Window: support adding and removing filters with :addfilter :rmfilter

src/main.cc

@@ -427,6 +427,32 @@ void show_buffer(const CommandParameters& params)
         current_window = buffer->get_or_create_window();
 }
 
+void add_filter(const CommandParameters& params)
+{
+    if (params.size() < 1)
+        throw wrong_argument_count();
+
+    try
+    {
+        FilterRegistry& registry = FilterRegistry::instance();
+        FilterParameters filter_params(params.begin()+1, params.end());
+        FilterAndId filter_and_id = registry.get_filter(params[0], filter_params);
+        current_window->add_filter(std::move(filter_and_id));
+    }
+    catch (runtime_error& err)
+    {
+        print_status("error: " + err.description());
+    }
+}
+
+void rm_filter(const CommandParameters& params)
+{
+    if (params.size() != 1)
+        throw wrong_argument_count();
+
+    current_window->remove_filter(params[0]);
+}
+
 void do_command()
 {
     try
@@ -585,6 +611,8 @@ int main(int argc, char* argv[])
                                      PerArgumentCommandCompleter{ complete_filename });
     command_manager.register_command(std::vector<std::string>{ "b", "buffer" }, show_buffer,
                                      PerArgumentCommandCompleter { complete_buffername });
+    command_manager.register_command(std::vector<std::string>{ "af", "addfilter" }, add_filter);
+    command_manager.register_command(std::vector<std::string>{ "rf", "rmfilter" }, rm_filter);
 
     register_filters();
 

src/window.cc

@@ -114,10 +114,8 @@ Window::Window(Buffer& buffer)
       m_current_inserter(nullptr)
 {
     m_selections.push_back(Selection(buffer.begin(), buffer.begin()));
-    m_filters.push_back(colorize_cplusplus);
+    m_filters.push_back(FilterAndId("show_tabs", expand_tabulations));
-    m_filters.push_back(expand_tabulations);
+    m_filters.push_back(FilterAndId("show_selection", HighlightSelections(*this)));
-    m_filters.push_back(HighlightSelections(*this));
-    m_filters.push_back(show_line_numbers);
 }
 
 void Window::check_invariant() const
@@ -329,7 +327,7 @@ void Window::update_display_buffer()
 
     for (auto& filter : m_filters)
     {
-        filter(m_display_buffer);
+        filter.second(m_display_buffer);
         m_display_buffer.check_invariant();
     }
 }
@@ -377,6 +375,28 @@ std::string Window::status_line() const
     return oss.str();
 }
 
+void Window::add_filter(FilterAndId&& filter)
+{
+    for (auto it = m_filters.begin(); it != m_filters.end(); ++it)
+    {
+        if (it->first == filter.first)
+            throw filter_id_not_unique(filter.first);
+    }
+    m_filters.push_back(filter);
+}
+
+void Window::remove_filter(const std::string& id)
+{
+    for (auto it = m_filters.begin(); it != m_filters.end(); ++it)
+    {
+        if (it->first == id)
+        {
+            m_filters.erase(it);
+            return;
+        }
+    }
+}
+
 IncrementalInserter::IncrementalInserter(Window& window, Mode mode)
     : m_window(window)
 {

src/window.hh

@@ -6,6 +6,7 @@
 #include "buffer.hh"
 #include "dynamic_buffer_iterator.hh"
 #include "display_buffer.hh"
+#include "filter.hh"
 
 namespace Kakoune
 {
@@ -69,6 +70,15 @@ public:
 
     std::string status_line() const;
 
+    struct filter_id_not_unique : public runtime_error
+    {
+        filter_id_not_unique(const std::string& id)
+            : runtime_error("filter id not unique: " + id) {}
+    };
+
+    void add_filter(FilterAndId&& filter);
+    void remove_filter(const std::string& id);
+
 private:
     friend class Buffer;
 
@@ -93,7 +103,7 @@ private:
     SelectionList m_selections;
     DisplayBuffer m_display_buffer;
 
-    typedef std::vector<std::function<void (DisplayBuffer&)>> FilterList;
+    typedef std::vector<FilterAndId> FilterList;
     FilterList m_filters;
 };