qmake: Add support for running lrelease

CONFIG+=lrelease enables that all .ts files in
TRANSLATIONS or EXTRA_TRANSLATIONS are compiled by
lrelease.

EXTRA_TRANSLATIONS is a new variable that is only
processed by lrelease, but not lupdate - this
is useful for translation files that are supposed to
be empty, because they match the language of the
original translation sources.

If embed_translations is also set, the generated .qm
files will be made available through the Qt resource
system under :/i18n/. Alternatively, the user can
specify an installation target by setting
QM_FILES_INSTALL_PATH.

Note that relative paths in TRANSLATIONS are not taken
into account. That is,

  TRANSLATIONS = component1/de.ts component2/de.ts

will cause a conflict.

[ChangeLog][qmake] New CONFIG options lrelease and
embed_translations were added. CONFIG+=lrelease does
run lrelease on translation files listed in TRANSLATIONS
and EXTRA_TRANSLATIONS. CONFIG+=embed_translations does
include the generated .qm files as resources under
:/i18n/.

Change-Id: I94db5b8431d07b24f59b2c332ede91450f9c0c58
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>

1 files changed, 57 insertions, 0 deletions

diff --git a/qmake/doc/src/qmake-manual.qdoc b/qmake/doc/src/qmake-manual.qdoc
index fa907ef57f..22c34adccd 100644
--- a/qmake/doc/src/qmake-manual.qdoc
+++ b/qmake/doc/src/qmake-manual.qdoc
@@ -977,6 +977,14 @@
             By default, they are enabled.
     \row    \li depend_includepath \li Appending the value of INCLUDEPATH to
             DEPENDPATH is enabled. Set by default.
+    \row    \li lrelease \li Run \c lrelease for all files listed in
+            \l TRANSLATIONS and \l EXTRA_TRANSLATIONS. If \c embed_translations
+            is not set, install the generated .qm files into
+            QM_FILES_INSTALL_PATH. Use QMAKE_LRELEASE_FLAGS to add options to
+            the lrelease call. Not set by default.
+    \row    \li embed_translations \li Embed the generated translations from
+            \c lrelease in the executable, under \l{QM_FILES_RESOURCE_PREFIX}.
+            Requires \c lrelease to be set, too. Not set by default.
     \endtable
 
     When you use the \c debug_and_release option (which is the default under
@@ -1162,6 +1170,24 @@
 
     Specifies where to copy the \l{#TARGET}{target} dll.
 
+    \target EXTRA_TRANSLATIONS
+    \section1 EXTRA_TRANSLATIONS
+
+    Specifies a list of translation (.ts) files that contain
+    translations of the user interface text into non-native languages.
+
+    In contrast to \l TRANSLATIONS, translation files in \c EXTRA_TRANSLATIONS
+    will be processed only by \l{Using lrelease}{lrelease}, not
+    \l{Using lupdate}{lupdate}.
+
+    You can use \l{CONFIG}{CONFIG += lrelease} to automatically compile the
+    files during the build, and
+    \l{CONFIG}{CONFIG += lrelease embed_translations} to make them available in
+    \l{The Qt Resource System}.
+
+    See the \l{Qt Linguist Manual} for more information about
+    internationalization (i18n) and localization (l10n) with Qt.
+
     \target FORMS
     \section1 FORMS
 
@@ -1432,6 +1458,21 @@
 
     \note Do not attempt to overwrite the value of this variable.
 
+    \target QM_FILES_RESOURCE_PREFIX
+    \section1 QM_FILES_RESOURCE_PREFIX
+
+    Specifies the directory in the resource system where \c .qm files will
+    be made available by \l{CONFIG}{CONFIG += embed_translations}.
+
+    The default is \c{:/i18n/}.
+
+    \target QM_FILES_INSTALL_PATH
+    \section1 QM_FILES_INSTALL_PATH
+
+    Specifies the target directory \c .qm files generated by
+    \l{CONFIG}{CONFIG += lrelease} will be installed to. Does not have any
+    effect if \l{CONFIG}{CONFIG += embed_translations} is set.
+
     \target QMAKE_systemvariable
     \section1 QMAKE
 
@@ -2147,6 +2188,12 @@
     value of this variable is typically handled by qmake or
      \l{#QMAKESPEC}{qmake.conf} and rarely needs to be modified.
 
+    \target QMAKE_LRELEASE_FLAGS
+    \section1 QMAKE_LRELEASE_FLAGS
+
+    List of additional options passed to \l{Using lrelease}{lrelease} when
+    enabled through \l{CONFIG}{CONFIG += lrelease}.
+
     \section1 QMAKE_OBJECTIVE_CFLAGS
 
     Specifies the Objective C/C++ compiler flags for building
@@ -2624,11 +2671,21 @@
     determine how the project is built, it is necessary to declare TEMPLATE on
     the command line rather than use the \c -t option.
 
+    \target TRANSLATIONS
     \section1 TRANSLATIONS
 
     Specifies a list of translation (.ts) files that contain
     translations of the user interface text into non-native languages.
 
+    Translation files in \c TRANSLATIONS will be processed by both
+    \l{Using lrelease}{lrelease} and \l{Using lupdate} tools. Use
+    \l EXTRA_TRANSLATIONS if you want only \c lrelease to process a file.
+
+    You can use \l{CONFIG}{CONFIG += lrelease} to automatically compile the
+    files during the build, and
+    \l{CONFIG}{CONFIG += lrelease embed_translations} to make them available in
+    \l{The Qt Resource System}.
+
     See the \l{Qt Linguist Manual} for more information about
     internationalization (i18n) and localization (l10n) with Qt.