I'm trying to use XInput API for my game engine (I'm using DirectX11 and C++). I just want to test if a controller is found so I #included and call XInputGetState but I get a strange behavior:
XINPUT_STATE state;
ZeroMemory(&state, sizeof(XINPUT_STATE));
DWORD result;
for (DWORD i = 0; i < XUSER_MAX_COUNT; i++)
{
result = XInputGetState(i, &state);
if (result == ERROR_SUCCESS)
ErrorBox(L"found controller on port ");
}
if I connect a controller the program hangs and freezes, while if I disconnect the controller the game launches. If I step into the code with the debugger the result is that the controller is found and the message box is displayed.
Why?
EDIT the problem seems to be in the call to ErrorBox: this function just displays a Message Box using Win32 API.
There is a performance hit when you check for a controller that wasn't attached last time you called it because it has to enumerate device, open driver connects, etc. Therefore, you are recommended to round-robin calls to check for new controllers. If you get ERROR_DEVICE_NOT_CONNECTED back, you shouldn't call XInputGetState again for that slot for a little while. For an example of this, see GamePad class in the Directx Tool Ki and the ThrottleRetry function.
In other words, the loop you wrote before is not a good idea to call every frame unless there are XUSER_MAX_COUNT controllers actually connected.
Related
I'm working on an application for taking screenshots on Windows, OSX and Linux in C++/Qt. Now I need to set global hotkeys, so the user can take screenshots when the application is running in the background. I tried with Qxt and UGlobalHotkey, which are both Qt libraries, but neither of them seemed to work.
I tried to implement it for OSX with Carbon (tutorial), but I need to call a class member function, which just doesn't work. Could someone provide me with an example? You can find my code here. The function i need to call is new_screenshot().
Or is there any other way to achieve something like this? I really need my application to take a screenshot from the background, otherwise it's pretty useless (yes, I should probably have implemented it at the very beginning to see if it even works). Would it maybe be better to have a separate client for every platform (Cocoa Swift for OSX, GTK for Linux, C# client for Windows)? I have often thought about this the past few days.
Do I understand correctly that you want to call new_screenshot from the hot key event handler? If so, InstallApplicationEventHandler lets you pass a pointer to user data in 4th argument. Pass a pointer to your MainWindow instance (based on code from the tutorial):
MainWindow *mainWindow = ... // get main window somehow
InstallApplicationEventHandler(&MyHotKeyHandler,1,&eventType,mainWindow,NULL);
Then you can use it in the event handler.
OSStatus MyHotKeyHandler(EventHandlerCallRef nextHandler,EventRef theEvent, void *userData)
{
//Do something once the key is pressed
static_cast<MainWindow*>(userData)->new_screenshot();
return noErr;
}
I did something in the past with MFC and WIN32 API....so it only works on Windows...but pressing ALT+F10 was able to hide/show a window...
void CWinHideDlg::OnButtonActive()
{
CString tmp;
GetDlgItemText(IDC_BUTTON_ACTIVE,tmp);
if(0 == strcmp(tmp.GetBuffer(tmp.GetLength()),"Activate"))
{
m_myAtom=GlobalAddAtom("MY_GLOBAL_HOT_HIDE_KEY");
int err=RegisterHotKey(this->GetSafeHwnd(),m_myAtom,MOD_ALT,VK_F10);
SetDlgItemText(IDC_BUTTON_ACTIVE,"Stop");
CButton *pBtn = (CButton *)GetDlgItem(IDC_BUTTON_UNHIDE);
pBtn->EnableWindow(TRUE);
SetDlgItemText(IDC_STATIC_INFO,"Set the mouse over the window \nand press ALT + F10 to hide it...");
}
else
{
UnregisterHotKey(this->GetSafeHwnd(),m_myAtom);
GlobalDeleteAtom(m_myAtom);
CButton *pBtn = (CButton *)GetDlgItem(IDC_BUTTON_UNHIDE);
pBtn->EnableWindow(FALSE);
SetDlgItemText(IDC_BUTTON_ACTIVE,"Activate");
}
}
Basically this code activates/deactivates the hot key ALT+F10, once it activates you can hide/unhide a running window on the system by setting the mouse pointer over the window and press ALT+F10...
