Buffer: add filter support

filters are functions called prior to applying a modification
to a buffer. They can manipulate the modification to change
the editor behaviour.

1 files changed, 21 insertions, 0 deletions

diff --git a/src/buffer.cc b/src/buffer.cc
index 0587cf45..2d2e106c 100644
--- a/src/buffer.cc
+++ b/src/buffer.cc
@@ -227,6 +227,9 @@ void Buffer::apply_modification(const BufferModification& modification)
 
 void Buffer::append_modification(BufferModification&& modification)
 {
+    for (auto filter : m_filters)
+        filter.second(*this, modification);
+
     apply_modification(modification);
     m_current_undo_group.push_back(std::move(modification));
 }
@@ -277,4 +280,22 @@ void Buffer::unregister_modification_listener(BufferModificationListener* listen
     m_modification_listeners.erase(it);
 }
 
+void Buffer::add_filter(FilterAndId&& filter)
+{
+    if (m_filters.contains(filter.first))
+        throw filter_id_not_unique(filter.first);
+    m_filters.append(filter);
+}
+
+void Buffer::remove_filter(const std::string& id)
+{
+    m_filters.remove(id);
+}
+
+CandidateList Buffer::complete_filterid(const std::string& prefix,
+                                        size_t cursor_pos)
+{
+    return m_filters.complete_id<str_to_str>(prefix, cursor_pos);
+}
+
 }