Implement scrolling in command view

data/core/commandview.lua

@@ -29,6 +29,7 @@ local default_state = {
 function CommandView:new()
   CommandView.super.new(self, SingleLineDoc())
   self.suggestion_idx = 1
+  self.suggestion_offset = 0
   self.suggestions = {}
   self.suggestions_height = 0
   self.last_change_id = 0
@@ -82,6 +83,11 @@ end
 function CommandView:move_suggestion_idx(dir)
   local n = self.suggestion_idx + dir
   self.suggestion_idx = common.clamp(n, 1, #self.suggestions)
+  if self.suggestion_idx > max_suggestions then
+    self.suggestion_offset = self.suggestion_idx - max_suggestions
+  else
+    self.suggestion_offset = 0
+  end
   self:complete()
   self.last_change_id = self.doc:get_change_id()
 end
@@ -145,9 +151,6 @@ function CommandView:update_suggestions()
   local t = self.state.suggest(self:get_text()) or {}
   local res = {}
   for i, item in ipairs(t) do
-    if i == max_suggestions then
-      break
-    end
     if type(item) == "string" then
       item = { text = item }
     end
@@ -155,6 +158,7 @@ function CommandView:update_suggestions()
   end
   self.suggestions = res
   self.suggestion_idx = 1
+  self.suggestion_offset = 0
 end
 
 
@@ -184,11 +188,11 @@ function CommandView:update()
 
   -- update suggestions box height
   local lh = self:get_suggestion_line_height()
-  local dest = #self.suggestions * lh
+  local dest = math.min(#self.suggestions, max_suggestions) * lh
   self:move_towards("suggestions_height", dest)
 
   -- update suggestion cursor offset
-  local dest = self.suggestion_idx * self:get_suggestion_line_height()
+  local dest = (self.suggestion_idx - self.suggestion_offset) * self:get_suggestion_line_height()
   self:move_towards("selection_offset", dest)
 
   -- update size based on whether this is the active_view
@@ -234,8 +238,10 @@ local function draw_suggestions_box(self)
   -- draw suggestion text
   core.push_clip_rect(rx, ry, rw, rh)
   for i, item in ipairs(self.suggestions) do
+    local irel = (i - self.suggestion_offset)
+    if irel >= 0 then
       local color = (i == self.suggestion_idx) and style.accent or style.text
-    local y = self.position.y - i * lh - dh
+      local y = self.position.y - irel * lh - dh
       common.draw_text(self:get_font(), color, item.text, nil, x, y, 0, lh)
 
       if item.info then
@@ -243,6 +249,7 @@ local function draw_suggestions_box(self)
         common.draw_text(self:get_font(), style.dim, item.info, "right", x, y, w, lh)
       end
     end
+  end
   core.pop_clip_rect()
 end