Custom Paper Sizes

[bradparker]

Being able to feed in GTK paper size names is awesome, thank you. However we wondered what might involved in adding something even more flexible.

We'd love to contribute more directly but we don't speak c/c++, sorry. We're also unfamiliar with v8 / WebKitGTK. We figured we'd talk through how we thought this might work and try to help as much as we can.

I'm not sure how this would work on the c++ side but having that paper param be polymorphic would be pretty cool, perhaps...

Webkit(99).load('google.com').wait('idle').pdf({
  paper: { 
    width: 210, 
    height: 297, 
    unit: 'mm' 
  }
});

// Or

Webkit(99).load('google.com').wait('idle').pdf({
  paper: 'iso_a4'
});

... and here's some pseudo code which may / may not be of any help.

GtkPageSetup* setup = gtk_page_setup_new();
  Local<Object> paper = opts.paper->ToObject();
  if (paper.width == NULL) { 
    paper = gtk_paper_size_get_default();
    GtkPaperSize* paperSize = gtk_paper_size_new(paper);
  } else {
    const gchar custom_paper_name = 'some_placeholder_name';
    const gchar custom_paper_display_name = 'again_some_placeholder_name';
    const gdouble width = NanUInt32OptionValue(paper, H("width"), 210);
    const gdouble height = NanUInt32OptionValue(paper, H("height"), 297);
    const gchar unitStr = getStr(paper, "unit"); // assign the correct GTK unit based on this string...
    const GtkUnit unit = //  ... here? GTK_UNIT_POINTS || GTK_UNIT_MM || GTK_UNIT_INCH
    GtkPaperSize* paperSize = gtk_paper_size_new_custom(
      custom_paper_name,
      custom_paper_display_name,
      width,
      height,
      unit
    );   
  }

  gtk_page_setup_set_paper_size_and_default_margins(setup, paperSize);
  if (NanBooleanOptionValue(opts, H("fullpage"), false)) {
    gtk_page_setup_set_right_margin(setup, 0, GTK_UNIT_POINTS);
    gtk_page_setup_set_left_margin(setup, 0, GTK_UNIT_POINTS);
    gtk_page_setup_set_top_margin(setup, 0, GTK_UNIT_POINTS);
    gtk_page_setup_set_bottom_margin(setup, 0, GTK_UNIT_POINTS);
  }
  webkit_print_operation_set_page_setup(op, setup);

I really hope that's helpful. Thanks.

[kapouer]

Also it's probably good to allow setting margins in GtkPageSetup.
This will have to wait a little longer though.

[bradparker]

Yeah for sure! Another good polymorphic candidate?

Webkit().load('google.com').wait('idle').pdf({
  margins: 0
});

// Or

Webkit().load('google.com').wait('idle').pdf({
  margins: {
    left: 20,
    right: 20,
    top: 15,
    bottom: 25,
    unit: 'mm'
  }
});

Removes the need for full page?

[bradparker]

Would it be easier to translate the opts object on the JS end?

WebKit.prototype.pdf = function() {
  var filepath = arguments[0];
  var opts, cb;

  if (arguments[1] instanceof Function) {
    opts = {};
    cb = arguments[1];
  } else {
    opts = arguments[1] || {};
    cb = arguments[2] || noop;
  }

  if (typeof opts.paper === 'string') {
    opts.gtkPaperName = opts.paper;
  } else if (opts.paper) {
    opts.customPaperWidth   = opts.paper.width;
    opts.customPaperHeight  = opts.paper.height;
    opts.customPaperUnit    = opts.paper.unit || 'mm';
  }
  delete opts.paper;

  if (typeof opts.margins === 'number') {
    opts.marginLeft = opts.marginRight = opts.marginTop = opts.marginBottom = opts.margins;
  } else if (opts.margins) {
    opts.marginLeft   = opts.margins.left || 0;
    opts.marginRight  = opts.margins.right || 0;
    opts.marginTop    = opts.margins.top || 0;
    opts.marginBottom = opts.margins.bottom || 0;
    opts.marginUnit   = opts.margins.unit;
  }
  opts.marginUnit = opts.marginUnit || 'mm';
  delete opts.margins;

  pdf.call(this, filepath, opts, cb);
};

... roughly. This might make the job on the extension side easier.

Or would you prefer no translation between the opts in the JS / c++ APIs?

[bradparker]

Having a look at this. Nearly there, going to add some tests, and seek out c++ advice :)
net-engine/node-webkitgtk@kapouer:master...master

[kapouer]

Great !
But

• talk about "vm in osx" in the wiki, not in the readme
• do not include npm-debug.log in git
• +!test/shots/.gitkeep this should go into your userdir .gitignore, not into this project
• i don't understand why you had to change lib -> obj in binding.gyp - a change in latest node-gyp ?
• and about the code itself : good start - you have to make sure you destroy what you create, like gtk_paper_size_new_custom maybe.
• return gtk_paper_size_new(gtk_paper_size_get_default()); isn't reached ?

[kapouer]

Also note that you can also leave it like this and i can take inspiration from your code instead of merging your commits if you don't want to bother with the details :)

[bradparker]

No problem! Happy to help as much as I can.

Will add tests for variations of that paper object, including not having one (to see if that default ever gets executed).

I've been looking around for info on lib > obj... no idea, I can't find any relevant information unfortunately. My node-gyp version is 0.12.2.

The cache/.gitkeep and test/shots/.gitkeepss were intended to make setup easier for people running the tests the first time. Tests fail without the cache and test/shots folders. Happy to remove them if you think it's better as user configuration.

Will remove the OSX notes and set up an Installation guide in the wiki.

Oh, and will definitely make sure to keep npm-debug.log out, whoops.

Thanks.

[kapouer]

@bradparker if you're still printing pdf out of webkitgtk, maybe you'd have something to say about https://lists.webkit.org/pipermail/webkit-gtk/2015-September/002435.html