I'm trying to come up with a solution for setting up a notification when focus enters a text field. The end goal in mind is to recreate the type of functionality you see on mobile devices with on screen keyboards.
So far I've been exploring SetWinEventHook with EVENT_OBJECT_FOCUS and GetGUIThreadInfo with GUI_CARETBLINKING.
From the docs:
EVENT_OBJECT_FOCUS
An object has received the keyboard focus. The system sends this event
for the following user interface elements: list-view control, menu
bar, pop-up menu, switch window, tab control, tree view control, and
window object.
GUI_CARETBLINKING The caret's blink state. This bit is set if the
caret is visible.
Using these methods I've come up with this solution:
void TextInputHelper::setupEventHook(FREContext iCtx)
{
ctx = iCtx;
CoInitialize(NULL);
evHook = SetWinEventHook(EVENT_OBJECT_FOCUS, EVENT_OBJECT_END, NULL,
handleEventObjectFocus, 0, 0,
WINEVENT_OUTOFCONTEXT | WINEVENT_SKIPOWNPROCESS);
}
void CALLBACK handleEventObjectFocus(HWINEVENTHOOK hook, DWORD evt, HWND hwnd,
LONG idObj, LONG idChild, DWORD thread, DWORD time)
{
GUITHREADINFO threadInfo;
threadInfo.cbSize = sizeof(GUITHREADINFO);
BOOL result = GetGUIThreadInfo(thread, &threadInfo);
if(threadInfo.flags & GUI_CARETBLINKING)
{
//text field focus
}
}
This does seem to work in some cases but its definitely not reliable. Programs like Notepad an IE seem to work fine but others like Firefox do not. This also will not work for things like text fields on websites because it doesn't look like handleEventObjectFocus will get called.
Does anyone know of another way to approach this problem? I've been searching around and it seems like I might be looking for something in the Accessibility APIs but I haven't been able to dig up to much on it.
Thanks!
edit
To clarify, I'm looking to receive a notification when focus enters any text field. This application is a win32 dll and will never have focus its self.
If you're using standard Windows controls WM_SETFOCUS should do the trick. No need to get fancy with hooking etc.
EDIT: For system wide behavior you can check out SetWindowsHookEx. To catch events system-wide you need to use it from within a DLL. You can use a combination of hooks including one that catches WM_SETFOCUS.
If you're trying to supply an alternative text input method, you should look into "IME" - "Input Method Editor". These are directly supported by the OS.
You can catch the entrance into a text field using the EN_SETFOCUS notification.
WM_FOCUS is for the window itself, not for controls that are in it. Otherwise said, if you want to use WM_FOCUS, you'll have to subclass your EDIT field. It's not necessary here.
EDIT: it wasn't completely clear that you wanted a system-wide behavior. IN that case you have to use an hook (cf. SetWindowsHookEx) as explained in the answer above. Sorry.
Related
I have 2 windows and I want to know which window is on the top of the other?
I tried to test using GetWindowLong and comparing the results but no chance.
LONG wndState1 = ::GetWindowLong(handler1, GWL_EXSTYLE);
LONG wndState2 = ::GetWindowLong(handler2, GWL_EXSTYLE);
both results is equal to 256.
Edited: In the picture below I have the dialog of notepad++ is on top of the FileZilla, How do I Get That by Code.
Is there a trick for that ?
THank you
GetWindowLong is used to retrieve style information for a particular window.
In order to get the top-most window, use
HWND WINAPI GetForegroundWindow(void);
You will still need to know the window handles (HWND) for the processes you're interested in so that you can find out which process owns the foreground window.
Note that this API can only return the window that the user is interacting with (or has interacted with most recently).
