I've just added an Item-Filter-Feature to a CComboBox derived class called
ComboBoxFbp in an old MFC application.
BOOL CComboBoxFbp::OnEditChange()
{
CString csText;
if (m_wFbpMode & _FbpMode_UserTextFiltersList) {
GetWindowText(csText);
// This makes the DropDown "flicker"
// ShowDropDown(false);
// Just insert items that match
FilterItems(csText);
// Open DropDown (does nothing if already open)
ShowDropDown(true);
}
return FALSE; // Notification weiterleiten
}
void CComboBoxFbp::FilterItems(CString csFilterText)
{
CString csCurText;
int nCurItem;
DWORD wCurCursor;
// Text/selection/cursos restore
GetWindowText(csCurText);
nCurItem = GetCurSel();
if (nCurItem != CB_ERR && nCurItem >= 0 && nCurItem < GetCount()) {
CString csCurItemText;
GetLBText(nCurItem, csCurItemText);
if (csCurItemText == csCurText) csCurText = csCurItemText;
else nCurItem = CB_ERR;
} else {
nCurItem = CB_ERR;
}
wCurCursor = GetEditSel();
// Delete all items
ResetContent();
csFilterText.MakeLower();
// Add just the items (from the vector of all possibles) that fit
for (auto item : m_vItems)
{
CString csItemText = item.first;
csItemText.MakeLower();
if (!csFilterText.IsEmpty() && csItemText.Find(csFilterText) < 0)
continue;
const int i = AddString(item.first);
SetItemData(i, item.second);
}
// Text/selection/cursos restore
if (nCurItem != CB_ERR) SelectString(-1, csCurText);
else SetWindowText(csCurText);
SetEditSel(LOWORD(wCurCursor), HIWORD(wCurCursor));
}
So when the user types, the long list of items in the DropDown gets filtered accordingly. Everything's fine so far.
The size/height of the ListBox/DropDown doesn't change once its open. It does change accordingly when die DropDown opens. Meaning if there are only 2 items the DropDown is only 2 items high.
My issue
When the user enters a text where just one item fits the DropDown is only 1 item in height (this happens with some user workflows, i.e. user manually closes & opens the DropDown).
Now when the user now changes the text so multiple items are fitting the height stays 1 item and it looks weird as even the scrollbar doesn't look correct as it doesn't fit.
What I've tried so far
I cannot use CComboBox::SetMinVisibleItems (or the MSG behind it) as it only works in a Unicode CharacterSet (which I'm not able to change in this old application) and from WinVista onwards (app runs on WinXP).
The only other option is to close and open the DropDown so it gets redrawn correctly with the correct height (see // This makes the DropDown "flicker" in Source Code above).
Now going with option 2 I don't want the user to see the closing and opening ("flicker") of the DropDown after every key he is pressing.
To prevent this I've tried a couple of solutions I've found but none works in my case with a ComboBox-DropDown. Here's a list of methods I've put just before the ShowDropDown(false) and just after the ShowDropDown(true).
EnableWindow(false/true);
(Un)LockWindowUpdate();
SendMessage(WM_SETREDRAW, FALSE/TRUE, 0)
With all three calls I still see the DropDown closing/opening.
Do you guys have other ideas how I can prevent this flicker?
Thanks in advance
Soko
This is an XY question.
It should be easier to use the following approach to adjust the height of the ComboBox
Use GetComboBoxInfo to get the handle of the list control.
Use OnChildNotify or ON_CONTROL_REFLECT and capture CBN_DROPDOWN.
In the handler of the message resize the window as needed Use SetWindowPos and just change the size.
VS2010 with an MDI document layout using tabs along the top to switch between documents. Each document is a "live" view into a database, where the persistent data per document is a group of configuration settings.
We would like to allow the user to rearrange the tabs (this functionality is built in), but need to persist this new order. Right now it appears the document z-order is not affected by moving the tabs around. when closing the app, the documents close in the order they were opened so this is not helpful in determining the final tab order on close.
We are using the EnableMDITabbedGroups(TRUE, mdiTabParams) with m_bEnableTabSwap = TRUE which is the default.
