I have some window. User can drag it, resize etc. At some point there can be a message that should be shown in modal window. I'm creating such a window as child and setting parent window to disabled. Everything works ok except the case when I'm dragging a parent window during the child creation. I used spy to see messages and found that in that case my child window doesn't receives WM_ENTERSIZEMOVE message. It seems that parent's WM_ENTERSIZEMOVE blocks one for child. I tried to manually send WM_EXITSIZEMOVE for the parent but unfortunatelly this doesn't works.
Send the WM_CANCELMODE message to your parent window before displaying the dialog box.
Sent to cancel certain modes, such as mouse capture. For example, the
system sends this message to the active window when a dialog box or
message box is displayed. Certain functions also send this message
explicitly to the specified window regardless of whether it is the
active window. For example, the EnableWindow function sends this
message when disabling the specified window
It is possible to check whenever the X/Y position of the window changed? Also, if it's possible to check if the Window Width/Height changed too.
You're looking for the WM_MOVE and WM_SIZE messages.
As already answered, you can handle WM_SIZE and WM_MOVE. But you can also intercept the messages before they have any effect by checking WM_WINDOWPOSCHANGING (except in the case where a call to SetWindowPos passes SWP_NOSENDCHANGING - but that is usually deliberate and completely under your control). This message is useful for cleanly handling window size/position restrictions or doing window snapping. If you force stuff to happen during WM_SIZE or WM_MOVE you will get flickering etc.
I tried to create button (child window) inside WM_NCCREATE message, and its position seemed to be created respected to screen coordinates, rather than client coordinates. At first, I thought WM_CREATE and WM_NCCREATE provide us the same handle to window, but this seem to be untrue. Therefore, can anyone explain me the differences between WM_CREATE and WM_NCCREATE messages? Also what are the differences between handle to window in WM_CREATE and in WM_NCCREATE?
WM_NCCREATE is an example of an arms race in progress. It seems to have been introduced to serve a need where DefWindowProc (or the base window proc of a commonly subclassed window) needed to perform some initialization perhaps before WM_CREATE was processed (or to make up for the fact that many window implementations handle WM_CREATE directly and return TRUE rather than passing it on to DefWindowProc).
WM_NCCREATE therefore is the message you should respond to if you are implementing a default window procedure, that needs to perform initialization before the users window proc handles the WM_CREATE message. WM_NCCREATE also MUST be passed on to the appropriate DefWindowProc, probably before you do your own processing as some lower level aspects of the window are clearly in an uninitialized state before WM_NCCREATE is processed.
If trying to guarantee first-look processing is NOT your consideration, then WM_CREATE is the appropriate place to perform your window initialization: All other layers that might have jist-in-time setup via WM_NCCREATE have been done, and the window is in a stable state wrt things like its non client metrics, screen position etc.
Or: If you don't know why you should use WM_NCCREATE over WM_CREATE, then you should not be using WM_NCCREATE.
The WM_NC messages are for the non-client area, i.e. the window border and caption. For your needs you are not interested in these non-client messages.
Per MSDN:
WM_NCCREATE:
Sent prior to the WM_CREATE message
when a window is first created.
Return Value:
If an application processes this
message, it should return TRUE to
continue creation of the window. If
the application returns FALSE, the
CreateWindow or CreateWindowEx
function will return a NULL handle.
WM_CREATE:
Sent when an application requests that
a window be created by calling the
CreateWindowEx or CreateWindow
function. (The message is sent before
the function returns.) The window
procedure of the new window receives
this message after the window is
created, but before the window becomes
visible.
Return Value:
If an application processes this
message, it should return zero to
continue creation of the window. If
the application returns –1, the window
is destroyed and the CreateWindowEx or
CreateWindow function returns a NULL
handle.
This device context includes the window title bar, menu, scroll bars, and frame in addition to the client
area. Applications programs rarely use the GetWindowDC function. If you want to experiment with it,
you should also trap the WM_NCPAINT ("nonclient paint") message, which is the message Windows
uses to draw on the nonclient areas of the window.
from:《Programming Windows Fifth Edition》 -Charles Petzold
So I think it's believable, although MSDN didn't say it。
Not sure why you're creating a button in the WM_NCCREATE -- because the window onto which the button will appear doesn't exist yet, hence (I believe) the destop coords. WM_NCCREATE gets sent to you when the 'non-client' areas of the window are about to be created (non-client areas such as the window's border, title bar, etc.)
Are you needing to put a button on the non-client area? If the answer is no, then why not do the button create inside
WM_CREATE.
If you have to create the button for some reason inside WM_NCCREATE, then why not store the window handle returned by your Createwindow() call. Then, inside your WM_CREATE message handler, grab that button's window handle and do a 'MoveWindow(...)' on it using the app window which you should now have coordinates to when you're in the WM_CREATE message handler.
I believe one of the parameters you can pass to your CreateWindow(...) call to create the button allows you to specify an 'SW_...'
flag, such as 'SW_HIDE' if memory serves me correct. So create but don't show the button in WM_NCCREATE handling if you must, then when WM_CREATE comes quickly afterward, do a 'MoveWindow(....window coords,......SW_SHOW,......) etc.
to position and make visible the button.
I have a (parent) window in which a child-window is created by a another library (Ogre3d). Window initialization uses the bare Win32 API.
I'd like to capture the mouse input in my parent window, but it seems like I my WM_MOUSEMOVE events are received only by the child-window, which makes sense, since that fills all of my client-area.
Is there a way to capture the WM_MOUSEMOVE messages in the parent window or (unintrusively) redirect those messages from the child-window?
If you can obtain a handle to the window in question you can subclass it.
In a nutshell, you get to register a callback function that gets a crack at all of the messages sent to the sub-classed window.
The linked article should get you where you need to be.
I'm facing a problem on the Win32 API. I have a program that, when it handles WM_PAINT messages, it calls BeginPaint to clip the region and validate the update region, but the BeginPaint function is always generating a WM_NCPAINT message with the same update region, even if the touched part that needs repainting is only inside the client region.
Do anyone has any clue why this is happening? It's on child windows with the WS_CHILD style.
The MSDN entry for WM_PAINT says:
The function may also send the WM_NCPAINT message to the window procedure if the window frame must be painted and send the WM_ERASEBKGND message if the window background must be erased.
I'm trying to figure out why it is always sending even if the border isn't touched. I test that opening a small Notepad inside the control and minimizing. It doesn't touch the borders of the control, just inside and BeginPaint() generates a WM_NCPAINT.
What happens if you call SetWindowPos and pass SWP_DEFERERASE as argument for the uFlags parameter?
This should prevent generation of the WM_SYNCPAINT message, which would indirectly cause the WM_NCPAINT message to be sent.
I guess the WM_NCPAINT message is always sent with the assumption that the border needs to be repainted as well!