Plugin devs: Upcoming migration to Qt 6

[kiwidude]

Originally Posted by theducks

(And Thanks to you Kiwidude if you are lurking)

Ha, I do lurk now and again and also thankful to the maintainers who have persisted with keeping my plugins alive particularly through these Python/Qt upgrades. I still use many of them myself each week so grateful for everyone here keeping the dream alive...

[davidfor]

Originally Posted by iamagloworm

I wonder if anyone could have a look at this plugin? davidfor has updated it for python 3, and collects some metadata from FictionDB, but genre, classification and time period are not added to tags, and I want to add age-level as well, ideally to a separate column.

I really appreciate davidfor reviving this plugin and thought some extra support would be welcome.

FictionDB Plug-In thread

Are you saying the plugin doesn't work with the beta? It seemed to when I tried. If it doesn't, report the problem in the plugins thread and I'll look at it.

[Mick2nd]

Hi Kovid,


my Plugin Toc View Generator is no longer working. The code generated by PyQt designer generates the following error message (displayed in error dialog):

calibre, version 6.1.0
FEHLER: Unbehandelter Ausnahmefehler: <b>AttributeError</b>:type object 'QLocale' has no attribute 'English'

calibre 6.1  embedded-python: True
Windows-10-10.0.22000-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.22000')
Python 3.10.1
Windows: ('10', '10.0.22000', 'SP0', 'Multiprocessor Free')
Interface language: de
Successfully initialized third party plugins: Gather KFX-ZIP (from KFX Input) (1, 49, 0) && DeDRM (10, 0, 3) && Package KFX (from KFX Input) (1, 49, 0) && Count Pages (1, 11, 2) && KFX metadata reader (from KFX Input) (1, 49, 0) && KFX Input (1, 49, 0) && TOC View Generator (2, 1, 3)
Traceback (most recent call last):
  File "calibre\gui2\preferences\plugins.py", line 301, in customize_plugin
  File "calibre\gui2\preferences\plugins.py", line 379, in modify_plugin
  File "calibre\customize\__init__.py", line 166, in do_user_config
  File "calibre_plugins.toc_view_generator.__init__", line 128, in config_widget
  File "calibre_plugins.toc_view_generator.gui.Config", line 44, in __init__
  File "calibre_plugins.toc_view_generator.gui.TempConfig", line 38, in __init__
  File "calibre_plugins.toc_view_generator.gui.Config_ui", line 16, in setupUi
AttributeError: type object 'QLocale' has no attribute 'English'

I assume it has to do with the compatibility layer for PyQt5.


Can You help?
Mick2nd

[kovidgoyal]

Use the pyqt6 designer and you will be fine. Or manually replace QLocale.English with QLocale.Language.English

[Mick2nd]

Originally Posted by kovidgoyal

Use the pyqt6 designer and you will be fine. Or manually replace QLocale.English with QLocale.Language.English

Thanks, I will give it a try later this day.

[Nicolas F]

Originally Posted by kovidgoyal

calibre 6 (to be released in a few months), will be based on Qt 6. Qt 6 has various minor incompatibilities with Qt 5, many of which I have implemented compatibility layers for. However if your plugins use Qt then they need to be tested against Qt 6. Beta builds of calibre you can use for that purpose are available here: https://download.calibre-ebook.com/betas/

As of 5.99.3 the betas have support for proper icon themeing with support for using different icon themes for light and dark mode and calibre switches between them automatically. In order to use icons from themes that support your plugin you should pass the plugin name to the get_icons() function to load an icon. For example:

[...]

Hi,

if I understand this correctly I should be able to create an icon theme with light and dark versions for plugin icons too?

I'm on windows 10,
I tried to create icons in the "resources\images\Name of the plugin" folder but it works when I use icon.png but if I use icon-for-dark-theme.png or icon-for-light-theme.png the icon doesn't show up in calibre.

Even with @JimmXinu plugin's like EpubMerge which specifies in the version note "Use Cal6 get_icons() so icon themes apply" I can't get it to work.

