Parenthesize what I have highlighted

Question

I want to highlight a piece of equation, click a button and have that part taken into parentheses.

Answer 1

I have this palette open all the time:

CreatePalette@Row@
  {
  Button["(\[SelectionPlaceholder])",
              FrontEndExecute[
              FrontEndToken[SelectedNotebook[], "SelectionParenthesize"]]],
  Button["[\[SelectionPlaceholder]]",
         FrontEndExecute[
         FrontEndToken[SelectedNotebook[], "SelectionBracket"]]],
  Button["{\[SelectionPlaceholder]}",
         FrontEndExecute[
         FrontEndToken[SelectedNotebook[], "SelectionBrace"]]],
  Button["\"\[SelectionPlaceholder]\"",
         With[{e = NotebookRead@SelectedNotebook[]},
              NotebookWrite[SelectedNotebook[], RowBox@{"\"", e, "\""}];
              SelectionMove[SelectedNotebook[], All, Expression, 2]]]
  }

By the way, in some text editors (e.g. Sublime Text, Texmate), when you make a selection and press a (, [, { or ", you automatically get the selection wrapped with the corresponding character. I really wish that the Mathematica editor worked like that.

UPDATE: I have simplified the code and modified the last button (wrap selection in quotes) so that the modified string is selected. This is how the other three buttons behave. I borrowed some of @halirutan answer's code in order to make this work (thanks!).

Answer 2

Please start playing with NotebookRead and NotebookWrite and look what expressions are returned when you select different things. You could use a simple button like this

Button["Print Selection", Print[NotebookRead[SelectedNotebook[]]]]

Now, you want to change you selection by putting parenthesis around it. A first very simple version looks like this:

Button["Parenthesize",
 With[{e = NotebookRead[SelectedNotebook[]]},
  NotebookWrite[SelectedNotebook[], RowBox[{"(", e, ")"}]]
  ]]

Answer 3

Cross posted in community: Put parentheses around selection

Limitations and problems with .tr files made me create live templates: Live code templates

Once installed you can set package's stylesheet or add templates menu to all notebooks by:

SetOptions[$FrontEnd, NotebookEventActions -> {
     {"MenuCommand", "InsertNewGraphic"} :> Block[{$ContextPath}
        , Needs["DevTools`"]    ; DevTools`OpenNotebookMenu["CodeTemplates"]
        ]
      , ParentList
      }
    ]

and you are ready to go, with a caret just after the symbol (or when you select something) you can hit Ctrl+1 followed by ( and wrapped it is.