QStandardPaths: add GenericCacheLocation.

Much like DataLocation = GenericDataLocation + domain + appname,
this makes CacheLocation = GenericCacheLocation + domain + appname.
This way a framework library can have an application-independent cache
(like ksycoca).

Change-Id: I6a8c47ff85b7d5c68b594cc8b071a752d96b029d
Reviewed-by: Bradley T. Hughes <bradley.hughes@nokia.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/io/qstandardpaths.cpp

@@ -83,6 +83,8 @@ QT_BEGIN_NAMESPACE
            returned for GenericDataLocation.
     \value CacheLocation Returns a directory location where user-specific
            non-essential (cached) data should be written.
+    \value GenericCacheLocation Returns a directory location where user-specific
+           non-essential (cached) data, shared across applications, should be written.
     \value GenericDataLocation Returns a directory location where persistent
            data shared across applications can be stored.
     \value RuntimeLocation Returns a directory location where runtime communication

src/corelib/io/qstandardpaths.h

@@ -73,7 +73,8 @@ public:
         GenericDataLocation,
         RuntimeLocation,
         ConfigLocation,
-        DownloadLocation
+        DownloadLocation,
+        GenericCacheLocation
     };
 
     static QString writableLocation(StandardLocation type);

src/corelib/io/qstandardpaths_mac.cpp

@@ -82,6 +82,7 @@ OSType translateLocation(QStandardPaths::StandardLocation type)
     case QStandardPaths::RuntimeLocation:
     case QStandardPaths::DataLocation:
         return kApplicationSupportFolderType;
+    case QStandardPaths::GenericCacheLocation:
     case QStandardPaths::CacheLocation:
         return kCachedDataFolderType;
     default:
@@ -128,6 +129,7 @@ QString QStandardPaths::writableLocation(StandardLocation type)
         return QDir::tempPath();
     case GenericDataLocation:
     case DataLocation:
+    case GenericCacheLocation:
     case CacheLocation:
     case RuntimeLocation:
         return macLocation(type, kUserDomain);
@@ -140,7 +142,7 @@ QStringList QStandardPaths::standardLocations(StandardLocation type)
 {
     QStringList dirs;
 
-    if (type == GenericDataLocation || type == DataLocation || type == CacheLocation) {
+    if (type == GenericDataLocation || type == DataLocation || type == GenericCacheLocation || type == CacheLocation) {
         const QString path = macLocation(type, kOnAppropriateDisk);
         if (!path.isEmpty())
             dirs.append(path);

src/corelib/io/qstandardpaths_unix.cpp

@@ -62,15 +62,18 @@ QString QStandardPaths::writableLocation(StandardLocation type)
     case TempLocation:
         return QDir::tempPath();
     case CacheLocation:
+    case GenericCacheLocation:
     {
         // http://standards.freedesktop.org/basedir-spec/basedir-spec-0.6.html
         QString xdgCacheHome = QFile::decodeName(qgetenv("XDG_CACHE_HOME"));
         if (xdgCacheHome.isEmpty())
             xdgCacheHome = QDir::homePath() + QLatin1String("/.cache");
-        if (!QCoreApplication::organizationName().isEmpty())
-            xdgCacheHome += QLatin1Char('/') + QCoreApplication::organizationName();
-        if (!QCoreApplication::applicationName().isEmpty())
-            xdgCacheHome += QLatin1Char('/') + QCoreApplication::applicationName();
+        if (type == QStandardPaths::CacheLocation) {
+            if (!QCoreApplication::organizationName().isEmpty())
+                xdgCacheHome += QLatin1Char('/') + QCoreApplication::organizationName();
+            if (!QCoreApplication::applicationName().isEmpty())
+                xdgCacheHome += QLatin1Char('/') + QCoreApplication::applicationName();
+        }
         return xdgCacheHome;
     }
     case DataLocation:

src/corelib/io/qstandardpaths_win.cpp

@@ -160,6 +160,9 @@ QString QStandardPaths::writableLocation(StandardLocation type)
         // cache directory located in their AppData directory
         return writableLocation(DataLocation) + QLatin1String("\\cache");
 
+    case GenericCacheLocation:
+        return writableLocation(GenericDataLocation) + QLatin1String("\\cache");
+
     case RuntimeLocation:
     case HomeLocation:
         result = QDir::homePath();