all tr() which aren't prefixed with QObject doesn't work

AlexLuya

in a QT(C++) based GUI,all .hpp files have been marked with Macro Q_OBJECT,corresponded .cpp files have many tr("keys to translate"),and these lines has been put in CMakeLists.txt

file(GLOB_RECURSE SRC_FILES CONFIGURE_DEPENDS "${PROJECT_SOURCE_DIR}/src/*.cpp" "${PROJECT_SOURCE_DIR}/shonDyCommon/*.cpp")
file(GLOB_RECURSE UI_FILES "${PROJECT_SOURCE_DIR}/src/*.ui")
file(GLOB_RECURSE HEADER_FILES CONFIGURE_DEPENDS "${PROJECT_SOURCE_DIR}/src/*.hpp" "${PROJECT_SOURCE_DIR}/src/*.h" "${PROJECT_SOURCE_DIR}/shonDyCommon/*.hpp")

set(TRANS_QRC ${CMAKE_CURRENT_BINARY_DIR}/trans_resources.qrc)
configure_file(
        ${PROJECT_SOURCE_DIR}/src/resource/trans_resources.qrc.in
        ${TRANS_QRC}
        COPYONLY
)
set(TS_FILES
        ${PROJECT_SOURCE_DIR}/src/resource/translate/shonDy_zh_CN.ts
        ${PROJECT_SOURCE_DIR}/src/resource/translate/shonDy_en_US.ts
        )
set_source_files_properties(${TS_FILES} PROPERTIES OUTPUT_LOCATION ${PROJECT_BINARY_DIR})
qt5_create_translation(QM_FILES ${TS_FILES} ${SRC_FILES} ${UI_FILES} ${HEADER_FILES})

qt5_add_big_resources(GUI_RESOURCES "${PROJECT_SOURCE_DIR}/src/resource/resources.qrc")

All keys got generated in .ts file after compilation,no matter it comes from .ui file or .cpp file.

When GUI opened,all keys which come from .ui files or QObject:tr("") got translated correctly,but all keys come from .cpp with tr("") which are not prefixed with QObject:: don't got translated.

If picking any tr("specificKey") in a .cpp,prefixing it like this: QObject::tr("specificKey"),recompiling without any extra efforts,and open it again,this key got translated correctly.

Question is:

Why don't the keys in .cpp got translated?

Christian Ehrlicher

Works fine for me. Please provide a minimal, compilable example to reproduce the problem - a simple main.cpp showing a QLabel should be enough. No need for a CMakeLists.txt

Alex Luya

@Christian-Ehrlicher The reuslt is shown like this:

And all codes are listed as blow,including .ui and CMakeLists.txt

main.cpp

#include "shonDyMainWindow.h"
#include <QApplication>

int main(int argc, char** argv)
{
    using namespace shonCloud;

    QApplication application(argc, argv);

    shonDyMainWindow mainWindow;
    mainWindow.show();
    return application.exec();
}

shonDyMainWindow.h

#pragma once
#include <QMainWindow>


namespace Ui
{
class shonDyMainWindow;
}
namespace shonCloud
{

class shonDyMainWindow : public QMainWindow
{
    Q_OBJECT

   public:
    explicit shonDyMainWindow(QWidget *parent = nullptr);

   private:
    Ui::shonDyMainWindow *ui;
};

}  // namespace shonCloud

shonDyMainWindow.cpp

#include "shonDyMainWindow.h"
#include "ui_shonDyMainWindow.h"
#include <QTranslator>
#include <QPushButton>

namespace shonCloud
{
shonDyMainWindow::shonDyMainWindow(QWidget *parent)
    : ui(new Ui::shonDyMainWindow)
{
    ui->setupUi(this);
    auto pb=new QPushButton(tr("Add by tr"),ui->centralwidget);
    ui->verticalLayout->addWidget(pb);
    auto translator = new QTranslator;
    translator->load(R"(shonDy_zh_CN.qm)");
    QCoreApplication::instance()->installTranslator(translator);
    ui->pushButton->setText(tr("Hello World"));
}

