docs/latex/wx/ttips.tex

   1 \section{wxTipProvider overview}\label{tipsoverview}
   2
   3 Many "modern" Windows programs have a feature (some would say annoyance) of
   4 presenting the user tips at program startup. While this is probably useless to
   5 the advanced users of the program, the experience shows that the tips may be
   6 quite helpful for the novices and so more and more programs now do this.
   7
   8 For a wxWidgets programmer, implementing this feature is extremely easy. To
   9 show a tip, it is enough to just call \helpref{wxShowTip}{wxshowtip} function
  10 like this:
  11
  12 \begin{verbatim}
  13     if ( ...show tips at startup?... )
  14     {
  15         wxTipProvider *tipProvider = wxCreateFileTipProvider("tips.txt", 0);
  16         wxShowTip(windowParent, tipProvider);
  17         delete tipProvider;
  18     }
  19 \end{verbatim}
  20
  21 Of course, you need to get the text of the tips from somewhere - in the example
  22 above, the text is supposed to be in the file tips.txt from where it is read by
  23 the {\it tip provider}. The tip provider is just an object of a class deriving
  24 from \helpref{wxTipProvider}{wxtipprovider}. It has to implement one pure
  25 virtual function of the base class: \helpref{GetTip}{wxtipprovidergettip}.
  26 In the case of the tip provider created by
  27 \helpref{wxCreateFileTipProvider}{wxcreatefiletipprovider}, the tips are just
  28 the lines of the text file.
  29
  30 If you want to implement your own tip provider (for example, if you wish to
  31 hardcode the tips inside your program), you just have to derive another class
  32 from wxTipProvider and pass a pointer to the object of this class to wxShowTip
  33 - then you don't need wxCreateFileTipProvider at all.
  34
  35 You will probably want to save somewhere the index of the tip last
  36 shown - so that the program doesn't always show the same tip on startup. As you
  37 also need to remember whether to show tips or not (you shouldn't do it if the
  38 user unchecked "Show tips on startup" checkbox in the dialog), you will
  39 probably want to store both the index of the
  40 last shown tip (as returned by
  41 \helpref{wxTipProvider::GetCurrentTip}{wxtipprovidergetcurrenttip} and the flag
  42 telling whether to show the tips at startup at all.
  43
  44 In a tips.txt file, lines that begin with a \# character are considered comments
  45 and are automatically skipped. Blank lines and lines only having spaces are also
  46 skipped.
  47
  48 You can easily add runtime-translation capacity by placing each line of the
  49 tips.txt file inside the usual translation macro. For example, your tips.txt
  50 file would look like this:
  51
  52 \begin{verbatim}
  53 _("This is my first tip")
  54 _("This is my second tip")
  55 \end{verbatim}
  56
  57 Now add your tips.txt file into the list of files that gettext searches
  58 for translatable strings. The tips will thus get included into your
  59 generated .po file catalog and be translated at runtime along with the rest of
  60 your application's translatable strings.
  61 Note1: Each line in the tips.txt file needs to strictly begin with exactly the
  62 3 characters of underscore-parenthesis-doublequote, and end with
  63 doublequote-parenthesis, as shown above.
  64 Note2: Remember to escape any doublequote characters within the tip string with
  65 a backslash-doublequote.
  66
  67 See the dialogs program in your samples folder for a working example inside a
  68 program.
  69