Bug 154015 - Mark selected object center on rulers
Summary: Mark selected object center on rulers
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Impress (show other bugs)
Version:
(earliest affected)
Inherited From OOo
Hardware: All All
: medium enhancement
Assignee: Not Assigned
URL:
Whiteboard:
Keywords:
Depends on:
Blocks: Rulers Shapes
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Reported: 2023-03-06 15:59 UTC by Eyal Rozenberg
Modified: 2023-05-25 10:21 UTC (History)
3 users (show)

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Crash report or crash signature:


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Description Eyal Rozenberg 2023-03-06 15:59:08 UTC
When we select an object in Impress/Draw, we see its X and Y axis boundaries on the rulers. It would be useful if we also saw an indication of its center. 

The indication could be a single line or a double line as is used for the object boundaries.
Comment 1 Heiko Tietze 2023-03-07 11:43:14 UTC
Why do you need the center? Something like "I want to position the rectangle exactly at..." makes not much sense for the center.
Comment 2 Eyal Rozenberg 2023-03-07 16:50:39 UTC
(In reply to Heiko Tietze from comment #1)
> Why do you need the center? Something like "I want to position the rectangle
> exactly at..." makes not much sense for the center.

I want to position my shape so that its center is exactly at some point, e.g. 5 cm away from the page edge, or 2 cm away from center of another shape.
Comment 3 Heiko Tietze 2023-03-07 21:12:43 UTC
(In reply to Eyal Rozenberg from comment #2)
> (In reply to Heiko Tietze from comment #1)
> > Why do you need the center? Something like "I want to position the rectangle
> > exactly at..." makes not much sense for the center.
> 
> I want to position my shape so that its center is exactly at some point,
> e.g. 5 cm away from the page edge, or 2 cm away from center of another shape.

That's not an explanation, it just repeats the wish.

In other words, it makes a lot of sense to show the edges of the object to not exceed available space. Adding something nice-to-have without a good reason makes the use of existing functionality more difficult. Not to speak about effort, maintenance, follow-up issues...
Comment 4 Eyal Rozenberg 2023-03-07 21:36:05 UTC
(In reply to Heiko Tietze from comment #3)
> That's not an explanation, it just repeats the wish.

But it's literally what I want to do. I have a slide of a certain size, and sometimes I design aspects of it via a decision of where to put one or both of the edges of some objects, while sometimes I decide where to put the centers of objects.

> In other words, it makes a lot of sense to show the edges of the object to
> not exceed available space.

That does not actually make sense at all, since you can see _that_ by examining the slide / page edges. You want to see the edges on the ruler in order to _measure_, place them exactly.

> Not to speak about effort

Effort is likely very low, given the existing implementation for edges

> maintenance

How much maintenance have we expended on showing edges on rulers, since that feature was introduced? 

> follow-up issues...

Quite unlikely to have a followup issue about the center mark that isn't an issue about the edge marks.
Comment 5 V Stuart Foote 2023-03-07 22:42:07 UTC
I would suggest instead a modification to the Helplines guide. 

Marking the object center is helpful for some cases, but could be exposed via the helplines guide (perhaps a different line style). As they extend off canvas all the way to the rulers (vert and horiz) that is sufficient without having to overload the ruler UI.
Comment 6 Heiko Tietze 2023-05-16 10:02:47 UTC
Rather than fiddling around with the ruler, a flexible solution would be to not only define the base point regarding the object but also the page itself. This allows to define the x/y position from top-left (as today), bottom right (only negative values make sense here), and the center.
Comment 7 Eyal Rozenberg 2023-05-16 17:43:38 UTC
(In reply to Heiko Tietze from comment #6)

Heiko, it is rude to change the essence of a bug without discussing it with the reporter - especially when it's not even closed.

Also, if you're suggesting something which would solve an overlapping, but not identical, problem, and would do so in a different way - just open a new bug and suggest the old one be closed.

Changed the title back.

> Rather than fiddling around with the ruler, a flexible solution would be to
> not only define the base point regarding the object but also the page
> itself. 

But the user doesn't want to do something complex like that. They want to move the object - without any special prior planning - and when they do that, they may reasonably expect to see where the center will end up.

Changing objects' base points is an interesting meriting its own bug.

(In reply to V Stuart Foote from comment #5)

About helplines... 