Thanks! Ended up with the following solution in the MainFrame::OnClose() method.
Note that this code example uses two custom classes of 1) CSpectraAnalysisUtilityView which inherits from CView and 2) CReviewDataFolder which is our object that we needed to update the recent Tab Order.
This code solution also implements the GetMDITabGroups in case there are multiple group windows open.
void CMainFrame::OnClose()
{
iReviewDataFolderOrder = 1;
const CObList& tabGroups =m_wndClientArea.GetMDITabGroups();
if (0 < tabGroups.GetCount())
{
POSITION pos = tabGroups.GetHeadPosition();
CMFCTabCtrl* pCrtTabCtrl;
while(pos != NULL)
{
pCrtTabCtrl=DYNAMIC_DOWNCAST(CMFCTabCtrl, tabGroups.GetNext(pos));
int count = pCrtTabCtrl->GetTabsNum();
for(int i = 0; i < count; i++)
{
CWnd* pWnd = pCrtTabCtrl->GetTabWndNoWrapper(i);
CMDIChildWnd *pChild = ((CMDIChildWnd*)(pWnd));
if (pChild)
{
CView *pView = pChild->GetActiveView();
if (pView)
{
if (pView->IsKindOf(RUNTIME_CLASS(CSpectraAnalysisUtilityView)))
{
CSpectraAnalysisUtilityView* specUtilView;
specUtilView = (CSpectraAnalysisUtilityView*)pView;
CReviewDataFolder* pDataFolder = specUtilView->GetSpecReviewDataFolder();
if(pDataFolder)
{
pDataFolder->SetRecentOrder(iReviewDataFolderOrder);
iReviewDataFolderOrder++;
}
}
}
}
}
}
}
CMDIFrameWnd::OnClose();
}
Upon destruction of the outer main frame (OnDestroy) you can access the the CMFCTabCtrl members and can loop over each tab and determine the current sequence stored in the tab. GetTabWnd will allow you to access each tab by its index.
To access the tab control use CMDIClientAreaWnd::GetMDITab.
case 1 : I have a MFC dialog box having a LisBox.
I have added two items in listbox.
Whenever i am double clicking on empty area of list box i.e. not double clicking
on either of two item.
Double click is detecting on empty area of listbox.
case 2: When i created a small MFC test application with listbox. it iis detecting double click only on item, not on empty area.
I compared all properties of both cases but couldn't figure out what is the problem.
Anyone has idea what is going wrong in case 1.
I think it is abnormal process. I've tested your situation in VS2010. In my MFC test application sent LBN_DBLCLK when I double clicked on empty area. If you do not really want to know the reason this weired situation, you can just check whether double click event is occurred on empty area or not. I think it is better way for saving your time.
void CMfcDlgTestDlg::OnLbnDblclkList2()
{
// TODO: Add your control notification handler code here
CListBox* list = (CListBox*)(GetDlgItem(IDC_LIST2));
int cur_sel = list->GetCurSel();
if (cur_sel == -1)
{
return;
}
}
EDIT : FOR ANOTHER CASE
When one of list box item is already selected, how can it handle on ON_LBN_DBLCLK handler?
I think there will be some available methods for solving this, however I use below code and it can be useful way, also.
void CMfcDlgTestDlg::OnLbnDblclkList2()
{
// TODO: Add your control notification handler code here
CListBox* list = (CListBox*)(GetDlgItem(IDC_LIST2));
CPoint cursor;
cursor.x = GetCurrentMessage()->pt.x;
cursor.y = GetCurrentMessage()->pt.y;
list->ScreenToClient(&cursor);
BOOL is_outside = FALSE;
UINT item_index = list->ItemFromPoint(cursor, is_outside);
if(is_outside)
{
//mouse clicked on empty area
return ;
}
else
{
// do something with 'item_index'
}
}
I hope this will help you a little.
I'd like to know more about how this system works, specifically when and how the framework actually decides to update a UI element.
