libui/util_windows.c

41 lines
1.3 KiB
C

// 6 april 2015
#include "uipriv_windows.h"
intmax_t uiWindowsWindowTextWidth(HWND hwnd)
{
LRESULT len;
WCHAR *text;
HDC dc;
HFONT prevfont;
SIZE size;
size.cx = 0;
size.cy = 0;
// first we need the window text
len = SendMessageW(hwnd, WM_GETTEXTLENGTH, 0, 0);
if (len == 0) // no text; nothing to do
return 0;
text = (WCHAR *) uiAlloc((len + 1) * sizeof (WCHAR), "WCHAR[]");
// note the comparison: the size includes the null terminator, but the return does not
if (GetWindowText(hwnd, text, len + 1) != len)
logLastError("error getting window text in uiWindowsWindowTextWidth()");
// now we can do the calculations
dc = GetDC(hwnd);
if (dc == NULL)
logLastError("error getting DC in uiWindowsWindowTextWidth()");
prevfont = (HFONT) SelectObject(dc, hMessageFont);
if (prevfont == NULL)
logLastError("error loading control font into device context in uiWindowsWindowTextWidth()");
if (GetTextExtentPoint32W(dc, text, len, &size) == 0)
logLastError("error getting text extent point in uiWindowsWindowTextWidth()");
if (SelectObject(dc, prevfont) != hMessageFont)
logLastError("error restoring previous font into device context in uiWindowsWindowTextWidth()");
if (ReleaseDC(hwnd, dc) == 0)
logLastError("error releasing DC in uiWindowsWindowTextWidth()");
uiFree(text);
return size.cx;
}