tkwinfont.c

linux系统下的音频通信

Tk_MeasureChars(tkfont, source, numChars, maxLength, flags, lengthPtr)
    Tk_Font tkfont;		/* Font in which characters will be drawn. */
    CONST char *source;		/* Characters to be displayed.  Need not be
				 * '\0' terminated. */
    int numChars;		/* Maximum number of characters to consider
				 * from source string. */
    int maxLength;		/* If > 0, maxLength specifies the longest
				 * permissible line length; don't consider any
				 * character that would cross this
				 * x-position.  If <= 0, then line length is
				 * unbounded and the flags argument is
				 * ignored. */
    int flags;			/* Various flag bits OR-ed together:
				 * TK_PARTIAL_OK means include the last char
				 * which only partially fit on this line.
				 * TK_WHOLE_WORDS means stop on a word
				 * boundary, if possible.
				 * TK_AT_LEAST_ONE means return at least one
				 * character even if no characters fit. */
    int *lengthPtr;		/* Filled with x-location just after the
				 * terminating character. */
{
    WinFont *fontPtr;
    HDC hdc;
    HFONT hFont;
    int curX, curIdx;

    fontPtr = (WinFont *) tkfont;

    hdc = GetDC(fontPtr->hwnd);
    hFont = SelectObject(hdc, fontPtr->hFont);

    if (numChars == 0) {
	curX = 0;
	curIdx = 0;
    } else if (maxLength <= 0) {
	SIZE size;

	GetTextExtentPoint32(hdc, source, numChars, &size);
	curX = size.cx;
	curIdx = numChars;
    } else {
	int max;
	int *partials;
	SIZE size;
	
	partials = (int *) ckalloc(numChars * sizeof (int));
	GetTextExtentExPoint(hdc, source, numChars, maxLength, &max,
		partials, &size);
	
	if ((flags & TK_WHOLE_WORDS) && max < numChars) {
	    int sawSpace;
	    int i;
	    
	    sawSpace = 0;
	    i = max;
	    while (i >= 0 && !isspace(source[i])) {
    		--i;
            }
	    while (i >= 0 && isspace(source[i])) {
		sawSpace = 1;
		--i;
            }

	    /*
	     * If a space char was not found, and the flag for forcing
	     * at least on (or more) chars to be drawn is false, then
	     * set MAX to zero so no text is drawn.  Otherwise, if a
	     * space was found, set max to be one char past the space.
	     */
	    
	    if ((i < 0) && !(flags & TK_AT_LEAST_ONE)) {
		max = 0;
	    } else if (sawSpace) {
		max = i + 1;
	    }
		
	}

	if (max == 0) {
	    curX = 0;
	} else {
	    curX = partials[max - 1];
	}

	if (((flags & TK_PARTIAL_OK) && max < numChars && curX < maxLength)
		|| ((flags & TK_AT_LEAST_ONE) && max == 0 && numChars > 0)) {
	    /*
	     * We want to include the first character that didn't
	     * quite fit.  Call the function again to include the
	     * width of the extra character.
             */
	    
	    GetTextExtentExPoint(hdc, source, max + 1, 0, NULL, partials,
                       &size);
	    curX = partials[max];
	    ++max;

	} 
		
	ckfree((char *) partials);
	curIdx = max;
    }

    SelectObject(hdc, hFont);
    ReleaseDC(fontPtr->hwnd, hdc);

    *lengthPtr = curX;
    return curIdx;
}

/*
 *---------------------------------------------------------------------------
 *
 * Tk_DrawChars --
 *
 *	Draw a string of characters on the screen.  
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Information gets drawn on the screen.
 *
 *---------------------------------------------------------------------------
 */

void
Tk_DrawChars(display, drawable, gc, tkfont, source, numChars, x, y)
    Display *display;		/* Display on which to draw. */
    Drawable drawable;		/* Window or pixmap in which to draw. */
    GC gc;			/* Graphics context for drawing characters. */
    Tk_Font tkfont;		/* Font in which characters will be drawn;
				 * must be the same as font used in GC. */
    CONST char *source;		/* Characters to be displayed.  Need not be
				 * '\0' terminated.  All Tk meta-characters
				 * (tabs, control characters, and newlines)
				 * should be stripped out of the string that
				 * is passed to this function.  If they are
				 * not stripped out, they will be displayed as
				 * regular printing characters. */
    int numChars;		/* Number of characters in string. */
    int x, y;			/* Coordinates at which to place origin of
				 * string when drawing. */
{
    HDC dc;
    HFONT hFont;
    TkWinDCState state;
    WinFont *fontPtr;

    fontPtr = (WinFont *) gc->font;
    display->request++;

    if (drawable == None) {
	return;
    }

    dc = TkWinGetDrawableDC(display, drawable, &state);

    SetROP2(dc, tkpWinRopModes[gc->function]);

    if ((gc->fill_style == FillStippled
	    || gc->fill_style == FillOpaqueStippled)
	    && gc->stipple != None) {
	TkWinDrawable *twdPtr = (TkWinDrawable *)gc->stipple;
	HBRUSH oldBrush, stipple;
	HBITMAP oldBitmap, bitmap;
	HDC dcMem;
	TEXTMETRIC tm;
	SIZE size;

	if (twdPtr->type != TWD_BITMAP) {
	    panic("unexpected drawable type in stipple");
	}

	/*
	 * Select stipple pattern into destination dc.
	 */
	
	dcMem = CreateCompatibleDC(dc);

	stipple = CreatePatternBrush(twdPtr->bitmap.handle);
	SetBrushOrgEx(dc, gc->ts_x_origin, gc->ts_y_origin, NULL);
	oldBrush = SelectObject(dc, stipple);

