Fwd: [QUESTION] why there is a horizontal line in middle of text-property displayed image?

Fwd: [QUESTION] why there is a horizontal line in middle of text-property displayed image?

[Christopher M. Miles]

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The original email (contains image) is in bellowing link in case this
forwarded email does not contain images.

https://lists.gnu.org/archive/html/help-gnu-emacs/2022-09/msg00179.html

"Christopher M. Miles" <numbchild@gmail.com> writes:

> [[PGP Signed Part:Undecided]]
>
> Question: As the email subject said.
>
> Here is the two screenshots:
>
> *NOTE*: The image itself does not have this horizontal line.
>
> The point is on image:
>
>
>
>
> The point is not on image:
>
>
>
>
> Here is the prototype code which displaying image with text-property:
>
> #+begin_src emacs-lisp
> (put-text-property start end
>                    'display (create-image thumbnail nil nil :ascent 'center :max-height thumbnail-size))
> #+end_src
>
> - If this is some kind of internal mechanism of Emacs, can someone explain why?
>
> - If have some method to remove those horizontal lines. How to do it?


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Re: Fwd: [QUESTION] why there is a horizontal line in middle of text-property displayed image?

[Ihor Radchenko]

"Christopher M. Miles" <numbchild@gmail.com> writes:

>> Here is the prototype code which displaying image with text-property:
>>
>> #+begin_src emacs-lisp
>> (put-text-property start end
>>                    'display (create-image thumbnail nil nil :ascent 'center :max-height thumbnail-size))
>> #+end_src
>>
>> - If this is some kind of internal mechanism of Emacs, can someone explain why?
>>
>> - If have some method to remove those horizontal lines. How to do it?

Could you please detail the steps required to reproduce the problem,
starting from emacs -Q?

-- 
Ihor Radchenko,
Org mode contributor,
Learn more about Org mode at https://orgmode.org/.
Support Org development at https://liberapay.com/org-mode,
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Re: Fwd: [QUESTION] why there is a horizontal line in middle of text-property displayed image?

[Christopher M. Miles]

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Ihor Radchenko <yantar92@gmail.com> writes:

> "Christopher M. Miles" <numbchild@gmail.com> writes:
>
>>> Here is the prototype code which displaying image with text-property:
>>>
>>> #+begin_src emacs-lisp
>>> (put-text-property start end
>>>                    'display (create-image thumbnail nil nil :ascent 'center :max-height thumbnail-size))
>>> #+end_src
>>>
>>> - If this is some kind of internal mechanism of Emacs, can someone explain why?
>>>
>>> - If have some method to remove those horizontal lines. How to do it?
>
> Could you please detail the steps required to reproduce the problem,
> starting from emacs -Q?

Here is the steps to reproduce with "emacs -Q"

  1. =$ emacs -Q=
  2. install package =[M-x package-install RET org-link-beautify RET]=
  3. load the package =[M-x load-library org-link-beautify RET]=, 
     the package source code URL here: https://repo.or.cz/org-link-beautify.git
  4. open an Org file which has content which has a "file:" link to a video file (You can replace
     the video file link as yours) :
     #+begin_src org
     ,* headline 1

     link [[file:~/Downloads/3veEPJrQrV1EtpH9.mp4]]
     #+end_src
  5. enable minor mode =[M-x org-link-beautify-mode RET]=. This mode will auto thumbnail for video
     file and display it with /text-property/.
  6. The displayed thumbnail on link has a center-line.
  7. But open the generated thumbnail image file =file:.thumbnails/3veEPJrQrV1EtpH9.png= with external
     program, it does not have this center-line.

-- 

[ stardiviner ]
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Re: Fwd: [QUESTION] why there is a horizontal line in middle of text-property displayed image?

[Christopher M. Miles]

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Ihor Radchenko <yantar92@gmail.com> writes:

> "Christopher M. Miles" <numbchild@gmail.com> writes:
>
>>> Here is the prototype code which displaying image with text-property:
>>>
>>> #+begin_src emacs-lisp
>>> (put-text-property start end
>>>                    'display (create-image thumbnail nil nil :ascent 'center :max-height thumbnail-size))
>>> #+end_src
>>>
>>> - If this is some kind of internal mechanism of Emacs, can someone explain why?
>>>
>>> - If have some method to remove those horizontal lines. How to do it?
>
> Could you please detail the steps required to reproduce the problem,
> starting from emacs -Q?