This is from the WindowProc function:
if(message == WM_HOTKEY)
{
CString tmp;
POINT pc;
GetCursorPos(&pc);
if(GetAsyncKeyState(VK_F10))
{
HWND hwnd=::WindowFromPoint(pc);
if(hwnd)
{
tmp.Format("%08Xh",hwnd);
m_HideWins.InsertString(m_HideWins.GetCount(),tmp);
::ShowWindow(hwnd,SW_HIDE);
}
}
}
You can use the code to register your own HOT Key and use it to take a screenshot...
Hope it helps...
Update: Answer: Two normal lines of code required. Thanks Noseratio!
I banged my head on the keyboard for more hours than I would have cared to trying to simulate IEs Ctrl+N behavior in my hosted Browser control app. Unfortunately, due to complications which I've abstracted out of my code examples below, I can't just let IE do Ctlr+N itself. So I have to do it manually.
Keep in mind that I am running a hosted browser. So typically, opening links in new windows will actuall open it within a new "tab" within my application (it's not really a tab, but another window... but appearance-wise it's a tab). However, Ctrl+N is different -- here, it is expected a fully-fledged IE window will launch when pressed.
I think my problem is that of framing the questions -- admittedly I am new to WebBrowser control and I find it to be a lot of yucky. Regardless, I've scoured the Internet for the past day and couldn't come up with an elegant solution.
Basically, the ideal solution would be to call a "NewWindow" function within WebBrowser control or its affiliate libraries; however, all I was able to find where the *On*NewWindow methods, which were event handlers, not event signallers. Which I understand that most of the time, the user will be creating the events... but what about programmatic simulation?
I tried looking into an SENDMESSAGE approach where I could use the IDs that the OnNewWindow events use... that ended up in nothing than crashes. Perhaps I could go back to get it work, but I'd like confirmation is that approach is even worth my time.
The next approach, which should have been the most elegeant, but sadly didn't pan out, was like the following:
Navigate2(GetLocationURL().GetBuffer(), BrowserNavConstants::navOpenInNewWindow);
It would have worked marvelously if it weren't for the fact that the new window would open in the background, blinking in the taskbar. needing clicking to bring it to the front.
I tried to get around the limitation in a myriad of ways, including getting the dispatcher of the current context, then calling OnNewWindow2 with that IDispatch object. Then I would invoke QueryInterface on the dispatch object for an IWebBrowser control. The webBrowser control (presumably under the control of the new window) could then navigate to the page of the original context. However... this too was a pretty messy solution and in the end would cause crashes.
Finally, I resorted to manually invoking JavaScript to get the desired behavior. Really?? Was there really no more elegant a solution to my problem than the below mess of code?
if ((pMsg->wParam == 'N') && (GetKeyState(VK_CONTROL) & 0x8000) && !(GetKeyState(VK_SHIFT) & 0x8000) && !(GetKeyState(VK_MENU) & 0x8000))
{
LPDISPATCH pDisp = CHtmlView::GetHtmlDocument();
IHTMLDocument2 *pDoc;
if (SUCCEEDED(pDisp->QueryInterface(IID_IHTMLDocument2, (void **)&pDoc)))
{
IHTMLWindow2* pWnd;
pDoc->get_parentWindow(&pWnd);
BSTR bStrLang = ::SysAllocString(L"JavaScript");
CString sCode(L"window.open(\"");
sCode.Append(GetLocationURL().GetBuffer());
sCode.Append(L"\");");
BSTR bStrCode = sCode.AllocSysString();
COleVariant retVal;
pWnd->execScript(bStrCode, bStrLang, retVal);
::SysFreeString(bStrLang);
::SysFreeString(bStrCode);
pDoc->Release();
}
pDisp->Release();
I find it hard to believe that I must resort to such hackery as this to get something as simple as opening a new window when the user presses Ctrl+N.