UPDATE:
I agree with Remy that there isn't any API to do that. The only way I can think of to actually do that is to install a global hook and intercept certain messages (e.g. WM_ACTIVATE, WM_SETFOCUS and so on). Since you will also retrieve the timestamps for the messages, it should be simple to infer which window is on top of any other window. This will require you to write a dll but this is relatively simple to do. I can't guarantee this will work either though I think it will (I've written a global hook but never used it to find out the z-order of windows)
I am trying to make my program click the button of another program. The part I am having issues with is identifying the handle of the button. This is the code I have so far:
BOOL CALLBACK EnumChildProc(HWND windowHandle, LPARAM lParam)
{
cout << "hwnd_Child = " << windowHandle << endl;
cout<<"WindowId: "<<GetWindowLongPtr(windowHandle, GWLP_ID)<<endl;
return TRUE;
}
HWND windowHandle = FindWindow(NULL, "nameOfProgramWindow");
EnumChildWindows(windowHandle, EnumChildProc, 0);
What is happening so far is that I find the handle of the parent window of the program. With that handle, I use the EnumChildWindows function to go through each of the child windows... and in 1 of those child windows I will have the window which contains 3 buttons, 1 of which is the button I want to press. In the callback function I need to put the GetWindowLongPtr() function to get the ID of the window I am looking for ... there is a problem though...
The problem is that each time I run this program again, the handle and the ID of the window which contains the buttons will change... So I can't use spy++ to get an ID to compare with the ID gotten since The ID changes. I have tested it out even (thats why i have all the "cout" code there);
Question: How do I then identify the window I am looking for in the callback function (and possibly the button I am looking for)?? PLEASE DON'T say spy++ cause the ID and Handle values change every time I open the program
The handle is always going to change each time that the code runs. Windows dynamically assigns handles. Nothing you or anyone else can do about that. It would be more surprising if it didn't change.
And it's no particular conspiracy that the control's ID changes. The only way that stays the same is if it's hard-coded in the original application, most probably via the use of a resource file. But if the programmer dynamically generates the controls at run-time, then there's no reason they would need to use the same ID. Just so long as they keep track of that ID in some kind of data structure if and when they need it.
You may be able to find another property of the button control that is constant—like the caption. But that's certainly not guaranteed. Lots of programs change the caption to reflect the current state.
The application developer is under no obligation to make it easy for another program to mess with the internals of something that does not belong to them.
Have you considered doing this the right way using UI Automation?
I would like to use c++ without mfc(and not clr) in order to modify textbox's and activate a button on a form outside of my project. I don't know where to start. I've done a lot of searching but can only find information for VB. A starting point would help.
Thanks.
I tried this and it doesn't seem to work.
HWND fWindow = FindWindow(NULL ,(LPCWSTR)"title");
and I also tried this
HWND fWindow = FindWindow(NULL ,LPCWSTR("title"));
I ALSO tried using LPTSTR instead of LPCWSTR, incase it was a unicode deal.
Maybe I don't understand this microsoft LPCWSTR and LPTSTR crap.
I also tried
HWND fWindow = FindWindow(NULL,TEXT("title"));
and that didn't work.
I guess the windows api must just be broken.
I tried the function on other programs...I'm using xp and I tried catching the calculator, and an explorer window, and something else. But I got nothing.
Heres some of the exact code I'm using to try and figure this out.
HWND face = NULL;
face = FindWindow(NULL,TEXT("My Computer"));
LPSTR title = TEXT("");
GetWindowText(face,title,250);
if(face != NULL)
{
MessageBox(NULL,title,TEXT("WOOP"),1);
}
face = nothing.
title = ""
Bear in mind, I'm not actually trying to hook explorer, I just want to figure out how to get it to work.
Use spy++ or winspector to see the actual "text" of the window.
(Strictly speaking, the caption of the window need not match it's window text. Especially true of "fancy" windows which paint their own caption.)
The following works fine for me (using Calc.exe to test).
HWND hwnd = NULL;
hwnd = FindWindow(NULL,_T("Calculator"));
TCHAR title[251];
if(hwnd != NULL)
{
GetWindowText(hwnd,title,250);
MessageBox(NULL,title,_T("WOOP"),MB_OK);
}
else
MessageBox(NULL,_T("No such window."),_T("OOPS"),MB_OK);
Edit: You should have used _TEXT instead of TEXT.
One way to do this is to use FindWindow to get a handle to the form. Then if you know the button and edit window Ids, you can use GetDlgItem to get their window handles. If you dont know the ids, you can use EnumChildWindows to examine all of the controls on the form.
Once you have the window handles for the controls, you can use SetWindowText to set the text on the edit control, and send a WM_COMMAND message to the form window with the button ID as the command value to make the form think that the button has been clicked.
