I have derived the CHtmlEditCtrl, and want to be able to react when the control gets or looses its focus. However the standard MFC OnSetFocus and OnKillFocus handling routines are not being called.
I presume it has something to do with the control actualy being a wrapped ActiveX control.
I have tried giving it the WS_EX_CONTROLPARENT and WS_TABSTOP styles on creation as suggested here, but it did not help.
I found somewhere that I should make my control the event sink for HTMLDocumentEvents2, but I would rather avoid that if possible.
EDIT: Spy++ says I should be getting WM_PARENTNOTIFY and WM_MOUSEACTIVATE messages. However, my Derived Class receives absolutely no messages. I tried it with OnSize and OnCreate too. No message whatsoever is being sent. Any idea?
Related
I have "n" dialogs which have the same base dialog. Each dialog has its own controls
edit boxes
combo boxes
list controls
etc.
In base dialog, how do I set focus messages of each control and,for example, give a Message box with
text("Hello I got focus, my ID is %d")?
The easiest way is using the classical subclassing method. The problem is that WM_SETFOCUS is not pumped through the message Loop, so PreTranslateMessage will not help.
Thee are some nice classes that help to do additional subclassing without disturbing the MFC stuff.
Paul Di Lascia wrote CSubclassWnd. PJ Naughter wrote CHookWnd. And with the ATL has CWindowsImpl.
All this classes allow easy additional subclassing even if a window is already subclassed by the MFC.
You can use "standard subclassing" GetWindowLong/SetWindowLong too.
According to this SO article, you can hook the WM_SETFOCUS message.
You can get the Control ID by using GetDlgCtrlID with the hwnd returned by the hook.
But beware of popping up a MessageBox, that will change the focus and trigger your hook proc, making it go into a loop!
As Jerry already said make a hook, get parent window handler via GetParent() and SendMessage(hParentWND, WM_MESSAGE, lParam, wParam).
Of course, you should handle WM_MESSAGE in your parent window.
Btw, framework calls OnSetFocus function when window gained focus.
I am writing a fairly simple wrapper around Win32 controls/dialogs/windows.
The issue I have is that ListBox's and ComboBox's seem to behave rather differently.
In the base Widget class that I am inheriting from, I override the existing WNDPROC for the control and then handle messages in the new WNDPROC, primarily promoting them to boost::signal events.
The issue is that, while ComboBox's WndProc receives the CBN_SELCHANGE - as expected - ListBox's WndProc does not receive the LBN_SELCHANGE command.
I realize that the dialog/window that owns the control will likely receive this, but I've kind of gone down this rabbit hole already and it feels like a pretty neat solution. Need I back out and have the owners of the controls handle the WM_COMMAND messages (and from there promote it to an event on the control itself).
This is a learning exercise, so please don't remind me about MFC or comment on the value of doing this.
Notification messages are typically sent to a control's parent. Presumably all the windows (i.e. both parent windows and controls) are using the same window procedure? In this case the usual solution is: in the notification handler in your window procedure check if the notification came from the current window. If it did, raise an event; if it didn't resend the message back to the control it came from (where it will be raised as an event).
In .Net there is a feature called KeyPreview. How can I do this in WinApi. Maybe I don't necessarily need this but my hWnd has WM_KEYDOWN, but it does not receive it when my Text Box has focus. How can I achieve this?
Thanks
*Using pure Win32API...
is there an alternative, how could I handle the Text Box's WM_KEYDOWN?
You can try subclassing the edit control. Either "instance subclassing", to trap messages for only one window, or "global subclassing" to trap messages for all windows of that class (in your application, not system-wide).
The example here (http://msdn.microsoft.com/en-us/library/ms997565.aspx) shows how to subclass an edit control and trap the WM_GETDLGCODE message -it wouldn't be that difficult to change it to WM_KEYDOWN.
You may have problems previewing the keys used for dialog commands, e.g. TAB or RETURN, as they may be trapped higher up the food chain. You may need to look at changing WM_GETDLGCODE as well.
If you use MFC you can look at PreTranslateMessage (I am not sure regarding to PreTranslateMessage, but you can easily to verify whether to enough to override the function).
You can set keyboard hook.
There is no such a possibility in WinAPI to catch the messages belonging to controls in window procedure of parent window (although some exceptions exist).
What .NET basically does is that it routes all messages of all controls including their parent window to a single window procedure. Then it's easy to catch all the messages in one place.
This is your way to go - to set window procedures of all the controls into single procedure and there to catch all the messages
As window procedure also receives hwnd parameter, it's then also easy to determine the control to which the message belongs.
I have a custom CWnd-derived MFC control, which works like this:
the control has its own OnPaint, and a black background
clicking anywhere on the control causes an edit control to appear at that location, borderless and with black-background, so it blends in
the user types in this box and hits enter, the box disappears and the control's custom paint functionality renders the same text in the same position on the background.
So our control owns a CCustomEdit, when you click on the background the control is either created or moved, and made visible:
CCustomEdit::Show(Rect &rc,CCustomControl *pParent)
{
if ( !::IsWindow( m_hWnd ) )
{
Create( ES_LEFT | ES_AUTOHSCROLL | WS_CHILD | ES_NOHIDESEL | ES_CENTER | ES_UPPERCASE, rc, pParent, 999 );
}
else
MoveWindow( &rc );
}
The main parts actually work OK (and we're stuck with the approach). But one thing that's not working is that CCustomEdit self-registers for EN_CHANGE events and so on. When CCustomEdit is created as a normal dialog control (CEdit on the dialog template, DDX-bound to a CCustomEdit variable) these work, but within CCustomControl they are not.
CCustomEdit::PreSubclassWindow() calls SetEventmask() and is being called. And CCustomEdit's ON_CHAR handler is also being called for key-presses in the edit box, however the handlers for edit-box messages like EN_CHANGE are not.
Are there any obvious things like changing the style flags? Otherwise, why is my custom control stopping these events reaching the contained edit control?
I'm not sure I understand the situation, but I have a number of control that work roughly in the same way as what I think is happening and they all work, it is possible.
EN_CHANGE for the edit control is send to your CWnd-derived control. Are you reflecting the messages? Have you tried if EN_CHANGE gets to the custom control? From what you are describing, you are expecting EN_CHANGE to end up in CCustomEdit's message dispatcher macro chain automatically, but it doesn't; you need the help of the containing window. Now MFC does most of that for you in a CDialog, but if you roll your own you need to do it manually, or use the message reflection macro's.
I found it... somehow, my SetEventMask() was being overriden. I don't know how or where but when I added an extra call later on to test, most event handlers started getting called.
I can only assume some part of the init code in MFC is responsible.
Just wondering where is best to put functionality in an MFC application that is triggered when the whole window is resized. I was thinking mainfrm but I couldn't seem to capture any OnSize messages...
Can someone tell me what I am doing wrong?
Can someone tell me what I am doing wrong?
You didn't include any interesting details, so here are a few guesses (because of course the mainframe normally gets sent WM_SIZE messages...):
You didn't set up your message handler properly. Perhaps you forgot the message map entry?
You have an existing handler in place for WM_WINDOWPOSCHANGED that fails to call the default window procedure, thereby preventing WM_SIZE messages from being sent.
I am guessing that you are using the Multiple Document Interface ( MDI ) application type. In this case, you should capture the WM_SIZE message in each of your views - the classes you have derived from CView.