Please stackoverflow, please point out the clearly obvious thing I overlooked.
Ctrl-N in IE starts a new window on the same session. In your case, window.open or webBrowser.Navigate2 will create a window on a new session, because it will be run by iexplore.exe process which is separate from your app. The session is shared per-process, this is how the underlying UrlMon library works. So you'll loose all cookies and authentication cache for the new window. On the other hand, when you create a new window which hosts WebBrowser control within your own app process, you'll keep the session.
If such behavior is OK for your needs, try first your initial Navigate2 approach, precededing it with AllowSetForegroundWindow(ASFW_ANY) call. If the new window still doesn't receive the focus correctly, you can try creating an instance of InternetExplorer.Application out-of-proc COM object, and use the same IWebBrowser2 interface to automate it. Below is a simple C# app which works OK for me, the new window is correctly brought to the foreground, no focus issues. It should not be a problem to do the same with MFC.
using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace IeApp
{
public partial class MainForm : Form
{
// get the underlying WebBrowser ActiveX object;
// this code depends on SHDocVw.dll COM interop assembly,
// generate SHDocVw.dll: "tlbimp.exe ieframe.dll",
// and add as a reference to the project
public MainForm()
{
InitializeComponent();
}
private void NewWindow_Click(object sender, EventArgs e)
{
AllowSetForegroundWindow(ASFW_ANY);
// could do: var ie = new SHDocVw.InternetExplorer()
var ie = (SHDocVw.InternetExplorer)Activator.CreateInstance(Type.GetTypeFromProgID("InternetExplorer.Application"));
ie.Visible = true;
ie.Navigate("http://www.example.com");
}
const int ASFW_ANY = -1;
[DllImport("user32.dll")]
static extern bool AllowSetForegroundWindow(int dwProcessId);
}
}
I have a setup application that if user clicks the same setup twice, they would get the pop up message "Another setup instance already running". Upon clicking OK on that message I want to put focus back on the existing installation window which has been running. I currently have the following codes:
if("setup.exe" == CString(buffer))
EnumWindows(EnumWindowsProc,(LPARAM)processID);
BOOL CALLBACK EnumWindowsProc(HWND windowHandle,LPARAM lParam)
{
DWORD searchedProcessId = (DWORD)lParam;
DWORD windowProcessId = 0;
GetWindowThreadProcessId(windowHandle,&windowProcessId);
if(searchedProcessId == windowProcessId)
{
//Set focus when detects the right window.
SetForegroundWindow(windowHandle);
return FALSE;
}
return TRUE;
}
The above code works if I stay on the first screen/step on the installation wizard (install shield).
When I move to the next screen on the installation wizard, this focus logic no longer works. Upon debugging I found that the function GetWindowThreadProcessId could not find any windowProcessID that match searchedProcessId. I also confirmed the following:
the searchProcessId value remains the same whether I am on the 1st or 2nd installation screen.
I confirmed I see the searchProcessID value exists when I view in in the window task manager.
I read up on GetWindowThreadProcessId and see the following note: "The return value is the identifier of the thread that created the window." In my own interpretation, was this because the 2nd step/screen on the wizard is generated by its own thread?
I tried to play around with EnumChildWindow() function but that did not help. I'd be very appricated if anyone able to point me in the right direction of trying to get this to work?
I would use Spy++ which comes with Visual Studio or a similar system monitoring tool to show you all the windows/threads so you can try to confirm exactly what the install wizard is doing. Chances are EnumWindows() is working just fine and it is a problem with your code or your assumptions of how things work.
So I thought this would be pretty simple, but I forgot it's MFC. Instead of registering a notification listener for data model changes that would possibly require a GUI update on each individual control I figure why not register it once and then send a message to all the open dock panes and allow them to update their controls as needed on their own terms for efficiency.
