Unify common functions for finding tags.

Several classes have exactly identical functions for finding tags.
This also hides the functions from public headers.

13 files changed, 146 insertions, 201 deletions

diff --git a/taglib/CMakeLists.txt b/taglib/CMakeLists.txt
index 31e2c49b..5a047bf1 100644
--- a/taglib/CMakeLists.txt
+++ b/taglib/CMakeLists.txt
@@ -334,6 +334,7 @@ set(tag_LIB_SRCS
   tagunion.cpp
   fileref.cpp
   audioproperties.cpp
+  tagutils.cpp
 )
 
 add_library(tag ${tag_LIB_SRCS} ${tag_HDRS})
diff --git a/taglib/ape/apefile.cpp b/taglib/ape/apefile.cpp
index 1349dfa3..caefe737 100644
--- a/taglib/ape/apefile.cpp
+++ b/taglib/ape/apefile.cpp
@@ -38,9 +38,9 @@
 #include <id3v1tag.h>
 #include <id3v2header.h>
 #include <tpropertymap.h>
+#include <tagutils.h>
 
 #include "apefile.h"
-
 #include "apetag.h"
 #include "apefooter.h"
 
@@ -258,7 +258,7 @@ void APE::File::read(bool readProperties)
 {
   // Look for an ID3v2 tag
 
-  d->ID3v2Location = findID3v2();
+  d->ID3v2Location = Utils::findID3v2(this);
 
   if(d->ID3v2Location >= 0) {
     seek(d->ID3v2Location);
@@ -269,7 +269,7 @@ void APE::File::read(bool readProperties)
 
   // Look for an ID3v1 tag
 
-  d->ID3v1Location = findID3v1();
+  d->ID3v1Location = Utils::findID3v1(this);
 
   if(d->ID3v1Location >= 0) {
     d->tag.set(ApeID3v1Index, new ID3v1::Tag(this, d->ID3v1Location));
@@ -278,7 +278,7 @@ void APE::File::read(bool readProperties)
 
   // Look for an APE tag
 
-  d->APELocation = findAPE();
+  d->APELocation = Utils::findAPE(this, d->ID3v1Location);
 
   if(d->APELocation >= 0) {
     d->tag.set(ApeAPEIndex, new APE::Tag(this, d->APELocation));
@@ -314,48 +314,3 @@ void APE::File::read(bool readProperties)
     d->properties = new Properties(this, streamLength);
   }
 }
-
-long APE::File::findAPE()
-{
-  if(!isValid())
-    return -1;
-
-  if(d->hasID3v1)
-    seek(-160, End);
-  else
-    seek(-32, End);
-
-  long p = tell();
-
-  if(readBlock(8) == APE::Tag::fileIdentifier())
-    return p;
-
-  return -1;
-}
-
-long APE::File::findID3v1()
-{
-  if(!isValid())
-    return -1;
-
-  seek(-128, End);
-  long p = tell();
-
-  if(readBlock(3) == ID3v1::Tag::fileIdentifier())
-    return p;
-
-  return -1;
-}
-
-long APE::File::findID3v2()
-{
-  if(!isValid())
-    return -1;
-
-  seek(0);
-
-  if(readBlock(3) == ID3v2::Header::fileIdentifier())
-    return 0;
-
-  return -1;
-}
diff --git a/taglib/ape/apefile.h b/taglib/ape/apefile.h
index 1d2e5c67..e638d865 100644
--- a/taglib/ape/apefile.h
+++ b/taglib/ape/apefile.h
@@ -219,9 +219,6 @@ namespace TagLib {
       File &operator=(const File &);
 
       void read(bool readProperties);
-      long findAPE();
-      long findID3v1();
-      long findID3v2();
 
       class FilePrivate;
       FilePrivate *d;
diff --git a/taglib/flac/flacfile.cpp b/taglib/flac/flacfile.cpp
index dc8f4011..252907d0 100644
--- a/taglib/flac/flacfile.cpp
+++ b/taglib/flac/flacfile.cpp
@@ -29,6 +29,7 @@
 #include <tdebug.h>
 #include <tagunion.h>
 #include <tpropertymap.h>
+#include <tagutils.h>
 
 #include <id3v2header.h>
 #include <id3v2tag.h>
@@ -362,7 +363,7 @@ void FLAC::File::read(bool readProperties)
 {
   // Look for an ID3v2 tag
 
-  d->ID3v2Location = findID3v2();
+  d->ID3v2Location = Utils::findID3v2(this);
 
   if(d->ID3v2Location >= 0) {
 
@@ -378,7 +379,7 @@ void FLAC::File::read(bool readProperties)
 