Additional info: The package "org-link-beautify" generating video
thumbnails require external command-line tools, you maybe need to
install it depend on your system platform. More details you can check
the package source code: https://repo.or.cz/org-link-beautify.git

-- 

[ stardiviner ]
I try to make every word tell the meaning that I want to express without misunderstanding.

Blog: https://stardiviner.github.io/
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Re: Fwd: [QUESTION] why there is a horizontal line in middle of text-property displayed image?

[Ihor Radchenko]

"Christopher M. Miles" <numbchild@gmail.com> writes:

>   2. install package =[M-x package-install RET org-link-beautify RET]=

Hmm. Can you also reproduce without org-link-beautify?

-- 
Ihor Radchenko,
Org mode contributor,
Learn more about Org mode at https://orgmode.org/.
Support Org development at https://liberapay.com/org-mode,
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Re: Fwd: [QUESTION] why there is a horizontal line in middle of text-property displayed image?

[Christopher M. Miles]

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Ihor Radchenko <yantar92@gmail.com> writes:

> "Christopher M. Miles" <numbchild@gmail.com> writes:
>
>>   2. install package =[M-x package-install RET org-link-beautify RET]=
>
> Hmm. Can you also reproduce without org-link-beautify?

I replaced step 5 with step 6 by extracting the logic code of
org-link-beautify, but I found it does not have center-line. That's
really weird.

  1. =$ emacs -Q=
  2. install package =[M-x package-install RET org-link-beautify RET]=
  3. load the package =[M-x load-library org-link-beautify RET]=
  4. open an Org file which has content which has a "file:" link to a video file (You can replace
     the video file link as yours) :
     #+begin_src org
     ,* headline 1

     link [[file:~/Downloads/3veEPJrQrV1EtpH9.mp4]]
     #+end_src
  5. enable minor mode =[M-x org-link-beautify-mode RET]=. This mode will auto thumbnail for video
     file and display it with /text-property/.
  6. reproduce without org-link-beautify

     #+begin_src emacs-lisp
     (let ((start (point))
           (end (save-excursion (forward-word) (point))))
       (org-link-beautify--add-overlay-marker start end)
       (put-text-property
        start end
        'display (create-image "~/Downloads/.thumbnails/3veEPJrQrV1EtpH9.png" nil nil :ascent 'center :max-height 512))
       (make-local-variable 'image-map)
       (define-key image-map (kbd "<mouse-1>") 'org-open-at-point))
     #+end_src

  7. The displayed thumbnail on link has a center-line.
  8. But open the generated thumbnail image file =file:.thumbnails/3veEPJrQrV1EtpH9.png= with external
     program, it does not have this center-line.

-- 

[ stardiviner ]
I try to make every word tell the meaning that I want to express without misunderstanding.

Blog: https://stardiviner.github.io/
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GPG: F09F650D7D674819892591401B5DF1C95AE89AC3

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Re: Fwd: [QUESTION] why there is a horizontal line in middle of text-property displayed image?

[Ihor Radchenko]

"Christopher M. Miles" <numbchild@gmail.com> writes:

> I replaced step 5 with step 6 by extracting the logic code of
> org-link-beautify, but I found it does not have center-line. That's
> really weird.
> ...
>        (put-text-property
>         start end
>         'display (create-image "~/Downloads/.thumbnails/3veEPJrQrV1EtpH9.png" nil nil :ascent 'center :max-height 512))
>        (make-local-variable 'image-map)
>        (define-key image-map (kbd "<mouse-1>") 'org-open-at-point))
>      #+end_src

On my side, the put-text-property does have center-line.
But only when buffer is in Org mode.
Yet, it is not Org's fault.

The reason you are seeing the horizontal line is org-link face.
org-link has underline. And the "center" line you are seeing is actually
underline coming from the face. I'd say it is emacs bug.

