libui/windows/text.cpp

108 lines
2.2 KiB
C++

// 9 april 2015
#include "uipriv_windows.h"
WCHAR *windowTextAndLen(HWND hwnd, LRESULT *len)
{
LRESULT n;
WCHAR *text;
n = SendMessageW(hwnd, WM_GETTEXTLENGTH, 0, 0);
if (len != NULL)
*len = n;
// WM_GETTEXTLENGTH does not include the null terminator
text = (WCHAR *) uiAlloc((n + 1) * sizeof (WCHAR), "WCHAR[]");
// note the comparison: the size includes the null terminator, but the return does not
if (GetWindowTextW(hwnd, text, n + 1) != n) {
logLastError(L"error getting window text");
// on error, return an empty string to be safe
*text = L'\0';
if (len != NULL)
*len = 0;
}
return text;
}
WCHAR *windowText(HWND hwnd)
{
return windowTextAndLen(hwnd, NULL);
}
void setWindowText(HWND hwnd, WCHAR *wtext)
{
if (SetWindowTextW(hwnd, wtext) == 0)
logLastError(L"error setting window text");
}
void uiFreeText(char *text)
{
uiFree(text);
}
intmax_t uiWindowsWindowTextWidth(HWND hwnd)
{
LRESULT len;
WCHAR *text;
HDC dc;
HFONT prevfont;
SIZE size;
size.cx = 0;
size.cy = 0;
text = windowTextAndLen(hwnd, &len);
if (len == 0) // no text; nothing to do
goto noTextOrError;
// now we can do the calculations
dc = GetDC(hwnd);
if (dc == NULL) {
logLastError(L"error getting DC");
// on any error, assume no text
goto noTextOrError;
}
prevfont = (HFONT) SelectObject(dc, hMessageFont);
if (prevfont == NULL) {
logLastError(L"error loading control font into device context");
ReleaseDC(hwnd, dc);
goto noTextOrError;
}
if (GetTextExtentPoint32W(dc, text, len, &size) == 0) {
logLastError("error getting text extent point");
// continue anyway, assuming size is 0
size.cx = 0;
size.cy = 0;
}
// continue on errors; we got what we want
if (SelectObject(dc, prevfont) != hMessageFont)
logLastError(L"error restoring previous font into device context");
if (ReleaseDC(hwnd, dc) == 0)
logLastError(L"error releasing DC");
uiFree(text);
return size.cx;
noTextOrError:
uiFree(text);
return 0;
}
char *uiWindowsWindowText(HWND hwnd)
{
WCHAR *wtext;
char *text;
wtext = windowText(hwnd);
text = toUTF8(wtext);
uiFree(wtext);
return text;
}
void uiWindowsSetWindowText(HWND hwnd, const char *text)
{
WCHAR *wtext;
wtext = toUTF16(text);
setWindowText(hwnd, wtext);
uiFree(wtext);
}