‘SciViews::R’ - Standard Dialog Boxes using Tcl/Tk

Philippe Grosjean (phgrosjean@sciviews.org)

2025-08-26

This package demonstrate how to reimplement the {svDialogs} functions using different widgets and GUI. Only a couple of dialog boxes are currently implementation, just for the sake of that demonstration.

You should execute the code in this vignette in an R interactive session that supports Tcl/Tk display in order to get the various dialog boxes!

# This must be TRUE in order to see the Tcl/Tk dialog boxes
capabilities("tcltk")
#> tcltk 
#>  TRUE

When {svDialogs} is loaded, it creates a default .GUI object using nativeGUI (native dialog boxes) in priority, followed by textual versions at the command line as fallback alternative (textCLI).

library(svGUI)
library(svDialogs)
# The default GUI
.GUI
#> The default SciViews GUI (.GUI)
#> using widgets from: nativeGUI, textCLI
def_widgets <- gui_widgets(.GUI)
def_widgets
#> [1] "nativeGUI" "textCLI"

This means that {svDialogs} will use a native box (or a text version, depending from where you run the code in R) for this code:

dlg_message("Hello world!")$res

To use the Tcl/Tk dialog boxes implemented in {svDialogstcltk} in the default GUI without changing anything in the subsequent code that uses the dialog boxes, you just have to load this package before use:

library(svDialogstcltk)
#> Loading required package: tcltk
gui_widgets(.GUI)
#> [1] "tcltkGUI"  "nativeGUI" "textCLI"

A new item, tcltkGUI, is inserted at the first position of the gui_widgets() specification in the .GUI object. The consequence is the use of the corresponding methods, if they are defined for the dlg_xxx() functions. For instance, you should now get a Tcl/Tk version of a message box with the following code:

dlg_message("Hello world!")$res

Using Tcl/Tk dialog boxes in a custom GUI

The {svDialogs} logic allows to implement simultaneously various GUIs, with different features. For instance, you may be interested to implement a Tcl/Tk-only GUI side-by-side with native dialog boxes that are used for the rest of the R process. In this case, you must manually insert the GUI you want to use in the GUI object.

# Restore nativeGUI + textual fallback for the default .GUI
gui_change('.GUI', widgets = def_widgets, reset = TRUE)
#> The default SciViews GUI (.GUI)
#> using widgets from: nativeGUI, textCLI

# Add a new GUI called myGUI
gui_add("myGUI")
#> Graphical User Interface: myGUI
#> using widgets from: nativeGUI, textCLI
myGUI
#> Graphical User Interface: myGUI
#> using widgets from: nativeGUI, textCLI
# Switch to Tcl/Tk version of the dialog boxes exclusively for myGUI
gui_change('myGUI', widgets = "tcltkGUI", reset = TRUE)
#> Graphical User Interface: myGUI
#> using widgets from: tcltkGUI

Now, with this configuration, all code that use the default GUI will display native dialog boxes. However, code using myGUI will always display the Tcl/Tk version of the dialog boxes.

# A message box in the default GUI (native)
dlg_message("Hello from the default GUI!")$res
#> [1] "ok"

# A message box in myGUI (Tcl/Tk version)
dlg_message("Hello from myGUI (Tcl/Tk)!", gui = myGUI)$res
#> [1] "ok"