Fix EcoBraille and Lilly braille display drivers

source/braille.py

@@ -1769,7 +1769,7 @@ def __init__(self, handler):
 		#: The translated braille representation of the entire buffer.
 		#: @type: [int, ...]
 		self.brailleCells = []
-		self._windowRowBufferOffsets: list[tuple[int, int]] = [(0, 1)]
+		self._windowRowBufferOffsets: list[tuple[int, int]] = [(0, 0)]
 		"""
 		A list representing the rows in the braille window,
 		each item being a tuple of start and end braille buffer offsets.
@@ -1879,6 +1879,8 @@ def windowPosToBufferPos(self, windowPos: int) -> int:
 		"""
 		Converts a position relative to the braille window to a position relative to the braille buffer.
 		"""
+		if self.handler.displaySize == 0:
+			return 0
 		windowPos = max(min(windowPos, self.handler.displaySize), 0)
 		row, col = divmod(windowPos, self.handler.displayDimensions.numCols)
 		if row < len(self._windowRowBufferOffsets):
@@ -1905,7 +1907,7 @@ def _calculateWindowRowBufferOffsets(self, pos: int) -> None:
 		self._windowRowBufferOffsets.clear()
 		if len(self.brailleCells) == 0:
 			# Initialising with no actual braille content.
-			self._windowRowBufferOffsets = [(0, 1)]
+			self._windowRowBufferOffsets = [(0, 0)]
 			return
 		doWordWrap = config.conf["braille"]["wordWrap"]
 		bufferEnd = len(self.brailleCells)
@@ -2539,9 +2541,14 @@ def _set_displaySize(self, value):
 	_cache_displayDimensions = True
 
 	def _get_displayDimensions(self) -> DisplayDimensions:
+		if not self.display:
+			numRows = numCols = 0
+		else:
+			numRows = self.display.numRows
+			numCols = self.display.numCols if numRows > 1 else self.display.numCells
 		rawDisplayDimensions = DisplayDimensions(
-			numRows=self.display.numRows if self.display else 0,
-			numCols=self.display.numCols if self.display else 0,
+			numRows=numRows,
+			numCols=numCols,
 		)
 		filteredDisplayDimensions = filter_displayDimensions.apply(rawDisplayDimensions)
 		# Would be nice if there were a more official way to find out if the displaySize filter is currently registered by at least 1 handler.
@@ -3284,7 +3291,9 @@ class BrailleDisplayDriver(driverHandler.Driver):
 	containing a BrailleDisplayDriver class which inherits from this base class.
 
 	At a minimum, drivers must set L{name} and L{description} and override the L{check} method.
-	To display braille, L{numCells} and L{display} must be implemented.
+	To display braille, :meth:`display` must be implemented.
+	For a single line display, :attr:`numCells` must be implemented.
+	For a multi line display, :attr:`numRows` and :attr:`numCols` must be implemented.
 
 	To support automatic detection of braille displays belonging to this driver:
 		* The driver must be thread safe and L{isThreadSafe} should be set to C{True}