Making a ROS GUI QT6 and C++ in Ubuntu 20.04

Question

I'm trying to make a ROS GUI with QTCreator 6. For some reason I'm always getting some include problems either with QT-Libraries, own header files or ROS. I'm using the ros_qtc_plugin.

Project architecture:

catkin_ws
-anayzer_gui
--include
---analyzer_gui
----analyzer_gui.h
----analyzergui.ui
--nodes
---analyzer_gui_node.cpp
--src
---analyzer_gui.cpp
-CMakeLists.txt
-package.xml

CMakeLists.txt:
cmake_minimum_required(VERSION 3.0.2)
project(analyzer_gui)

## Compile as C++11, supported in ROS Kinetic and newer
add_compile_options(-std=c++11)

find_package(catkin REQUIRED COMPONENTS
  roscpp
  std_msgs
)
find_package(pluginlib REQUIRED)
find_package(Qt6 REQUIRED COMPONENTS Widgets)


catkin_package(
  INCLUDE_DIRS include
  CATKIN_DEPENDS roscpp std_msgs
)


include_directories(
  ${CMAKE_CURRENT_SOURCE_DIR}/include/analyzer_gui
  ${CMAKE_CURRENT_SOURCE_DIR}/nodes
  ${catkin_INCLUDE_DIRS}
)


add_executable(${PROJECT_NAME}_node nodes/analyzer_gui_node.cpp)
target_link_libraries(${PROJECT_NAME}_node PRIVATE Qt6::Widgets)


add_dependencies(${PROJECT_NAME}_node ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})`

package.xml:

<?xml version="1.0"?>
<package format="2">
  <name>analyzer_gui</name>
  <version>0.0.0</version>
  <description>The analyzer_gui package</description

  <buildtool_depend>catkin</buildtool_depend>

  <build_depend>pkg-config</build_depend>
  <build_depend>qt6-qmake</build_depend>
  <build_depend>qtbase6-dev</build_depend>
  <build_depend>roscpp</build_depend>
  <build_depend>std_msgs</build_depend>
  <build_depend>qt_build</build_depend>
  <build_depend>libqt6</build_depend>
  <build_export_depend>roscpp</build_export_depend>
  <build_export_depend>std_msgs</build_export_depend>
  <exec_depend>roscpp</exec_depend>
  <exec_depend>std_msgs</exec_depend>
  <exec_depend>qt_build</exec_depend>
  <exec_depend>libqt6</exec_depend>
  <exec_depend>roscpp</exec_depend>


  <!-- The export tag contains other, unspecified, tags -->
  <export>
    <!-- Other tools can request additional information be placed here -->

  </export>
</package>

analyzer_gui.h:

#ifndef ANALYZER_GUI_H
#define ANALYZER_GUI_H

#include <QWidget>
#include <ros/ros.h>

namespace Ui {
class AnalyzerGui;
}

class AnalyzerGui : public QWidget
{
    Q_OBJECT

public:
    explicit AnalyzerGui(QWidget *parent = nullptr);
    ~AnalyzerGui();

private:
    Ui::AnalyzerGui *ui;
};

#endif // ANALYZER_GUI_H

analyzer_gui_node.cpp:

#include <QApplication>
#include "analyzer_gui/analyzer_gui.h"

int main(int argc, char *argv[]){
    ros::init(argc, argv, "analyzer_gui_node");
    QApplication a(argc, argv);

    AnalyzerGui w;
    w.setWindowTitle(QString::fromStdString(ros::this_node::getName()));
    w.show();
    return a.exec();
}

analyzer_gui.cpp:

#include "analyzer_gui.h"
#include "ui_analyzergui.h"

AnalyzerGui::AnalyzerGui(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::AnalyzerGui)
{
    ui->setupUi(this);
}

AnalyzerGui::~AnalyzerGui()
{
    delete ui;
}`

Error messages:

:-1: error: CMakeFiles/analyzer_gui_node.dir/nodes/analyzer_gui_node.cpp.o: in function `main':
/home/bryan/catkin_ws/src/analyzer_gui/nodes/analyzer_gui_node.cpp:5: error: undefined reference to `ros::init(int&, char**, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, unsigned int)'

:-1: error: /home/bryan/catkin_ws/src/analyzer_gui/nodes/analyzer_gui_node.cpp:8: undefined reference to `AnalyzerGui::AnalyzerGui(QWidget*)'

:-1: error: /home/bryan/catkin_ws/src/analyzer_gui/nodes/analyzer_gui_node.cpp:9: undefined reference to `ros::this_node::getName[abi:cxx11]()'

:-1: error: /home/bryan/catkin_ws/src/analyzer_gui/nodes/can_analyzer_gui_node.cpp:8: undefined reference to `AnalyzerGui::~AnalyzerGui()'

:-1: error: /home/bryan/catkin_ws/src/analyzer_gui/nodes/analyzer_gui_node.cpp:8: undefined reference to `AnalyzerGui::~AnalyzerGui()'

:-1: error: collect2: error: ld returned 1 exit status

:-1: error: [analyzer_gui/CMakeFiles/analyzer_gui_node.dir/build.make:89: /home/bryan/catkin_ws/devel/lib/analyzer_gui/analyzer_gui_node] Error 1

Thank you!

The CMakeLists and package look pretty messy since I'm a beginner and tried a lot of stuff that didn't work. In Qt the content of the header files is recognized (class names are highlighted) but while building they are not found.

Answer 1

File analyzer_gui.cpp is not compiled. Try adding it into add_executable(...)

catkin libraries are missing from link stage, also try:

target_link_libraries(${PROJECT_NAME}_node 
   PRIVATE 
      Qt6::Widgets 
      ${catkin_LIBRARIES}
)