CRichEditCtrl how to ignore a keypress? - c++

i have a rich edit box in one of my dialog of MFC dialog based app.
it can only have numeric values.
Now what i am trying to do is dont allow user to enter a value greater then 4567899.
if user is entering numbers in the the rich edit box and by pressing the number key will make the value already enterd in text box greater then 4567899 then just make the app behave like no key is pressed or just ignore that key press.
I did some research and found that this can be done by EN_MSGFILTER event but i m not sure about that.
so this is the function
void CMyDialog::OnMsgfilterObjectid(NMHDR* pNMHDR, LRESULT* pResult)
{
char tempID[10];
MSGFILTER *pMsgFilter = reinterpret_cast<MSGFILTER *>(pNMHDR);
// TODO: The control will not send this notification unless you override the
// CDialog::OnInitDialog() function to send the EM_SETEVENTMASK message
// to the control with either the ENM_KEYEVENTS or ENM_MOUSEEVENTS flag
// ORed into the lParam mask.
// TODO: Add your control notification handler code here
*pResult = 0;
if((pMsgFilter->wParam >= 48) || pMsgFilter->wParam<=57) // check if 0-9 is pressed
{
m_objectIDInstance.GetLine(NULL,tempID); //m_objectIDInstance is a CRichEditCtrl
tempID[m_objectIDInstance.LineLength()] = '\0';
if ((atol(tempID) + (pMsgFilter->wParam-48)) > 4567899)
{
*pResult=1;
}
}
}
in OnInitDialog() i added following line:
m_objectIDInstance.SendMessage(EM_SETEVENTMASK, 0, ENM_KEYEVENTS);
Buts its not working so please if somebody can help or can suggest a different way to do what i am trying to implement.
Thanks

You seem to be sending the message to the dialog. It has to be sent to the edit control.
m_objectIDInstance.SendMessage(...)

Related

MFC) Making TreeCtrl loses its item focus

I have used TVN_SELCHANGED message to find out what user select in item tree (Menu).
However, if user continually click same item, that message does not occur.
I want treeCtrl to lose its item selection for occurring TVN_SELCHANGED.
(In other words, I want to make event happened even if user click same item consecutively)
How do I do that?
TVN_SELCHANGE will not help. Nothing is changed, so the notification isn't sent. Even it makes no sense for me. What should a UI do, if a user clicks on an already selected item? Nothing... I would guess.
If you want to handle this, you have to do it by yourself.
You can use WM_LBUTTONDOWN or NM_CLICK, to track the click.
Than use TVM_HITTEST to check what was clicked by the user.
Now you can compare the current selection (TVM_GETNEXTITEM and check for TVGN_CARET)
compare old and new selection.
After all, pass the click to the default handler.
The only time the TreeCtrl will get notified when an item is selected is: TVN_SELCHANGE. In case of same selection, this won't help. But there is another way to get notified.
Add PreTranslateMessage command in your dialog class where TreeCtrl is used and add the code written below.
//---------------------------------------------------------------------------
BOOL MyDlgClass::PreTranslateMessage(MSG* pMsg)
{
UINT msgValue = pMsg->message;
//here I have compared L button down event, you can use any
//mouse/keyboard event that you want to compare.
if (msgValue == WM_LBUTTONDOWN)
{
CPoint point;
point.x = (int)(short)LOWORD(pMsg->lParam);
point.y = (int)(short)HIWORD(pMsg->lParam);
OnLButtonDown(pMsg->message, point);
}
}
void MyDlgClass::OnLButtonDown(UINT nType, CPoint point)
{
UINT uFlags;
HTREEITEM hItem = m_treeCtrl.HitTest(point, &uFlags);
if ((hItem != NULL) && (TVHT_ONITEMBUTTON & uFlags))
{
return;
}
//TVHT_ONITEMBUTTON detects if user has clicked + or - button of tree
//view.
//Add code to perform your operations on hItem.
}

Refreshing List Control with F5 key press C++

I have a List Control that shows a list of my database users. I also have a function that refreshes the list control (currently it is mapped to a "Refresh" button).
When the user presses the "F5" key, I want to call my refresh function.
I have found an event LVN_KEYDOWN (Indicates that a key has been pressed). After some research, I have found that the virtual keycode for "F5" is VK_F5. I am having trouble putting the two together, how can I check to see (in my event) that the "F5" key was the one that was pressed? I have tried several things similar to the code below:
void ListOption::OnLvnKeydownList1(NMHDR *pNMHDR, LRESULT *pResult)
{
LPNMLVKEYDOWN pLVKeyDow = reinterpret_cast<LPNMLVKEYDOWN>(pNMHDR);
// TODO: Add your control notification handler code here
if(pLVKeyDow == (LPNMLVKEYDOWN)VK_F5)
callRefreshFunction();
*pResult = 0;
}
The wVKey member contains the virtual key code:
if(pLVKeyDow->wVKey == VK_F5) {
callRefreshFunction();
*rResult = 1;
}
According to comments on MSDN you have to set the return value to 1
if you handle the message.

