Made copy_from_start() more clear and probably faster.

Commented out a check that would prevent characters smaller than B_UTF8_ELLIPSIS
to be rendered (ie. the maximum width could be less than the ellipsisWidth but
greater than the complete string width for small strings).
Minor cleanup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@13013 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kits/interface/InterfaceDefs.cpp

@@ -735,44 +735,46 @@ do_minimize_team(BRect zoomRect, team_id team, bool zoom)
 	// ToDo: implement me, needed for Deskbar!
 }
 
-// copy_from_start
+
+//	#pragma mark - truncate string
+
+
 static char*
-copy_from_start(const char* src, char* dst, uint32 numChars,
+copy_from_start(const char* source, char* dest, uint32 numChars,
 	const float* escapementArray, float width, float ellipsisWidth, float size)
 {
-//printf("copy_from_start: %.1f\n", width);
 	float currentWidth = 0.0;
-	for (uint32 c = 0; c < numChars; c++) {
+	ellipsisWidth /= size;	// test if this is as accurate as escapementArray * size
-//printf("forward: %c (%ld) (%.1f + %.1f = %.1f)\n", *src, c, currentWidth, escapementArray[c] * size, currentWidth + escapementArray[c] * size);
+	width /= size;
-		currentWidth += escapementArray[c] * size;
+	uint32 lastFit = 0, c;
-		if (currentWidth > width) {
+
-//*dst = *src;
+	for (c = 0; c < numChars; c++) {
-			// ups, we definitely don't fit. go back until the ellipsis fits
+		currentWidth += escapementArray[c];
-			currentWidth += ellipsisWidth;
+		if (currentWidth + ellipsisWidth <= width)
-			for (int32 c2 = c; c2 >= 0; c2--) {
+			lastFit = c;
-//printf(" backward: %c (%ld) (%.1f - %.1f = %.1f)\n", *dst, c2, currentWidth, escapementArray[c2] * size, currentWidth - escapementArray[c2] * size);
+
-				currentWidth -= escapementArray[c2] * size;
+		if (currentWidth > width)
-				do {
-					dst--;
-				} while (IsInsideGlyph(*dst));
-				// see if we went back enough
-				if (currentWidth <= width)
 			break;
 	}
-			// dst needs to point behind the last glyph we want to use
-			dst++;
-			break;
-		} else {
-			// copy one glyph
-			do {
-				*dst++ = *src++;
-			} while (IsInsideGlyph(*src));
-		}
-	}
-	return dst;
-}
 
-// copy_from_end
+	if (c < numChars) {
+		// string does not fit into width
+		c = lastFit + 1;
+	}
+
+	// copy string to destination
+
+	for (uint32 i = 0; i < c; i++) {
+		// copy one glyph
+		do {
+			*dest++ = *source++;
+		} while (IsInsideGlyph(*source));
+	}
+
+	return dest;
+}
+
+
 static char*
 copy_from_end(const char* src, char* dst, uint32 numChars, uint32 length,
 	const float* escapementArray, float width, float ellipsisWidth, float size)
@@ -811,24 +813,26 @@ copy_from_end(const char* src, char* dst, uint32 numChars, uint32 length,
 	return dst;
 }
 
+
 static char*
 write_ellipsis(char* dst)
 {
 	strcpy(dst, B_UTF8_ELLIPSIS);
-//strcpy(dst, "...");
 	return dst + 3;
 }
 
-// truncated_string
+
 void
-truncate_string(const char* string,
+truncate_string(const char* string, uint32 mode, float width,
-				uint32 mode, float width, char* result,
+	char* result, const float* escapementArray, float fontSize,
-				const float* escapementArray, float fontSize,
 	float ellipsisWidth, int32 length, int32 numChars)
 {
-	if (string) {
+	// ToDo: that's actually not correct: the string could be smaller than ellipsisWidth
-		// skip calculation if we don't even have enough room for that
+	if (string == NULL /*|| width < ellipsisWidth*/) {
-		if (width >= ellipsisWidth) {
+		// we don't have room for a single glyph
+		strcpy(result, "");
+		return;
+	}
 
 	// iterate over glyphs and copy source into result string
 	// one glyph at a time as long as we have room for the "…" yet
@@ -837,7 +841,6 @@ truncate_string(const char* string,
 
 	switch (mode) {
 		case B_TRUNCATE_BEGINNING: {
-
 			dst = copy_from_end(src, dst, numChars, length,
 								escapementArray, width, ellipsisWidth, fontSize);
 			// "dst" points to the position behind the last glyph that
@@ -864,9 +867,9 @@ truncate_string(const char* string,
 		}
 
 		case B_TRUNCATE_END:
+			dst = copy_from_start(src, dst, numChars, escapementArray,
+				width, ellipsisWidth, fontSize);
 
-					dst = copy_from_start(src, dst, numChars,
-										  escapementArray, width, ellipsisWidth, fontSize);
 			// "dst" points to the position behind the last glyph that
 			// was copied.
 			if (dst - result < length) {
@@ -896,11 +899,6 @@ truncate_string(const char* string,
 			*dst = 0;
 			break;
 	}
-		} else {
-			// we don't have room for a single glyph
-			strcpy(result, "");
-		}
-	}
 }