The TestButtonPress command simulates a button press action in a given canvas.  This is useful when developing a Maple Learn application.  After deploying a canvas, you can interact with it, then share the new document including the interaction, and use the share-link as the canvas argument to this command.  This allows you to debug the button press action inside Maple.

When more than one button is present in the canvas, the second argument, button, can be used to specify which button-press event to actuate.

By default, commands behind a button action are wrapped inside a procedure.  The unwrap option allows you to remove the procedure wrapper before executing the script commands.

A button event typically includes an entire procedure definition.  When developing a canvas application in Maple, you may have the same procedure already defined inside your worksheet.  Executing TestButtonPress will cause that procedure to be redefined to the unpacked version in the canvas.  In order to set breakpoints in the unpacked version, it is useful to specify the name of the procedure using the 'stopat'=[YourProcName] option.  Multiple breakpoints can be specified in the list.

$\mathrm{with}\left(\mathrm{DocumentTools}:-\mathrm{Canvas}\right)\:$

VarVersusFunc := proc(canvas)
   local m := GetMath(canvas):
   local sc := Script(':-canvas'=canvas):
   for local mi in m do
       SetActive(sc,mi);
       local vars := indets(mi:-math,symbol):
       for local v in vars do
           Highlight(sc,v);
       end do:
       Annotate(sc,`if`(vars={},"no variables present","variables highlighted"));
       SetMath(sc,mi:-math,where="below");
       local funs := indets(mi:-math,function):
       for local F in funs do
          Highlight(sc,op(0,F));
       end do:
       Annotate(sc,`if`(funs={},"no functions present","functions highlighted"));
   end do;
   sc:-ToString(sc);
end proc:

$\mathrm{cv}≔\mathrm{NewCanvas}\left(\left[''Write\; An\; Expression\; with\; Variables''\,x+y\,\sin \left(x^2\right)-\cos \left(y\right)\,\mathrm{ScriptButton}\left(''Find\; Variables\; and\; Functions''\,\mathrm{VarVersusFunc}\,\mathrm{position}=\left[500\,50\right]\right)\right]\right)\:$

$\mathrm{ShareCanvas}\left(\mathrm{cv}\right)$

$\mathrm{url}≔\mathrm{ShareCanvas}\left(\mathrm{cv}\,'\mathrm{showlink}'=\mathrm{false}\right)$

$\mathrm{TestButtonPress}\left(\mathrm{url}\right)$

The DocumentTools[Canvas][TestButtonPress] command was introduced in Maple 2021.

For more information on Maple 2021 changes, see Updates in Maple 2021.