* I don't think it's easier to implement center help-lines than to add a marker. Am I wrong?
* For the two edges, we have both the ruler marking and help-lines if you enable them. The center point is a stronger candidate to get both of these, since, the edges are more easy to extrude into lines in your mind.
* I'll open another bug about them :-)
Comment 8 Heiko Tietze 2023-05-17 05:54:14 UTC
-1 from my side for a special handling of the ruler. Plus, centering an object is easily done per Align Objects (see also bug 154025).
Comment 9 Eyal Rozenberg 2023-05-17 06:27:03 UTC
(In reply to Heiko Tietze from comment #8)
>  Plus, centering an
> object is easily done per Align Objects (see also bug 154025).

So is aligning the left and right edges of the shape...
Comment 10 V Stuart Foote 2023-05-17 06:43:17 UTC
Would really prefer to keep the overloading of the ruler to a minimum, showing object center via the help guides would be a better use of dev effort.

-1 from me as well.
Comment 11 Telesto 2023-05-17 09:18:26 UTC
(In reply to V Stuart Foote from comment #5)
> I would suggest instead a modification to the Helplines guide. 

It's indeed a Grid and Helplines kind of feature, IMHO. If we assume it is, how should it be implemented..

* Show a center marking by a new uno-command placed under Grid and Helplines
* As part of snap to grid feature; snap to center 
* A new grid-line (distinct from the others) marking the horizontal/vertical center (bug 155361)

Note: this isn't specific Impress/Draw feature. It would also be of use in Writer (see bug 148128). Except in Writer the question is what is the center actually entails. The center of the page. Or center adjusted for page margins. 

---
Side-note: The amount of bug reports orbiting center markings appears (IMHO) to inflate because of the tendency to request detailed enhancement proposals. So the whole bug is closed, if if the suggestion implementation being unacceptable. The stubborn people will start posting multiple bugs with same in essence the same request, but different angles. 

In principle agree with the notion that 'center marking' is lacking. However I lack a concrete idea how :-)
Comment 12 V Stuart Foote 2023-05-17 14:51:23 UTC
(In reply to Telesto from comment #11)
bug 155361 should be duped here to become more generic workflow of alignment on object center.  Don't need a half dozen issues for the same UX design/workflow discussion.

@Hieko, pick a BZ issue and lets please take it through UX/Design process of handling by object centers in the UI
Comment 13 Heiko Tietze 2023-05-23 11:56:30 UTC
(In reply to V Stuart Foote from comment #12)
> @Hieko, pick a BZ issue and lets please take it through UX/Design process of
> handling by object centers in the UI

What do you expect given your -1 in comment 10 and mine in comment 8?
Comment 14 V Stuart Foote 2023-05-23 15:27:58 UTC
(In reply to Heiko Tietze from comment #13)
> (In reply to V Stuart Foote from comment #12)
> > @Hieko, pick a BZ issue and lets please take it through UX/Design process of
> > handling by object centers in the UI
> 
> What do you expect given your -1 in comment 10 and mine in comment 8?

My -1 here was to adding to the already over stressed menu given that there are other viable alternatives.

I think there is merit to providing indicator in UI of object centers, it just does not have to be on the rulers (although it could).  To keep the complexity of the ruler widgets under control, to me using the help guides in conjunction with dialog based object centering would suffice.

There are multiple BZ issues asking for UI visual indication of object center to use for positioning.  Suggestion was for a UX-advise driven effort to consolidate and move forward with an implementation guide for dev effort.
Comment 15 V Stuart Foote 2023-05-23 15:47:34 UTC
(In reply to V Stuart Foote from comment #14)

> over stressed menu 

s/menu/ruler/
Comment 16 Heiko Tietze 2023-05-24 09:03:00 UTC
What we can do is to show the center indicator on the ruler while moving. Alternatively a center cross overlaid at the document canvas (sd only) could also be helpful, although centering horizontally and vertically may move it out of sight. My preference for exact placement is still ti use the dialog and add some option there (see comment 6).
Comment 17 Eyal Rozenberg 2023-05-25 10:21:40 UTC
(In reply to Heiko Tietze from comment #16)
> What we can do is to show the center indicator on the ruler while moving.

Hmm... well, that's better than nothing. I would still like the center to be displayed always, but - if this would be implemented, I would not object to this bug being closed. Although if someone else asks for the full implementation, I would support that request.

> Alternatively a center cross overlaid at the document canvas (sd only)

sd? You mean Draw?

> could
> also be helpful, although centering horizontally and vertically may move it
> out of sight. My preference for exact placement is still ti use the dialog
> and add some option there (see comment 6).

I believe both dragging and placement via dialog should support attention the shape center.