Validating an Edit Control's text while the user types MFC

Question/Problem: I have an edit control (text box) that the user enters a username into. I am attempting to compare the username entered to the ones listed in my List Control. If the username given matches, my button's text should change from Create User to Update User.
My problem is in finding the correct event/time to compare the strings, without creating an infinite loop.
What I have tried: I have tried using the edit control events EN_CHANGE and EN_UPDATE. Both of these events cause stack-overflow exception or an infinite loop. I thought that one of these events would be called every time something is typed or the backspace was used within my edit control.
In my EN_CHANGE / EN_UPDATE event, I compare the username strings and set the button's text. With either event, it is called infinite times:
void Users::OnEnUpdateLoginName() //EN_UPDATE Event
{
bool match = false;
//Compare the edit control text with each List Control text.
for(int i = 0; i<m_UserList.GetItemCount(); i++)
{
if(strcmp(m_UserList.GetItemText(i,0),m_loginName)==0)
match = true;
}
//If the usernames match, change the button's text to "Update User"
if(match)
{
CWnd *currentSelection = GetDlgItem(TXTC_LOGIN_NAME);
currentSelection->SetWindowTextA("Update User");
}
else
{
CWnd *currentSelection = GetDlgItem(TXTC_LOGIN_NAME);
currentSelection->SetWindowTextA("Create User");
}
}
.
If the text in red matches, change the text of the button highlighted in blue.
Should I be using a different event to validate the string in real-time as the user types?
My code had two issues. I needed to use UpdateData, so that data for all my dialog controls would be current. I also was updating the wrong variables. Thanks #rrirower

