corrected issues for detecting deleted lines

code needed to consider if the selection start and end positions were
at the beginning or end of the line they are at

selection class modified to return status of whether the start and end
selection positions are at the begin or end of the line, replaced
lines() function with newLines(), so if the selection is contained on
a single line, the number of new lines in the selection is zero; also
added comments to the selection class functions

editbox.cpp

@@ -555,10 +555,32 @@ void EditBox::captureDeletedLines(void)
 {
 	if (!m_beforeSelection.isEmpty() && m_charsRemoved > 0)
 	{
-		if (m_beforeSelection.lines() > 1)
+		if (m_beforeSelection.newLines() > 0)
 		{
-			emit linesDeleted(m_beforeSelection.startLine(),
-				m_beforeSelection.lines() - 1);
+			int firstLine = m_beforeSelection.startLine();
+
+			// if start is not at begin of line
+			// or start is at end of line and end is not at begin of line
+			// then don't report first line as deleted
+			if (!m_beforeSelection.startAtLineBegin()
+				|| m_beforeSelection.startAtLineEnd()
+				&& !m_beforeSelection.endAtLineBegin())
+			{
+				firstLine++;
+			}
+
+			// if start and end are at begin of line
+			// or start and end are at end of line
+			// then current line after deltion should not be set as modified
+			if (m_beforeSelection.startAtLineBegin()
+				&& m_beforeSelection.endAtLineBegin()
+				|| m_beforeSelection.startAtLineEnd()
+				&& m_beforeSelection.endAtLineEnd())
+			{
+				m_lineModified = -1;
+			}
+
+			emit linesDeleted(firstLine, m_beforeSelection.newLines());
 		}
 	}
 	// reset charaters removed and added variables

editbox.h

@@ -37,35 +37,68 @@ class Selection
 	int m_end;						// end position of selection
 	int m_startLine;				// start line of selection
 	int m_endLine;					// end line of selection
+	int m_startLineBegin;			// position of begin of start line
+	int m_startLineEnd;				// position of end of start line
+	int m_endLineBegin;				// position of begin of end line
+	int m_endLineEnd;				// position of end of end line
 
 public:
 	Selection(void) {}
+	// set selction info from a text cursor
 	void setFromCursor(const QTextCursor &cursor)
 	{
 		m_start = cursor.selectionStart();
 		m_end = cursor.selectionEnd();
 
 		QTextBlock block = cursor.document()->findBlock(m_start);
 		m_startLine = block.blockNumber();
+		m_startLineBegin = block.position();
+		m_startLineEnd = m_startLineBegin + block.length() - 1;
 		block = cursor.document()->findBlock(m_end);
 		m_endLine = block.blockNumber();
+		m_endLineBegin = block.position();
+		m_endLineEnd = m_endLineBegin + block.length() - 1;
 	}
+	// return if there is no selection
 	bool isEmpty(void)
 	{
 		return m_start == m_end;
 	}
-	int lines(void)
+	// return number of new lines in selection
+	int newLines(void)
 	{
-		return m_endLine - m_startLine + 1;
+		return m_endLine - m_startLine;
 	}
+	// return start selection line number
 	int startLine(void)
 	{
 		return m_startLine;
 	}
+	// return end selection line number
 	int endLine(void)
 	{
 		return m_endLine;
 	}
+	// return if start selection position is at the begin of the line
+	bool startAtLineBegin(void)
+	{
+		return m_start == m_startLineBegin;
+	}
+	// return if start selection position is at the end of the line
+	bool startAtLineEnd(void)
+	{
+		return m_start == m_startLineEnd;
+	}
+	// return if end selection position is at being of the line
+	bool endAtLineBegin(void)
+	{
+		return m_end == m_endLineBegin;
+	}
+	// return if end selection position is at end of the line
+	bool endAtLineEnd(void)
+	{
+		return m_end == m_endLineEnd;
+	}
 };