Im using a spin button and want to read it's position.
I've overwritten OnDeltaposSpin(...) , but then i have to evaluate the NMHDR. If I set *pResult=0, it will do the calculations for me, but my value lags behind.
void CClass::OnDeltaposSpin(NMHDR *pNMHDR, LRESULT *pResult)
{
LPNMUPDOWN pNMUpDown = reinterpret_cast<LPNMUPDOWN>(pNMHDR);
*pResult = 0;
UpdateData(TRUE);
// I want to use the data here
}
So if the Spin is initially 0, the first click won't do anything to my data, the second click gets it to 1, and so on.
Is there another message i can handle that triggers after UDN_DELTAPOS that would work like EN_CHANGE for other controls? Or can i tell the spin control to use the *pResult to do it's calculations inside OnDeltaposSpin?
It looks like UDN_DELTAPOS is used for overriding the position change amount, or preventing a change, but the actual change happens with a WM_VSCROLL (or WM_HSCROLL) message. I suspect those might be the messages you would need to handle to get the results....
(I'm basing this on this doc.)
Related
I have a weird issue with a CTreeView context menu. I was just calling pPopup->TrackPopupMenu() as is active in the code below. No problems, but doesn't automatically update status text and icons. So searching the Internet I found there is a ContextMenuManager for this in the MFC Feature Pack (I'm now using the BCGControlBar Pro which is what the feature pack was based on).
I tried using the ContextMenuManager in the code below (change the #if 1 to 0) and while it works, I find that sometimes (many times) afterwards the selected tree item will not show the highlight, it just flashes and goes back to the item that was right clicked on like TVGN_DROPHIILITE is still on. (I confirmed TVGN_DROPHILITE is what the right click uses to select the tree item via the debug print items on the OnNMRClick() function). Also if I enabled the treeCtrl.SelectDropTarget(NULL) it fixes the issue but I shouldn't have to do that?
I'd really like to use the ContextMenuManager but this issue is a show stopper. Does anyone know what is going on?
void CMyTreeView::OnNMRClick(NMHDR *pNMHDR, LRESULT *pResult)
{
CDebugPrint::DebugPrint(_T("NMRClick: In DropHighlightItem %p\n"), GetTreeCtrl().GetDropHilightItem());
// Send WM_CONTEXTMENU to self
SendMessage(WM_CONTEXTMENU, (WPARAM)m_hWnd, GetMessagePos());
CDebugPrint::DebugPrint(_T("NMRClick: Out DropHighlightItem %p\n"), GetTreeCtrl().GetDropHilightItem());
*pResult = 0;
}
void CMyTreeView::OnContextMenu(CWnd* pWnd, CPoint ptMousePos)
{
HTREEITEM htItem;
CTreeCtrl &treeCtrl=GetTreeCtrl();
//
// ...
//
// the popup is stored in a resource
CMenu menu;
menu.LoadMenu(IDR_TREE_CONTEXT_MENU);
CMenu* pPopup = menu.GetSubMenu(0);
#if 1
UINT id=pPopup->TrackPopupMenu(TPM_LEFTALIGN|TPM_RETURNCMD, ptMousePos.x, ptMousePos.y, this);
#else
CBCGPContextMenuManager *manager = theApp.GetContextMenuManager();
UINT id;
if (manager) {
id=manager->TrackPopupMenu(pPopup->GetSafeHmenu(), ptMousePos.x, ptMousePos.y, this);
// treeCtrl.SelectDropTarget(NULL); // fixes issue
}
else id=0;
#endif
//
// ...
//
}
The TVGN_DROPHILITE is a temporary selection, only valid for the duration of drag-and-drop operation. Why are you messing with that?
You should use TVGN_CARET, if anything.
However, the problem is that right-click doesn't select the clicked item. If you like that behavior (I do), select it yourself.
It is also strange that you // Send WM_CONTEXTMENU to self - the WM_CONTEXTMENU should be sent to you by the system, in response to right click.
I am currently writing a wrapper for an existing application that has its own GUI. I don't have access to original application's source code (unfortunately). The program that I am writing is in C++ and I am making use of WinAPI. I am manipulating target application by simulating button-clocks, ticking checkboxes etc.
The problem I am facing at the moment is following:
I need to make a selection in droplist implemented as WinAPI ComboBox. I am doing it by using macro ComboBox_SetCurSel. The selection in the droplist changes correctly. However in the original application there is a read-only textbox that changes the value depending on the selection in combobox. And this one does not change when I execute ComboBox_SetCurSel.
