4 files changed, 43 insertions, 0 deletions

diff --git a/gtk/ScintillaGTK.cxx b/gtk/ScintillaGTK.cxx
index 35622bc02..46a4b488f 100644
--- a/gtk/ScintillaGTK.cxx
+++ b/gtk/ScintillaGTK.cxx
@@ -175,6 +175,7 @@ ScintillaGTK::ScintillaGTK(_ScintillaObject *sci_) :
 		rgnUpdate(0),
 		repaintFullWindow(false),
 		styleIdleID(0),
+		accessibilityEnabled(SC_ACCESSIBILITY_ENABLED),
 		accessible(0) {
 	sci = sci_;
 	wMain = GTK_WIDGET(sci);
@@ -875,6 +876,19 @@ sptr_t ScintillaGTK::WndProc(unsigned int iMessage, uptr_t wParam, sptr_t lParam
 			return ret;
 		}
 
+		case SCI_GETACCESSIBILITY:
+			return accessibilityEnabled;
+
+		case SCI_SETACCESSIBILITY:
+			accessibilityEnabled = wParam;
+			if (accessible) {
+				ScintillaGTKAccessible *sciAccessible = ScintillaGTKAccessible::FromAccessible(accessible);
+				if (sciAccessible) {
+					sciAccessible->SetAccessibility();
+				}
+			}
+			break;
+
 		default:
 			return ScintillaBase::WndProc(iMessage, wParam, lParam);
 		}
diff --git a/gtk/ScintillaGTK.h b/gtk/ScintillaGTK.h
index 6f69661f2..4ee55a6c8 100644
--- a/gtk/ScintillaGTK.h
+++ b/gtk/ScintillaGTK.h
@@ -68,6 +68,7 @@ class ScintillaGTK : public ScintillaBase {
 	bool repaintFullWindow;
 
 	guint styleIdleID;
+	int accessibilityEnabled;
 	AtkObject *accessible;
 
 	// Private so ScintillaGTK objects can not be copied
diff --git a/gtk/ScintillaGTKAccessible.cxx b/gtk/ScintillaGTKAccessible.cxx
index 4fcfcda99..001f2703f 100644
--- a/gtk/ScintillaGTKAccessible.cxx
+++ b/gtk/ScintillaGTKAccessible.cxx
@@ -788,6 +788,10 @@ void ScintillaGTKAccessible::AtkEditableTextIface::init(::AtkEditableTextIface *
 	//~ iface->set_run_attributes = SetRunAttributes;
 }
 
+bool ScintillaGTKAccessible::Enabled() const {
+	return sci->accessibilityEnabled == SC_ACCESSIBILITY_ENABLED;
+}
+
 // Callbacks
 
 void ScintillaGTKAccessible::UpdateCursor() {
@@ -820,6 +824,10 @@ void ScintillaGTKAccessible::UpdateCursor() {
 }
 
 void ScintillaGTKAccessible::ChangeDocument(Document *oldDoc, Document *newDoc) {
+	if (!Enabled()) {
+		return;
+	}
+
 	if (oldDoc == newDoc) {
 		return;
 	}
@@ -854,7 +862,15 @@ void ScintillaGTKAccessible::NotifyReadOnly() {
 #endif
 }
 
+void ScintillaGTKAccessible::SetAccessibility() {
+	// Called by ScintillaGTK when application has enabled or disabled accessibility
+	character_offsets.resize(0);
+	character_offsets.push_back(0);
+}
+
 void ScintillaGTKAccessible::Notify(GtkWidget *, gint, SCNotification *nt) {
+	if (!Enabled())
+		return;
 	switch (nt->nmhdr.code) {
 		case SCN_MODIFIED: {
 			if (nt->modificationType & (SC_MOD_INSERTTEXT | SC_MOD_DELETETEXT)) {
@@ -864,6 +880,13 @@ void ScintillaGTKAccessible::Notify(GtkWidget *, gint, SCNotification *nt) {
 					character_offsets.resize(line + 1);
 				}
 			}
+			if (nt->modificationType & (SC_MOD_INSERTTEXT | SC_MOD_DELETETEXT)) {
+				// invalidate character offset cache if applicable
+				const Position line = sci->pdoc->LineFromPosition(nt->position);
+				if (character_offsets.size() > static_cast<size_t>(line + 1)) {
+					character_offsets.resize(line + 1);
+				}
+			}
 			if (nt->modificationType & SC_MOD_INSERTTEXT) {
 				int startChar = CharacterOffsetFromByteOffset(nt->position);
 				int lengthChar = sci->pdoc->CountCharacters(nt->position, nt->position + nt->length);
diff --git a/gtk/ScintillaGTKAccessible.h b/gtk/ScintillaGTKAccessible.h
index 88256e0ca..1905c0619 100644
--- a/gtk/ScintillaGTKAccessible.h
+++ b/gtk/ScintillaGTKAccessible.h
@@ -23,12 +23,16 @@ private:
 	// cache holding character offset for each line start, see CharacterOffsetFromByteOffset()
 	std::vector<Position> character_offsets;
 
+	// cache holding character offset for each line start, see CharacterOffsetFromByteOffset()
+	std::vector<Position> character_offsets;
+
 	// cached length of the deletion, in characters (see Notify())
 	int deletionLengthChar;
 	// local state for comparing
 	Position old_pos;
 	std::vector<SelectionRange> old_sels;
 
+	bool Enabled() const;
 	void UpdateCursor();
 	void Notify(GtkWidget *widget, gint code, SCNotification *nt);
 	static void SciNotify(GtkWidget *widget, gint code, SCNotification *nt, gpointer data) {
@@ -136,6 +140,7 @@ public:
 	// So ScintillaGTK can notify us
 	void ChangeDocument(Document *oldDoc, Document *newDoc);
 	void NotifyReadOnly();
+	void SetAccessibility();
 
 	// Helper GtkWidget methods
 	static AtkObject *WidgetGetAccessibleImpl(GtkWidget *widget, AtkObject **cache, gpointer widget_parent_class);