wxWidgets/samples/dll/my_dll.cpp
Vadim Zeitlin 5f7a6bd15b Replace Connect() with Bind() in all samples and utils too
Still use Connect() in unit tests which were written explicitly for it
and in EventConnector, which can't use Bind() as it uses a variable for
the event type.

No real changes, just use the newer and more convenient function.
2018-05-31 16:19:23 +02:00

310 lines
9.9 KiB
C++

/////////////////////////////////////////////////////////////////////////////
// Name: my_dll.cpp
// Purpose: Sample showing how to use wx from a DLL
// Author: Vaclav Slavik
// Created: 2009-12-03
// Copyright: (c) 2009 Vaclav Slavik
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
// ============================================================================
// declarations
// ============================================================================
// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------
#include "wx/wxprec.h"
#ifdef __BORLANDC__
#pragma hdrstop
#endif
#ifndef __WINDOWS__
#error "This sample is Windows-only"
#endif
#include "wx/app.h"
#include "wx/dynlib.h"
#include "wx/frame.h"
#include "wx/panel.h"
#include "wx/sizer.h"
#include "wx/stattext.h"
#include "wx/button.h"
#include "wx/thread.h"
#include "wx/msgdlg.h"
#include "wx/msw/wrapwin.h"
#include <process.h> // for _beginthreadex()
#include "my_dll.h"
// ----------------------------------------------------------------------------
// GUI classes
// ----------------------------------------------------------------------------
class MyDllFrame : public wxFrame
{
public:
MyDllFrame(wxWindow *parent, const wxString& label);
void OnAbout(wxCommandEvent& event);
wxDECLARE_EVENT_TABLE();
};
static const int CMD_SHOW_WINDOW = wxNewId();
static const int CMD_TERMINATE = wxNewId();
class MyDllApp : public wxApp
{
public:
MyDllApp();
private:
void OnShowWindow(wxThreadEvent& event);
void OnTerminate(wxThreadEvent& event);
};
// ============================================================================
// implementation
// ============================================================================
// ----------------------------------------------------------------------------
// MyDllFrame
// ----------------------------------------------------------------------------
wxBEGIN_EVENT_TABLE(MyDllFrame, wxFrame)
EVT_BUTTON(wxID_ABOUT, MyDllFrame::OnAbout)
wxEND_EVENT_TABLE()
MyDllFrame::MyDllFrame(wxWindow *parent, const wxString& label)
: wxFrame(parent, wxID_ANY, label)
{
wxPanel *p = new wxPanel(this, wxID_ANY);
wxSizer *sizer = new wxBoxSizer(wxVERTICAL);
sizer->Add
(
new wxStaticText
(
p, wxID_ANY,
wxString::Format
(
"Running using %s\n"
"wxApp instance is %p, thread ID %ld",
wxVERSION_STRING,
wxApp::GetInstance(),
wxThread::GetCurrentId()
)
),
wxSizerFlags(1).Expand().Border(wxALL, 10)
);
sizer->Add
(
new wxButton(p, wxID_ABOUT, "Show info"),
wxSizerFlags(0).Right().Border(wxALL, 10)
);
p->SetSizerAndFit(sizer);
wxSizer *fsizer = new wxBoxSizer(wxVERTICAL);
fsizer->Add(p, wxSizerFlags(1).Expand());
SetSizerAndFit(fsizer);
}
void MyDllFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
{
wxMessageBox("This window is running in its own thread,\n"
"using private wxWidgets instance compiled into the DLL.",
"About",
wxOK | wxICON_INFORMATION);
}
// ----------------------------------------------------------------------------
// MyDllApp
// ----------------------------------------------------------------------------
MyDllApp::MyDllApp()
{
// Keep the wx "main" thread running even without windows. This greatly
// simplifies threads handling, because we don't have to correctly
// implement wx-thread restarting.
//
// Note that this only works if you don't explicitly call ExitMainLoop(),
// except in reaction to wx_dll_cleanup()'s message. wx_dll_cleanup()
// relies on the availability of wxApp instance and if the event loop
// terminated, wxEntry() would return and wxApp instance would be
// destroyed.
//
// Also note that this is efficient, because if there are no windows, the
// thread will sleep waiting for a new event. We could safe some memory
// by shutting the thread down when it's no longer needed, though.
SetExitOnFrameDelete(false);
Bind(wxEVT_THREAD, &MyDllApp::OnShowWindow, this, CMD_SHOW_WINDOW);
Bind(wxEVT_THREAD, &MyDllApp::OnTerminate, this, CMD_TERMINATE);
}
void MyDllApp::OnShowWindow(wxThreadEvent& event)
{
