Bug Fix: It was assumed that kerning did not exist when the code was written.

This behavior has since been changed.  Added new API calls to get the font
measurment for chars (kerning or not)


FossilOrigin-Name: 02cb8cce3aec4c1c46e9e56cbed0789cd1d3e861

1 files changed, 54 insertions, 69 deletions

diff --git a/win/tkWinFont.c b/win/tkWinFont.c
index c1d5161..5aa63b0 100644
--- a/win/tkWinFont.c
+++ b/win/tkWinFont.c
@@ -26,7 +26,6 @@ typedef struct WinFont {
     HFONT hFont;		/* Windows information about font. */
     HWND hwnd;			/* Toplevel window of application that owns
 				 * this font, used for getting HDC. */
-    int widths[256];		/* Widths of first 256 chars in this font. */
 } WinFont;
 
 /*
@@ -332,14 +331,6 @@ Tk_MeasureChars(tkfont, source, numChars, maxLength, flags, lengthPtr)
     HFONT hFont;
     int curX, curIdx;
 
-    /*
-     * On the authority of the Gates Empire, Windows does not use kerning
-     * or fractional character widths when displaying text on the screen.
-     * So that means we can safely measure individual characters or spans
-     * of characters and add up the widths w/o any "off-by-one pixel" 
-     * errors.  
-     */
-
     fontPtr = (WinFont *) tkfont;
 
     hdc = GetDC(fontPtr->hwnd);
@@ -351,75 +342,70 @@ Tk_MeasureChars(tkfont, source, numChars, maxLength, flags, lengthPtr)
     } else if (maxLength <= 0) {
 	SIZE size;
 
-	GetTextExtentPoint(hdc, source, numChars, &size);
+	GetTextExtentPoint32(hdc, source, numChars, &size);
 	curX = size.cx;
 	curIdx = numChars;
     } else {
-	int newX, termX, sawNonSpace;
-	CONST char *term, *end, *p;
-	int ch;
-
-	ch = UCHAR(*source);
-	newX = curX = termX = 0;
+	int max;
+	int *partials;
+	SIZE size;
 	
-	term = source;
-	end = source + numChars;
-
-	sawNonSpace = !isspace(ch);
-	for (p = source; ; ) {
-	    newX += fontPtr->widths[ch];
-	    if (newX > maxLength) {
-		break;
-	    }
-	    curX = newX;
-	    p++;
-	    if (p >= end) {
-		term = end;
-		termX = curX;
-		break;
-	    }
-
-	    ch = UCHAR(*p);
-	    if (isspace(ch)) {
-		if (sawNonSpace) {
-		    term = p;
-		    termX = curX;
-		    sawNonSpace = 0;
-		}
-	    } else {
-		sawNonSpace = 1;
-	    }
-	}
-
-	/*
-	 * P points to the first character that doesn't fit in the desired
-	 * span.  Use the flags to figure out what to return.
-	 */
+	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 ((flags & TK_PARTIAL_OK) && (p < end) && (curX < maxLength)) {
 	    /*
-	     * Include the first character that didn't quite fit in the desired
-	     * span.  The width returned will include the width of that extra
-	     * character.
+	     * 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.
 	     */
-
-	    curX = newX;
-	    p++;
-	}
-	if ((flags & TK_AT_LEAST_ONE) && (term == source) && (p < end)) {
-	    term = p;
-	    termX = curX;
-	    if (term == source) {
-		term++;
-		termX = newX;
+	    
+	    if ((i < 0) && !(flags & TK_AT_LEAST_ONE)) {
+		max = 0;
+	    } else if (sawSpace) {
+		max = i + 1;
 	    }
-	} else if ((p >= end) || !(flags & TK_WHOLE_WORDS)) {
-	    term = p;
-	    termX = curX;
+		
+	}
+
+	if (max == 0) {
+	    curX = 0;
+	} else {
+	    curX = partials[max - 1];
 	}
 
-	curX = termX;
-	curIdx = term - source;	
+	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);
@@ -613,7 +599,6 @@ AllocFont(tkFontPtr, tkwin, hFont)
     hFont = SelectObject(hdc, hFont);
     GetTextFace(hdc, sizeof(buf), buf);
     GetTextMetrics(hdc, &tm);
-    GetCharWidth(hdc, 0, 255, fontPtr->widths);
 
     fontPtr->font.fid	= (Font) fontPtr;