diff --git a/lib/reline.rb b/lib/reline.rb
index cf668c79e3..18ccce2058 100644
--- a/lib/reline.rb
+++ b/lib/reline.rb
@@ -18,7 +18,7 @@ class ConfigEncodingConversionError < StandardError; end
 
   Key = Struct.new('Key', :char, :combined_char, :with_meta)
   CursorPos = Struct.new(:x, :y)
-  DialogRenderInfo = Struct.new(:pos, :contents, :pointer, :bg_color, :height, keyword_init: true)
+  DialogRenderInfo = Struct.new(:pos, :contents, :pointer, :bg_color, :width, :height, keyword_init: true)
 
   class Core
     ATTR_READER_NAMES = %i(
diff --git a/lib/reline/line_editor.rb b/lib/reline/line_editor.rb
index e654d6b757..382f638d25 100644
--- a/lib/reline/line_editor.rb
+++ b/lib/reline/line_editor.rb
@@ -538,12 +538,13 @@ def call
   end
 
   class Dialog
-    attr_reader :name
-    attr_accessor :scroll_top, :column, :vertical_offset, :contents, :lines_backup
+    attr_reader :name, :contents, :width
+    attr_accessor :scroll_top, :column, :vertical_offset, :lines_backup
 
     def initialize(name, proc_scope)
       @name = name
       @proc_scope = proc_scope
+      @width = nil
       @scroll_top = 0
     end
 
@@ -551,6 +552,17 @@ def set_cursor_pos(col, row)
       @proc_scope.set_cursor_pos(col, row)
     end
 
+    def width=(v)
+      @width = v
+    end
+
+    def contents=(contents)
+      @contents = contents
+      if contents and @width.nil?
+        @width = contents.map{ |line| Reline::Unicode.calculate_width(line, true) }.max
+      end
+    end
+
     def call
       @proc_scope.set_dialog(self)
       @proc_scope.call
@@ -577,9 +589,8 @@ def add_dialog_proc(name, p, context = nil)
     end
     dialog.set_cursor_pos(cursor_column, @first_line_started_from + @started_from)
     dialog_render_info = dialog.call
-    old_dialog_contents = dialog.contents
-    old_dialog_column = dialog.column
-    old_dialog_vertical_offset = dialog.vertical_offset
+    dialog.width = dialog_render_info.width if dialog_render_info and dialog_render_info.width
+    old_dialog = dialog.clone
     if dialog_render_info and dialog_render_info.contents and not dialog_render_info.contents.empty?
       height = dialog_render_info.height || DIALOG_HEIGHT
       pointer = dialog_render_info.pointer
@@ -612,7 +623,7 @@ def add_dialog_proc(name, p, context = nil)
     upper_space = @first_line_started_from - @started_from
     lower_space = @highest_in_all - @first_line_started_from - @started_from - 1
     dialog.column = dialog_render_info.pos.x
-    diff = (dialog.column + DIALOG_WIDTH) - (@screen_size.last - 1)
+    diff = (dialog.column + dialog.width) - (@screen_size.last - 1)
     if diff > 0
       dialog.column -= diff
     end
@@ -628,7 +639,7 @@ def add_dialog_proc(name, p, context = nil)
       dialog.vertical_offset = dialog_render_info.pos.y + 1
     end
     Reline::IOGate.hide_cursor
-    reset_dialog(dialog, old_dialog_contents, old_dialog_column, old_dialog_vertical_offset)
+    reset_dialog(dialog, old_dialog)
     move_cursor_down(dialog.vertical_offset)
     Reline::IOGate.move_cursor_column(dialog.column)
     dialog.contents.each_with_index do |item, i|
@@ -641,7 +652,7 @@ def add_dialog_proc(name, p, context = nil)
           bg_color = '46'
         end
       end
-      @output.write "\e[#{bg_color}m%-#{DIALOG_WIDTH}s\e[49m" % item.slice(0, DIALOG_WIDTH)
+      @output.write "\e[#{bg_color}m%-#{dialog.width}s\e[49m" % Reline::Unicode.take_range(item, 0, dialog.width)
       Reline::IOGate.move_cursor_column(dialog.column)
       move_cursor_down(1) if i < (dialog.contents.size - 1)
     end
@@ -657,8 +668,8 @@ def add_dialog_proc(name, p, context = nil)
     }
   end
 
