Qt5 support broken in autotools #3120

Since merging autotools it is no longer possible to build with Qt5. Or at least it is not automatically detected.

Once this is resolved please revert documentation commit 62568f9.

Its been so much time since I stop coding in C++ and Qt. these days I'm going to start reviewing, and trying to understand the code of the project.

An example of how you could solve part of the problem:

 dnl
 dnl QT
 dnl
 AC_ARG_ENABLE(qt, [
   AS_HELP_STRING([--disable-qt], [Qt UI support (default enabled)])],, [
   AS_IF([test "${SYS}" = "darwin"], [
     enable_qt="no"
   ])
 ])
 AS_IF([test "${enable_qt}" != "no"], [
   PKG_CHECK_MODULES([QT], [Qt5Core >= 5 Qt5Widgets Qt5Gui], [
       QT_PATH="$(eval $PKG_CONFIG --variable=exec_prefix QtCore)"
       AC_PATH_PROGS(MOC, [moc-qt5 moc], moc, [${QT_PATH}/bin ${CONTRIB_DIR}/bin])
       AC_PATH_PROG(RCC, [rcc-qt5 rcc], rcc, [${QT_PATH}/bin ${CONTRIB_DIR}/bin])
       AC_PATH_PROGS(UIC, [uic-qt5 uic], uic, [${QT_PATH}/bin ${CONTRIB_DIR}/bin])
     ], [
       PKG_CHECK_MODULES([QT], [QtCore QtGui >= 4.6.0],, [
         AS_IF([test -n "${enable_qt}"],[
           AC_MSG_ERROR([${QT_PKG_ERRORS}.])
         ],[
           AC_MSG_WARN([${QT_PKG_ERRORS}.])
         ])
         enable_qt="no"
       ])
       QT_PATH="$(eval $PKG_CONFIG --variable=exec_prefix QtCore)"
       AC_PATH_PROGS(MOC, [moc-qt4 moc], moc, [${QT_PATH}/bin ${CONTRIB_DIR}/bin])
       AC_PATH_PROG(RCC, rcc, rcc, [${QT_PATH}/bin ${CONTRIB_DIR}/bin])
       AC_PATH_PROGS(UIC, [uic-qt4 uic], uic, [${QT_PATH}/bin ${CONTRIB_DIR}/bin])
     ])
 ])
 AS_IF([test "${enable_qt}" != "no"], [
   VLC_ADD_PLUGIN([qt4])
   ALIASES="${ALIASES} qvlc"

   AC_LANG_PUSH([C++])
   VLC_SAVE_FLAGS

   AC_MSG_CHECKING([whether Qt uses Xlib])
   CPPFLAGS="${CPPFLAGS} ${QT_CFLAGS}"
   AC_PREPROC_IFELSE([AC_LANG_SOURCE([
 #include <QWidget>
 #if !defined (Q_WS_X11)
 # error Fail
 #endif
   ])], [
     AC_MSG_RESULT([yes])
   ], [
     AC_MSG_RESULT([no])
   ])

   VLC_RESTORE_FLAGS
   AC_LANG_POP([C++])

 ])
 AM_CONDITIONAL(ENABLE_QT4, [test "$enable_qt" != "no"]) 

Regards from Uruguay

There needs to be Qt5 support, before I'm trying autotools... so I whished there would be some patches for it :).

Yes the problem is that no one in the dev team is an autotools wizard, so we're kind of reliant on other's patches here.

See #3346