-- 
Ihor Radchenko,
Org mode contributor,
Learn more about Org mode at https://orgmode.org/.
Support Org development at https://liberapay.com/org-mode,
or support my work at https://liberapay.com/yantar92

Fwd: [BUG] text-property displayed image has a center-line when the text face has underline attribute

[Christopher M. Miles]

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Ihor Radchenko <yantar92@gmail.com> writes:

> "Christopher M. Miles" <numbchild@gmail.com> writes:
>
>> I replaced step 5 with step 6 by extracting the logic code of
>> org-link-beautify, but I found it does not have center-line. That's
>> really weird.
>> ...
>>        (put-text-property
>>         start end
>>         'display (create-image "~/Downloads/.thumbnails/3veEPJrQrV1EtpH9.png" nil nil :ascent 'center :max-height 512))
>>        (make-local-variable 'image-map)
>>        (define-key image-map (kbd "<mouse-1>") 'org-open-at-point))
>>      #+end_src
>
> On my side, the put-text-property does have center-line.
> But only when buffer is in Org mode.
> Yet, it is not Org's fault.
>
> The reason you are seeing the horizontal line is org-link face.
> org-link has underline. And the "center" line you are seeing is actually
> underline coming from the face. I'd say it is emacs bug.

Thanks very much for figuring out this issue, Ihor.

I see, I originally post this issue on Emacs-help mailing list, Eli let
me forward this thread to Org mode mailing list. Now I need to forward
to Emacs-devel mailing list.

In case the background info is missing, link original message here:

https://list.orgmode.org/87mtae2718.fsf@localhost/T/#m35d40f37fdf80f413ddb8d40e3017a6f102651e9

-- 

[ stardiviner ]
I try to make every word tell the meaning that I want to express without misunderstanding.

Blog: https://stardiviner.github.io/
IRC(libera.chat, freenode): stardiviner, Matrix: stardiviner
GPG: F09F650D7D674819892591401B5DF1C95AE89AC3

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Re: Fwd: [BUG] text-property displayed image has a center-line when the text face has underline attribute

[Eli Zaretskii]

> From: "Christopher M. Miles" <numbchild@gmail.com>
> Cc: "Christopher M. Miles" <numbchild@gmail.com>, Org Mode
>  <emacs-orgmode@gnu.org>
> Date: Sun, 02 Oct 2022 15:03:26 +0800
> 
> Ihor Radchenko <yantar92@gmail.com> writes:
> 
> > "Christopher M. Miles" <numbchild@gmail.com> writes:
> >
> >> I replaced step 5 with step 6 by extracting the logic code of
> >> org-link-beautify, but I found it does not have center-line. That's
> >> really weird.
> >> ...
> >>        (put-text-property
> >>         start end
> >>         'display (create-image "~/Downloads/.thumbnails/3veEPJrQrV1EtpH9.png" nil nil :ascent 'center :max-height 512))
> >>        (make-local-variable 'image-map)
> >>        (define-key image-map (kbd "<mouse-1>") 'org-open-at-point))
> >>      #+end_src
> >
> > On my side, the put-text-property does have center-line.
> > But only when buffer is in Org mode.
> > Yet, it is not Org's fault.
> >
> > The reason you are seeing the horizontal line is org-link face.
> > org-link has underline. And the "center" line you are seeing is actually
> > underline coming from the face. I'd say it is emacs bug.
> 
> Thanks very much for figuring out this issue, Ihor.
> 
> I see, I originally post this issue on Emacs-help mailing list, Eli let
> me forward this thread to Org mode mailing list. Now I need to forward
> to Emacs-devel mailing list.
> 
> In case the background info is missing, link original message here:
> 
> https://list.orgmode.org/87mtae2718.fsf@localhost/T/#m35d40f37fdf80f413ddb8d40e3017a6f102651e9

Please report this as a bug, with "M-x report-emacs-bug", and please
include there all the details, including the recipe to reproduce the
issue.

Thanks.

[CLOSED] text-property displayed image has a center-line when the text face has underline attribute

[Christopher M. Miles]

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I hate to rewrite those steps more than 3 times. But I also know Emacs
contributors should not be forced to fix bug for me. Also I can't fix
this bug by myself. So I think it's not a bug, I can tolerate this
center line. Maybe I mastered skill for modify code in Emacs, I might
come back to fix this bug by myself. But now, let me close it. I'm not
hating anybody, just hate this process. Thanks for checking out.