There are a lot of ways to go about this once you have the correct window handles. There are security issues when you use the window handles of another process, but if the process isn't secured, then inter-process use of window handles just works. For a secured process, you won't be able to find out the window handles.
The windows API provides Methods for this. These should be independent of MFC and CLR, as they are plain win32. I had a project once accessing the Form fields of an Applictation from a loaded DLL (don't ask why).
you might want to look here (Codeproject)
or here (msdn)
At first, you need to obtain a handle to the process you want to access.
When have this, you can use GetDlgItem() (search msdn for that) to retrieve a handle to the desired textbox.
With this handle, you should be able to modify the control in question.
If your trying to get big (and do some more UI automation), you sould have a closer look at these:
Microsoft Active Accessibility
IAccessible2
Microsoft UI Automation
Windows Automation API (Win7)
I need to enumerate all running applications. In particular, all top windows. And for every window I need to add my custom item to the system menu of that window.
How can I accomplish that in C++?
Update.
I would be more than happy to have a solution for Windows, MacOS, and Ubuntu (though, I'm not sure if MacOS and Ubuntu have such thing as 'system menu').
For Windows, another way to get the top-level windows (besides EnumWindows, which uses a callback) is to get the first child of the desktop and then retrieve all its siblings:
HWND wnd = GetWindow(GetDesktopWindow(), GW_CHILD);
while (wnd) {
// handle 'wnd' here
// ...
wnd = GetNextWindow(wnd, GW_HWNDNEXT);
}
As for getting the system menu, use the GetSystemMenu function, with FALSE as the second argument. The GetMenu mentioned in the other answers returns the normal window menu.
Note, however, that while adding a custom menu item to a foreign process's window is easy, responding to the selection of that item is a bit tricky. You'll either have to inject some code to the process in order to be able to subclass the window, or install a global hook (probably a WH_GETMESSAGE or WH_CBT type) to monitor WM_SYSCOMMAND messages.
Once you have another window's top level handle, you may be able to call GetMenu() to retrieve the Window's system menu and then modify it, eg:
HMENU hMenu = GetMenu(hwndNext);
You can use EnumWindows() to enumerate top level Windows.
I don't have a specific answer for the second part of your question, but if you subclass the window, I imagine you can modify the system menu.
EDIT: or do what Chris said: call GetMenu()
Re: the update - please note that not even Microsoft Windows requires windows to have a sytem menu. GetMenu( ) may return 0. You'll need to intercept window creation as well, because each new top window presumably needs it too.
Also, what you propose is rather intrusive to other applications. How are you going to ensure they don't break when you modify their menus? And how are you going to ensure you suppress the messages? In particular, how will you ensure you intercept them before anyone else sees them? To quote Raymond Chen, imagine what happens if two programs would try that.
I have the following unmanaged C++ code:
MessageBox( NULL, strMessage, "Cool Product", MB_RETRYCANCEL | MB_ICONEXCLAMATION);
I want to disable the RETRY button for 10 seconds (for example), then enable it.
How can I do this?
Like #ffpf says, you need to make your own dialog to do this, using MFC, ATL, raw Win32, etc.
Then create a timer that would enable and disable the button.
You cannot directly manipulate the MessageBox controls, but you can use a hack. Install a WH_CBT hook just before displaying the dialog and handle the HCBT_ACTIVATE event. This will give you the HWND of the message box, so that you can do whatever you want with it (subclass it, manage its buttons and set a timer).
You can find a Custom MessageBox tutorial with demo code in James Brown's site.
With the standard MessageBox call, you can't. You'd need to implement your own MessageBox in order to do this.
I don't believe this is possible with the standard message box call.
You would probably be better off writing your own message box that includes this functionality.
(Or, you could write a separate thread that continually watches the screen waiting for that message box to appear, disable the retry button, wait 10 seconds and reenable it. Not fun. Seriously, do it the other way.)
Since Vista you can use taskdialog -- a more sophisticated dialog than a simple message box. More info and links here.
I agree with efotinis, it's not impossible, once you have the HWND you can do whatever you want with it. It is just a matter of "do you really need the hacks or are you better off with just creating your own message box dialog"?
Another not so nice way of finding the HWND (which would obviously give you access to eveything in the message box) would be to start a thread and ciclically poll for the message box handle by using EnumChildWindows. But I personally would prefer the WH_CBT hook also.