Bug 75544 - [GTK][META] Add printing support to WebKit2
: [GTK][META] Add printing support to WebKit2
Status: NEW
: WebKit
: 528+ (Nightly build)
: PC Linux
: P2 Normal
Assigned To:
: Gtk
: 76172 76448 76536 76616 77197 78715 78793 78799 78805 78823 79226
  Show dependency treegraph
Reported: 2012-01-04 06:58 PST by
Modified: 2012-02-22 05:07 PST (History)



You need to log in before you can comment on or make changes to this bug.

Description From 2012-01-04 06:58:59 PST
The UI client has a callback to request printing a frame. The main problem is that printing happens in the WebProcess, but the GtkPrintOperation is created in the UI process. The GtkPrintOperation creates the cairo context we should render into (UI). A solution might be not using GtkPrintOperation and create the print dialog in the UI process with GtkPrintUnixDialog and GtkPrintJob directly.
------- Comment #1 From 2012-01-04 09:12:17 PST -------
Hrm. The issue with just passing a bitmap here is that we'd like to render onto a PDF surface, right?
------- Comment #2 From 2012-01-04 23:39:35 PST -------
Right, we can't use bitmaps, the surface created by GtkPrintOperation might be pdf or ps when using cups, ps when using papi and lpr, pdf, ps or svg when printing to a file and win32 printing surface in windows. 
Another solution might be to run the print dialog in the web process like we currently do for auth dialogs. I don't like the idea but it might work.
------- Comment #3 From 2012-01-05 02:33:27 PST -------
Chromium uses GtkPrintUnixDialog + GtkPrintJob in unix FWIW.
------- Comment #4 From 2012-01-09 08:27:09 PST -------
For the record, I'm pro the creation of the dialog in the UI process with the settings then piped through the IPC to the web process for the actual printing, like Carlos proposed, and with the creation of the WebKitPrintOperation object.
------- Comment #5 From 2012-01-09 08:39:27 PST -------
Yes, the idea is to use GtkPrintDialogUnix in the UI process, without exposing it in the API, using WebKitPrintOperation, the same way GtkPrintOperation does. This way someone could add win32 support using the window native printing dialog, using the same API. This object will run the dialog and send the print settings and page setup to the web process thought IPC. In the web process a GtkPrintJob object will be created using the print settings. GtkPrintJob creates the cairo surface using gtk printing backends. Then the frame is rendered into the printing surface and the job sent to the printer. This is the general ideal for the basic functionality.
------- Comment #6 From 2012-01-12 06:41:58 PST -------
Making this a meta bug since I'm going to split the work into several patches: 

 - Initial printing support in WebProcess
 - Initial API
 - Manual capabilities (copies, collate, reverse, multiple pages per sheet, scale, etc.). Maybe using a different bug per capability.