}  // namespace shonCloud

shonDyMainWindow.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>shonDyMainWindow</class>
 <widget class="QMainWindow" name="shonDyMainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>1156</width>
    <height>765</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <widget class="QWidget" name="centralwidget">
   <layout class="QVBoxLayout" name="verticalLayout">
    <item>
     <widget class="QPushButton" name="pushButton">
      <property name="font">
       <font>
        <pointsize>19</pointsize>
       </font>
      </property>
      <property name="text">
       <string>Clicked Me</string>
      </property>
     </widget>
    </item>
   </layout>
  </widget>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>1156</width>
     <height>18</height>
    </rect>
   </property>
   <widget class="QMenu" name="menuFile">
    <property name="title">
     <string>File</string>
    </property>
    <addaction name="separator"/>
   </widget>
   <addaction name="menuFile"/>
  </widget>
 </widget>
 <resources/>
 <connections/>
</ui>

shonDy_zh_CN.ts

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE TS>
<TS version="2.1" language="zh_CN">
<context>
    <name>shonCloud::shonDyMainWindow</name>
    <message>
        <location filename="src/shonDyMainWindow.cpp" line="14"/>
        <source>Add by tr</source>
        <translation type="unfinished">在CPP中添加</translation>
    </message>
    <message>
        <location filename="src/shonDyMainWindow.cpp" line="19"/>
        <source>Hello World</source>
        <translation type="unfinished">你好，世界</translation>
    </message>
</context>
<context>
    <name>shonDyMainWindow</name>
    <message>
        <location filename="src/shonDyMainWindow.ui" line="14"/>
        <source>MainWindow</source>
        <translation type="unfinished"></translation>
    </message>
    <message>
        <location filename="src/shonDyMainWindow.ui" line="26"/>
        <source>Clicked Me</source>
        <translation></translation>
    </message>
    <message>
        <location filename="src/shonDyMainWindow.ui" line="43"/>
        <source>File</source>
        <translation type="unfinished">文件</translation>
    </message>
</context>
</TS>

CMakeLists.txt

cmake_minimum_required(VERSION 3.16.3)

project(shonDyGUI LANGUAGES CXX C VERSION 2.6)


###############################
# Setup project
###############################
set(CMAKE_AUTOUIC ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)

set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
set(CMAKE_INSTALL_MESSAGE LAZY)
set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -DJSON_DIAGNOSTICS=1")

find_package(VTK REQUIRED)
find_package(Qt5 REQUIRED COMPONENTS Core Widgets LinguistTools Network Gui OpenGL Concurrent)
find_package(Qt5Test REQUIRED)

file(GLOB_RECURSE SRC_FILES CONFIGURE_DEPENDS "${PROJECT_SOURCE_DIR}/src/*.cpp")
file(GLOB_RECURSE UI_FILES "${PROJECT_SOURCE_DIR}/src/*.ui")
file(GLOB_RECURSE HEADER_FILES CONFIGURE_DEPENDS "${PROJECT_SOURCE_DIR}/src/*.h")

set(TS_FILES
        ${PROJECT_SOURCE_DIR}/shonDy_zh_CN.ts
        )
set_source_files_properties(${TS_FILES} PROPERTIES OUTPUT_LOCATION ${PROJECT_BINARY_DIR})
qt5_create_translation(QM_FILES ${SRC_FILES} ${UI_FILES} ${HEADER_FILES} ${TS_FILES})

add_executable(${PROJECT_NAME}
        ${SRC_FILES}
        ${UI_FILES}
        ${HEADER_FILES}
        ${QM_FILES}
        )


target_link_libraries(${PROJECT_NAME}
        PRIVATE
        Qt5::Widgets
        )

JonB

@Alex-Luya
Your title is "all tr() which aren't prefixed with QObject doesn't work". I don't see where any QObject is involved?

You do tr("Add by tr") before you call translator->load(R"(shonDy_zh_CN.qm)"); while you do tr("Hello World") after calling it. I don't use translation, but I imagine tr() translates according to the loaded QTranslator in effect at the moment tr() is executed? If you change translator after any tr()s have been called I imagine you have to retranslate to force them to be re-evaluated?