MFC tooltips only show up on special occasions

I have been tasked with assigning tooltips to each item in a configuration menu. I have completed "adding" the tooltip to each control on the page, but it seems sometimes the tooltip shows up and sometimes it does not, depending on the position of the control on the screen.
To tooltip-erize the pages I first
EnableToolTips(TRUE);
In each CPropertyPage's OnInitDialog method.
I then add the notification map
ON_NOTIFY_EX(TTN_NEEDTEXT, 0, OnToolTipText)
With the function OnToolTipText looking as such
BOOL CCfgPrefPage::OnToolTipText( UINT id, NMHDR * pNMHDR, LRESULT * pResult )
{
TOOLTIPTEXT *pTTT = (TOOLTIPTEXT *)pNMHDR;
UINT nID = pNMHDR->idFrom;
if (pTTT->uFlags & TTF_IDISHWND)
{
nID = ::GetDlgCtrlID((HWND)nID);
if(nID)
{
if( nID == GetDlgItem(IDC_PICKDIST_EDIT)->GetDlgCtrlID())
_tcsncpy_s(pTTT->szText, _T("Tool Tip Text"), _TRUNCATE);
else if( nID == GetDlgItem(IDC_ENDPTTOL_EDIT)->GetDlgCtrlID())
_tcsncpy_s(pTTT->szText, _T("Tool Tip Text"), _TRUNCATE);
pTTT->lpszText = pTTT->szText; // Sanity Check
pTTT->hinst = AfxGetResourceHandle(); // Don't think this is needed at all
return TRUE;
}
}
return FALSE;
}
It seems for some of my controls the tool tip will not show up. For most of the check box controls the tool tip displays, but for a few they just do not show. There are no other controls covering them up, they are not disabled.
Another thing, if I use the non-standard cursor windows repeatedly flashes the tool tip, so much so it is unreadable in some cases. How can I fix this? This is not a problem on CEdit controls, so why is it a problem elsewhere?
EDIT: Update, the controls that have been on the pages for years seem to show tool tips. Any control that I try to add now/today will not show tool tips at all. No matter the position, control type, settings, I cannot get a single tool tip to show on a newly inserted control.
If you do not want to use helper class I have proposed then fix the problems in your code.
First, use ON_NOTIFY_EX_RANGE macro when mapping the even handler, like this (this will cover all IDs):
ON_NOTIFY_EX_RANGE(TTN_NEEDTEXTA, 0, 0xFFFF, OnToolTipText)
Next, you need to fix your function. I see a few problems here. First, when testing for TTF_IDISHWND flag you only need to re-initalise the nID. You do not need to apply this to the whole function. Second, after all manipulations, your nID will be the actual dialog ID. There is no need to GetDlgItem() function
BOOL CCfgPrefPage::OnToolTipText( UINT id, NMHDR * pNMHDR, LRESULT * pResult )
{
TOOLTIPTEXT *pTTT = (TOOLTIPTEXT *)pNMHDR;
UINT nID = pNMHDR->idFrom;
if (pTTT->uFlags & TTF_IDISHWND)
{
nID = ::GetDlgCtrlID((HWND)nID);
}
if(nID)
{
if( nID == IDC_PICKDIST_EDIT)
_tcsncpy_s(pTTT->szText, _T("Tool Tip Text"), _TRUNCATE);
else if( nID == IDC_ENDPTTOL_EDIT)
_tcsncpy_s(pTTT->szText, _T("Tool Tip Text"), _TRUNCATE);
//pTTT->lpszText = pTTT->szText; // Sanity Check
*pResult = 0;
return TRUE;
}
return FALSE;
}
Working with a toolbar which repeats some menu items from menus of an older MFC application, I have worked on this issue of tool tips as well as (1) modifying the toolbar bit map to include additional icons and (2) providing user feedback on current application state. My problem is that I have to do most of this by hand rather than using the various wizards and tools.
What I have done is to (1) add new members to the CView derived class to handle additional messages, (2) modified the toolbar bit map to add in the additional icons using both MS Paint and the Resource Editor, and (3) added new event ids and event handlers to the message map for the CView derived class.
One problem I ran into with the toolbar bitmap change was that since I was inserting an icon, I had to shift an existing icon in the bitmap to the right. My first attempt at this resulted in the shifted icon showing as a blank on the application toolbar. Then I realized that I needed to add a bit more to the length of the toolbar bitmap. After adding a couple more columns to the last icon in the toolbar bitmap to make it a standard width in pixels, the icon displayed properly.
For tooltips I added the following to the message map:
ON_NOTIFY_EX(TTN_NEEDTEXT, 0, OnToolTipText)
I then added the following method to my class to handle the notifications for my menu items. As a side note, it appears that OnToolTipText() is the standard method used in CFrameWnd class and CMDIChildWnd class however CView derives from CWnd as does CFrameWnd so I doubt it makes a difference as to what the method is named.
inline BOOL CPCSampleView::OnToolTipText( UINT id, NMHDR * pNMHDR, LRESULT * pResult )
{
static wchar_t toolTextToggleExportSylk [64] = L"Toggle SYLK export.";
static wchar_t toolTextClearWindow [64] = L"Clear the log displayed.";
static wchar_t toolTextConnectLan [64] = L"Log on the POS terminal through the LAN.";
TOOLTIPTEXT *pTTT = (TOOLTIPTEXT *)pNMHDR;
switch (pNMHDR->idFrom) {
case ID_TOGGLE_SYLK_EXPORT:
pTTT->lpszText = toolTextToggleExportSylk;
return TRUE;
case ID_WINDOW_CLEAR:
pTTT->lpszText = toolTextClearWindow;
return TRUE;
case ID_CONNECT_LAN_ON:
pTTT->lpszText = toolTextConnectLan;
return TRUE;
}
// if we do not handle the message then return FALSE to let someone else do it.
return FALSE;
}
For the user feedback on a menu item which toggles a file export when doing reports I provided the following changes to the message map and then implemented the necessary methods. There are two types of messages involved so I had to add two methods and two new message map entries:
// New message map entries to handle the menu item selection event
// and to update the menu item and the toolbar icon with state changes
ON_COMMAND(ID_TOGGLE_SYLK_EXPORT, OnToggleExportSylk)
ON_UPDATE_COMMAND_UI(ID_TOGGLE_SYLK_EXPORT, OnUpdateToggleExportSylk)
// New methods added to the CView derived class
// handle the menu selection event generated by either selecting the menu item
// from the menu or by clicking on the icon in the toolbar.
void CPCSampleView::OnToggleExportSylk()
{
// Exclusive Or to toggle the indicator bit from 0 to 1 and 1 to 0.
GetDocument()->ulReportOptionsMap ^= CPCSampleDoc::ulReportOptionsExportSylk;
}
// handle the request from the MFC framework to update the displayed state this
// not only does a check mark against the menu item it also causes the toolbar
// icon to appear depressed if click is set or non-depressed if click is not set
inline void CPCSampleView::OnUpdateToggleExportSylk (CCmdUI* pCmdUI)
{
if (GetDocument()->ulReportOptionsMap & CPCSampleDoc::ulReportOptionsExportSylk)
{
// SYLK export is turned on so indicate status to the user. This will
// put a check mark beside the menu item and show the toolbar button depressed
pCmdUI->SetCheck (1);
}
else
{
// SYLK export is turned off so indicate status to the user. This will
// remove the check mark beside the menu item and show the toolbar button as raised.
pCmdUI->SetCheck (0);
}
}
The resource file changes were needed to provide a new button for the toggle action as well as to add a new menu item for the toggle action. I am using the same resource id for several different things since these are all separate. So the id for the resource string is the same as for the menu item and is same for the toolbar button so as to simplify my life and make it easy to find all the particular bits and pieces.
The toolbar resource file definition looks like:
IDR_MAINFRAME TOOLBAR 16, 15
BEGIN
BUTTON ID_CONNECT_LAN_ON
SEPARATOR
BUTTON ID_WINDOW_CLEAR
SEPARATOR
BUTTON ID_TOGGLE_SYLK_EXPORT
SEPARATOR
BUTTON ID_APP_ABOUT
END
And the specific part of the menu, which uses the same resource id for the toggle event id looks like:
MENUITEM "Export to SYLK file", ID_TOGGLE_SYLK_EXPORT
Then to provide the status bar text which shows up with a mouse over there is a string table addition:
ID_TOGGLE_SYLK_EXPORT "Toggle export of SYLK format report files for spreadsheets."
The lpszText member of the struct is describe in the MSDN documentation for the TOOLINFO struct as:
Pointer to the buffer that contains the text for the tool, or
identifier of the string resource that contains the text. This member
is sometimes used to return values. If you need to examine the
returned value, must point to a valid buffer of sufficient size.
Otherwise, it can be set to NULL. If lpszText is set to
LPSTR_TEXTCALLBACK, the control sends the TTN_GETDISPINFO notification
code to the owner window to retrieve the text.
Reviewing the existing answer to this question, I wondered about the if statement check for the TTF_IDISHWND flag. The MSDN documentation for the TOOLINFO struct has this to say:
Indicates that the uId member is the window handle to the tool. If
this flag is not set, uId is the tool's identifier.