Eli Zaretskii <eliz@gnu.org> writes:

>> From: "Christopher M. Miles" <numbchild@gmail.com>
>> Cc: "Christopher M. Miles" <numbchild@gmail.com>, Org Mode
>>  <emacs-orgmode@gnu.org>
>> Date: Sun, 02 Oct 2022 15:03:26 +0800
>> 
>> Ihor Radchenko <yantar92@gmail.com> writes:
>> 
>> > "Christopher M. Miles" <numbchild@gmail.com> writes:
>> >
>> >> I replaced step 5 with step 6 by extracting the logic code of
>> >> org-link-beautify, but I found it does not have center-line. That's
>> >> really weird.
>> >> ...
>> >>        (put-text-property
>> >>         start end
>> >>         'display (create-image "~/Downloads/.thumbnails/3veEPJrQrV1EtpH9.png" nil nil :ascent 'center :max-height 512))
>> >>        (make-local-variable 'image-map)
>> >>        (define-key image-map (kbd "<mouse-1>") 'org-open-at-point))
>> >>      #+end_src
>> >
>> > On my side, the put-text-property does have center-line.
>> > But only when buffer is in Org mode.
>> > Yet, it is not Org's fault.
>> >
>> > The reason you are seeing the horizontal line is org-link face.
>> > org-link has underline. And the "center" line you are seeing is actually
>> > underline coming from the face. I'd say it is emacs bug.
>> 
>> Thanks very much for figuring out this issue, Ihor.
>> 
>> I see, I originally post this issue on Emacs-help mailing list, Eli let
>> me forward this thread to Org mode mailing list. Now I need to forward
>> to Emacs-devel mailing list.
>> 
>> In case the background info is missing, link original message here:
>> 
>> https://list.orgmode.org/87mtae2718.fsf@localhost/T/#m35d40f37fdf80f413ddb8d40e3017a6f102651e9
>
> Please report this as a bug, with "M-x report-emacs-bug", and please
> include there all the details, including the recipe to reproduce the
> issue.
>
> Thanks.


-- 

[ stardiviner ]
I try to make every word tell the meaning that I want to express without misunderstanding.

Blog: https://stardiviner.github.io/
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Re: [CLOSED] text-property displayed image has a center-line when the text face has underline attribute

[Ihor Radchenko]

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On Sun, Oct 2, 2022 at 6:51 PM Christopher M. Miles <numbchild@gmail.com>
wrote:

>
> I hate to rewrite those steps more than 3 times. But I also know Emacs
> contributors should not be forced to fix bug for me. Also I can't fix
> this bug by myself. So I think it's not a bug, I can tolerate this
> center line. Maybe I mastered skill for modify code in Emacs, I might
> come back to fix this bug by myself. But now, let me close it. I'm not
> hating anybody, just hate this process. Thanks for checking out.
>
> Come on.

1. find an image file in your system
2. emacs -Q
3. M-: (erase-buffer)
4. Insert "askdjaklsdj lasasd"
5. M-: (require 'org)
6. M-x font-lock-mode
7. M-: (put-text-property (point-min) (point-max) 'face 'org-link)
8.  M-: (put-text-property (point-min) (point-max) 'display (create-image
"/path/to/image" nil nil :ascent 'center :max-height 512))

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Re: [CLOSED] text-property displayed image has a center-line when the text face has underline attribute

[Eli Zaretskii]

> From: "Christopher M. Miles" <numbchild@gmail.com>
> Cc: numbchild@gmail.com, yantar92@gmail.com, emacs-devel@gnu.org,
>  emacs-orgmode@gnu.org
> Date: Sun, 02 Oct 2022 18:45:41 +0800
> 
> I hate to rewrite those steps more than 3 times.

The problem is, I've read the correspondence on the Org list, and I
still don't understand what are the steps needed, that don't require
the extra Org package.  That is why I( asked for the details: so that
the bug tracker could have them clearly and unambiguously.

I do want to look into the issue and see if there's anything that
needs to be fixed in Emacs.

> But I also know Emacs
> contributors should not be forced to fix bug for me. Also I can't fix
> this bug by myself. So I think it's not a bug, I can tolerate this
> center line. Maybe I mastered skill for modify code in Emacs, I might
> come back to fix this bug by myself. But now, let me close it. I'm not
> hating anybody, just hate this process. Thanks for checking out.

I'm sorry you feel like that.  Perhaps Ihor or someone else could fill
in the blanks and allow us to investigate.

Thanks.

