implement a more generic ShowList method

apt-get is displaying various lists of package names, which until now it
was building as a string before passing it to ShowList, which inserted
linebreaks at fitting points and showed a title if needed, but it never
really understood what it was working with. With the help of C++11 the
new generic knows not only what it works with, but generates the list on
the fly rather than asking for it and potentially discarding parts of
the input (= the non-default verbose display). It also doubles as a test
for how usable the CacheSets are with C++11.

(Not all callers are adapted yet.)

Git-Dch: Ignore

1 files changed, 66 insertions, 1 deletions

diff --git a/apt-private/private-output.h b/apt-private/private-output.h
index d5b57adec..b9151b245 100644
--- a/apt-private/private-output.h
+++ b/apt-private/private-output.h
@@ -1,9 +1,11 @@
 #ifndef APT_PRIVATE_OUTPUT_H
 #define APT_PRIVATE_OUTPUT_H
 
+#include <apt-pkg/configuration.h>
 #include <apt-pkg/pkgcache.h>
 #include <apt-pkg/macros.h>
 
+#include <functional>
 #include <fstream>
 #include <string>
 #include <iostream>
@@ -32,8 +34,63 @@ void ListSingleVersion(pkgCacheFile &CacheFile, pkgRecords &records,
 APT_PUBLIC void ShowBroken(std::ostream &out, CacheFile &Cache, bool const Now);
 APT_PUBLIC void ShowBroken(std::ostream &out, pkgCacheFile &Cache, bool const Now);
 
-APT_PUBLIC bool ShowList(std::ostream &out, std::string Title, std::string List,
+template<class Container> APT_PUBLIC bool ShowList(std::ostream &out, std::string const &Title,
+      Container const &cont,
+      std::function<bool(pkgCache::PkgIterator const &)> Predicate,
+      std::function<std::string(pkgCache::PkgIterator const &)> PkgDisplay,
+      std::function<std::string(pkgCache::PkgIterator const &)> VerboseDisplay)
+{
+   size_t const ScreenWidth = (::ScreenWidth > 3) ? ::ScreenWidth - 3 : 0;
+   int ScreenUsed = 0;
+   bool const ShowVersions = _config->FindB("APT::Get::Show-Versions", false);
+   bool printedTitle = false;
+
+   for (auto const &Pkg: cont)
+   {
+      if (Predicate(Pkg) == false)
+	 continue;
+
+      if (printedTitle == false)
+      {
+	 out << Title;
+	 printedTitle = true;
+      }
+
+      if (ShowVersions == true)
+      {
+	 out << std::endl << "   " << PkgDisplay(Pkg);
+	 std::string const verbose = VerboseDisplay(Pkg);
+	 if (verbose.empty() == false)
+	    out << " (" << verbose << ")";
+      }
+      else
+      {
+	 std::string const PkgName = PkgDisplay(Pkg);
+	 if (ScreenUsed == 0 || (ScreenUsed + PkgName.length()) >= ScreenWidth)
+	 {
+	    out << std::endl << "  ";
+	    ScreenUsed = 0;
+	 }
+	 else if (ScreenUsed != 0)
+	 {
+	    out << " ";
+	    ++ScreenUsed;
+	 }
+	 out << PkgName;
+	 ScreenUsed += PkgName.length();
+      }
+   }
+
+   if (printedTitle == true)
+   {
+      out << std::endl;
+      return false;
+   }
+   return true;
+}
+APT_DEPRECATED APT_PUBLIC bool ShowList(std::ostream &out, std::string Title, std::string List,
               std::string VersionsList);
+
 void ShowNew(std::ostream &out,CacheFile &Cache);
 void ShowDel(std::ostream &out,CacheFile &Cache);
 void ShowKept(std::ostream &out,CacheFile &Cache);
@@ -49,4 +106,12 @@ void Stats(std::ostream &out, pkgDepCache &Dep);
 bool YnPrompt(bool Default=true);
 bool AnalPrompt(const char *Text);
 
+APT_PUBLIC std::string PrettyFullName(pkgCache::PkgIterator const &Pkg);
+APT_PUBLIC std::string CandidateVersion(pkgCacheFile * const Cache, pkgCache::PkgIterator const &Pkg);
+APT_PUBLIC std::function<std::string(pkgCache::PkgIterator const &)> CandidateVersion(pkgCacheFile * const Cache);
+APT_PUBLIC std::string CurrentToCandidateVersion(pkgCacheFile * const Cache, pkgCache::PkgIterator const &Pkg);
+APT_PUBLIC std::function<std::string(pkgCache::PkgIterator const &)> CurrentToCandidateVersion(pkgCacheFile * const Cache);
+APT_PUBLIC std::string EmptyString(pkgCache::PkgIterator const &);
+APT_PUBLIC bool AlwaysTrue(pkgCache::PkgIterator const &);
+
 #endif