Implement word wrapping when pasting plain text, wrt #6

When the clipboard has plain text data copied from a plain text or ASCII
text editor, pasting the text will perform word wrapping.

The text will originate from the cursor position and subsequent lines will
by default start from column 1 to provide room for alphanumeric colour
control codes in column 0.

If the cursor is at column 0 then all lines will start at column 0.

If a box selection is dragged before pasting the text will originate at
the top left of the selection box and be confined to the box. This can be
used if the second and subsequent lines need to start at a different
column, or if the pasted text must not overwrite an existing feature at
the right side of the page.

Note that cutting or copying text from within QTeletextMaker itself will
not be word wrapped on paste.

levelonecommands.cpp

@@ -415,8 +415,18 @@ PasteCommand::PasteCommand(TeletextDocument *teletextDocument, int pageCharSet,
 	if (m_selectionActive) {
 		m_selectionCornerRow = m_teletextDocument->selectionCornerRow();
 		m_selectionCornerColumn = m_teletextDocument->selectionCornerColumn();
+		m_pasteTopRow = m_teletextDocument->selectionTopRow();
+		m_pasteBottomRow = m_teletextDocument->selectionBottomRow();
+		m_pasteLeftColumn = m_teletextDocument->selectionLeftColumn();
+		m_pasteRightColumn = m_teletextDocument->selectionRightColumn();
+	} else {
+		m_pasteTopRow = m_row;
+		m_pasteLeftColumn = m_column;
+		// m_pasteBottomRow and m_pasteRightColumn will be filled in later
+		// when the size of the clipboard data is known
 	}
 
+	// Zero size here represents invalid or empty clipboard data
 	m_clipboardDataHeight = m_clipboardDataWidth = 0;
 
 	// Try to get something from the clipboard
@@ -424,6 +434,7 @@ PasteCommand::PasteCommand(TeletextDocument *teletextDocument, int pageCharSet,
 	nativeData = mimeData->data("application/x-teletext");
 	if (nativeData.size() > 2) {
 		// Native clipboard data: we put it there ourselves
+		m_plainText = false;
 		m_clipboardDataHeight = nativeData.at(0);
 		m_clipboardDataWidth = nativeData.at(1);
 
@@ -431,25 +442,119 @@ PasteCommand::PasteCommand(TeletextDocument *teletextDocument, int pageCharSet,
 		if (m_clipboardDataHeight > 0 && m_clipboardDataWidth > 0 && m_clipboardDataHeight <= 25 && m_clipboardDataWidth <= 40 && nativeData.size() == m_clipboardDataHeight * m_clipboardDataWidth + 2)
 			for (int r=0; r<m_clipboardDataHeight; r++)
 				m_pastingCharacters.append(nativeData.mid(2 + r * m_clipboardDataWidth, m_clipboardDataWidth));
-		else
+		else {
 			// Invalidate
 			m_clipboardDataHeight = m_clipboardDataWidth = 0;
+			return;
+		}
+
+		if (!m_selectionActive) {
+			m_pasteBottomRow = m_row + m_clipboardDataHeight - 1;
+			m_pasteRightColumn = m_column + m_clipboardDataWidth - 1;
+		}
 	} else if (mimeData->hasText()) {
 		// Plain text
+		m_plainText = true;
+
+		const int rightColumn = m_selectionActive ? m_pasteRightColumn : 39;
+
+		// Parse line-feeds in the clipboard data
 		QStringList plainTextData = mimeData->text().split(QRegExp("\n|\r\n|\r"));
 
