Problems with inconsistent script results.

[Sean Houghton]

I'm having a really difficult time getting the HorizontalSizer to work.  My brute force approach to the problem was to keep deleting things until my script looked exactly like the HelloWorld example.  I did this and it was still broken.  The only difference was one variable name.  I renamed this and all of a sudden the sizer started working.  I renamed it back to the original name and it still worked, which is pretty weird.  I started from scratch again and I've included the script below.  How do I make the controls stack?


#include <pjsr/Sizer.jsh>
#include <pjsr/FrameStyle.jsh>
#include <pjsr/TextAlign.jsh>
#include <pjsr/StdButton.jsh>
#include <pjsr/StdIcon.jsh>
#include <pjsr/NumericControl.jsh>

#define TITLE Demonstration
#define VERSION 0.1

function DemonstrationDialog()
{
   this.__base__ = Dialog;
   this.__base__();

   this.helpLabel = new Label( this );
   with ( this.helpLabel )
   {
      frameStyle = FrameStyle_Box;
      margin = 4;
      wordWrapping = true;
      useRichText = true;
      text = "This is a helpful label";
   }

   this.findExposureButton = new PushButton( this );
   this.findExposureButton.text = "Press me";

   this.contentSizer = new VerticalSizer;
   this.contentSizer.add(this.helpLabel);
   this.contentSizer.add(this.findExposureButton);


   this.windowTitle = #TITLE + " Script";
   this.adjustToContents();
}


DemonstrationDialog.prototype = new Dialog;

var dialog = new DemonstrationDialog;
dialog.execute();

[Juan Conejero]

Hi Sean,

Welcome to PixInsight development.

The problem is here:

   this.contentSizer = new VerticalSizer;
   this.contentSizer.add(this.helpLabel);
   this.contentSizer.add(this.findExposureButton);

With these sentences you are defining a contentSizer property of your dialog. That's fine syntactically but it doesn't work as you expect.

What you need to define is the Control.sizer property, which has been inherited by the Dialog object, which in turn your DemonstrationDialog inherits from because you execute Dialog's constructor at the beginning of your dialog's constructor:

   this.__base__ = Dialog;
   this.__base__();

So the correct code is:

   this.sizer = new VerticalSizer;
   this.sizer.add(this.helpLabel);
   this.sizer.add(this.findExposureButton);

Now, the Sizer object (the HorizontalSizer and VerticalSizer objects are just wrappers to Sizer defined in pjsr/Sizer.jsh) doesn't provide automatic separation between items and a margin between the dialog and its contents by default (this is common to both PJSR and PCL). For a sizer object defining the entire layout of a dialog, you must set these properties explicitly with reasonable values:

   this.sizer = new VerticalSizer;
   this.sizer.margin = 8;
   this.sizer.spacing = 6;
   this.sizer.add(this.helpLabel);
   this.sizer.add(this.findExposureButton);

Next, you usually want to ensure reasonable minimum dimensions for your dialog so that the user cannot reduce it down to a few pixels. This is best done by calling the inherited Control.setMinSize() method. For example:

   this.setMinSize( 300, 200 );

Finally, you normally don't want the console to remain visible during normal operation of your script. For scripts that provide a graphical user interface, it is customary hiding the console by invoking:

   console.hide();

With all of these modifications your script works fine and looks like this:

Code: [Select]

#include <pjsr/Sizer.jsh>
#include <pjsr/FrameStyle.jsh>
#include <pjsr/TextAlign.jsh>
#include <pjsr/StdButton.jsh>
#include <pjsr/StdIcon.jsh>
#include <pjsr/NumericControl.jsh>

#define TITLE Demonstration
#define VERSION 0.1

function DemonstrationDialog()
{
   this.__base__ = Dialog;
   this.__base__();

   this.helpLabel = new Label( this );
   with ( this.helpLabel )
   {
      frameStyle = FrameStyle_Box;
      margin = 4;
      wordWrapping = true;
      useRichText = true;
      text = "This is a helpful label";
   }

   this.findExposureButton = new PushButton( this );
   this.findExposureButton.text = "Press me";

   this.sizer = new VerticalSizer;
   this.sizer.margin = 8;
   this.sizer.spacing = 6;
   this.sizer.add( this.helpLabel );
   this.sizer.add( this.findExposureButton );

   this.setMinSize( 300, 200 );

   this.windowTitle = #TITLE + " Script";
  
   this.adjustToContents();
}

DemonstrationDialog.prototype = new Dialog;

console.hide();

var dialog = new DemonstrationDialog;
dialog.execute();

Hope this helps.

[Sean Houghton]

Aha!  Javascript's automatic member variable creation on assignment is ripe for these kinds of mistakes    The JS API was pretty easy to work with (other than the sizer snafu) but at some point I'll give the c++ interface a try too.

I'll post my new script tonight.