wxFrame *f = new MyDllFrame(NULL, event.GetString());
f->Show(true);
}
void MyDllApp::OnTerminate(wxThreadEvent& WXUNUSED(event))
{
ExitMainLoop();
}
// ----------------------------------------------------------------------------
// application startup
// ----------------------------------------------------------------------------
// we can't have WinMain() in a DLL and want to start the app ourselves
wxIMPLEMENT_APP_NO_MAIN(MyDllApp);
namespace
{
// Critical section that guards everything related to wxWidgets "main" thread
// startup or shutdown.
wxCriticalSection gs_wxStartupCS;
// Handle of wx "main" thread if running, NULL otherwise
HANDLE gs_wxMainThread = NULL;
// wx application startup code -- runs from its own thread
unsigned wxSTDCALL MyAppLauncher(void* event)
{
// Note: The thread that called run_wx_gui_from_dll() holds gs_wxStartupCS
// at this point and won't release it until we signal it.
// We need to pass correct HINSTANCE to wxEntry() and the right value is
// HINSTANCE of this DLL, not of the main .exe, use this MSW-specific wx
// function to get it. Notice that under Windows XP and later the name is
// not needed/used as we retrieve the DLL handle from an address inside it
// but you do need to use the correct name for this code to work with older
// systems as well.
const HINSTANCE
hInstance = wxDynamicLibrary::MSWGetModuleHandle("my_dll",
&gs_wxMainThread);
if ( !hInstance )
return 0; // failed to get DLL's handle
// wxIMPLEMENT_WXWIN_MAIN does this as the first thing
wxDISABLE_DEBUG_SUPPORT();
// We do this before wxEntry() explicitly, even though wxEntry() would
// do it too, so that we know when wx is initialized and can signal
// run_wx_gui_from_dll() about it *before* starting the event loop.
wxInitializer wxinit;
if ( !wxinit.IsOk() )
return 0; // failed to init wx
// Signal run_wx_gui_from_dll() that it can continue
HANDLE hEvent = *(static_cast<HANDLE*>(event));
if ( !SetEvent(hEvent) )
return 0; // failed setting up the mutex
// Run the app:
wxEntry(hInstance);
return 1;
}
} // anonymous namespace
// ----------------------------------------------------------------------------
// public DLL interface
// ----------------------------------------------------------------------------
extern "C"
{
void run_wx_gui_from_dll(const char *title)
{
// In order to prevent conflicts with hosting app's event loop, we
// launch wx app from the DLL in its own thread.
//
// We can't even use wxInitializer: it initializes wxModules and one of
// the modules it handles is wxThread's private module that remembers
// ID of the main thread. But we need to fool wxWidgets into thinking that
// the thread we are about to create now is the main thread, not the one
// from which this function is called.
//
// Note that we cannot use wxThread here, because the wx library wasn't
// initialized yet. wxCriticalSection is safe to use, though.
wxCriticalSectionLocker lock(gs_wxStartupCS);
if ( !gs_wxMainThread )
{
HANDLE hEvent = CreateEvent
(
NULL, // default security attributes
FALSE, // auto-reset
FALSE, // initially non-signaled
NULL // anonymous
);
if ( !hEvent )
return; // error
// NB: If your compiler doesn't have _beginthreadex(), use CreateThread()
gs_wxMainThread = (HANDLE)_beginthreadex
(
NULL, // default security
0, // default stack size
&MyAppLauncher,
&hEvent, // arguments
0, // create running
NULL
);
if ( !gs_wxMainThread )
{
CloseHandle(hEvent);
return; // error
}
// Wait until MyAppLauncher signals us that wx was initialized. This
// is because we use wxMessageQueue<> and wxString later and so must
// be sure that they are in working state.
WaitForSingleObject(hEvent, INFINITE);
CloseHandle(hEvent);
}
// Send a message to wx thread to show a new frame:
wxThreadEvent *event =
new wxThreadEvent(wxEVT_THREAD, CMD_SHOW_WINDOW);
event->SetString(title);
wxQueueEvent(wxApp::GetInstance(), event);
}
void wx_dll_cleanup()
{
wxCriticalSectionLocker lock(gs_wxStartupCS);
if ( !gs_wxMainThread )
return;
// If wx main thread is running, we need to stop it. To accomplish this,
// send a message telling it to terminate the app.
wxThreadEvent *event =
new wxThreadEvent(wxEVT_THREAD, CMD_TERMINATE);
wxQueueEvent(wxApp::GetInstance(), event);
// We must then wait for the thread to actually terminate.
WaitForSingleObject(gs_wxMainThread, INFINITE);
CloseHandle(gs_wxMainThread);
gs_wxMainThread = NULL;
}
} // extern "C"