   // Look for an ID3v1 tag
 
-  d->ID3v1Location = findID3v1();
+  d->ID3v1Location = Utils::findID3v1(this);
 
   if(d->ID3v1Location >= 0) {
     d->tag.set(FlacID3v1Index, new ID3v1::Tag(this, d->ID3v1Location));
@@ -539,30 +540,3 @@ void FLAC::File::scan()
 
   d->scanned = true;
 }
-
-long FLAC::File::findID3v1()
-{
-  if(!isValid())
-    return -1;
-
-  seek(-128, End);
-  long p = tell();
-
-  if(readBlock(3) == ID3v1::Tag::fileIdentifier())
-    return p;
-
-  return -1;
-}
-
-long FLAC::File::findID3v2()
-{
-  if(!isValid())
-    return -1;
-
-  seek(0);
-
-  if(readBlock(3) == ID3v2::Header::fileIdentifier())
-    return 0;
-
-  return -1;
-}
diff --git a/taglib/flac/flacfile.h b/taglib/flac/flacfile.h
index 1c055d33..6cbcb5a0 100644
--- a/taglib/flac/flacfile.h
+++ b/taglib/flac/flacfile.h
@@ -295,8 +295,6 @@ namespace TagLib {
 
       void read(bool readProperties);
       void scan();
-      long findID3v2();
-      long findID3v1();
 
       class FilePrivate;
       FilePrivate *d;
diff --git a/taglib/mpc/mpcfile.cpp b/taglib/mpc/mpcfile.cpp
index 6d8dae5a..1d798212 100644
--- a/taglib/mpc/mpcfile.cpp
+++ b/taglib/mpc/mpcfile.cpp
@@ -28,6 +28,7 @@
 #include <tagunion.h>
 #include <tdebug.h>
 #include <tpropertymap.h>
+#include <tagutils.h>
 
 #include "mpcfile.h"
 #include "id3v1tag.h"
@@ -266,7 +267,7 @@ void MPC::File::read(bool readProperties)
 {
   // Look for an ID3v1 tag
 
-  d->ID3v1Location = findID3v1();
+  d->ID3v1Location = Utils::findID3v1(this);
 
   if(d->ID3v1Location >= 0) {
     d->tag.set(MPCID3v1Index, new ID3v1::Tag(this, d->ID3v1Location));
@@ -275,7 +276,7 @@ void MPC::File::read(bool readProperties)
 
   // Look for an APE tag
 
-  d->APELocation = findAPE();
+  d->APELocation = Utils::findAPE(this, d->ID3v1Location);
 
   if(d->APELocation >= 0) {
     d->tag.set(MPCAPEIndex, new APE::Tag(this, d->APELocation));
@@ -290,7 +291,7 @@ void MPC::File::read(bool readProperties)
 
   // Look for an ID3v2 tag
 
-  d->ID3v2Location = findID3v2();
+  d->ID3v2Location = Utils::findID3v2(this);
 
   if(d->ID3v2Location >= 0) {
     seek(d->ID3v2Location);
@@ -323,48 +324,3 @@ void MPC::File::read(bool readProperties)
     d->properties = new Properties(this, streamLength);
   }
 }
-
-long MPC::File::findAPE()
-{
-  if(!isValid())
-    return -1;
-
-  if(d->hasID3v1)
-    seek(-160, End);
-  else
-    seek(-32, End);
-
-  long p = tell();
-
-  if(readBlock(8) == APE::Tag::fileIdentifier())
-    return p;
-
-  return -1;
-}
-
-long MPC::File::findID3v1()
-{
-  if(!isValid())
-    return -1;
-
-  seek(-128, End);
-  long p = tell();
-
-  if(readBlock(3) == ID3v1::Tag::fileIdentifier())
-    return p;
-
-  return -1;
-}
-
-long MPC::File::findID3v2()
-{
-  if(!isValid())
-    return -1;
-
-  seek(0);
-
-  if(readBlock(3) == ID3v2::Header::fileIdentifier())
-    return 0;
-
-  return -1;
-}
diff --git a/taglib/mpc/mpcfile.h b/taglib/mpc/mpcfile.h
index 0980a5cd..98e7480f 100644
--- a/taglib/mpc/mpcfile.h
+++ b/taglib/mpc/mpcfile.h
@@ -222,9 +222,6 @@ namespace TagLib {
       File &operator=(const File &);
 
       void read(bool readProperties);
-      long findAPE();
-      long findID3v1();
-      long findID3v2();
 
