cleanup code

Author: tobias-melcher

bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/StyledText.java

@@ -1080,12 +1080,10 @@ void calculateTopIndex(int delta) {
 		int lineCount = content.getLineCount();
 		if (delta >= 0) {
 			delta -= topIndexY;
-			int lineIndex = topIndex;
+			int lineIndex = Math.max(0, topIndex);
 			while (lineIndex < lineCount) {
 				if (delta <= 0) break;
-				if (lineIndex >= 0 && lineIndex < lineCount) {
-					delta -= renderer.getCachedLineHeight(lineIndex);
-				}
+				delta -= renderer.getCachedLineHeight(lineIndex);
 				lineIndex++;
 			}
 			int lineHeight = 0;
@@ -1097,11 +1095,10 @@ void calculateTopIndex(int delta) {
 				topIndexY = -delta;
 			} else {
 				topIndex = lineIndex - 1;
-				int topIndexHeight = 0;
 				if (topIndex >= 0 && topIndex < lineCount) {
-					topIndexHeight = renderer.getCachedLineHeight(topIndex);
+					topIndexY = -renderer.getCachedLineHeight(topIndex);
 				}
-				topIndexY = -topIndexHeight - delta;
+				topIndexY -= delta;
 			}
 		} else {
 			delta -= topIndexY;
@@ -3902,10 +3899,7 @@ public int getLinePixel(int lineIndex) {
 		return topIndexY + topMargin;
 	int height = topIndexY;
 	if (lineIndex > topIndex) {
-		for (int i = topIndex; i < lineIndex; i++) {
-			if (i < 0 || i >= lineCount) {
-				continue;
-			}
+		for (int i = Math.max(topIndex, 0); i < Math.min(lineIndex, lineCount); i++) {
 			height += renderer.getLineHeight(i);
 		}
 	} else {