Custom external commands in the GUI

[janvanmaar]

I have several custom scripts that perform some (ebook/ereader related) actions that Calibre does not implement on its own. I was wondering whether there exists a mechanism to integrate them in the Calibre GUI. It could simply mean adding a button with user specified name to user specified group which would simply run a user specified command and return information about success/failure (through or besides the Calibre job management).
In case there is no mechanism for custom commands from GUI: it should not be difficult for me to write Calibre GUI plugins that would do what I describe above. But is there a way to set things up so that the custom plugins survive a binary Calibre update while all the remaining 'stock' Calibre functionality comes in binary form? I have read about the development environment but I am not sure it would enable this?

[kiwidude]

Originally Posted by janvanmaar

I have several custom scripts that perform some (ebook/ereader related) actions that Calibre does not implement on its own. I was wondering whether there exists a mechanism to integrate them in the Calibre GUI. It could simply mean adding a button with user specified name to user specified group which would simply run a user specified command and return information about success/failure (through or besides the Calibre job management).
In case there is no mechanism for custom commands from GUI: it should not be difficult for me to write Calibre GUI plugins that would do what I describe above. But is there a way to set things up so that the custom plugins survive a binary Calibre update while all the remaining 'stock' Calibre functionality comes in binary form? I have read about the development environment but I am not sure it would enable this?

Someone like Kovid can give you the 100% facts about it but from my experiences it seems that the plug-in architecture unfortunately does not include zip plugins for gui interface actions. See this thread for my experiences of the first gui action I tried to add. It is so close to being possible but there is a unfortunately one existing file (builtins.py) which you have to modify each time for every action you add.

I've made a number of modifications to the source for various gui actions (some submitted as patches, others not), and I just keep pulling down the latest source and merging it into my version of the code. Not a big deal once you know what to do - I was a complete noob to Python and Bazaar so it took a while but got there eventually. As time goes on I make more and more tweaks and "improvements" so it may all go wrong one day of course.

[janvanmaar]

Thanks kiwidude, this is exactly the information I needed!
I will try to get to the point so that (only) builtins.py manual rewrites are needed and then perhaps think of a workaround for that need (although it is extremely unlikely to find one if you did not).

[kiwidude]

Originally Posted by janvanmaar

Thanks kiwidude, this is exactly the information I needed!
I will try to get to the point so that (only) builtins.py manual rewrites are needed and then perhaps think of a workaround for that need (although it is extremely unlikely to find one if you did not).

Well if you can think of a way to convince Kovid that your requirement would be useful to others and submit it as a patch then that would solve your update problem ;-)

For instance a "Run command" type menu action, with the definition of what that command is stored in the tweaks. So you and anyone else going forward could customise what it does without touching the source code, and if the menu action wasn't included in the default menu then no-one else will see it unless they customise their menu to include it. Whether something like that still fits your need of course is another issue...

[janvanmaar]

The tweak you mention sounds interesting but I have actually gone through the tweaks before asking my question and could not find anything like that - these are all the tweaks available for me (in 0.7.28 GUI):

series_index_auto_increment = 'next'
author_sort_copy_method = 'invert'
bool_custom_columns_are_tristate = 'yes'
sort_columns_at_startup = None
gui_pubdate_display_format = 'MMM yyyy'
gui_timestamp_display_format = 'dd MMM yyyy'
title_series_sorting = 'library_order'
save_template_title_series_sorting = 'library_order'
title_sort_articles=r'^(A|The|An)\s+'
auto_connect_to_folder = ''
sony_collection_renaming_rules={}
sony_collection_sorting_rules = []
grouped_search_terms = {}
add_new_book_tags_when_importing_books = False
max_content_server_tags_shown=5
content_server_will_display = ['*']
content_server_wont_display = ['']
maximum_resort_levels = 5
generate_cover_title_font = None
generate_cover_foot_font = None
doubleclick_on_library_view = 'open_viewer'

Where can I find the tweak you mention?

[kovidgoyal]

Actually, I just committed code to make interface action plugins also loadable from zip files. For details, see the commit (it includes documentation).

[janvanmaar]

wow, this sounds great!!!
going to make a coffee and download the latest commit

[kiwidude]

Originally Posted by janvanmaar

Where can I find the tweak you mention?

It was just an idea for a possible implementation - you would have to code it yourself. Trivial to do though - code like this will allow you to grab a value from the tweaks set on your machine (from a patch I did today to allow disabling bookmarks):

from calibre.utils.config import tweaks
...
self.disable_bookmarks = tweaks['disable_bookmarks_in_ebook_viewer']

If you want to put it all together as a patch to submit then you would also want to modify resources\default_tweaks.py so that other users would know what the possible values are.

Thanks Kovid for the latest fix for zip interface actions, will change the two I have written so far to use that approach.

[janvanmaar]

Kovid: I cannot find the documentation, where is it located?
kiwidude: I get it now, it might be an option too

[kovidgoyal]

look at the patch accompanying the commit. Specifically the patch to plugins.rst and __init__.py

Basically you just have to create the InterfaceActionBase and InterfaceAction subclasses and have the load_actual_plugin method of your InterfaceActionBase subclass return the InterfaceAction subclass

[kiwidude]

Originally Posted by kovidgoyal

look at the patch accompanying the commit. Specifically the patch to plugins.rst and __init__.py

Basically you just have to create the InterfaceActionBase and InterfaceAction subclasses and have the load_actual_plugin method of your InterfaceActionBase subclass return the InterfaceAction subclass

Kovid, do you have an example py you could post, just like the HelloWorld one?

I'm going through trial and error here and going in circles a bit. It was blowing up on my imports being defined at the top (giving errors like "ImportError: cannot import name error_dialog"). So I moved those into my InterfaceAction subclass and now get this error:

Failed to initialize plugin...
Traceback (most recent call last):
  File "D:\CalibreDev\latest\calibre\src\calibre\customize\ui.py", line 518, in initialize_plugins
  File "D:\CalibreDev\latest\calibre\src\calibre\customize\ui.py", line 83, in load_plugin
  File "<string>", line 8, in <module>
  File "D:\CalibreDev\latest\calibre\src\calibre\gui2\actions\__init__.py", line 12, in <module>
ImportError: cannot import name Dispatcher

[janvanmaar]

ImportError: cannot import name Dispatcher

That's exactly the same error message I am getting it looks so simple but we are still doing something wrong apparently...

[kovidgoyal]

Hold your horses, I'll put together a GUI helloWorld plugin later today.

[kovidgoyal]

Here you go:

#!/usr/bin/env python
# vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai

__license__   = 'GPL v3'
__copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
__docformat__ = 'restructuredtext en'


from calibre.customize import InterfaceActionBase

class HelloWorldBase(InterfaceActionBase):

    name = 'Hello World GUI'
    author = 'The little green man'

    def load_actual_plugin(self, gui):
        from calibre.gui2.actions import InterfaceAction

        class HelloWorld(InterfaceAction):
            name = 'Hello World GUI'
            action_spec = ('Hello World!', 'add_book.png', None,
                    _('Ctrl+Shift+H'))

            def genesis(self):
                self.qaction.triggered.connect(self.hello_world)

            def hello_world(self, *args):
                from calibre.gui2 import info_dialog
                info_dialog(self.gui, 'Hello World!', 'Hellooo World!',
                        show=True)

        return HelloWorld(gui, None)

Add this plugin and press Ctrl+Shift+H in the gui to see a nice Hello World popup

[janvanmaar]

It works perfectly now, I have my first simple plugin working and it even does what it should (refresh screen on the device)!