The assumption I made is that CBN_SELENDOK and/or CBN_SELCHANGE are sent when selecting an entry in ComboBox manually and this is the bit I am not doing when setting the selection with ComboBox_SetCurSel macro.
However due to lack of experience I cannot figure out how to resolve the problem. Who is normally listening for CBN_SELENDOK and CBN_SELCHANGE. Is it main application window, parent element of the combobox or main application thread? How do I find out.
Is there a macro that would do the whole thing? Like changing the selected item in ComboBox and sending all necessary notifications? Is there some smart workaround?
Any help on the subject, or any additional questions that would help to make situation more clear are welcome.
UPDATE: thanks for comment by Jonathan Potter. I am now attempting to send messages explicitly. Here is the part of the code where I am doing it:
int res = ComboBox_SetCurSel(this->handle, index);
if (res == CB_ERR)
{
return false;
}
PostMessage(GetParent(this->handle),WM_COMMAND, MAKEWPARAM(0,CBN_SELENDOK),0);
PostMessage(GetParent(this->handle),WM_COMMAND, MAKEWPARAM(0,CBN_SELCHANGE),0);
Note this->handle is just a handle to ComboBox itself as I have packed it into the structure for convenience. GetParent(this->handle) Should get immediate parent of ComboBox
Still no result. Does the order of messages matter? Also how do I obtain the identifier that needs to go into LOWORD of WPARAM sent along with WM_COMMAND?
ANSWER:
Thanks to AlwaysLearningNewStuff I have found and an answer. I have been sending messages with 0 as LPARAM. Apparently a handle to ComboBox itself neets to be sent as LPARAM in order for solution to work. This would take me ages to figure it out.
#AlwaysLearningNewStuff, you should have posted this as an answer, not a comment.
Also the bit about using GetDlgCtrlID() to get ControlID of the ComboBox is very useful. This makes code more reliable.
Thank you, everyone who participated.
Here is my final code:
if (this->handle == NULL)
{
return false;
}
int res = ComboBox_SetCurSel(this->handle, index);
if (res == CB_ERR)
{
return false;
}
PostMessage(GetParent(this->handle), WM_COMMAND, MAKEWPARAM(GetDlgCtrlID( this->handle ),CBN_SELENDOK),
(LPARAM)(this->handle));
PostMessage(GetParent(this->handle), WM_COMMAND, MAKEWPARAM(GetDlgCtrlID( this->handle ),CBN_SELCHANGE),
(LPARAM)(this->handle));
return true;
You are correct that CBN_SELCHANGE is not sent when using ComboBox_SetCurSel(), and the documentation says as much:
The CBN_SELCHANGE notification code is not sent when the current selection is set using the CB_SETCURSEL message.
So you have to send the notifications manually. However, you are missing key elements in your messages - the ComboBox's Control ID and HWND. The parent window uses those to identify which child control is sending messages to it so it can then act accordingly.
Try this instead:
int res = ComboBox_SetCurSel(this->handle, index);
if (res == CB_ERR)
{
return false;
}
HWND hParent = GetParent(this->handle);
int iCtrlId = GetDlgCtrlID(this->handle);
if (GetWindowLong(this->handle, GWL_STYLE) & CBS_SIMPLE)
PostMessage(hParent, WM_COMMAND, MAKEWPARAM(iCtrlId,CBN_SELENDOK), LPARAM(this->handle));
PostMessage(hParent, WM_COMMAND, MAKEWPARAM(iCtrlId,CBN_SELCHANGE), LPARAM(this->handle));
I have 3 list control on one dialog box but only one is showing focus.
if i clicked on 2nd list control then focus disaappear from 1st one.
Means at a time only one list showing focus.
How to make focus remain on all list control on same dialog box?
I don't think that this is technically possible. 'Focus' is an attribute that can only be applied to an individual element.
Think of it in terms of 'focus' is the element that the user is currently interacting with. How would a user be expected to interact with 3 distinct elements at the same time?
