Implement bracketed paste

Text pasted into Kakoune's normal mode is interpreted as command
sequence, which is probably never what the user wants. Text
pasted during insert mode will be inserted fine but may trigger
auto-indentation hooks which is likely not what users want.

Bracketed paste is pair of escape codes sent by terminals that allow
applications to distinguish between pasted text and typed text.

Let's use this feature to always insert pasted text verbatim, skipping
keymap lookup and the InsertChar hook. In future, we could add a
dedicated Paste hook.

We need to make a decision on whether to paste before or after the
selection. I chose "before" because that's what I'm used to.

TerminalUI::set_on_key has

	EventManager::instance().force_signal(0);

I'm not sure if we want the same for TerminalUI::set_on_paste?
I assume it doesn't matter because they are always called in tandem.

Closes #2465

1 files changed, 25 insertions, 7 deletions

diff --git a/src/remote.cc b/src/remote.cc
index 50dda1b0..5b97f985 100644
--- a/src/remote.cc
+++ b/src/remote.cc
@@ -43,6 +43,7 @@ enum class MessageType : uint8_t
     SetOptions,
     Exit,
     Key,
+    Paste,
 };
 
 class MsgWriter
@@ -413,6 +414,9 @@ public:
     void set_on_key(OnKeyCallback callback) override
     { m_on_key = std::move(callback); }
 
+    void set_on_paste(OnPasteCallback callback) override
+    { m_on_paste = std::move(callback); }
+
     void set_ui_options(const Options& options) override;
 
     void exit(int status);
@@ -430,6 +434,7 @@ private:
     MsgReader     m_reader;
     DisplayCoord  m_dimensions;
     OnKeyCallback m_on_key;
+    OnPasteCallback m_on_paste;
     RemoteBuffer  m_send_buffer;
 };
 
@@ -479,17 +484,25 @@ RemoteUI::RemoteUI(int socket, DisplayCoord dimensions)
                   if (not m_reader.ready())
                       continue;
 
-                   if (m_reader.type() != MessageType::Key)
+                   if (m_reader.type() == MessageType::Key)
+                   {
+                       auto key = m_reader.read<Key>();
+                       m_reader.reset();
+                       if (key.modifiers == Key::Modifiers::Resize)
+                           m_dimensions = key.coord();
+                       m_on_key(key);
+                   }
+                   else if (m_reader.type() == MessageType::Paste)
+                   {
+                       auto content = m_reader.read<String>();
+                       m_reader.reset();
+                       m_on_paste(content);
+                   }
+                   else
                    {
                        m_socket_watcher.close_fd();
                        return;
                    }
-
-                   auto key = m_reader.read<Key>();
-                   m_reader.reset();
-                   if (key.modifiers == Key::Modifiers::Resize)
-                       m_dimensions = key.coord();
-                   m_on_key(key);
               }
           }
           catch (const disconnected& err)
@@ -660,6 +673,11 @@ RemoteClient::RemoteClient(StringView session, StringView name, std::unique_ptr<
         msg.write(key);
         m_socket_watcher->events() |= FdEvents::Write;
      });
+    m_ui->set_on_paste([this](StringView content){
+        MsgWriter msg(m_send_buffer, MessageType::Paste);
+        msg.write(content);
+        m_socket_watcher->events() |= FdEvents::Write;
+     });
 
     m_socket_watcher.reset(new FDWatcher{sock, FdEvents::Read | FdEvents::Write, EventMode::Urgent,
                            [this, reader = MsgReader{}](FDWatcher& watcher, FdEvents events, EventMode) mutable {