[vlc-devel] [PATCH 02/20] mkv: cleaned `chapters.{cpp,hpp}`

[Filip Roséen]

: `chapters.cpp`
----------------

  - `delete` is a NOOP if the operand is NULL, if-check removed.

: `chapters.{hpp,cpp}`
----------------------

  - introduced helper for `chapter_item_c::{Enter,Leave}` since they
    are extremely similar in their implementation.

    The helper makes use of <algorithm> and <functional> to make the
    code more error-proof, as a plus it is a little bit cleaner.
---
 modules/demux/mkv/chapters.cpp | 70 +++++++++++++++++++-----------------------
 modules/demux/mkv/chapters.hpp |  3 ++
 2 files changed, 35 insertions(+), 38 deletions(-)

diff --git a/modules/demux/mkv/chapters.cpp b/modules/demux/mkv/chapters.cpp
index b8dab0c..6242143 100644
--- a/modules/demux/mkv/chapters.cpp
+++ b/modules/demux/mkv/chapters.cpp
@@ -26,12 +26,13 @@
 
 #include "chapter_command.hpp"
 
+#include <functional>
+#include <algorithm>
+
 chapter_item_c::~chapter_item_c()
 {
-    if( p_segment_uid )
-        delete p_segment_uid;
-    if( p_segment_edition_uid )
-        delete p_segment_edition_uid;
+    delete p_segment_uid;
+    delete p_segment_edition_uid;
     vlc_delete_all( codecs );
     vlc_delete_all( sub_chapters );
 }
@@ -98,7 +99,7 @@ std::string chapter_item_c::GetCodecName( bool f_for_title ) const
     while ( index != codecs.end() )
     {
         result = (*index)->GetCodecName( f_for_title );
-        if ( result != "" )
+        if ( !result.empty () )
             break;
         ++index;
     }
@@ -138,50 +139,43 @@ bool chapter_item_c::ParentOf( const chapter_item_c & item ) const
     return false;
 }
 
-bool chapter_item_c::Enter( bool b_do_subs )
-{
+bool chapter_item_c::EnterLeaveHelper_ ( bool do_subs,
+    bool (chapter_codec_cmds_c::* co_cb) (),
+    bool (chapter_item_c      ::* ch_cb) (bool)
+) {
     bool f_result = false;
-    std::vector<chapter_codec_cmds_c*>::iterator index = codecs.begin();
-    while ( index != codecs.end() )
-    {
-        f_result |= (*index)->Enter();
-        ++index;
-    }
 
-    if ( b_do_subs )
+    f_result |= std::count_if ( codecs.begin (), codecs.end (),
+      std::mem_fun (co_cb)
+    );
+
+    if ( do_subs )
     {
-        // sub chapters
-        std::vector<chapter_item_c*>::iterator index_ = sub_chapters.begin();
-        while ( index_ != sub_chapters.end() )
-        {
-            f_result |= (*index_)->Enter( true );
-            ++index_;
-        }
+        f_result |= count_if ( sub_chapters.begin (), sub_chapters.end (),
+          std::bind2nd( std::mem_fun( ch_cb ), true )
+        );
     }
+
     return f_result;
 }
 
+bool chapter_item_c::Enter( bool b_do_subs )
+{
+    return EnterLeaveHelper_ (b_do_subs,
+      &chapter_codec_cmds_c::Enter,
+      &chapter_item_c::Enter
+    );
+}
+
 bool chapter_item_c::Leave( bool b_do_subs )
 {
-    bool f_result = false;
     b_is_leaving = true;
-    std::vector<chapter_codec_cmds_c*>::iterator index = codecs.begin();
-    while ( index != codecs.end() )
-    {
-        f_result |= (*index)->Leave();
-        ++index;
-    }
 
-    if ( b_do_subs )
-    {
-        // sub chapters
-        std::vector<chapter_item_c*>::iterator index_ = sub_chapters.begin();
-        while ( index_ != sub_chapters.end() )
-        {
-            f_result |= (*index_)->Leave( true );
-            ++index_;
-        }
-    }
+    bool f_result = EnterLeaveHelper_ (b_do_subs,
+      &chapter_codec_cmds_c::Leave,
+      &chapter_item_c::Leave
+    );
+
     b_is_leaving = false;
     return f_result;
 }
diff --git a/modules/demux/mkv/chapters.hpp b/modules/demux/mkv/chapters.hpp
index 1b0885a..501c1cd 100644
--- a/modules/demux/mkv/chapters.hpp
+++ b/modules/demux/mkv/chapters.hpp
@@ -88,6 +88,9 @@ public:
     bool Enter( bool b_do_subchapters );
     bool Leave( bool b_do_subchapters );
     bool EnterAndLeave( chapter_item_c *p_item, bool b_enter = true );
+
+  protected:
+      bool EnterLeaveHelper_ (bool, bool(chapter_codec_cmds_c::*)(), bool(chapter_item_c::*)(bool));
 };
 
 class chapter_edition_c : public chapter_item_c
-- 
2.7.2