Re: [CLOSED] text-property displayed image has a center-line when the text face has underline attribute

[Eli Zaretskii]

> From: Ihor Radchenko <yantar92@gmail.com>
> Date: Sun, 2 Oct 2022 18:57:56 +0800
> Cc: Eli Zaretskii <eliz@gnu.org>, emacs-devel@gnu.org, emacs-orgmode@gnu.org
> 
> 1. find an image file in your system
> 2. emacs -Q
> 3. M-: (erase-buffer)
> 4. Insert "askdjaklsdj lasasd"
> 5. M-: (require 'org)
> 6. M-x font-lock-mode
> 7. M-: (put-text-property (point-min) (point-max) 'face 'org-link)
> 8.  M-: (put-text-property (point-min) (point-max) 'display (create-image
> "/path/to/image" nil nil :ascent 'center :max-height 512))

Thanks.

This is because of the ":ascent 'center" part, isn't it?

What would you want Emacs to do instead in this case?

Re: [CLOSED] text-property displayed image has a center-line when the text face has underline attribute

[Ihor Radchenko]

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>
> This is because of the ":ascent 'center" part, isn't it?
>
I guess so. The image bottom is below the text baseline and thus the
underline cuts through the image.


> What would you want Emacs to do instead in this case?
>

I do understand how Emacs renders what we get here from the perspective of
glyph composition. Putting underline over the glyph does make sense in many
cases. However, it is clearly not expected in this specific scenario of a
bitmap image.

I think that it could be useful to allow images to be drawn "on top" of the
underlines, cross-lines, etc.

Best,
Ihor

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Re: [CLOSED] text-property displayed image has a center-line when the text face has underline attribute

[Christopher M. Miles]

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Eli Zaretskii <eliz@gnu.org> writes:

>> From: "Christopher M. Miles" <numbchild@gmail.com>
>> Cc: numbchild@gmail.com, yantar92@gmail.com, emacs-devel@gnu.org,
>>  emacs-orgmode@gnu.org
>> Date: Sun, 02 Oct 2022 18:45:41 +0800
>> 
>> I hate to rewrite those steps more than 3 times.
>
> The problem is, I've read the correspondence on the Org list, and I
> still don't understand what are the steps needed, that don't require
> the extra Org package.  That is why I( asked for the details: so that
> the bug tracker could have them clearly and unambiguously.
>
> I do want to look into the issue and see if there's anything that
> needs to be fixed in Emacs.
>
>> But I also know Emacs
>> contributors should not be forced to fix bug for me. Also I can't fix
>> this bug by myself. So I think it's not a bug, I can tolerate this
>> center line. Maybe I mastered skill for modify code in Emacs, I might
>> come back to fix this bug by myself. But now, let me close it. I'm not
>> hating anybody, just hate this process. Thanks for checking out.
>
> I'm sorry you feel like that.  Perhaps Ihor or someone else could fill
> in the blanks and allow us to investigate.
>
> Thanks.

No, it's my personal character and feeling caused this behavior. Not
your fault. I really don't blame anybody.

In bellowing Ihor's email wrote the reproduce steps. Thanks very much Ihor.

-- 

[ stardiviner ]
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Blog: https://stardiviner.github.io/
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[SOLVED] Re: [CLOSED] text-property displayed image has a center-line when the text face has underline attribute

[Christopher M. Miles]

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Eli Zaretskii <eliz@gnu.org> writes:

>> From: Ihor Radchenko <yantar92@gmail.com>
>> Date: Sun, 2 Oct 2022 18:57:56 +0800
>> Cc: Eli Zaretskii <eliz@gnu.org>, emacs-devel@gnu.org, emacs-orgmode@gnu.org
>> 
>> 1. find an image file in your system
>> 2. emacs -Q
>> 3. M-: (erase-buffer)
>> 4. Insert "askdjaklsdj lasasd"
>> 5. M-: (require 'org)
>> 6. M-x font-lock-mode
>> 7. M-: (put-text-property (point-min) (point-max) 'face 'org-link)
>> 8.  M-: (put-text-property (point-min) (point-max) 'display (create-image
>> "/path/to/image" nil nil :ascent 'center :max-height 512))
>
> Thanks.
>
> This is because of the ":ascent 'center" part, isn't it?
>
> What would you want Emacs to do instead in this case?

I checked out the docstring of `create-image' have not found related
info about `:ascent'. Today (which is after some days) I review this
problem and searched the `:ascent' in emacs info manual, found this
property explanation. I set it to `:ascent 100` solved the problem. Now
the baseline is at the bottom of image.

Thanks a lot for pointing it out which fixed a big issue of my extension code.

-- 

[ stardiviner ]
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