+		// "if" statement will be false if clipboard data is a single line of text
+		// that will fit from the cursor position
+		if (plainTextData.size() != 1 || m_pasteLeftColumn + plainTextData.at(0).size() - 1 > rightColumn) {
+			bool wrappingNeeded = false;
+
+			if (!m_selectionActive) {
+				// If selection is NOT active, use the full width of the page to paste.
+				// The second and subsequent lines will start at column 1, unless the
+				// cursor is explicitly on column 0.
+				if (m_pasteLeftColumn != 0)
+					m_pasteLeftColumn = 1;
+
+				// Check if first word in the first line will fit from the cursor position
+				bool firstWordFits = true;
+				const int firstSpace = plainTextData.at(0).indexOf(' ');
+
+				if (firstSpace == -1 && m_column + plainTextData.at(0).size() > 40)
+					firstWordFits = false; // Only one word in first line, and it won't fit
+				else if (m_column + firstSpace > 40)
+					firstWordFits = false; // First word in first line won't fit
+
+				// If the first word WILL fit at the cursor position, pad the first line
+				// to match the cursor position using null characters.
+				// In the QString null characters represent character cells in the
+				// pasting rectangle that won't overwrite what's on the page.
+				// If the first word WON'T fit, start pasting at the beginning of the next row.
+				if (firstWordFits)
+					plainTextData[0] = QString(m_column-m_pasteLeftColumn, QChar::Null) + plainTextData.at(0);
+				else if (m_pasteTopRow < 24)
+					m_pasteTopRow++;
+				else
+					return;
+			}
+
+			const int pasteWidth = rightColumn - m_pasteLeftColumn + 1;
+
+			// Find out if we need to word-wrap
+			for (int i=0; i<plainTextData.size(); i++)
+				if (plainTextData.at(i).size() > pasteWidth) {
+					wrappingNeeded = true;
+					break;
+				}
+
+			if (wrappingNeeded) {
+				QStringList wrappedText;
+
+				for (int i=0; i<plainTextData.size(); i++) {
+					// Split this line into individual words
+					QStringList lineWords = plainTextData.at(i).split(' ');
+
+					// If there's any words which are too long to fit,
+					// break them across multiple lines
+					for (int j=0; j<lineWords.size(); j++)
+						if (lineWords.at(j).size() > pasteWidth) {
+							lineWords.insert(j+1, lineWords.at(j).mid(pasteWidth));
+							lineWords[j].truncate(pasteWidth);
+						}
+
+					// Now reassemble the words into lines that will fit
+					QString currentLine = lineWords.at(0);
+
+					for (int j=1; j<lineWords.size(); j++)
+						if (currentLine.size() + 1 + lineWords.at(j).size() <= pasteWidth)
+							currentLine.append(' ' + lineWords.at(j));
+						else {
+							wrappedText.append(currentLine);
+							currentLine = lineWords.at(j);
+						}
+
+					wrappedText.append(currentLine);
+				}
+				plainTextData.swap(wrappedText);
+			}
+		}
+
 		m_clipboardDataHeight = plainTextData.size();
 		m_clipboardDataWidth = 0;
 
+		// Convert the unicode clipboard text into teletext bytes matching the current Level 1
+		// character set of this page
 		for (int r=0; r<m_clipboardDataHeight; r++) {
 			m_pastingCharacters.append(QByteArray());
 			for (int c=0; c<plainTextData.at(r).size(); c++) {
-				// Try to map the unicode character to the current Level 1 character set of this page
-
 				char convertedChar;
 				const QChar charToConvert = plainTextData.at(r).at(c);
 
-				if (keymapping[pageCharSet].contains(charToConvert))
+				// Map a null character in the QString to 0xff (or -1)
+				// In the QByteArray 0xff bytes represent character cells in the pasting rectangle
+				// that won't overwrite what's on the page
+				if (charToConvert == QChar::Null)
+					convertedChar = -1;
+				else if (charToConvert >= 0x01 && charToConvert <= 0x1f)
+					convertedChar = ' ';
+				else if (keymapping[pageCharSet].contains(charToConvert))
 					// Remapped character or non-Latin character converted successfully
 					convertedChar = keymapping[pageCharSet].value(charToConvert);
 				else {
@@ -465,26 +570,19 @@ PasteCommand::PasteCommand(TeletextDocument *teletextDocument, int pageCharSet,
 			}
 			m_clipboardDataWidth = qMax(m_pastingCharacters.at(r).size(), m_clipboardDataWidth);
 		}
-		// Pad short lines with spaces to make a box
+		// Pad the end of short lines with spaces to make a box
 		for (int r=0; r<m_clipboardDataHeight; r++)
 			m_pastingCharacters[r] = m_pastingCharacters.at(r).leftJustified(m_clipboardDataWidth);
+
+		if (!m_selectionActive) {
+			m_pasteBottomRow = m_pasteTopRow + m_clipboardDataHeight - 1;
+			m_pasteRightColumn = m_pasteLeftColumn + m_clipboardDataWidth - 1;
+		}
 	}
 
 	if (m_clipboardDataWidth == 0 || m_clipboardDataHeight == 0)
 		return;
 
-	if (m_selectionActive) {
-		m_pasteTopRow = m_teletextDocument->selectionTopRow();
-		m_pasteBottomRow = m_teletextDocument->selectionBottomRow();
-		m_pasteLeftColumn = m_teletextDocument->selectionLeftColumn();
-		m_pasteRightColumn = m_teletextDocument->selectionRightColumn();
-	} else {
-		m_pasteTopRow = m_row;
-		m_pasteBottomRow = m_row + m_clipboardDataHeight - 1;
-		m_pasteLeftColumn = m_column;
-		m_pasteRightColumn = m_column + m_clipboardDataWidth - 1;
-	}
-
 	// Store copy of the characters that we're about to overwrite
 	for (int r=m_pasteTopRow; r<=m_pasteBottomRow; r++) {
 		QByteArray rowArray;
@@ -519,11 +617,21 @@ void PasteCommand::redo()
 		for (int c=m_pasteLeftColumn; c<=m_pasteRightColumn; c++)
 			// Guard against size of pasted block going beyond last line or column
 			if (r < 25 && c < 40) {
-				m_teletextDocument->currentSubPage()->setCharacter(r, c, m_pastingCharacters[arrayR].at(arrayC++));
+				// Check for 0xff bytes using "-1"
+				// gcc complains about "comparision always true due to limited range"
+				if (m_pastingCharacters.at(arrayR).at(arrayC) != -1)
+					m_teletextDocument->currentSubPage()->setCharacter(r, c, m_pastingCharacters.at(arrayR).at(arrayC));
+
+				arrayC++;
 
 				// If paste area is wider than clipboard data, repeat the pattern
-				if (arrayC == m_clipboardDataWidth)
+				// if it wasn't plain text
+				if (arrayC == m_clipboardDataWidth) {
+					if (!m_plainText)
 						arrayC = 0;
+					else
+						break;
+				}
 			}
 
 		if (r < 25)
@@ -531,8 +639,13 @@ void PasteCommand::redo()
 
 		arrayR++;
 		// If paste area is taller than clipboard data, repeat the pattern
-		if (arrayR == m_clipboardDataHeight)
+		// if it wasn't plain text
+		if (arrayR == m_clipboardDataHeight) {
+			if (!m_plainText)
 				arrayR = 0;
+			else
+				break;
+		}
 	}
 
 	if (m_selectionActive) {
@@ -558,8 +671,11 @@ void PasteCommand::undo()
 		arrayC = 0;
 		for (int c=m_pasteLeftColumn; c<=m_pasteRightColumn; c++)
 			// Guard against size of pasted block going beyond last line or column
-			if (r < 25 && c < 40)
+			if (r < 25 && c < 40) {
-				m_teletextDocument->currentSubPage()->setCharacter(r, c, m_deletedCharacters[arrayR].at(arrayC++));
+				m_teletextDocument->currentSubPage()->setCharacter(r, c, m_deletedCharacters[arrayR].at(arrayC));
+
+				arrayC++;
+			}
 
 		if (r < 25)
 			emit m_teletextDocument->contentsChange(r);

levelonecommands.h

@@ -179,7 +179,7 @@ private:
 	int m_pasteTopRow, m_pasteBottomRow, m_pasteLeftColumn, m_pasteRightColumn;
 	int m_clipboardDataHeight, m_clipboardDataWidth;
 	int m_selectionCornerRow, m_selectionCornerColumn;
-	bool m_selectionActive;
+	bool m_selectionActive, m_plainText;
 };
 #endif // !QT_NO_CLIPBOARD