My application has a 'tools' system where a single tool can be active at a time. I used the "ON_UPDATE_COMMAND_UI" message to 'check' the tool's icon/button in the UI, which affected both the application menu and the toolbars. Anyway, this was all working great until some point in the last couple of days, when the toolbar icons stopped getting highlighted properly.
I investigated a little and found that the update command was only being received when the icon was actually clicked. What's strange is this is only affecting the toolbars, not the menu, which is still working fine. Even when the buttons in the menu are updated the toolbar icon stays the same.
Obviously I've done something to break it - any ideas?
EDIT:
Never mind. I'd overwritten the Application's OnIdle() method and hadn't called the original base class method - that is, CWinApp::OnIdle() - which I guess is where the update gets called most of the time. This code snippet from https://msdn.microsoft.com/en-us/library/3e077sxt.aspx illustrates:
BOOL CMyApp::OnIdle(LONG lCount)
{
// CWinApp's original method is involved in the update message handling!
// Removing this call will break things
BOOL bMore = CWinApp::OnIdle(lCount);
if (lCount == 0)
{
TRACE(_T("App idle for short period of time\n"));
bMore = TRUE;
}
// ... do work
return bMore;
// return TRUE as long as there are any more idle tasks
}
Here's a good article that kinda explains how to do it. Don't use his code example with WM_KICKIDLE though, instead scroll down to the comments section. There are two code samples that explain how to do it better. I quote:
//Override WM_INITMENUPOPUP
void CDialog::OnInitMenuPopup(CMenu* pPopupMenu, UINT nIndex, BOOL bSysMenu)
{
CDialog::OnInitMenuPopup(pPopupMenu, nIndex, bSysMenu);
// TODO: Add your message handler code here
if(pPopupMenu &&
!bSysMenu)
{
CCmdUI CmdUI;
CmdUI.m_nIndexMax = pPopupMenu->GetMenuItemCount();
for(UINT i = 0; i < CmdUI.m_nIndexMax; i++)
{
CmdUI.m_nIndex = i;
CmdUI.m_nID = pPopupMenu->GetMenuItemID(i);
CmdUI.m_pMenu = pPopupMenu;
// There are two options:
// Option 1. All handlers are in dialog
CmdUI.DoUpdate(this, FALSE);
// Option 2. There are handlers in dialog and controls
/*
CmdUI.DoUpdate( this, FALSE );
// If dialog handler doesn't change state route update
// request to child controls. The last DoUpdate will
// disable menu item with no handler
if( FALSE == CmdUI.m_bEnableChanged )
CmdUI.DoUpdate( m_pControl_1, FALSE );
...
if( FALSE == CmdUI.m_bEnableChanged )
CmdUI.DoUpdate( m_pControl_Last, TRUE );
*/
}
}
}
See if this helps - http://msdn.microsoft.com/en-us/library/essk9ab2(v=vs.80).aspx
Commence V 2.0 of this question.
My VC++ MFC application compiles and runs just fine. That is, until I switch to another window. As soon as my program loses focus, it freezes; I cannot switch back to it and if I move a window that is in front of it, my app window displays white in the space that the other window was covering.
Since I first posted this question I have been able to pinpoint what portion of my program is causing this behavior, but I still don't know what lines of code are wrong or why.
The main dialog of my MFC application contains a CTabCtrl called m_MainTabControl. This main tab control holds onto two tabs labeled "Basic Design" and "Advanced Design", each of which are tied to their own dialogs. Both dialogs contain a CTabCtrl with several tabs. And thus my problem is born.
When I first created this tab-within-tab structure, I was having problems with my program freezing up when I tried to switch between inner tabs. Needless to say I was puzzled by this, until I noticed that if I first clicked on a control on one of the inner tabs I could then switch tabs just fine. So without fully understanding what the problem was, I set the focus to the first inner tab of the first inner tab on program startup. Problem half solved. When I ran the program I could click around on the first set of inner tabs just fine; if I switched to the second outer tab and tried clicking around its inner tabs without first clicking on a dialog control, it would freeze again. So I made a Focus function to focus the currently selected inner tab of the currently selected outer tab and called that in my tab change event (the one that goes off when you click on another tab).
