wxWidgets Accessing TopFrame of Another Process - c++

Question

I have an application which has the parent frame as the MainFrame and two child frames, ChildA and ChildB. This should be a document oriented GUI such that when user clicks a document, it should be able to open another instance of FrameA.
When I click the executable of GUI MainFrame, ChildA and ChildB loads normally. However when the executable is running and when I click a document I realized that Windows is opening it as another process such that MainFrame, ChildA and ChildB loads again which I dont want cause I only want to open another instance of ChildA to show the contents of the document.
My code is as follows:
bool MainFrameApp::OnInit()
{
m_AnotherInstanceRunning=false;
m_checker = new wxSingleInstanceChecker;
if(m_checker->IsAnotherRunning()) m_AnotherInstanceRunning=true;
//Some other code
if(!m_AnotherInstanceRunning)
{
frame= new MainFrame(0L);
std::cout<<"Frame:"<<frame; //Prints the address
auto m_ChildA=new SomeChildFrame(frame);
frame->Show();
m_FrameA->Show(true);
wxTheApp->SetTopWindow(frame);
}
if(m_AnotherInstanceRunning)
{
frame=dynamic_cast<MainFrame*>(wxTheApp->GetTopWindow());
std::cout<<"Frame:"<<frame; //prints 0
frame->OpenDocument(frame,strDocDirectory,strDocName); //Does not work
return false;
}
My question is, when I click on a document how can I open that document within an already running MainFrame.
EDIT 1:
This is how I achieved it after countless of hours...
Below is the code for MainFrame.h
const int SERVER_ID=wxNewId();
const int SERVERSOCKET_ID=wxNewId();
const int CLIENTSOCKET_ID=wxNewId();
class MainFrame;
class MainFrameApp : public wxApp
{
bool m_AnotherInstanceRunning;
wxSocketServer* m_server;
wxString m_DocDirectoryPath;
wxString m_DocFullName; //including extension
protected:
virtual void OnServerEvent(wxSocketEvent& event);
virtual void OnServerSocketEvent(wxSocketEvent& event);
virtual void OnClientSocketEvent(wxSocketEvent& event);
public:
MainFrame* m_MainFrame;
wxSingleInstanceChecker* m_checker;
};
static const wxCmdLineEntryDesc cmdLineDesc[] =
{
{wxCMD_LINE_PARAM, NULL, NULL, "", wxCMD_LINE_VAL_STRING, wxCMD_LINE_PARAM_MULTIPLE},
{wxCMD_LINE_NONE},
};
Below is the code for MainFrame.cpp
bool ScienceSuitApp::OnInit()
{
m_AnotherInstanceRunning=false;
m_checker = new wxSingleInstanceChecker;
if(m_checker->IsAnotherRunning()) m_AnotherInstanceRunning=true;
wxFileName exePath(wxStandardPaths::Get().GetExecutablePath());
glbStrExeDir=exePath.GetPath()+wxFileName::GetPathSeparator();
wxString strDocFullPath; //This is directory+name
if(argc>1)
{
wxCmdLineParser parser(cmdLineDesc, argc, argv);
parser.Parse();
strDocFullPath=argv[1];
wxFileName docPath(strDocFullPath);
m_DocDirectoryPath=docPath.GetPath()+wxFileName::GetPathSeparator();
m_DocFullName=docPath.GetFullName(); //we needed extension of document as well
}
if(!m_AnotherInstanceRunning)
{
//Some other code
//Here Process #1
m_MainFrame= new MainFrame(0L);
m_MainFrame->Show();
wxIPV4address addr;
addr.Service(3000);
m_server = new wxSocketServer(addr,wxSOCKET_WAITALL);
if (!m_server->Ok())
{
if (m_server->LastError() == wxSOCKET_INVPORT) wxMessageBox(wxT("Port in use!"));
m_server->Destroy();
}
m_server->SetEventHandler(*this, SERVER_ID);
m_server->SetNotify(wxSOCKET_CONNECTION_FLAG);
m_server->Notify(true);
Connect(SERVER_ID,wxID_ANY, wxEVT_SOCKET,wxSocketEventHandler(MainFrameApp::OnServerEvent));
Connect(SERVERSOCKET_ID,wxID_ANY,wxEVT_SOCKET,wxSocketEventHandler(MainFrameApp::OnServerSocketEvent));
}
if(m_AnotherInstanceRunning)
{
//Here is for Process #2
Connect(CLIENTSOCKET_ID,wxID_ANY,wxEVT_SOCKET,wxSocketEventHandler(MainFrameApp::OnClientSocketEvent));
wxIPV4address addr;
addr.Hostname(wxT("localhost"));
addr.Service(3000);
wxSocketClient* Socket = new wxSocketClient();
Socket->SetEventHandler(*this, CLIENTSOCKET_ID);
Socket->SetNotify(wxSOCKET_CONNECTION_FLAG | wxSOCKET_INPUT_FLAG | wxSOCKET_LOST_FLAG);
Socket->Notify(true);
if(!Socket->Connect(addr, true)) wxMessageBox("Failed to connect to server");
return true;
}
return true;
}
void MainFrameApp::OnServerEvent(wxSocketEvent& event) //Process #1
{
wxSocketBase* sock = m_server->Accept(false);
sock->SetEventHandler(*this, SERVERSOCKET_ID);
sock->SetNotify(wxSOCKET_INPUT_FLAG | wxSOCKET_LOST_FLAG);
sock->Notify(true);
}
void MainFrameApp::OnServerSocketEvent(wxSocketEvent& event) //Process #1
{
wxSocketBase *sock = event.GetSocket();
wxCharBuffer buf(256);
switch(event.GetSocketEvent())
{
case wxSOCKET_CONNECTION:
{
break;
}
case wxSOCKET_INPUT:
{
sock->Read(buf.data(), 255);
wxString pathstr=wxString::FromUTF8(buf);
sock->Destroy();
wxFileName docPath(pathstr);
wxString DocDirectoryPath=docPath.GetPath()+wxFileName::GetPathSeparator();
wxString DocFullName=docPath.GetFullName(); //we needed extension of document as well
m_MainFrame->OpenDocument(m_MainFrame,DocDirectoryPath,DocFullName);
break;
}
case wxSOCKET_LOST:
{
sock->Destroy();
break;
}
}
}
void MainFrameApp::OnClientSocketEvent(wxSocketEvent& event) //Process #2
{
wxString str=m_DocDirectoryPath+m_DocFullName;
wxSocketBase* sock = event.GetSocket();
switch(event.GetSocketEvent())
{
case wxSOCKET_CONNECTION:
{
sock->Write(str.mb_str(),str.length());
}
}
//Exit the client process (Process #2) staying in the background, otherwise and no messages are sent
//Also we dont want to spawn background processes
exit(0);
}

Answer 1

If you want to prevent more than one instance of your application running at the same time, you can use wxSingleInstanceChecker to check if another one is running and use the IPC classes to send the name of the document to open to the other instance if it is.