LiveText: pumped generator follow-up

source/NVDAObjects/behaviors.py

@@ -1,8 +1,8 @@
 # A part of NonVisual Desktop Access (NVDA)
 # This file is covered by the GNU General Public License.
 # See the file COPYING for more details.
-# Copyright (C) 2006-2025 NV Access Limited, Peter Vágner, Joseph Lee, Bill Dengler,
-# Burman's Computer and Education Ltd, Cary-rowen, Cyrille Bougot
+# Copyright (C) 2006-2026 NV Access Limited, Peter Vágner, Joseph Lee, Bill Dengler,
+# Burman's Computer and Education Ltd, Cary-rowen, Cyrille Bougot, Ethin Probst
 
 """Mix-in classes which provide common behaviour for particular types of controls across different APIs.
 Behaviors described in this mix-in include providing table navigation commands for certain table rows, terminal input and output support, announcing notifications and suggestion items and so on.
@@ -11,6 +11,7 @@
 import os
 import time
 import threading
+import math
 import tones
 import queueHandler
 import eventHandler
@@ -383,10 +384,6 @@ class LiveText(NVDAObject):
 	# If the text is live, this is definitely content.
 	presentationType = NVDAObject.presType_content
 
-	MAX_LINES: int = 100
-	"""The maximum number of lines that will be reported when a large number of lines are queued.
-	Subclasses may override this to allow custom line reporting batches.
-	"""
 	announceNewLineText = False
 
 	def initOverlayClass(self):
@@ -468,20 +465,55 @@ def _reportNewLines(self, lines: list[str]) -> None:
 		Subclasses may override this method to provide custom filtering of new text,
 		where logic depends on multiple lines.
 		"""
-		droppedCount = len(lines) - self.MAX_LINES
-		if droppedCount > 0:
-			lines = lines[-self.MAX_LINES :]
+		maxNewLines: int = config.conf["terminals"]["maxNewLines"]
+		if maxNewLines:
+			droppedCount = len(lines) - maxNewLines
+			if droppedCount > 0:
+				if (
+					config.conf["terminals"]["beepForSkippedLines"]
+					and speech.getState().speechMode == speech.SpeechMode.talk
+				):
+					tones.beep(
+						config.conf["terminals"]["skippedLinesBeepHz"],
+						self._getSkippedLinesBeepLength(droppedCount),
+					)
+				lines = lines[-maxNewLines:]
 		if self._reportNewLinesGenID is not None:
 			queueHandler.cancelGeneratorObject(self._reportNewLinesGenID)
 			self._reportNewLinesGenID = None
-		self._reportNewLinesGenID = queueHandler.registerGeneratorObject(self._reportNewLinesGenerator(lines))
+		newLinesBatchSize: int = config.conf["terminals"]["newLinesBatchSize"]
+		if newLinesBatchSize <= 0:  # Report synchronously
+			for line in lines:
+				self._reportNewText(line)
+		else:
+			self._reportNewLinesGenID = queueHandler.registerGeneratorObject(
+				self._reportNewLinesGenerator(
+					lines,
+					newLinesBatchSize,
+				),
+			)
 
-	def _reportNewLinesGenerator(self, lines: list[str]) -> Generator[None, None, None]:
-		YIELD_EVERY = 5  # Sweet spot between yielding on every line and a batch
+	@staticmethod
+	def _getSkippedLinesBeepLength(droppedCount: int) -> int:
+		minLengthMs: int = config.conf["terminals"]["skippedLinesBeepMinDurationMs"]
+		maxLengthMs: int = config.conf["terminals"]["skippedLinesBeepMaxDurationMs"]
+		if maxLengthMs < minLengthMs:
+			maxLengthMs = minLengthMs
+		droppedCount = max(droppedCount, 1)
+		maxNewLines: int = config.conf["terminals"]["maxNewLines"]
+		ratio = 1.0 if maxNewLines <= 1 else min(1.0, math.log(droppedCount, maxNewLines))
+		lengthRange = maxLengthMs - minLengthMs
+		return round(minLengthMs + lengthRange * ratio)
+
+	def _reportNewLinesGenerator(
+		self,
+		lines: list[str],
+		batchSize: int,
+	) -> Generator[None, None, None]:
 		try:
 			for i, line in enumerate(lines, 1):
 				self._reportNewText(line)
-				if i % YIELD_EVERY == 0:
+				if i % batchSize == 0:
 					yield
 		finally:
 			self._reportNewLinesGenID = None

source/config/configSpec.py

@@ -309,6 +309,12 @@
 [terminals]
 	speakPasswords = boolean(default=false)
 	keyboardSupportInLegacy = boolean(default=True)
+	maxNewLines = integer(min=0, default=100)
+	newLinesBatchSize = integer(min=0, default=5)
+	beepForSkippedLines = boolean(default=true)
+	skippedLinesBeepHz = integer(default=550, min=20)
+	skippedLinesBeepMinDurationMs = integer(default=10, min=5, max=5000)
+	skippedLinesBeepMaxDurationMs = integer(default=100, min=5, max=5000)
 	diffAlgo = option("auto", "dmp", "difflib", default="auto")
 	wtStrategy = featureFlag(optionsEnum="WindowsTerminalStrategyFlag", behaviorOfDefault="diffing")
 

