarning() << "Failed to activate INOTIFY!";
  95   }
  96 #endif
  97
  98   // start the editor
  99   QStringList params = KRun::processDesktopExec( *offer, list, false );
 100   mEditor = new KProcess( this );
 101   mEditor->setProgram( params );
 102   connect( mEditor, SIGNAL(finished(int,QProcess::ExitStatus)),
 103            SLOT(editorExited()) );
 104   mEditor->start();
 105   if ( !mEditor->waitForStarted() )
 106     return false;
 107   mEditorRunning = true;
 108
 109   mEditTime.start();
 110   return true;
 111 }
 112
 113 void EditorWatcher::inotifyEvent()
 114 {
 115   assert( mHaveInotify );
 116 #ifdef HAVE_SYS_INOTIFY_H
 117   int pending = -1;
 118   char buffer[4096];
 119   ioctl( mInotifyFd, FIONREAD, &pending );
 120   while ( pending > 0 ) {
 121     int size = read( mInotifyFd, buffer, qMin( pending, (int)sizeof(buffer) ) );
 122     pending -= size;
 123     if ( size < 0 )
 124       break; // error
 125     int offset = 0;
 126     while ( size > 0 ) {
 127       struct inotify_event *event = (struct inotify_event *) &buffer[offset];
 128       size -= sizeof( struct inotify_event ) + event->len;
 129       offset += sizeof( struct inotify_event ) + event->len;
 130       if ( event->mask & IN_OPEN )
 131         mFileOpen = true;
 132       if ( event->mask & IN_CLOSE )
 133         mFileOpen = false;
 134       if ( event->mask & IN_MODIFY )
 135         mFileModified = true;
 136     }
 137   }
 138 #endif
 139   mTimer.start( 500 );
 140
 141 }
 142
 143 void EditorWatcher::editorExited()
 144 {
 145   mEditorRunning = false;
 146   mTimer.start( 500 );
 147 }
 148
 149 void EditorWatcher::checkEditDone()
 150 {
 151   if ( mEditorRunning || (mFileOpen && mHaveInotify) || mDone )
 152     return;
 153
 154   static QStringList readOnlyMimeTypes;
 155   if ( readOnlyMimeTypes.isEmpty() ) {
 156     readOnlyMimeTypes << "message/rfc822"
 157                       << "application/pdf";
 158   }
 159
 160   // protect us against double-deletion by calling this method again while
 161   // the subeventloop of the message box is running
 162   mDone = true;
 163
 164   // check if it's a mime type that's mostly handled read-only
 165   const bool isReadOnlyMimeType = ( readOnlyMimeTypes.contains( mMimeType ) ||
 166                                     mMimeType.startsWith( "image/" ) );
 167
 168   // nobody can edit that fast, we seem to be unable to detect
 169   // when the editor will be closed
 170   if ( mEditTime.elapsed() <= 3000 && !isReadOnlyMimeType ) {
 171     KMessageBox::information( mParentWidget,
 172                         i18n( "KMail is unable to detect when the chosen editor is closed. "
 173                               "To avoid data loss, editing the attachment will be aborted." ),
 174                         i18n( "Unable to edit attachment" ),
 175                         "UnableToEditAttachment" );
 176   }
 177
 178   emit editDone( this );
 179   deleteLater();
 180 }
 181 }
 182 #include "editorwatcher.moc"