	SetTextAlign(dcMem, TA_LEFT | TA_TOP);
	SetTextColor(dcMem, gc->foreground);
	SetBkMode(dcMem, TRANSPARENT);
	SetBkColor(dcMem, RGB(0, 0, 0));

        hFont = SelectObject(dcMem, fontPtr->hFont);

	/*
	 * Compute the bounding box and create a compatible bitmap.
	 */

	GetTextExtentPoint(dcMem, source, numChars, &size);
	GetTextMetrics(dcMem, &tm);
	size.cx -= tm.tmOverhang;
	bitmap = CreateCompatibleBitmap(dc, size.cx, size.cy);
	oldBitmap = SelectObject(dcMem, bitmap);

	/*
	 * The following code is tricky because fonts are rendered in multiple
	 * colors.  First we draw onto a black background and copy the white
	 * bits.  Then we draw onto a white background and copy the black bits.
	 * Both the foreground and background bits of the font are ANDed with
	 * the stipple pattern as they are copied.
	 */

	PatBlt(dcMem, 0, 0, size.cx, size.cy, BLACKNESS);
	TextOut(dcMem, 0, 0, source, numChars);
	BitBlt(dc, x, y - tm.tmAscent, size.cx, size.cy, dcMem,
		0, 0, 0xEA02E9);
	PatBlt(dcMem, 0, 0, size.cx, size.cy, WHITENESS);
	TextOut(dcMem, 0, 0, source, numChars);
	BitBlt(dc, x, y - tm.tmAscent, size.cx, size.cy, dcMem,
		0, 0, 0x8A0E06);

	/*
	 * Destroy the temporary bitmap and restore the device context.
	 */

        SelectObject(dcMem, hFont);
	SelectObject(dcMem, oldBitmap);
	DeleteObject(bitmap);
	DeleteDC(dcMem);
	SelectObject(dc, oldBrush);
	DeleteObject(stipple);
    } else {
	SetTextAlign(dc, TA_LEFT | TA_BASELINE);
	SetTextColor(dc, gc->foreground);
	SetBkMode(dc, TRANSPARENT);
	hFont = SelectObject(dc, fontPtr->hFont);
	TextOut(dc, x, y, source, numChars);
        SelectObject(dc, hFont);
    }
    TkWinReleaseDrawableDC(drawable, dc, &state);
}

/*
 *---------------------------------------------------------------------------
 *
 * AllocFont --
 *
 *	Helper for TkpGetNativeFont() and TkpGetFontFromAttributes().
 *	Allocates and intializes the memory for a new TkFont that
 *	wraps the platform-specific data.
 *
 * Results:
 *	Returns pointer to newly constructed TkFont.  
 *
 *	The caller is responsible for initializing the fields of the
 *	TkFont that are used exclusively by the generic TkFont code, and
 *	for releasing those fields before calling TkpDeleteFont().
 *
 * Side effects:
 *	Memory allocated.
 *
 *---------------------------------------------------------------------------
 */ 

static TkFont *
AllocFont(tkFontPtr, tkwin, hFont)
    TkFont *tkFontPtr;		/* If non-NULL, store the information in
				 * this existing TkFont structure, rather than
				 * allocating a new structure to hold the
				 * font; the existing contents of the font
				 * will be released.  If NULL, a new TkFont
				 * structure is allocated. */
    Tk_Window tkwin;		/* For display where font will be used. */
    HFONT hFont;		/* Windows information about font. */
{
    HWND hwnd;
    WinFont *fontPtr;
    HDC hdc;
    TEXTMETRIC tm;
    Window window;
    char buf[LF_FACESIZE];
    TkFontAttributes *faPtr;

    if (tkFontPtr != NULL) {
        fontPtr = (WinFont *) tkFontPtr;
        DeleteObject(fontPtr->hFont);
    } else {
        fontPtr = (WinFont *) ckalloc(sizeof(WinFont));
    }
    
    window = Tk_WindowId(((TkWindow *) tkwin)->mainPtr->winPtr);
    hwnd = (window == None) ? NULL : TkWinGetHWND(window);

    hdc = GetDC(hwnd);
    hFont = SelectObject(hdc, hFont);
    GetTextFace(hdc, sizeof(buf), buf);
    GetTextMetrics(hdc, &tm);

    fontPtr->font.fid	= (Font) fontPtr;

    faPtr = &fontPtr->font.fa;
    faPtr->family	= Tk_GetUid(buf);
    faPtr->pointsize	= MulDiv(tm.tmHeight - tm.tmInternalLeading,
	    720 * WidthMMOfScreen(Tk_Screen(tkwin)),
	    254 * WidthOfScreen(Tk_Screen(tkwin)));
    faPtr->weight	= (tm.tmWeight > FW_MEDIUM) ? TK_FW_BOLD : TK_FW_NORMAL;
    faPtr->slant	= (tm.tmItalic != 0) ? TK_FS_ITALIC : TK_FS_ROMAN;
    faPtr->underline	= (tm.tmUnderlined != 0) ? 1 : 0;
    faPtr->overstrike	= (tm.tmStruckOut != 0) ? 1 : 0;

    fontPtr->font.fm.ascent	= tm.tmAscent;
    fontPtr->font.fm.descent	= tm.tmDescent;
    fontPtr->font.fm.maxWidth	= tm.tmMaxCharWidth;
    fontPtr->font.fm.fixed	= !(tm.tmPitchAndFamily & TMPF_FIXED_PITCH);

    hFont = SelectObject(hdc, hFont);
    ReleaseDC(hwnd, hdc);

    fontPtr->hFont		= hFont;
    fontPtr->hwnd		= hwnd;

    return (TkFont *) fontPtr;
}