-  private def reset_dialog(dialog, old_dialog_contents, old_dialog_column, old_dialog_vertical_offset)
-    return if dialog.lines_backup.nil? or old_dialog_contents.nil?
+  private def reset_dialog(dialog, old_dialog)
+    return if dialog.lines_backup.nil? or old_dialog.contents.nil?
     prompt, prompt_width, prompt_list = check_multiline_prompt(dialog.lines_backup[:lines], prompt)
     visual_lines = []
     visual_start = nil
@@ -674,76 +685,76 @@ def add_dialog_proc(name, p, context = nil)
     old_y = dialog.lines_backup[:first_line_started_from] + dialog.lines_backup[:started_from]
     y = @first_line_started_from + @started_from
     y_diff = y - old_y
-    if (old_y + old_dialog_vertical_offset) < (y + dialog.vertical_offset)
+    if (old_y + old_dialog.vertical_offset) < (y + dialog.vertical_offset)
       # rerender top
-      move_cursor_down(old_dialog_vertical_offset - y_diff)
-      start = visual_start + old_dialog_vertical_offset
-      line_num = dialog.vertical_offset - old_dialog_vertical_offset
+      move_cursor_down(old_dialog.vertical_offset - y_diff)
+      start = visual_start + old_dialog.vertical_offset
+      line_num = dialog.vertical_offset - old_dialog.vertical_offset
       line_num.times do |i|
-        Reline::IOGate.move_cursor_column(old_dialog_column)
+        Reline::IOGate.move_cursor_column(old_dialog.column)
         if visual_lines[start + i].nil?
-          s = ' ' * DIALOG_WIDTH
+          s = ' ' * dialog.width
         else
-          s = Reline::Unicode.take_range(visual_lines[start + i], old_dialog_column, DIALOG_WIDTH)
+          s = Reline::Unicode.take_range(visual_lines[start + i], old_dialog.column, dialog.width)
         end
-        @output.write "\e[39m\e[49m%-#{DIALOG_WIDTH}s\e[39m\e[49m" % s
+        @output.write "\e[39m\e[49m%-#{dialog.width}s\e[39m\e[49m" % s
         move_cursor_down(1) if i < (line_num - 1)
       end
-      move_cursor_up(old_dialog_vertical_offset + line_num - 1 - y_diff)
+      move_cursor_up(old_dialog.vertical_offset + line_num - 1 - y_diff)
     end
-    if (old_y + old_dialog_vertical_offset + old_dialog_contents.size) > (y + dialog.vertical_offset + dialog.contents.size)
+    if (old_y + old_dialog.vertical_offset + old_dialog.contents.size) > (y + dialog.vertical_offset + dialog.contents.size)
       # rerender bottom
       move_cursor_down(dialog.vertical_offset + dialog.contents.size - y_diff)
       start = visual_start + dialog.vertical_offset + dialog.contents.size
-      line_num = (old_dialog_vertical_offset + old_dialog_contents.size) - (dialog.vertical_offset + dialog.contents.size)
+      line_num = (old_dialog.vertical_offset + old_dialog.contents.size) - (dialog.vertical_offset + dialog.contents.size)
       line_num.times do |i|
-        Reline::IOGate.move_cursor_column(old_dialog_column)
+        Reline::IOGate.move_cursor_column(old_dialog.column)
         if visual_lines[start + i].nil?
-          s = ' ' * DIALOG_WIDTH
+          s = ' ' * dialog.width
         else
-          s = Reline::Unicode.take_range(visual_lines[start + i], old_dialog_column, DIALOG_WIDTH)
+          s = Reline::Unicode.take_range(visual_lines[start + i], old_dialog.column, dialog.width)
         end
-        @output.write "\e[39m\e[49m%-#{DIALOG_WIDTH}s\e[39m\e[49m" % s
+        @output.write "\e[39m\e[49m%-#{dialog.width}s\e[39m\e[49m" % s
         move_cursor_down(1) if i < (line_num - 1)
       end
       move_cursor_up(dialog.vertical_offset + dialog.contents.size + line_num - 1 - y_diff)
     end
-    if old_dialog_column < dialog.column
+    if old_dialog.column < dialog.column
       # rerender left
-      move_cursor_down(old_dialog_vertical_offset - y_diff)
-      width = dialog.column - old_dialog_column
-      start = visual_start + old_dialog_vertical_offset
-      line_num = old_dialog_contents.size
+      move_cursor_down(old_dialog.vertical_offset - y_diff)
+      width = dialog.column - old_dialog.column
+      start = visual_start + old_dialog.vertical_offset
+      line_num = old_dialog.contents.size
       line_num.times do |i|
-        Reline::IOGate.move_cursor_column(old_dialog_column)