       class FilePrivate;
       FilePrivate *d;
diff --git a/taglib/tagutils.cpp b/taglib/tagutils.cpp
new file mode 100644
index 00000000..dc047040
--- /dev/null
+++ b/taglib/tagutils.cpp
@@ -0,0 +1,79 @@
+/***************************************************************************
+    copyright            : (C) 2015 by Tsuda Kageyu
+    email                : tsuda.kageyu@gmail.com
+ ***************************************************************************/
+
+/***************************************************************************
+ *   This library is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU Lesser General Public License version   *
+ *   2.1 as published by the Free Software Foundation.                     *
+ *                                                                         *
+ *   This library is distributed in the hope that it will be useful, but   *
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of            *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     *
+ *   Lesser General Public License for more details.                       *
+ *                                                                         *
+ *   You should have received a copy of the GNU Lesser General Public      *
+ *   License along with this library; if not, write to the Free Software   *
+ *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA         *
+ *   02110-1301  USA                                                       *
+ *                                                                         *
+ *   Alternatively, this file is available under the Mozilla Public        *
+ *   License Version 1.1.  You may obtain a copy of the License at         *
+ *   http://www.mozilla.org/MPL/                                           *
+ ***************************************************************************/
+
+#include <tfile.h>
+
+#include "id3v1tag.h"
+#include "id3v2header.h"
+#include "apetag.h"
+
+#include "tagutils.h"
+
+using namespace TagLib;
+
+long Utils::findID3v1(File *file)
+{
+  if(!file->isValid())
+    return -1;
+
+  file->seek(-128, File::End);
+  const long p = file->tell();
+
+  if(file->readBlock(3) == ID3v1::Tag::fileIdentifier())
+    return p;
+
+  return -1;
+}
+
+long Utils::findID3v2(File *file)
+{
+  if(!file->isValid())
+    return -1;
+
+  file->seek(0);
+
+  if(file->readBlock(3) == ID3v2::Header::fileIdentifier())
+    return 0;
+
+  return -1;
+}
+
+long Utils::findAPE(File *file, long id3v1Location)
+{
+  if(!file->isValid())
+    return -1;
+
+  if(id3v1Location >= 0)
+    file->seek(id3v1Location - 32, File::Beginning);
+  else
+    file->seek(-32, File::End);
+
+  const long p = file->tell();
+
+  if(file->readBlock(8) == APE::Tag::fileIdentifier())
+    return p;
+
+  return -1;
+}
diff --git a/taglib/tagutils.h b/taglib/tagutils.h
new file mode 100644
index 00000000..fb11d1e0
--- /dev/null
+++ b/taglib/tagutils.h
@@ -0,0 +1,49 @@
+/***************************************************************************
+    copyright            : (C) 2015 by Tsuda Kageyu
+    email                : tsuda.kageyu@gmail.com
+ ***************************************************************************/
+
+/***************************************************************************
+ *   This library is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU Lesser General Public License version   *
+ *   2.1 as published by the Free Software Foundation.                     *
+ *                                                                         *
+ *   This library is distributed in the hope that it will be useful, but   *
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of            *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     *
+ *   Lesser General Public License for more details.                       *
+ *                                                                         *
+ *   You should have received a copy of the GNU Lesser General Public      *
+ *   License along with this library; if not, write to the Free Software   *
+ *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA         *
+ *   02110-1301  USA                                                       *
+ *                                                                         *
+ *   Alternatively, this file is available under the Mozilla Public        *
+ *   License Version 1.1.  You may obtain a copy of the License at         *
+ *   http://www.mozilla.org/MPL/                                           *
+ ***************************************************************************/
+
+#ifndef TAGLIB_TAGUTILS_H
+#define TAGLIB_TAGUTILS_H
+
+// THIS FILE IS NOT A PART OF THE TAGLIB API
+
+#ifndef DO_NOT_DOCUMENT  // tell Doxygen not to document this header
+
+namespace TagLib {
+
+  class File;
+
+  namespace Utils {
+
+    long findID3v1(File *file);
+
+    long findID3v2(File *file);
+
+    long findAPE(File *file, long id3v1Location);
+  }
+}
+
+#endif
+
+#endif
diff --git a/taglib/trueaudio/trueaudiofile.cpp b/taglib/trueaudio/trueaudiofile.cpp
index 4ca60915..0ff3fa5e 100644
--- a/taglib/trueaudio/trueaudiofile.cpp
+++ b/taglib/trueaudio/trueaudiofile.cpp
@@ -33,6 +33,7 @@
 #include <tagunion.h>
 #include <tstringlist.h>
 #include <tpropertymap.h>
+#include <tagutils.h>
 