My callback function for handling the notification from the server looks something like this:
void CMainFrame::ChangeCallback(uint32_t nNewVersion, const std::vector<uint32_t>& anChangedObjectTypes)
{
CObList panes;
GetDockingManager()->GetPaneList(panes); // assert failure
if (!panes.IsEmpty())
{
POSITION pos = panes.GetHeadPosition();
while (pos)
{
CDockablePane* pPane = dynamic_cast<CDockablePane*>(panes.GetNext(pos));
if (pPane)
pPane->PostMessage(DM_REFRESH, nNewVersion);
}
}
}
The error I am getting is an assertion failure on line 926 of wincore.cpp
CHandleMap* pMap = afxMapHWND();
ASSERT(pMap != NULL); // right here
There is a comment below this saying this can happen if you pass controls across threads however this is a single threaded MFC application and this is all being done from the main frame.
Does anyone know what else can cause this?
If there is another way to go about sending a message to all the open CDockablePane derived windows in MFC that works as well ...
Here's the obvious workaround that I didn't want to have to do but after hours of debugging and no response here I guess this is a viable answer:
I added std::vector<CDockPane*> m_dockList; to the members of CMainFrame
Now after each call to AddPane in various places that can create and open new dock panes I make a subsequent call to push_back and then I override CDockablePane::OnClose like so:
CMainFrame* pMainFrame = reinterpret_cast<CMainFrame*>(AfxGetMainWnd());
if (pMainFrame)
{
std::vector<CDockPane*>::const_iterator found(
std::find(pMainFrame->DockList()->begin(), pMainFrame->DockList()->end(), this));
if (found != pMainFrame->DockList()->end())
pMainFrame->DockList()->erase(found);
}
CDockablePane::OnClose();
Now this list will only contain pointers to open dock panes which allows me to handle the event notification in my callback and simply do a for loop and PostMessage to each.
My application (the bootstrap application for an installer that I'm working on needs to launch some other applications (my installer and third party installers for my installer's prerequisites) and wait for them to complete. In order to allow the GUI to do screen updates while waiting for an app to complete, I put a message pump in the wait loop using the 'MFC-compatible' example in the Visual Studio documentation on idle loop processing as a guideline. My code (which is in a member function of a CWinApp-derived class) is as follows:
if (::CreateProcess(lpAppName, szCmdLineBuffer, NULL, NULL, TRUE, 0, NULL, NULL,
&StartupInfo, &ProcessInfo))
{
::GetExitCodeProcess(ProcessInfo.hProcess, &dwExitCode);
if (bWait)
while (dwExitCode == STILL_ACTIVE)
{
// In order to allow updates of the GUI to happen while we're waiting for
// the application to finish, we must run a mini message pump here to
// allow messages to go through and get processed. This message pump
// performs much like MFC's main message pump found in CWinThread::Run().
MSG msg;
while (::PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE))
{
if (!PumpMessage())
{
// a termination message (e.g. WM_DESTROY)
// was processed, so we need to stop waiting
dwExitCode = ERROR_CANT_WAIT;
::PostQuitMessage(0);
break;
}
}
// let MFC do its idle processing
LONG nIdle = 0;
while (OnIdle(nIdle++))
;
if (dwExitCode == STILL_ACTIVE) // was a termination message processed?
{
// no; wait for .1 second to see if the application is finished
::WaitForSingleObject(ProcessInfo.hProcess, 100);
::GetExitCodeProcess(ProcessInfo.hProcess, &dwExitCode);
}
}
::CloseHandle(ProcessInfo.hProcess);
::CloseHandle(ProcessInfo.hThread);
}
else
dwExitCode = ::GetLastError();
The problem that I'm having is that, at some point, this message pump seems to free up window and menu handles on the window that I have open at the time this code is run. I did a walk through in the debugger, and at no time did it ever get into the body of the if (!PumpMessage()) statement, so I don't know what's going on here to cause the window and menu handles to go south. If I don't have the message pump, everything works fine, except that the GUI can't update itself while the wait loop is running.