As Brian says - focus can only be on one control at time. I'm guessing you are trying to change the other list controls based on the first list box. One way to do it is to associate a variable with each list control, like mListCtrl1, mListCtrl2. Then add a handler for the NM_CLICK event, and have some code like this:
void CTabTestDlg::OnNMClickList3(NMHDR *pNMHDR, LRESULT *pResult)
{
LPNMITEMACTIVATE pNMItemActivate = (LPNMITEMACTIVATE)(pNMHDR);
// TODO: Add your control notification handler code here
*pResult = 0;
UpdateData(true);
DWORD dwData = mListCtrl1.GetItemData(pNMItemActivate->iItem);
int max = mListCtrl2.GetItemCount();
for (int i=0;i<max;i++)
{
DWORD dwData2 = mListCtrl2.GetItemData(i);
if (dwData==dwData2)
{
mListCtrl2.SetItemState(i,LVIS_SELECTED,LVIS_SELECTED);
break;
}
}
UpdateData(false);
}
Note that I have the control set to "Always show selection", and "Single selection"
I have a dialog with a rich-text control. The dialog wants to intercept right-click events on the control; in some cases the dialog should do its own functionality and block the message reaching the control, in other cases it should let the control receive the message.
So I have:
ON_NOTIFY(EN_MSGFILTER, IDC_RICHTEXT, OnRichTextMsgfilter)
void CMyDialog::OnRichTextMsgfilter(NMHDR *pNMHDR, LRESULT *pResult)
{
MSGFILTER *pMsgFilter = reinterpret_cast<MSGFILTER *>(pNMHDR);
*pResult = 0;
if (pMsgFilter->msg == WM_RBUTTONUP)
{
if(...)
*pResult=1;
}
}
I step through the code and pResult is set when it should be, but the control still gets the message. Looking at MSDN it says:
If the control should process the
event, the message returns a zero
value. If the control should ignore
the event, the message returns a
nonzero value.
But the defined message handler signature has no return... I am assuming that's what *pResult is for. Is that not true? If so how do I achieve this?
So i've tried to reproduce this behavior in a simple dialog based app and i really can't -- however, i'm not sure what it is that intercepting the right button message is trying to solve.
That said the following code completely blocks the Left button mouse clicks in my testing (If this returns TRUE the control does not respond to left clicks - however focus will get set to the control on the initial click down and that is more a window manager issue than the control itself)
void CTestDlg::OnMsgfilterRichedit1(NMHDR* pNMHDR, LRESULT* pResult)
{
MSGFILTER *pMsgFilter = reinterpret_cast<MSGFILTER *>(pNMHDR);
if (pMsgFilter->msg == WM_LBUTTONUP || pMsgFilter->msg == WM_LBUTTONDOWN)
{
*pResult = TRUE;
return;
}
*pResult = FALSE;
}
If i change *pResult = TRUE to *pResult = FALSE then the left clicks start working again.
It could be that you want to catch and filter out the WM_RBUTTONDOWN rather than WM_RBUTTONUP to do what you intend, but since i'm unsure what functionality you are trying to filter out i can't say for sure.
The WM_RBUTTONDOWN is stil getting through...
I need to update a combobox with a new value so it changes the reflected text in it. The cleanest way to do this is after the comboboxhas been initialised and with a message.
So I am trying to craft a postmessage to the hwnd that contains the combobox.
So if I want to send a message to it, changing the currently selected item to the nth item, what would the postmessage look like?
I am guessing that it would involve ON_CBN_SELCHANGE, but I can't get it to work right.
You want ComboBox_SetCurSel:
ComboBox_SetCurSel(hWndCombo, n);
or if it's an MFC CComboBox control you can probably do:
m_combo.SetCurSel(2);
I would imagine if you're doing it manually you would also want SendMessage rather than PostMessage. CBN_SELCHANGE is the notification that the control sends back to you when the selection is changed.
Finally, you might want to add the c++ tag to this question.
A concise version:
const int index = 0;
m_comboBox.PostMessage(CBN_SELCHANGE, index);
What might be going wrong is the selection is being changed inside the selection change message handler, which result in another selection change message.
One way to get around this unwanted feedback loop is to add a sentinel to the select change message handler as shown below:
void onSelectChangeHandler(HWND hwnd)
{
static bool fInsideSelectChange = 0;
//-- ignore the change message if this function generated it
if (fInsideSelectChange == 0)
{
//-- turn on the sentinel
fInsideSelectChange = 1;
//-- make the selection changes as required
.....
//-- we are done so turn off the sentinel
fInsideSelectChange = 0;
}
}
if you fx want to change the title - which is the line shown when combobox is closed, then you can do following:
m_ComboBox.DeleteString(0); // first delete previous if any, 0 = visual string
m_ComboBox.AddString(_T("Hello there"));
put this in fx. in OnCloseupCombo - when event close a dropdownbox fires
ON_CBN_CLOSEUP(IDC_COMBO1, OnCloseupCombo)
This change is a new string not a selection of already assigned combobox elements