Step-by-step instructions for installing wxWidgets 3.0 and CMake on Ubuntu 18 for the purpose of building and running the Hello World! demo application.

wxWidgets3_Hello_World_Ubuntu_18_CMake.md

How to Build wxWidgets 3.0 Hello World! on Ubuntu 18 with CMake

Install wxWidgets 3.0

sudo apt-get update
sudo apt-get full upgrade
sudo apt install wx-common wx3.0-doc wx3.0-examples wx3.0-headers wx3.0-i18n \
cmake libwxbase3.0-dev libwxbase3.0-dev libwxgtk-media3.0-dev \
libwxgtk-media3.0-gtk3-dev libwxgtk-webview3.0-gtk3-dev libwxgtk3.0-dev \
libwxgtk3.0-gtk3-dev libwxsqlite3-3.0-dev libcanberra-gtk-dev \
libcanberra-gtk-module

Hello World!

1. cd ~
2. mkdir hello_wxwidgets
3. cd hello_wxwidgets
4. Create a file named main.cpp containing:

// wxWidgets "Hello world" Program
// For compilers that support precompilation, includes "wx/wx.h".
#include <wx/wxprec.h>

#ifndef WX_PRECOMP
  #include <wx/wx.h>
#endif

class MyApp : public wxApp {
public:
    virtual bool OnInit();
};

class MyFrame : public wxFrame {
public:
    MyFrame(const wxString &title, const wxPoint &pos, const wxSize &size);

private:
    void OnHello(wxCommandEvent &event);

    void OnExit(wxCommandEvent &event);

    void OnAbout(wxCommandEvent &event);

    wxDECLARE_EVENT_TABLE();
};

enum {
    ID_Hello = 1
};

wxBEGIN_EVENT_TABLE(MyFrame, wxFrame)
                EVT_MENU(ID_Hello,   MyFrame::OnHello)
                EVT_MENU(wxID_EXIT,  MyFrame::OnExit)
                EVT_MENU(wxID_ABOUT, MyFrame::OnAbout)
wxEND_EVENT_TABLE()

wxIMPLEMENT_APP(MyApp);

bool MyApp::OnInit() {
    MyFrame *frame = new MyFrame( "Hello World", wxPoint(50, 50), wxSize(450, 340) );
    frame->Show( true );
    return true;
}

MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size)
        : wxFrame(NULL, wxID_ANY, title, pos, size) {
    wxMenu *menuFile = new wxMenu;
    menuFile->Append(ID_Hello, "&Hello...\tCtrl-H",
                     "Help string shown in status bar for this menu item");
    menuFile->AppendSeparator();
    menuFile->Append(wxID_EXIT);
    wxMenu *menuHelp = new wxMenu;
    menuHelp->Append(wxID_ABOUT);
    wxMenuBar *menuBar = new wxMenuBar;
    menuBar->Append( menuFile, "&File" );
    menuBar->Append( menuHelp, "&Help" );
    SetMenuBar( menuBar );
    CreateStatusBar();
    SetStatusText( "Welcome to wxWidgets!" );
}

void MyFrame::OnExit(wxCommandEvent &event) {
    Close(true);
}

void MyFrame::OnAbout(wxCommandEvent &event) {
    wxMessageBox("This is a wxWidgets' Hello world sample",
                 "About Hello World", wxOK | wxICON_INFORMATION);
}

void MyFrame::OnHello(wxCommandEvent &event) {
    wxLogMessage("Hello world from wxWidgets!");
}

Configure CMake

1. Create a file name CMakeLists.txt containing:

cmake_minimum_required(VERSION 3.10)
project(Hello_WxWidgets)

set(CMAKE_VERBOSE_MAKEFILE  ON)
set(CMAKE_FIND_DEBUG_MODE ON)

set(CMAKE_CXX_STANDARD 17)

add_executable(Hello main.cpp)

set(wxWidgets_USE_DEBUG ON)
set(wxWidgets_USE_UNICODE ON)
find_package(wxWidgets REQUIRED net gl core base)
include(${wxWidgets_USE_FILE})
target_link_libraries(Hello ${wxWidgets_LIBRARIES})

Generate the Makefiles

cd cmake-build-debug
cmake -DCMAKE_BUILD_TYPE=Debug -G "CodeBlocks - Unix Makefiles" ~/hello_wxwidgets

Build Hello wxWidgets

cmake --build ~/hello_wxwidgets/cmake-build-debug --target Hello -- -j 4

Run Hello wxWidgets

./Hello

Very helpfull, thanks!