That is how I got to the point I was at when I first asked this question. I thought my program was working just fine, until I played around with it a bit more and noticed it wasn't playing nicely when I flipped back and forth between it and another window or program. More specifically, as soon as my program goes out of focus some process goes haywire and takes up an entire CPU's worth of processing.
And now, the reason I explained my little tab structure and focus problems in such great detail: after much experimentation, I found that if I commented out the second tab on my outer tab structure (i.e. the "Advanced Design" dialog and all of its little children tabs) the remaining bit of my program runs fine, and I can switch to another window and back without a fight. "Great," I thought, "that's only about 90% of my program that I just commented out to get this working. Let's try and pare it down further." I put the "Advanced Design" tabbed dialog back in, but commented out the tabbed dialogs created by the tab control within "Advanced Design" and everything still worked fine. One by one I put back the tabbed dialogs belonging to "Advanced Design"'s tab control and every time I reintroduced The Error regardless of what tab I uncommented. I should also point out that one of the first tabs I tried putting back in (alone, of course) was my "Margins" tab, which is a MarginDlg class that I ALSO USE UNDER MY "Basic Design" TAB WITHOUT TROUBLE. This leads me to believe that there is something specific I have to do when creating tabbed dialogs within tabbed dialogs that I am not doing, or am doing incorrectly, kind of like how I had to mess with focusing to make it work at first.
I would be EXTREMELY grateful for any light that can be shed on the situation. I am including what I think are relevant snippets of code; as always, let me know if more is needed.
variable declarations from main dialog's .h file:
//tab stuff
CTabCtrl m_MainTabControl;
vector<CDialog*> m_tabPages;
SimpDesDlg* simpDesDlg;
AdvDesDlg* advDesDlg;
When my application starts up, it creates my main dialog, and the OnInitDialog() is called:
(everything above the TODO: comment is default VS stuff dealing with the stupid about dialog)
BOOL CspAceDlg::OnInitDialog()
{
CDialog::OnInitDialog();
// Add "About..." menu item to system menu.
// IDM_ABOUTBOX must be in the system command range.
ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
ASSERT(IDM_ABOUTBOX < 0xF000);
CMenu* pSysMenu = GetSystemMenu(FALSE);
if (pSysMenu != NULL)
{
CString strAboutMenu;
strAboutMenu.LoadString(IDS_ABOUTBOX);
if (!strAboutMenu.IsEmpty())
{
pSysMenu->AppendMenu(MF_SEPARATOR);
pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
}
}
// Set the icon for this dialog. The framework does this automatically
// when the application's main window is not a dialog
SetIcon(m_hIcon, TRUE); // Set big icon
SetIcon(m_hIcon, FALSE); // Set small icon
// TODO: Add extra initialization here
///////////////////////////////////////
DrawResultsArea();
DrawTabs();
theApp.Calculate();
Focus();
//simpDesDlg->Focus();
//DrawToolbar();
return FALSE; // return TRUE unless you set the focus to a control
}
DrawTabs() is where I create the tabs for my outer tab control:
void CspAceDlg::DrawTabs()
{
simpDesDlg = new SimpDesDlg;
m_tabPages.push_back(simpDesDlg);
advDesDlg = new AdvDesDlg;
m_tabPages.push_back(advDesDlg);
// create a tcItem to hold the name of each tab during creation
// and then get inserted, and arrays holding the tab names and IDs of