Does anyone have any ideas as to how to make this work? Alternatively, I'd like to launch a worker thread to launch the second app if bWait is TRUE, but I've never done anything with threads before, so I'll need some advice on how to do it without introducing synchronization issues, etc. (Code examples would be greatly appreciated in either case.)
I've also posted this question on the Microsoft forums, and thanks to the help of one Doug Harris at Microsoft, I found out my problem with my HWND and HMENU values was, indeed due to stale CWwnd* and CMenu* pointers (obtained using GetMenu() and GetDialogItem() calls. Getting the pointers again after launching the second app solved that problem. Also, he pointed me to a web site* that showed a better way of doing my loop using MsgWaitForMultipleObjects() to control it that doesn't involve the busy work of waiting a set amount of time and polling the process for an exit code.
My loop now looks like this:
if (bWait)
{
// In order to allow updates of the GUI to happen while we're
// waiting for the application to finish, we must run a message
// pump here to allow messages to go through and get processed.
LONG nIdleCount = 0;
for (;;)
{
MSG msg;
if (::PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE))
PumpMessage();
else //if (!OnIdle(nIdleCount++))
{
nIdleCount = 0;
if (!PeekMessage(&msg, NULL, 0, 0, PM_NOREMOVE))
{
DWORD nRes = ::MsgWaitForMultipleObjects(1, &ProcessInfo.hProcess,
FALSE, INFINITE, QS_ALLEVENTS);
if (nRes == WAIT_OBJECT_0)
break;
}
}
}
}
::GetExitCodeProcess(ProcessInfo.hProcess, &dwExitCode);
*That Web site, if you're curious, is: http://members.cox.net/doug_web/threads.htm
I think your problem is in WaitForSingleObject
Looking in MSDN you see this
Use caution when calling the wait functions and code that directly or indirectly creates windows. If a thread creates any windows, it must process messages. Message broadcasts are sent to all windows in the system. A thread that uses a wait function with no time-out interval may cause the system to become deadlocked. Two examples of code that indirectly creates windows are DDE and the CoInitialize function. Therefore, if you have a thread that creates windows, use MsgWaitForMultipleObjects or MsgWaitForMultipleObjectsEx, rather than WaitForSingleObject.
In my code in the message pump use use MsgWaitForMultipleObjects (doc).
With a call this call.
MsgWaitForMultipleObjects(1, &ProcessInfo.hProcess, FALSE, 100, QS_ALLEVENTS);
This should stop your problem with the resources dissapearing.
When you say that window and menu handles seem to be being freed, do you mean that you've got actual HWND and HMENU values that no longer seem to work, or have you got MFC CWnd* and CMenu* variables that fail?
If the latter, the problem is most likely that you're getting the CWnd* pointers by calling CWnd::FromHandle() (or CMenu::FromHandle()) somewhere (or calling something that calls them), and OnIdle() is discarding them.
The underlying reason is that MFC maintains a map from window (or menu, etc.) handles to CWnd* objects in the system. When CWnd::FromHandle() is called, it looks for a match in the map: if one is found, it's returned. If not, a new, temporary CWnd is created, added to the map, and returned. The idea behind OnIdle() is that when it's called all message processing is done, so OnIdle() discards any of these temporary CWnd objects that still exist. That's why the CWnd::FromHandle() documentation warns that the returned pointer may be temporary.
The "correct" solution to this is to not hang onto the CWnd* pointers returned from CWnd::FromHandle(). Given the simplicity of your application, it might be easier to just remove the call OnIdle(): this shouldn't have any negative effects on an installer.
Of course, this is all something of a guess, but it sounds plausible...
There is a Windows function called DisableProcessWindowsGhosting (see http://msdn.microsoft.com/en-us/library/ms648415(v=vs.85).aspx) that prevents Windows from 'ghosting' your window, and continue updating the window (your animation).