how to use ribbon category to switch view?

I want to use two ribbon category buttons to switch between two different views, but I found it can't add event handler to the button.
Is there any hint to solve this problem? Better if there is some sample, actually I'm new to MFC.
You could try hooking into this event?
AFX_WM_ON_CHANGE_RIBBON_CATEGORY
An option I have found successful was to subclass CMFCRibbonBar and override PreTranslateMessage and check for mouse clicks. Below are the steps I took which have thus far worked well.
Subclass CMFCRibbon - in my example I created CCustomRibbonBar
Override PreTranslateMessage, and add an int value to keep track of the tab
Create a custom windows message that your applications MainForm handles -WM_ACTIVE_RIBBON_TAB_CHANGED in my example
Inside of PreTranslateMessage check for Left Mouse Up event
In the event of a left mouse button up, let the Ribbon finish handling the message and then query the Active Category.
Post the active category to MainForm (or other form)
In your MainForm, handle the category and take into account that with most events the category will not have changed.
Then in my override I check for the mouse up event and retrieve the Active category
Inside Class Declaration
virtual BOOL PreTranslateMessage(MSG* pMsg);
int m_LastActiveCategory;
Inside Class Definition
BOOL CCustomRibbonBar::PreTranslateMessage(MSG* pMsg)
{
//If command was finishing a click
if(pMsg->message == WM_LBUTTONUP && pMsg->wParam == 0)
{
//Allow ribbon to handle itself first
BOOL result = CMFCRibbonBar::PreTranslateMessage(pMsg);
//Get new active tab
int activeTab = GetCategoryIndex(GetActiveCategory());
//If tab has changed, forward message
if(activeTab != m_LastActiveCategory)
{
//forward message to parent
::SendMessage(GetParentFrame()->GetSafeHwnd(),WM_ACTIVE_RIBBON_TAB_CHANGED,activeTab,0);
m_LastActiveCategory = activeTab;
}
return result;
}
//Otherwise handle like normal
return CMFCRibbonBar::PreTranslateMessage(pMsg);
}