[orca] Filter out duplicate auto text events from Gecko apps

[Joanmarie Diggs <joanied src gnome org>]

commit 6b815e9540209a527e7bfc7082aa1ba3dd6a6f62
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Fri Oct 18 15:45:30 2019 -0400

    Filter out duplicate auto text events from Gecko apps

 src/orca/input_event.py                            | 18 +++++++++++++++++
 src/orca/script_utilities.py                       | 16 +++++++++++++++
 .../scripts/toolkits/Gecko/script_utilities.py     | 23 ++++++++++++++++++++++
 3 files changed, 57 insertions(+)
---
diff --git a/src/orca/input_event.py b/src/orca/input_event.py
index d335a46ac..96ae51686 100644
--- a/src/orca/input_event.py
+++ b/src/orca/input_event.py
@@ -296,6 +296,24 @@ class KeyboardEvent(InputEvent):
 
         return False
 
+    def isReleaseFor(self, other):
+        """Return True if this is the release event for other."""
+
+        if not other:
+            return False
+
+        if not other.isPressedKey() or self.isPressedKey():
+            return False
+
+        return self.id == other.id \
+            and self.hw_code == other.hw_code \
+            and self.modifiers == other.modifiers \
+            and self.event_string == other.event_string \
+            and self.keyval_name == other.keyval_name \
+            and self.is_text == other.is_text \
+            and self.keyType == other.keyType \
+            and self._clickCount == other._clickCount
+
     def isNavigationKey(self):
         """Return True if this is a navigation key."""
 
diff --git a/src/orca/script_utilities.py b/src/orca/script_utilities.py
index 2eb2880ba..260de4a7c 100644
--- a/src/orca/script_utilities.py
+++ b/src/orca/script_utilities.py
@@ -3295,6 +3295,20 @@ class Utilities:
 
         return text + delimiter + newText
 
+    def treatAsDuplicateEvent(self, event1, event2):
+        if not (event1 and event2):
+            return False
+
+        # The goal is to find event spam so we can ignore the event.
+        if event1 == event2:
+            return False
+
+        return event1.source == event2.source \
+            and event1.type == event2.type \
+            and event1.detail1 == event2.detail1 \
+            and event1.detail2 == event2.detail2 \
+            and event1.any_data == event2.any_data
+
     def isAutoTextEvent(self, event):
         """Returns True if event is associated with text being autocompleted
         or autoinserted or autocorrected or autosomethingelsed.
@@ -3325,6 +3339,8 @@ class Utilities:
                 return True
             if lastKey in ["Up", "Down", "Page_Up", "Page_Down"]:
                 return self.isEditableDescendantOfComboBox(event.source)
+            if not self.lastInputEventWasPrintableKey():
+                return False
 
             string = event.source.queryText().getText(0, -1)
             if string.endswith(event.any_data):
diff --git a/src/orca/scripts/toolkits/Gecko/script_utilities.py 
b/src/orca/scripts/toolkits/Gecko/script_utilities.py
index 21406d919..c1277d474 100644
--- a/src/orca/scripts/toolkits/Gecko/script_utilities.py
+++ b/src/orca/scripts/toolkits/Gecko/script_utilities.py
@@ -32,6 +32,7 @@ __license__   = "LGPL"
 
 import pyatspi
 import re
+import time
 
 from orca import debug
 from orca import orca_state
@@ -42,6 +43,9 @@ class Utilities(web.Utilities):
 
     def __init__(self, script):
         super().__init__(script)
+        self._lastAutoTextObjectEvent = None
+        self._lastAutoTextInputEvent = None
+        self._lastAutoTextEventTime = 0
 
     def _attemptBrokenTextRecovery(self, obj, **args):
         boundary = args.get('boundary')
@@ -322,3 +326,22 @@ class Utilities(web.Utilities):
         label = labels[0]
         label.clearCache()
         return label.name
+
+    def isAutoTextEvent(self, event):
+        if not super().isAutoTextEvent(event):
+            return False
+
+        if self.inDocumentContent(event.source):
+            return True
+
+        if self.treatAsDuplicateEvent(self._lastAutoTextObjectEvent, event) \
+           and time.time() - self._lastAutoTextEventTime < 0.5 \
+           and orca_state.lastInputEvent.isReleaseFor(self._lastAutoTextInputEvent):
+            msg = "GECKO: Event believed to be duplicate auto text event."
+            debug.println(debug.LEVEL_INFO, msg, True)
+            return False
+
+        self._lastAutoTextObjectEvent = event
+        self._lastAutoTextInputEvent = orca_state.lastInputEvent
+        self._lastAutoTextEventTime = time.time()
+        return True