source/gui/settingsDialogs.py

@@ -4455,6 +4455,22 @@ def __init__(self, parent):
 			["terminals", "keyboardSupportInLegacy"],
 		)
 		self.keyboardSupportInLegacyCheckBox.Enable(winVersion.getWinVer() >= winVersion.WIN10_1607)
+		# Translators: This is the label for a checkbox in the
+		# Advanced settings panel.
+		label = _("Beep for &skipped lines")
+		self.beepForSkippedLinesCheckBox = terminalsGroup.addItem(
+			wx.CheckBox(terminalsBox, label=label),
+		)
+		self.bindHelpEvent(
+			"AdvancedSettingsBeepForSkippedLines",
+			self.beepForSkippedLinesCheckBox,
+		)
+		self.beepForSkippedLinesCheckBox.SetValue(
+			config.conf["terminals"]["beepForSkippedLines"],
+		)
+		self.beepForSkippedLinesCheckBox.defaultValue = self._getDefaultValue(
+			["terminals", "beepForSkippedLines"],
+		)
 
 		# Translators: This is the label for a combo box for selecting a
 		# method of detecting changed content in terminals in the advanced
@@ -4750,6 +4766,7 @@ def haveConfigDefaultsBeenRestored(self):
 			== self.keyboardSupportInLegacyCheckBox.defaultValue
 			and self.winConsoleSpeakPasswordsCheckBox.IsChecked()
 			== self.winConsoleSpeakPasswordsCheckBox.defaultValue
+			and self.beepForSkippedLinesCheckBox.IsChecked() == self.beepForSkippedLinesCheckBox.defaultValue
 			and self.diffAlgoCombo.GetSelection() == self.diffAlgoCombo.defaultValue
 			and self.wtStrategyCombo.isValueConfigSpecDefault()
 			and self.cancelExpiredFocusSpeechCombo.GetSelection()
@@ -4782,6 +4799,9 @@ def restoreToDefaults(self):
 		self.brailleLiveRegionsCombo.resetToConfigSpecDefault()
 		self.winConsoleSpeakPasswordsCheckBox.SetValue(self.winConsoleSpeakPasswordsCheckBox.defaultValue)
 		self.keyboardSupportInLegacyCheckBox.SetValue(self.keyboardSupportInLegacyCheckBox.defaultValue)
+		self.beepForSkippedLinesCheckBox.SetValue(
+			self.beepForSkippedLinesCheckBox.defaultValue,
+		)
 		self.diffAlgoCombo.SetSelection(self.diffAlgoCombo.defaultValue)
 		self.wtStrategyCombo.resetToConfigSpecDefault()
 		self.cancelExpiredFocusSpeechCombo.SetSelection(self.cancelExpiredFocusSpeechCombo.defaultValue)
@@ -4824,6 +4844,7 @@ def onSave(self):
 		self.enhancedEventProcessingComboBox.saveCurrentValueToConf()
 		config.conf["terminals"]["speakPasswords"] = self.winConsoleSpeakPasswordsCheckBox.IsChecked()
 		config.conf["terminals"]["keyboardSupportInLegacy"] = self.keyboardSupportInLegacyCheckBox.IsChecked()
+		config.conf["terminals"]["beepForSkippedLines"] = self.beepForSkippedLinesCheckBox.IsChecked()
 		diffAlgoChoice = self.diffAlgoCombo.GetSelection()
 		config.conf["terminals"]["diffAlgo"] = self.diffAlgoVals[diffAlgoChoice]
 		self.wtStrategyCombo.saveCurrentValueToConf()

user_docs/en/changes.md

@@ -15,7 +15,7 @@
 ### Bug Fixes
 
 * When moving to an ARIA grid cell in focus mode in web browsers, NVDA no longer reports both the row and column headers even if only the row or only the column changed. (#17750, @jcsteh)
-* In live text regions, such as terminals, NVDA no longer freezes when substantial amounts of text are dumped to the screen. (#20177)
+* In live text regions, such as terminals, NVDA no longer freezes when substantial amounts of text are dumped to the screen. (#20177, #20216, @ethindp, @codeofdusk)
 * When an application stops responding, NVDA no longer freezes or floods its log with errors; it stays responsive and drops UIA and MSAA events from the unresponsive application until it recovers. (#16749, @heath-toby)
 * Reduced lag on UI Automation text change events, improving the responsiveness of controls such as combo boxes and of File Explorer, by using the cached element class name instead of a live cross-process fetch. (#16749, @heath-toby)
 * In Mozilla Firefox, reporting annotation details now works correctly in focus mode on controls which are not editable text. (#20208, @jcsteh)

user_docs/en/userGuide.md

@@ -4166,6 +4166,16 @@ This feature is available and enabled by default on Windows 10 versions 1607 and
 Warning: with this option enabled, typed characters that do not appear onscreen, such as passwords, will not be suppressed.
 In untrusted environments, you may temporarily disable [speak typed characters](#KeyboardSettingsSpeakTypedCharacters) and [speak typed words](#KeyboardSettingsSpeakTypedWords) when entering passwords.
 
+##### Beep for skipped lines {#AdvancedSettingsBeepForSkippedLines}
+
+| . {.hideHeaderRow} |.|
+|---|---|
+| Options | Disabled, Enabled |
+| Default | Enabled |
+
+This setting controls whether NVDA plays a short beep when too many new lines arrive before they can all be reported.
+The beep indicates that some lines were skipped, and becomes slightly longer as more lines are skipped.
+
 ##### Diff algorithm {#DiffAlgo}
 
 This setting controls how NVDA determines the new text to speak in terminals.