I have subclassed edit control to accept only floating numbers. I would like to pop a tooltip when user makes an invalid input. The behavior I target is like the one edit control with ES_NUMBER has :
So far I was able to implement tracking tooltip and display it when user makes invalid input.
However, the tooltip is misplaced. I have tried to use ScreenToClient and ClientToScreen to fix this but have failed.
Here are the instructions for creating SCCE :
1) Create default Win32 project in Visual Studio.
2) Add the following includes in your stdafx.h, just under #include <windows.h> :
#include <windowsx.h>
#include <commctrl.h>
#pragma comment( lib, "comctl32.lib")
#pragma comment(linker, \
"\"/manifestdependency:type='Win32' "\
"name='Microsoft.Windows.Common-Controls' "\
"version='6.0.0.0' "\
"processorArchitecture='*' "\
"publicKeyToken='6595b64144ccf1df' "\
"language='*'\"")
3) Add these global variables:
HWND g_hwndTT;
TOOLINFO g_ti;
4) Here is a simple subclass procedure for edit controls ( just for testing purposes ) :
LRESULT CALLBACK EditSubProc ( HWND hwnd, UINT message,
WPARAM wParam, LPARAM lParam,
UINT_PTR uIdSubclass, DWORD_PTR dwRefData )
{
switch (message)
{
case WM_CHAR:
{
POINT pt;
if( ! isdigit( wParam ) ) // if not a number pop a tooltip!
{
if (GetCaretPos(&pt)) // here comes the problem
{
// coordinates are not good, so tooltip is misplaced
ClientToScreen( hwnd, &pt );
/************************** EDIT #1 ****************************/
/******* If I delete this line x-coordinate is OK *************/
/*** y-coordinate should be little lower, but it is still OK **/
/**************************************************************/
ScreenToClient( GetParent(hwnd), &pt );
/************************* Edit #2 ****************************/
// this adjusts the y-coordinate, see the second edit
RECT rcClientRect;
Edit_GetRect( hwnd, &rcClientRect );
pt.y = rcClientRect.bottom;
/**************************************************************/
SendMessage(g_hwndTT, TTM_TRACKACTIVATE,
TRUE, (LPARAM)&g_ti);
SendMessage(g_hwndTT, TTM_TRACKPOSITION,
0, MAKELPARAM(pt.x, pt.y));
}
return FALSE;
}
else
{
SendMessage(g_hwndTT, TTM_TRACKACTIVATE,
FALSE, (LPARAM)&g_ti);
return ::DefSubclassProc( hwnd, message, wParam, lParam );
}
}
break;
case WM_NCDESTROY:
::RemoveWindowSubclass( hwnd, EditSubProc, 0 );
return DefSubclassProc( hwnd, message, wParam, lParam);
break;
}
return DefSubclassProc( hwnd, message, wParam, lParam);
}
5) Add the following WM_CREATE handler :
case WM_CREATE:
{
HWND hEdit = CreateWindowEx( 0, L"EDIT", L"edit", WS_CHILD | WS_VISIBLE |
WS_BORDER | ES_CENTER, 150, 150, 100, 30, hWnd, (HMENU)1000, hInst, 0 );
// try with tooltip
g_hwndTT = CreateWindow(TOOLTIPS_CLASS, NULL,
WS_POPUP | TTS_ALWAYSTIP | TTS_BALLOON,
0, 0, 0, 0, hWnd, NULL, hInst, NULL);
if( !g_hwndTT )
MessageBeep(0); // just to signal error somehow
g_ti.cbSize = sizeof(TOOLINFO);
g_ti.uFlags = TTF_TRACK | TTF_ABSOLUTE;
g_ti.hwnd = hWnd;
g_ti.hinst = hInst;
g_ti.lpszText = TEXT("Hi there");
if( ! SendMessage(g_hwndTT, TTM_ADDTOOL, 0, (LPARAM)&g_ti) )
MessageBeep(0); // just to have some error signal
// subclass edit control
SetWindowSubclass( hEdit, EditSubProc, 0, 0 );
}
return 0L;
6) Initialize common controls in MyRegisterClass ( before return statement ) :
// initialize common controls
INITCOMMONCONTROLSEX iccex;
iccex.dwSize = sizeof(INITCOMMONCONTROLSEX);
iccex.dwICC = ICC_BAR_CLASSES | ICC_WIN95_CLASSES |
ICC_TAB_CLASSES | ICC_TREEVIEW_CLASSES | ICC_STANDARD_CLASSES ;
if( !InitCommonControlsEx(&iccex) )
MessageBeep(0); // signal error
That's it, for the SSCCE.
My questions are following :
How can I properly position tooltip in my main window? How should I manipulate with caret coordinates?
Is there a way for tooltip handle and toolinfo structure to not be global?
Thank you for your time.
Best regards.
EDIT #1:
I have managed to achieve quite an improvement by deleting ScreenToClient call in the subclass procedure. The x-coordinate is good, y-coordinate could be slightly lower. I still would like to remove global variables somehow...
EDIT #2:
I was able to adjust y-coordinate by using EM_GETRECT message and setting y-coordinate to the bottom of the formatting rectangle:
RECT rcClientRect;
Edit_GetRect( hwnd, &rcClientRect );
pt.y = rcClient.bottom;
Now the end-result is much better. All that is left is to remove global variables...
EDIT #3:
It seems that I have cracked it! The solution is in EM_SHOWBALLOONTIP and EM_HIDEBALLOONTIP messages! Tooltip is placed at the caret position, ballon shape is the same as the one on the picture, and it auto-dismisses itself properly. And the best thing is that I do not need global variables!
Here is my subclass procedure snippet:
case WM_CHAR:
{
// whatever... This condition is for testing purpose only
if( ! IsCharAlpha( wParam ) && IsCharAlphaNumeric( wParam ) )
{
SendMessage(hwnd, EM_HIDEBALLOONTIP, 0, 0);
return ::DefSubclassProc( hwnd, message, wParam, lParam );
}
else
{
EDITBALLOONTIP ebt;
ebt.cbStruct = sizeof( EDITBALLOONTIP );
ebt.pszText = L" Tooltip text! ";
ebt.pszTitle = L" Tooltip title!!! ";
ebt.ttiIcon = TTI_ERROR_LARGE; // tooltip icon
SendMessage(hwnd, EM_SHOWBALLOONTIP, 0, (LPARAM)&ebt);
return FALSE;
}
}
break;
