fix: preview title key and a bug with dynamic_title (#1350)

3 files changed, 22 insertions, 52 deletions

diff --git a/lua/telescope/previewers/buffer_previewer.lua b/lua/telescope/previewers/buffer_previewer.lua
index fad5dc9..e26fed1 100644
--- a/lua/telescope/previewers/buffer_previewer.lua
+++ b/lua/telescope/previewers/buffer_previewer.lua
@@ -277,8 +277,6 @@ previewers.new_buffer_previewer = function(opts)
 
   local opt_setup = opts.setup
   local opt_teardown = opts.teardown
-  local opt_title = opts.title
-  local opt_dyn_title = opts.dyn_title
 
   local old_bufs = {}
   local bufname_table = {}
@@ -316,24 +314,6 @@ previewers.new_buffer_previewer = function(opts)
     end
   end
 
-  function opts.title(self)
-    if opt_title then
-      if type(opt_title) == "function" then
-        return opt_title(self)
-      else
-        return opt_title
-      end
-    end
-    return "Preview"
-  end
-
-  function opts.dyn_title(self, entry)
-    if opt_dyn_title then
-      return opt_dyn_title(self, entry)
-    end
-    return "Preview"
-  end
-
   function opts.setup(self)
     local state = {}
     if opt_setup then
diff --git a/lua/telescope/previewers/previewer.lua b/lua/telescope/previewers/previewer.lua
index d6eb9f1..834df2c 100644
--- a/lua/telescope/previewers/previewer.lua
+++ b/lua/telescope/previewers/previewer.lua
@@ -1,13 +1,25 @@
 local Previewer = {}
 Previewer.__index = Previewer
 
+local force_function_wrap = function(value)
+  if value ~= nil then
+    if type(value) ~= "function" then
+      return function()
+        return tostring(value)
+      end
+    else
+      return value
+    end
+  end
+end
+
 function Previewer:new(opts)
   opts = opts or {}
 
   return setmetatable({
     state = nil,
-    _title_fn = opts.title,
-    _dyn_title_fn = opts.dyn_title,
+    _title_fn = force_function_wrap(opts.title),
+    _dyn_title_fn = force_function_wrap(opts.dyn_title),
     _setup_func = opts.setup,
     _teardown_func = opts.teardown,
     _send_input = opts.send_input,
@@ -32,18 +44,16 @@ function Previewer:preview(entry, status)
   return self:preview_fn(entry, status)
 end
 
-function Previewer:title()
-  if self._title_fn then
-    return self:_title_fn()
-  end
-  return "Preview"
-end
-
-function Previewer:dynamic_title(entry)
-  if self._title_fn then
+function Previewer:title(entry, dynamic)
+  if dynamic == true and self._dyn_title_fn ~= nil then
+    if entry == nil then
+      return nil
+    end
     return self:_dyn_title_fn(entry)
   end
-  return "Preview"
+  if self._title_fn ~= nil then
+    return self:_title_fn()
+  end
 end
 
 function Previewer:teardown()
diff --git a/lua/telescope/previewers/term_previewer.lua b/lua/telescope/previewers/term_previewer.lua
index 375143d..1c28ae3 100644
--- a/lua/telescope/previewers/term_previewer.lua
+++ b/lua/telescope/previewers/term_previewer.lua
@@ -118,8 +118,6 @@ previewers.new_termopen_previewer = function(opts)
 
   local opt_setup = opts.setup
   local opt_teardown = opts.teardown
-  local opt_title = opts.title
-  local opt_dyn_title = opts.dyn_title
 
   local old_bufs = {}
 
@@ -155,24 +153,6 @@ previewers.new_termopen_previewer = function(opts)
     end
   end
 
-  function opts.title(self)
-    if opt_title then
-      if type(opt_title) == "function" then
-        return opt_title(self)
-      else
-        return opt_title
-      end
-    end
-    return "Preview"
-  end
-
-  function opts.dyn_title(self, entry)
-    if opt_dyn_title then
-      return opt_dyn_title(self, entry)
-    end
-    return "Preview"
-  end
-
   function opts.setup(self)
     local state = {}
     if opt_setup then