// the dialogs they refer to
TC_ITEM tcItem;
PSTR pszTabNames[] = {"Basic Design", "Advanced Design"};
UINT pszTabItems[] = {IDD_SIMPLEDESIGNTAB, IDD_ADVANCEDDESIGNTAB};
//every member of m_tabPages[] will become a tab
for (int i = 0; i < int(m_tabPages.size()); i++)
{
//set up the tab name
tcItem.mask = TCIF_TEXT;
tcItem.pszText = pszTabNames[i];
tcItem.cchTextMax = int(strlen(pszTabNames[i]));
//insert the new tab into the tab control and create the dialog window
m_MainTabControl.InsertItem(i, &tcItem);
m_tabPages[i]->Create(pszTabItems[i], &m_MainTabControl);
}
//redraw so that the dialogs don't appear in upper left corner and cover the tabs
CRect tabRect, itemRect;
int nX, nY, nXc, nYc;
m_MainTabControl.GetClientRect(&tabRect);
m_MainTabControl.GetItemRect(0, &itemRect);
nX=itemRect.left;
nY=itemRect.bottom+1;
nXc=tabRect.right-itemRect.left-1;
nYc=tabRect.bottom-nY-1;
m_tabPages[0]->SetWindowPos(&wndTop, nX, nY, nXc, nYc, SWP_SHOWWINDOW);
for(int nCount=1; nCount < int(m_tabPages.size()); nCount++){
m_tabPages[nCount]->SetWindowPos(&wndTop, nX, nY, nXc, nYc, SWP_HIDEWINDOW);
}
}
Main dialog's Focus() method:
void CspAceDlg::Focus()
{
int curSel = m_MainTabControl.GetCurSel();
m_tabPages[curSel]->SetFocus();
//if it's the basic design, we need to focus its first tab
if (curSel == 0)
{
simpDesDlg->Focus();
}
//if it's the advanced design, we need to focus its first tab
else if (curSel == 1)
{
advDesDlg->Focus();
}
}
code for m_MainTabControl's tab selection change event:
void CspAceDlg::OnTcnSelchangeBuildtabs(NMHDR *pNMHDR, LRESULT *pResult)
{
for (int i = 0; i < int(m_tabPages.size()); i++)
{
m_tabPages[i]->ShowWindow(m_MainTabControl.GetCurSel() == i ? SW_SHOW :
SW_HIDE);
}
Focus();
*pResult = 0;
}
SimpDesDlg and AdvDesDlg's tabs use identical code except for tab initialization (just creating different tabs for each) so here's the code for AdvDesDlg:
OnInitDialog():
BOOL AdvDesDlg::OnInitDialog()
{
CDialog::OnInitDialog();
DrawTabs();
return false;
}
adding in the tabbed dialogs:
void AdvDesDlg::DrawTabs()
{
//Make the dialogs for the tabs
antennaDlg = new AntennaDlg;
commSEDlg = new CommSEDlg;
encryptorDlg = new EncryptorDlg;
marginDlg = new MarginDlg;
miscDlg = new MiscDlg;
transRecDlg = new TransRecDlg;
//add them all to the tabPages vector
m_tabPages.push_back(antennaDlg);
m_tabPages.push_back(commSEDlg);
m_tabPages.push_back(encryptorDlg);
m_tabPages.push_back(marginDlg);
m_tabPages.push_back(miscDlg);
m_tabPages.push_back(transRecDlg);
//m_tabPages[0] = new AntennaDlg;
//m_tabPages[1] = new CommSEDlg;
//m_tabPages[2] = new EncryptorDlg;
//m_tabPages[3] = new MarginDlg;
//m_tabPages[4] = new MiscDlg;
//m_tabPages[5] = new TransRecDlg;
//antennaDlg = (AntennaDlg*) m_tabPages[0];
//commSEDlg = (CommSEDlg*) m_tabPages[1];
//encryptorDlg = (EncryptorDlg*) m_tabPages[2];
//marginDlg = (MarginDlg*) m_tabPages[3];
//miscDlg = (MiscDlg*) m_tabPages[4];
//transRecDlg = (TransRecDlg*) m_tabPages[5];
// create a tcItem to hold the name of each tab during creation
// and then get inserted, and arrays holding the tab names and IDs of
// the dialogs they refer to
TC_ITEM tcItem;
PSTR pszTabNames[] = {"Antenna", "Comm Support", "Encryptor", "Margins", "Misc", "Trasmitter/Receiver"};
UINT pszTabItems[] = {IDD_ANTENNATAB, IDD_COMMSETAB, IDD_ENCRYPTORTAB, IDD_MARGINTAB, IDD_MISCTAB, IDD_TRANSRECTAB};
//every member of m_tabPages[] will become a tab
for (int i = 0; i < int(m_tabPages.size())/*(sizeof(m_tabPages)/sizeof(m_tabPages[0]))*/; i++)
{
//set up the tab name
tcItem.mask = TCIF_TEXT;
tcItem.pszText = pszTabNames[i];
tcItem.cchTextMax = int(strlen(pszTabNames[i]));
//insert the new tab into the tab control and create the dialog window
advTab.InsertItem(i, &tcItem);
m_tabPages[i]->Create(pszTabItems[i], &advTab);
}
//redraw so that the dialogs don't appear in upper left corner and cover the tabs
CRect tabRect, itemRect;
int nX, nY, nXc, nYc;
advTab.GetClientRect(&tabRect);
advTab.GetItemRect(0, &itemRect);
nX=itemRect.left;
nY=itemRect.bottom+1;
nXc=tabRect.right-itemRect.left-1;
nYc=tabRect.bottom-nY-1;
//m_tabPages[0]->SetWindowPos(&wndTop, nX, nY, nXc, nYc, SWP_SHOWWINDOW);
for(int nCount=/*1*/0; nCount < int(m_tabPages.size())/*(sizeof(m_tabPages)/sizeof(m_tabPages[0]))*/; nCount++){
m_tabPages[nCount]->SetWindowPos(&wndTop, nX, nY, nXc, nYc, SWP_HIDEWINDOW);
}
}
And the Focus() and tab changing:
void AdvDesDlg::Focus()
{
this->SetFocus();
for (int i = 0; i < int(m_tabPages.size())/*(sizeof(m_tabPages)/sizeof(m_tabPages[0]))*/; i++)
{
m_tabPages[i]->ShowWindow(advTab.GetCurSel() == i ? SW_SHOW :
SW_HIDE);
}
int curSel = advTab.GetCurSel();
m_tabPages[curSel]->SetFocus();
}
void AdvDesDlg::OnTcnSelchangeAdvDesign(NMHDR *pNMHDR, LRESULT *pResult)
{
for (int i = 0; i < int(m_tabPages.size())/*(sizeof(m_tabPages)/sizeof(m_tabPages[0]))*/; i++)
{
m_tabPages[i]->ShowWindow(advTab.GetCurSel() == i ? SW_SHOW :
SW_HIDE);
}
int curSel = advTab.GetCurSel();
m_tabPages[curSel]->SetFocus();
*pResult = 0;
}
Debug your app, get it into this state, then go Debug / Break All. Find the main thread in the Threads window, then look at the call stack. Somewhere in the call stack will be your code that's causing the hang.
Note that in order to get a sensible call stack you'll need to point Visual Studio at Microsoft's symbol servers; see http://msdn.microsoft.com/en-us/library/b8ttk8zy.aspx
The behavior you describe usually occurs when you are running some process without allowing the message pump to run.
What does your app do? I assume you start it, and then either hit a button or select a menu item to start some process.
If the program behaves normally when you first start it (before you click to start your processing), but then behaves as you describe after starting the process, then that's your problem.
You'll have to move that processing into another thread to allow the MFC GUI to remain responsive.
I just stumbled about a very similar situation. My setup:
A CPropertySheet containing several CPropertyPages
A CTabCtrl inside one CPropertyPage
Several CDialogs as part of the CTabCtrl
Using a control in one specific CDialog and then switching to another application (e.g. Visual Studio via a hit breakpoint) will stall my application (the respective CPU core ends up at 100% load)
Using a control in the same specific CDialog but then switching to another CPropertyPage before switching to another application will not result in any problems
After some research I found this Knowledge Base article which hinted me to a solution. The specific CDialog which triggered the stall had the line EXSTYLE WS_EX_CONTROLPARENT in its resource definition. Removing the line solved the problem.
This prevents being able to tab into the CDialog, but that problem is slightly less serious and I might come back to it another day.
I had a similar issue. I had multiple nested windows, some with the WS_EX_CONTROLPARENT style, some not. The thing is: Either all inner windows have to have this style, or none of them (at least apparently).