if (getCharCount() == 0) { return; }
public void setTopIndex(int topIndex) {	checkWidget();	int lineCount = logicalContent.getLineCount();	int pageSize = Math.max(1, Math.min(lineCount, getLineCountWhole()));		if (getCharCount() == 0) {		return;	}		if (topIndex < 0) {		topIndex = 0;	}	else 	if (topIndex > lineCount - pageSize) {		topIndex = lineCount - pageSize;	}	if (wordWrap) {		int logicalLineOffset = logicalContent.getOffsetAtLine(topIndex);		topIndex = content.getLineAtOffset(logicalLineOffset);	}	setVerticalScrollOffset(topIndex * getVerticalIncrement(), true);}