How I can get a focus message in MFC? - mfc

I have a dialog box with some CListCtrl. I want that when I click on one of them, receive killfocus or setfocus message.
How I can get it?

The CListCtrl class wraps the Win32 ListView control. That control communicates with its parent (your dialog) via WM_NOTIFY messages.
So you can process WM_NOTIFY messages from your list control in your dialog class. Use the Properties window to create an OnChildNotify handler function and write a switch statement that handles the notification message(s) of interest.
The possible notification messages are listed here in the Windows SDK documentation.

Related

Calling the event handler programmatically in an MFC application

I am working on an MFC application (C++)
My checkbox has an event hander mapped to the ON_BN_CLICKED.
It works fine when the user check/uncheck the box, i.e. the event handler is called.
However, when I check the box programmatically: ((CButton *)this->GetDlgItem(x))-> ->SetCheck(1); the event handler is not called.
What should I do in order to call the event handler programmatically?
This is a normal behavior. The WM_COMMAND is sent when a "click" or "user entry" changed the button.
This is not contignous with child controls. Other child controls like an edit control also send a WM_COMMAND EN_CHANGE message when SetWindowText is executed by the program (the MFC blocks this message in a DoDataExchange).
Try to send BN_CLICKED:
this->SendMessage(WM_COMMAND,
MAKELONG(IDC_BUTTON1, BN_CLICKED),
((CButton *)this->GetDlgItem(x))->GetSafeHwnd());

MFC Message flow for controls?

In MFC, suppose I have a dialog box, and in this box, it has a child CListCtrl, then I use mouse to click this CListCtrl, we know that eventually an WM_LBUTTONDOWN message is sent to CListCtrl. My question is: How does this WM_LBUTTONDOWN message get there?
Two possibilities:
Dialog box first gets this WM_LBUTTONDOWN message , and it finds that mouse click occurs in its child window, then it forwards this message to CListCtrl.
CListCtrl first gets this WM_LBUTTONDOWN message, it can process this message, and if it doesn't care it will forward this message to parent window, i.e. dialog box for further processing.
Which one is true?
Thanks.
Input messages are never sent to a window. They are posted to the message queue associated with a window, waiting to be retrieved through one of the message retrieval functions (GetMessage, PeekMessage, etc.).
Depending on whether the dialog box is modal or modeless, messages are retrieved by the nested modal loop (for modal dialogs) or the application's message loop. The message is then passed on to DispatchMessage, to find the recipient (starting from the topmost visible window under the mouse pointer, that is neither disabled nor transparent), and call into the associated window's window procedure. The window procedure can decide, whether it handles the message or not. A window procedure typically calls DefWindowProc to perform default processing, if it doesn't handle a message.
To summarize: The application's message loop (or the nested modal message loop) gets to see the message first, and instructs the window manager to deliver the message to the respective recipient.
A thorough description on Windows message processing is available at About Messages and Message Queues. The description is specific to the Windows API. Since MFC is just a wrapper around the Windows API, the contents apply to MFC as well, even though some of the concepts are hidden in a typical MFC application.

Adding event handler to user defined window classes

I am using MFC MDI. I create a window the main document window. I create another window(lets call it second window) as child of MDI Window View, then I create child window(third window) of second window. Again I need to create another window, child window of third window. I have a button on the ribbon and I want to call message handler in the third window to handle this command. I have added message map and all required stuff but it is not calling the message handler. If I define the message handler in MDI window view, it catches the event. If I dont delare the message handler in my main CWinApp class or MDI window View class the button appears disabled.
All my child view classes are inherited from CWnd and main MDI window is derived from CView. Please let me know what I am missing here.
Saba
I am at the loss here. You are using MFC; why using events? use command messages and command message handlers instead events.
Use MFC implemented and well working command routing.
MFC doesnt route messages generated by clicking Ribbon buttons to child windows. If we want to send messages to child windows of MDI windows we need to do it ourselves. Ribbon button's messages are either passed to active MDI window or CWinApp class.

Visual C++ MFC Application- Event not receiving in child dialog

I have created a derived control handling events as mouse movement, left button down up,down etc.
And I have a popup dialog and within that dialog, three child dialogs.
When I use the derived control in my popup dialog, it is working properly.
But when I place my control in any of the child dialog, the mouse events are not handled.
Please suggest a solution.
Thanks in advance,
Madhan
Must to pass forward the events. Catch them on the child dialog with the respective message handlers and then forward them using the ::SendMessage method.
The popup dialog possibly catched up automatically the mouse events and enabled to be forwarded towards.

How to get notified of textbox focus?

Using a Windows 7 touch device Windows shows this little touch-keyboard indicator (tabing this will bring up the touch on screen keyboard) when you tab/focus a textbox or kind of input field (Notepad etc.).
I want to write an application that gets notified when exactly that happens, a textbox (etc.) gets focused (no matter which application).
Are applications informed about focusing in other applications, do I need to hook something?
Is there a way in doing so in c++?
I believe the SetWinEventHook function and specifically the EVENT_OBJECT_FOCUS event is what you are looking for.
From the MSDN description:
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. Server applications send this event for their accessible objects.
The hwnd parameter of the WinEventProc callback function identifies the window that receives the keyboard focus.