[gtksourceview/wip/chergert/vim] implement paragraph movements

[Christian Hergert <chergert src gnome org>]

commit 045d568777e37ee80c7fe300472e71c0bbd152a3
Author: Christian Hergert <chergert redhat com>
Date:   Sat Oct 23 16:18:34 2021 -0700

    implement paragraph movements

 gtksourceview/vim/gtk-source-vim-motion.c | 60 ++++++++++++++++++++++++++++---
 gtksourceview/vim/gtk-source-vim-normal.c |  2 ++
 2 files changed, 57 insertions(+), 5 deletions(-)
---
diff --git a/gtksourceview/vim/gtk-source-vim-motion.c b/gtksourceview/vim/gtk-source-vim-motion.c
index 4405a180..d7f60618 100644
--- a/gtksourceview/vim/gtk-source-vim-motion.c
+++ b/gtksourceview/vim/gtk-source-vim-motion.c
@@ -59,6 +59,12 @@ struct _GtkSourceVimMotion
 
 G_DEFINE_TYPE (GtkSourceVimMotion, gtk_source_vim_motion, GTK_SOURCE_TYPE_VIM_STATE)
 
+static gboolean
+line_is_empty (GtkTextIter *iter)
+{
+       return gtk_text_iter_starts_line (iter) && gtk_text_iter_ends_line (iter);
+}
+
 enum
 {
        CLASS_0,
@@ -723,17 +729,61 @@ motion_backward_sentence_start (GtkTextIter        *iter,
 }
 
 static gboolean
-motion_forward_paragraph_start (GtkTextIter        *iter,
-                                GtkSourceVimMotion *state)
+motion_forward_paragraph_end (GtkTextIter        *iter,
+                              GtkSourceVimMotion *state)
 {
-       return FALSE;
+       GtkTextIter before = *iter;
+
+       /* Work our way past the current empty lines */
+       if (line_is_empty (iter))
+       {
+               while (line_is_empty (iter))
+               {
+                       if (!gtk_text_iter_forward_line (iter))
+                               return FALSE;
+               }
+       }
+
+       /* Now find first line that is empty */
+       while (!line_is_empty (iter))
+       {
+               if (!gtk_text_iter_forward_line (iter))
+                       return FALSE;
+       }
+
+       if (gtk_text_iter_is_end (iter) &&
+           !gtk_text_iter_starts_line (iter))
+       {
+               gtk_text_iter_backward_char (iter);
+       }
+
+       return !gtk_text_iter_equal (&before, iter);
 }
 
 static gboolean
 motion_backward_paragraph_start (GtkTextIter        *iter,
                                  GtkSourceVimMotion *state)
 {
-       return FALSE;
+       GtkTextIter before = *iter;
+
+       /* Work our way past the current empty lines */
+       if (line_is_empty (iter))
+       {
+               while (line_is_empty (iter))
+               {
+                       if (!gtk_text_iter_backward_line (iter))
+                               return FALSE;
+               }
+       }
+
+       /* Now find first line that is empty */
+       while (!line_is_empty (iter))
+       {
+               if (!gtk_text_iter_backward_line (iter))
+                       return FALSE;
+       }
+
+       return !gtk_text_iter_equal (&before, iter);
 }
 
 GtkSourceVimState *
@@ -926,7 +976,7 @@ gtk_source_vim_motion_handle_keypress (GtkSourceVimState *state,
                        return gtk_source_vim_motion_complete (self, motion_backward_paragraph_start);
 
                case GDK_KEY_braceright:
-                       return gtk_source_vim_motion_complete (self, motion_forward_paragraph_start);
+                       return gtk_source_vim_motion_complete (self, motion_forward_paragraph_end);
 
                case GDK_KEY_n:
                case GDK_KEY_N:
diff --git a/gtksourceview/vim/gtk-source-vim-normal.c b/gtksourceview/vim/gtk-source-vim-normal.c
index c9362283..d5a06d34 100644
--- a/gtksourceview/vim/gtk-source-vim-normal.c
+++ b/gtksourceview/vim/gtk-source-vim-normal.c
@@ -401,6 +401,8 @@ key_handler_initial (GtkSourceVimNormal *self,
                        case GDK_KEY_bar:
                        case GDK_KEY_B:
                        case GDK_KEY_BackSpace:
+                       case GDK_KEY_braceleft:
+                       case GDK_KEY_braceright:
                        case GDK_KEY_dollar:
                        case GDK_KEY_Down:
                        case GDK_KEY_e: