Re: Re: suggestion for frontend
- To: mathgroup at smc.vnet.net
- Subject: [mg51954] Re: [mg51879] Re: suggestion for frontend
- From: "Ingolf Dahl" <ingolf.dahl at telia.com>
- Date: Fri, 5 Nov 2004 02:19:21 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
My reply is interwoven below: >-----Original Message----- >From: David Bailey [mailto:dave at Remove_Thisdbailey.co.uk] To: mathgroup at smc.vnet.net >Sent: Thursday, November 04, 2004 07:50 >To: mathgroup at smc.vnet.net >Subject: [mg51954] [mg51879] Re: suggestion for frontend > > >Hi, > >I wish someone would make the frontend API a bit more rounded. For >example, although you can set the selection in a notebook, there is no >way of determining EXACTLY where the selection is before you start - so >you can't perform a task and leave the user with his selection >unchanged. This seems to be typical of a lot of frontend functionality. You might use the undocumented function CellInformation, mentioned by John Fultz in [mg51798] and [mg51847] recently. You might use it wrapped into the following functions: ReadCellInformation[ notebook_NotebookObject] := (LinkWrite[$ParentLink, CellInformation[notebook]]; LinkRead[$ParentLink]); ReadCursorPosition[ notebook_NotebookObject] := ("CursorPosition" /. Flatten[ReadCellInformation[notebook]]); ReadCellSerialNumbers[notebook_NotebookObject] := Cases[ReadCellInformation[notebook], (Rule["CellSerialNumber", x_]) -> x, 2]; I would like the ability to get back to a given selection after I have moved away from it. >A few general priciples come to mind: > >1) If you can set the state of something you should also be able to read >it back. One example related to this is that NotebookWrite[nb, NotebookRead[nb]] does not always leave the notebook unaltered. If the selection is within a textcell, and the selection contains a inline cell, text content after the inline cell in turned into Box form, which is not always wanted. That is connected to the bad design choice (bug?) that the TextData wrapper is stripped off the item read by NotebookRead from a text cell. It then is impossible (without using CellInformation or reading the notebook in another way) to know if the read item is e.g. a set of ordinary cells or a set of inline cells. My way to handle this is to use the following replacement for NotebookRead: MyNotebookRead[nb_] := Module[{clipboardcontent, readitem, evalnb}, readitem = NotebookRead[nb]; Which[readitem == {}, Null, ListQ[readitem], evalnb = EvaluationNotebook[]; SelectionMove[ClipboardNotebook[], All, Notebook]; clipboardcontent = NotebookRead[ClipboardNotebook[]]; SetSelectedNotebook[nb]; FrontEndExecute[FrontEndToken["Copy"] ]; SetSelectedNotebook[evalnb]; SelectionMove[ClipboardNotebook[], All, Notebook]; readitem = NotebookRead[ClipboardNotebook[]]; SelectionMove[ClipboardNotebook[], All, Notebook]; NotebookWrite[ClipboardNotebook[], clipboardcontent]; If[MatchQ[readitem, Cell[TextData[__], "Text"]], readitem = readitem[[1]]]]; readitem] It should be possible to rewrite this routine, using CellInformation instead of ClipboardNotebook[], but that maybe should wait until CellInformation becomes an official documented function. >2) If there is a difficult way of achieving something - say augmenting >the Mathematica menus - and support has described this to customers, why >not add an easy-to-use API at the next version? > >3) Programmed notebook manipulations can go wrong if the user is >manipulating the notebook at the same time. It would be very valuable to >be able to lock the user out (unless perhaps they abort) while a >sequence of operations is performed. You might lock out the user from an individual notebook temporarily. Say that the notebook object is nb. Lock by SetOptions[nb, WindowClickSelect -> False, Editable -> False, Selectable -> False, Background -> GrayLevel[0.8]]; If[SelectedNotebook[] == nb, invisible=NotebookCreate[Visible -> False]; SetSelectedNotebook[invisible]]; Unlock by SetOptions[nb, WindowClickSelect -> True, Editable -> True, Selectable -> True, Background -> GrayLevel[1]]; If[SelectedNotebook[] == invisible, NotebookClose[invisible]; SetSelectedNotebook[nb]]; Maybe I am changing too many options, but this seems to work. You might of course remove the graying feature if you do not like it. >If there are already ways to do any of the above, I am sure someone here >will supply them! At least partially >David Bailey Regards Ingolf Dahl ingolf.dahl at telia.com Sweden