Ensure the cursor is visible when you move it

plugins/edit_view/lib/edit_view/actions/arrow_keys.rb

@@ -27,6 +27,10 @@ def self.imaginary_offset_to_real(line, width, offset)
           end
           real_ix + offset - imaginary_ix
         end
+
+        def self.ensure_cursor_in_view(edit_view)
+          edit_view.document.ensure_visible(edit_view.document.cursor_offset)
+        end
       end
 
       class ArrowLeftHandler < ArrowHandler
@@ -40,6 +44,8 @@ def self.handle(edit_view, modifiers)
           else
             doc.cursor_offset = move_left_offset(edit_view)
           end
+          ArrowHandler.ensure_cursor_in_view(edit_view)
+          true
         end
 
         def self.move_left_offset(edit_view)
@@ -85,6 +91,8 @@ def self.handle(edit_view, modifiers)
           else
             doc.cursor_offset = move_right_offset(edit_view)
           end
+          ArrowHandler.ensure_cursor_in_view(edit_view)
+          true
         end
 
         def self.move_right_offset(edit_view)

plugins/edit_view/lib/edit_view/document.rb

@@ -418,6 +418,10 @@ def biggest_visible_line
       @edit_view.controller.biggest_visible_line
     end
 
+    def ensure_visible(offset)
+      @edit_view.controller.ensure_visible(offset)
+    end
+
     def num_lines_visible
       biggest_visible_line - smallest_visible_line
     end

plugins/edit_view_swt/lib/edit_view_swt.rb

@@ -177,6 +177,10 @@ def biggest_visible_line
       @mate_text.viewer.get_bottom_index
     end
 
+    def ensure_visible(offset)
+      @mate_text.viewer.reveal_range(offset, 1)
+    end
+
     def update_grammar(new_mirror)
       title = new_mirror.title
       return if @mate_text.set_grammar_by_filename(title)