Bug [#2094]. gtk: Accessible: use the built-in character position cache

It's quite a lot faster even after trying and optimizing the custom
version, and it makes the code simpler.

Also improve ByteOffsetFromCharacterOffset() to make use of the cache,
making it drastically faster.

1 files changed, 6 insertions, 10 deletions

diff --git a/gtk/ScintillaGTKAccessible.cxx b/gtk/ScintillaGTKAccessible.cxx
index 5f2979894..714fde10d 100644
--- a/gtk/ScintillaGTKAccessible.cxx
+++ b/gtk/ScintillaGTKAccessible.cxx
@@ -163,6 +163,7 @@ ScintillaGTKAccessible::ScintillaGTKAccessible(GtkAccessible *accessible_, GtkWi
 		sci(ScintillaGTK::FromWidget(widget_)),
 		deletionLengthChar(0),
 		old_pos(-1) {
+	SetAccessibility(true);
 	g_signal_connect(widget_, "sci-notify", G_CALLBACK(SciNotify), this);
 }
 
@@ -866,10 +867,12 @@ void ScintillaGTKAccessible::NotifyReadOnly() {
 #endif
 }
 
-void ScintillaGTKAccessible::SetAccessibility() {
+void ScintillaGTKAccessible::SetAccessibility(bool enabled) {
 	// Called by ScintillaGTK when application has enabled or disabled accessibility
-	character_offsets.resize(0);
-	character_offsets.push_back(0);
+	if (enabled)
+		sci->pdoc->AllocateLineCharacterIndex(SC_LINECHARACTERINDEX_UTF32);
+	else
+		sci->pdoc->ReleaseLineCharacterIndex(SC_LINECHARACTERINDEX_UTF32);
 }
 
 void ScintillaGTKAccessible::Notify(GtkWidget *, gint, SCNotification *nt) {
@@ -877,13 +880,6 @@ void ScintillaGTKAccessible::Notify(GtkWidget *, gint, SCNotification *nt) {
 		return;
 	switch (nt->nmhdr.code) {
 		case SCN_MODIFIED: {
-			if (nt->modificationType & (SC_MOD_INSERTTEXT | SC_MOD_DELETETEXT)) {
-				// invalidate character offset cache if applicable
-				const Sci::Line 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);