What should I do concretely with the light and dark icons ?

[kovidgoyal]

Themeing means the user installs an icon theme that has support for your plugin, then get_icons() will use icons from that theme if available, falling back to the icons in the plugin zip file when no icon is found in the theme.

[thiago.eec]

Originally Posted by Nicolas F

Hi,

if I understand this correctly I should be able to create an icon theme with light and dark versions for plugin icons too?

I'm on windows 10,
I tried to create icons in the "resources\images\Name of the plugin" folder but it works when I use icon.png but if I use icon-for-dark-theme.png or icon-for-light-theme.png the icon doesn't show up in calibre.

Even with @JimmXinu plugin's like EpubMerge which specifies in the version note "Use Cal6 get_icons() so icon themes apply" I can't get it to work.

What should I do concretely with the light and dark icons ?

If I'm not mistaken, this is how calibre choose an icon:

1) Look for user overrides in '../resources/images/Plugin name'
2) Look for themed versions (for-dark-theme / for-light-theme)
3) Look in the theme package
4) Use the plugin zipped image

But, most of the plugins I checked, have their on implementation of a get_icon() function, created by @kiwidude. This was created back when calibre couldn't handle this.

The point is: calibre changed but many plugins still uses the old scheme. Some plugin developers updated their function, like you mentioned (@JimmXinu and @kiwidude, for example).

Also, I don't see anyone looking for themed icons (maybe I missed some). I implemented this for my plugins.

This is my calibre 6+ get_icon() function:

Spoiler:

def get_icon(icon_name):
    # Check to see whether the icon exists as a Calibre resource
    # This will enable skinning if the user stores icons within a folder like:
    # ...\AppData\Roaming\calibre\resources\images\Plugin Name\

    # General icons (..\resources\images\)
    general_icons = ['dialog_warning.png', 'marked.png']

    if icon_name not in general_icons:
        icon_name = 'images/' + icon_name

    # First, look for the themed icon (Qt resource files)
    tc = 'dark' if is_dark_theme() else 'light'
    sq, ext = os.path.splitext(icon_name)
    sq = f'{sq}-for-{tc}-theme{ext}'  # Yet to be implemented by theme creators, but...
    icon = QIcon.ic(PLUGIN_NAME + '/' + sq.replace('images/', ''))
    if icon.isNull():
        # Then, look for the regular icon (..\resources\images\Plugin Name\)
        sq, ext = os.path.splitext(icon_name)
        if 'help' not in icon_name:  # There is only one help icon
            sq = f'{sq}_{tc}{ext}'
        else:
            sq = icon_name
        icon = QIcon.ic(PLUGIN_NAME + '/' + sq.replace('images/', ''))
        if icon.isNull():
            # Then, look for it on general icons (Qt resource files)
            if not sq.startswith('images/'):  # Image does not come with the zip file
                return QIcon.ic(icon_name)
        else:
            return icon
    else:
        return icon

    # As we did not find an icon elsewhere, look within our zip resources
    return get_icons(sq)

This function also deals with themed icons inside the zip file. I always create two set of icons, to work with light and dark theme.

P.S.: 'Check books' and 'Reading goal' are examples of plugins that can handle themed versions.

[Nicolas F]

Originally Posted by thiago.eec

If I'm not mistaken, this is how calibre choose an icon:

1) Look for user overrides in '../resources/images/Plugin name'
2) Look for themed versions (for-dark-theme / for-light-theme)
3) Look in the theme package
4) Use the plugin zipped image

But, most of the plugins I checked, have their on implementation of a get_icon() function, created by @kiwidude. This was created back when calibre couldn't handle this.

The point is: calibre changed but many plugins still uses the old scheme. Some plugin developers updated their function, like you mentioned (@JimmXinu and @kiwidude, for example).

Also, I don't see anyone looking for themed icons (maybe I missed some). I implemented this for my plugins.