+        Reline::IOGate.move_cursor_column(old_dialog.column)
         if visual_lines[start + i].nil?
           s = ' ' * width
         else
-          s = Reline::Unicode.take_range(visual_lines[start + i], old_dialog_column, width)
+          s = Reline::Unicode.take_range(visual_lines[start + i], old_dialog.column, width)
         end
         @output.write "\e[39m\e[49m%-#{width}s\e[39m\e[49m" % s
         move_cursor_down(1) if i < (line_num - 1)
       end
-      move_cursor_up(old_dialog_vertical_offset + line_num - 1 - y_diff)
+      move_cursor_up(old_dialog.vertical_offset + line_num - 1 - y_diff)
     end
-    if (old_dialog_column + DIALOG_WIDTH) > (dialog.column + DIALOG_WIDTH)
+    if (old_dialog.column + old_dialog.width) > (dialog.column + dialog.width)
       # rerender right
-      move_cursor_down(old_dialog_vertical_offset + y_diff)
-      width = (old_dialog_column + DIALOG_WIDTH) - (dialog.column + DIALOG_WIDTH)
-      start = visual_start + old_dialog_vertical_offset
-      line_num = old_dialog_contents.size
+      move_cursor_down(old_dialog.vertical_offset + y_diff)
+      width = (old_dialog.column + old_dialog.width) - (dialog.column + dialog.width)
+      start = visual_start + old_dialog.vertical_offset
+      line_num = old_dialog.contents.size
       line_num.times do |i|
-        Reline::IOGate.move_cursor_column(old_dialog_column + DIALOG_WIDTH)
+        Reline::IOGate.move_cursor_column(old_dialog.column + dialog.width)
         if visual_lines[start + i].nil?
           s = ' ' * width
         else
-          s = Reline::Unicode.take_range(visual_lines[start + i], old_dialog_column + DIALOG_WIDTH, width)
+          s = Reline::Unicode.take_range(visual_lines[start + i], old_dialog.column + dialog.width, width)
         end
-        Reline::IOGate.move_cursor_column(dialog.column + DIALOG_WIDTH)
+        Reline::IOGate.move_cursor_column(dialog.column + dialog.width)
         @output.write "\e[39m\e[49m%-#{width}s\e[39m\e[49m" % s
         move_cursor_down(1) if i < (line_num - 1)
       end
-      move_cursor_up(old_dialog_vertical_offset + line_num - 1 + y_diff)
+      move_cursor_up(old_dialog.vertical_offset + line_num - 1 + y_diff)
     end
     Reline::IOGate.move_cursor_column((prompt_width + @cursor) % @screen_size.last)
   end
@@ -777,10 +788,10 @@ def add_dialog_proc(name, p, context = nil)
     dialog_vertical_size.times do |i|
       if i < visual_lines_under_dialog.size
         Reline::IOGate.move_cursor_column(0)
-        @output.write "\e[39m\e[49m%-#{DIALOG_WIDTH}s\e[39m\e[49m" % visual_lines_under_dialog[i]
+        @output.write "\e[39m\e[49m%-#{dialog.width}s\e[39m\e[49m" % visual_lines_under_dialog[i]
       else
         Reline::IOGate.move_cursor_column(dialog.column)
-        @output.write "\e[39m\e[49m#{' ' * DIALOG_WIDTH}\e[39m\e[49m"
+        @output.write "\e[39m\e[49m#{' ' * dialog.width}\e[39m\e[49m"
       end
       Reline::IOGate.erase_after_cursor
       move_cursor_down(1) if i < (dialog_vertical_size - 1)
diff --git a/lib/reline/unicode.rb b/lib/reline/unicode.rb
index 3bb08fac48..d111a849c4 100644
--- a/lib/reline/unicode.rb
+++ b/lib/reline/unicode.rb
@@ -186,9 +186,9 @@ def self.split_by_width(str, max_width, encoding = str.encoding)
   end
 
   # Take a chunk of a String with escape sequences.
-  def self.take_range(str, col, length, encoding = str.encoding)
+  def self.take_range(str, start_col, max_width, encoding = str.encoding)
     chunk = String.new(encoding: encoding)
-    width = 0
+    total_width = 0
     rest = str.encode(Encoding::UTF_8)
     in_zero_width = false
     rest.scan(WIDTH_SCANNER) do |gc|
@@ -206,9 +206,10 @@ def self.take_range(str, col, length, encoding = str.encoding)
         if in_zero_width
           chunk << gc
         else
-          width = get_mbchar_width(gc)
-          break if (width + length) <= col
-          chunk << gc if col <= width
+          mbchar_width = get_mbchar_width(gc)
+          total_width += mbchar_width
+          break if (start_col + max_width) < total_width
+          chunk << gc if start_col < total_width
         end
       end
     end