 #include "trueaudiofile.h"
 #include "id3v1tag.h"
@@ -248,7 +249,7 @@ void TrueAudio::File::read(bool readProperties)
 {
   // Look for an ID3v2 tag
 
-  d->ID3v2Location = findID3v2();
+  d->ID3v2Location = Utils::findID3v2(this);
 
   if(d->ID3v2Location >= 0) {
 
@@ -264,7 +265,7 @@ void TrueAudio::File::read(bool readProperties)
 
   // Look for an ID3v1 tag
 
-  d->ID3v1Location = findID3v1();
+  d->ID3v1Location = Utils::findID3v1(this);
 
   if(d->ID3v1Location >= 0) {
     d->tag.set(TrueAudioID3v1Index, new ID3v1::Tag(this, d->ID3v1Location));
@@ -296,30 +297,3 @@ void TrueAudio::File::read(bool readProperties)
     d->properties = new Properties(readBlock(TrueAudio::HeaderSize), streamLength);
   }
 }
-
-long TrueAudio::File::findID3v1()
-{
-  if(!isValid())
-    return -1;
-
-  seek(-128, End);
-  long p = tell();
-
-  if(readBlock(3) == ID3v1::Tag::fileIdentifier())
-    return p;
-
-  return -1;
-}
-
-long TrueAudio::File::findID3v2()
-{
-  if(!isValid())
-    return -1;
-
-  seek(0);
-
-  if(readBlock(3) == ID3v2::Header::fileIdentifier())
-    return 0;
-
-  return -1;
-}
diff --git a/taglib/trueaudio/trueaudiofile.h b/taglib/trueaudio/trueaudiofile.h
index 3fc515f6..4bcb722a 100644
--- a/taglib/trueaudio/trueaudiofile.h
+++ b/taglib/trueaudio/trueaudiofile.h
@@ -240,8 +240,6 @@ namespace TagLib {
       File &operator=(const File &);
 
       void read(bool readProperties);
-      long findID3v1();
-      long findID3v2();
 
       class FilePrivate;
       FilePrivate *d;
diff --git a/taglib/wavpack/wavpackfile.cpp b/taglib/wavpack/wavpackfile.cpp
index 90f79d16..7273e103 100644
--- a/taglib/wavpack/wavpackfile.cpp
+++ b/taglib/wavpack/wavpackfile.cpp
@@ -32,6 +32,7 @@
 #include <tdebug.h>
 #include <tagunion.h>
 #include <tpropertymap.h>
+#include <tagutils.h>
 
 #include "wavpackfile.h"
 #include "id3v1tag.h"
@@ -243,7 +244,7 @@ void WavPack::File::read(bool readProperties)
 {
   // Look for an ID3v1 tag
 
-  d->ID3v1Location = findID3v1();
+  d->ID3v1Location = Utils::findID3v1(this);
 
   if(d->ID3v1Location >= 0) {
     d->tag.set(WavID3v1Index, new ID3v1::Tag(this, d->ID3v1Location));
@@ -252,7 +253,7 @@ void WavPack::File::read(bool readProperties)
 
   // Look for an APE tag
 
-  d->APELocation = findAPE();
+  d->APELocation = Utils::findAPE(this, d->ID3v1Location);
 
   if(d->APELocation >= 0) {
     d->tag.set(WavAPEIndex, new APE::Tag(this, d->APELocation));
@@ -280,35 +281,3 @@ void WavPack::File::read(bool readProperties)
     d->properties = new Properties(this, streamLength);
   }
 }
-
-long WavPack::File::findAPE()
-{
-  if(!isValid())
-    return -1;
-
-  if(d->hasID3v1)
-    seek(-160, End);
-  else
-    seek(-32, End);
-
-  long p = tell();
-
-  if(readBlock(8) == APE::Tag::fileIdentifier())
-    return p;
-
-  return -1;
-}
-
-long WavPack::File::findID3v1()
-{
-  if(!isValid())
-    return -1;
-
-  seek(-128, End);
-  long p = tell();
-
-  if(readBlock(3) == ID3v1::Tag::fileIdentifier())
-    return p;
-
-  return -1;
-}
diff --git a/taglib/wavpack/wavpackfile.h b/taglib/wavpack/wavpackfile.h
index 24511581..abcabd94 100644
--- a/taglib/wavpack/wavpackfile.h
+++ b/taglib/wavpack/wavpackfile.h
@@ -208,8 +208,6 @@ namespace TagLib {
       File &operator=(const File &);
 
       void read(bool readProperties);
-      long findID3v1();
-      long findAPE();
 
       class FilePrivate;
       FilePrivate *d;