This is my calibre 6+ get_icon() function:

Spoiler:

def get_icon(icon_name):
    # Check to see whether the icon exists as a Calibre resource
    # This will enable skinning if the user stores icons within a folder like:
    # ...\AppData\Roaming\calibre\resources\images\Plugin Name\

    # General icons (..\resources\images\)
    general_icons = ['dialog_warning.png', 'marked.png']

    if icon_name not in general_icons:
        icon_name = 'images/' + icon_name

    # First, look for the themed icon (Qt resource files)
    tc = 'dark' if is_dark_theme() else 'light'
    sq, ext = os.path.splitext(icon_name)
    sq = f'{sq}-for-{tc}-theme{ext}'  # Yet to be implemented by theme creators, but...
    icon = QIcon.ic(PLUGIN_NAME + '/' + sq.replace('images/', ''))
    if icon.isNull():
        # Then, look for the regular icon (..\resources\images\Plugin Name\)
        sq, ext = os.path.splitext(icon_name)
        if 'help' not in icon_name:  # There is only one help icon
            sq = f'{sq}_{tc}{ext}'
        else:
            sq = icon_name
        icon = QIcon.ic(PLUGIN_NAME + '/' + sq.replace('images/', ''))
        if icon.isNull():
            # Then, look for it on general icons (Qt resource files)
            if not sq.startswith('images/'):  # Image does not come with the zip file
                return QIcon.ic(icon_name)
        else:
            return icon
    else:
        return icon

    # As we did not find an icon elsewhere, look within our zip resources
    return get_icons(sq)

This function also deals with themed icons inside the zip file. I always create two set of icons, to work with light and dark theme.

P.S.: 'Check books' and 'Reading goal' are examples of plugins that can handle themed versions.

Thank you for replying.

It works with your plugin with the for-dark-theme / for-light-theme like I was thinking.

I made the highlight theme a few years ago with icons for a majority of the plugins at the time and I wanted to update it to be compatible with light and dark themes

[Nicolas F]

Originally Posted by kovidgoyal

Themeing means the user installs an icon theme that has support for your plugin, then get_icons() will use icons from that theme if available, falling back to the icons in the plugin zip file when no icon is found in the theme.

Thanks for answering,

yes I've mad the material and highlight themes for calibre a few years ago but the for-dark-theme / for-light-theme icons don't seem to work for themes.

It works with thiago.eec's plugins but I downloaded the Interface Plugin Demo from calibre website (Interface Plugin Demo.zip) and it doesn't see the custom icons.

The code for the demo plugin is

icon = get_icons('images/icon.png', 'Interface Plugin Demo')

If I understand it correctly I should be able to use "images/Interface Plugin Demo/icon-for-dark-theme.png" and get the icon in dark mode.

thiago.eec's plugin that works doesn't seem to use the default implementation.

[kovidgoyal]

Yes the default implementation doesnt check for dark/light. But plugin authors are free to roll their own.

[Nicolas F]

Originally Posted by kovidgoyal

Yes the default implementation doesnt check for dark/light. But plugin authors are free to roll their own.

Ok thank you. I thought you had changed the default implementation in order to use the light and dark mode.

Do you think you will change this so that light and dark themes can be applied to plugins? Should I had a feature request in calibre bug tracker?

[kovidgoyal]

actually I think I am mis-remembering, the default implementation uses ICon.ic() and that does work with light/dark variants automatically.

[Nicolas F]

Then I don't know why but it doesn't seem to work.

Maybe @thiago.eec can confirm that it's not working with get_icons()

[thiago.eec]

Originally Posted by Nicolas F

Then I don't know why but it doesn't seem to work.

Maybe @thiago.eec can confirm that it's not working with get_icons()

Yes. Using get_icons('icon.png', PLUGIN_NAME) works.

You need this too:
..\resources\images\PLUGIN_NAME\icon-for-dark-theme.png
..\resources\images\PLUGIN_NAME\icon-for-light-theme.png