Re: Catalina scroll view issues
Re: Catalina scroll view issues
- Subject: Re: Catalina scroll view issues
- From: Sandor Szatmari via Cocoa-dev <email@hidden>
- Date: Thu, 19 Dec 2019 07:26:38 -0500
Eyal,
> On Dec 19, 2019, at 02:55, Redler Eyal via Cocoa-dev
> <email@hidden> wrote:
>
>
>>
>> Since you’re using CoreGraphics, it’s very likely there’s an edge case with
>> your customers’ systems that you aren’t encountering. CG is pretty much the
>> lowest practical level in the graphics stack. Since your app does reproduce
>> the issue but in other configurations than yours, you could still add it,
>> but if you can include the system configuration data from About This Mac and
>> data files from those affected customers, as well as screen shots, it can
>> help. You might be asked for a sysdiagnose after the problem happens, so
>> consider asking your customers to provide that as well.
>
> OK, I'll try to get the sysdiagnose from my users before submitting. I must
> say I'm really skeptic regarding the relation with my use of CG. It is not
> that CG is not used by CT and everything else is also using CG.
CG may not be the issue… and I cannot offer a better suggestion, but when I
rule out a possibility without proof, it usually turns out that I over look the
solution to the problem. Good luck!
Sandor
> The way it looks it seems very much related to the scrolling mechanism, the
> pre-rendered portion is not rendered but for some reason the scrolling
> mechanism thinks that it is. I really don't see how a core-graphic issue, and
> certainly not a misuse on my part could cause a view to be partially rendered.
> BTW, do you think this type of issue is appropriate for a DTS incident?
>
>> Here’s the developer release notes for Catalina:
>> https://developer.apple.com/documentation/macos_release_notes/macos_catalina_10_15_release_notes
>
> Thanks. I saw that but I recall that in the past you used to have app-kit
> specific release notes which were usually more detailed.
>
>> As an aside, it would be helpful to know why you chose CG for text
>> rendering. CT has gotten better with RTL and bidi text, but if you saw
>> particular issues there, reports about those can help everyone.
>
> When I started developing this app (2002), there was no choice other then CG
> since core text didn't exist and the other technologies didn't support Hebrew
> and RTL well, if at all. So I wrote my own text engine and this was very good
> for me commercially as my app was the the first and only word-processor to
> support Hebrew (and later Arabic) properly on Max OS X. I had a similar
> experience with OpenType which was not initially supported and that also gave
> me an edge. As time passed Apple did improve the RTL support and was offering
> more APIs so theoretically I could have rewritten my code to use the new APIs
> but in reality I actually did the opposite and relied less on Apple's APIs
> (for example, parsing 'cmap' tables) because there were always bugs and even
> regressions which could render my app unusable upon an OS upgrade. Beyond the
> bugs, I think my RTL is better, or at least as far as I'm concerned as a
> native Hebrew speaker and having such low-level control over something that
> is core to my app is essential IMO.
>
> Eyal Redler
> ------------------------------------------------------------------------------------------------
> "If Uri Geller bends spoons with divine powers, then he's doing it the hard
> way."
> --James Randi
> www.eyalredler.com
>
>
>
>
>
>
>> Gary L. Wade
>> http://www.garywade.com/
>>
>>>> On Dec 17, 2019, at 2:12 AM, Redler Eyal <email@hidden> wrote:
>>>
>>> I am drawing using core graphics. I tried turning copiesOnScroll and this
>>> didn't seem to help.
>>>
>>> I'll gladly write a feedback report but I'm not able to reproduce this so I
>>> can't give an xcode project that will reproduce this... Isn't that a
>>> requirement?
>>>
>>> BTW, perhaps you know: Are there no release notes for app kit with
>>> Catalina? All I can find are very general notes without mention of any
>>> specific API. I could not find, for example, any mention of the deprecation
>>> of copiesOnScroll and what it means (is is not always on, always off etc)
>>>
>>> Thanks,
>>>
>>> Eyal
>>>
>>>> On 16 Dec 2019, at 16:07, Gary L. Wade <email@hidden>
>>>> wrote:
>>>>
>>>> If you’re not involving a higher level class like NSTextView or a medium
>>>> level one like CoreText, it sounds like you might be going all the way
>>>> down to CoreGraphics? If so, you might find your disparity between your
>>>> system and your users in things like retina choice for a particular
>>>> display and changes with respect to layers, especially things like the
>>>> copiesOnScroll. If these don’t lead you to a solution where you say, “Oh,
>>>> I really should’ve done this rather than that,” (20/20 hindsight) then
>>>> write up a feedback report and add its URL here.
>>>> --
>>>> Gary L. Wade
>>>> http://www.garywade.com/
>>>>
>>>>> On Dec 16, 2019, at 1:03 AM, Redler Eyal via Cocoa-dev
>>>>> <email@hidden> wrote:
>>>>>
>>>>> Thanks!
>>>>> I don't use CoreText or NSTextView. I pretty much ruled out RTL vs LTR
>>>>> issues since this is showing up in documents containing either and both.
>>>>> I'm also unable to imagine how some text drawing code could produce such
>>>>> artifacts as splitting a subview in the middle.
>>>>> (http://eyalredler.com/stuff/catalina_glitch.png)
>>>>>
>>>>> Eyal
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>> On 14 Dec 2019, at 21:20, Gary L. Wade <email@hidden>
>>>>>> wrote:
>>>>>>
>>>>>> I see from your personal web site you know Hebrew. Is it possible the
>>>>>> affected/non-drawing pages contain some RTL text while those that don’t
>>>>>> only contain LTR? I have seen some bugs with RTL text within NSTextView
>>>>>> where the text was/wasn’t drawing in a similar manner. Do you operate at
>>>>>> a CoreText level?
>>>>>> --
>>>>>> Gary L. Wade
>>>>>> http://www.garywade.com/
>>>>>>
>>>>>>>> On Dec 14, 2019, at 6:17 AM, Redler Eyal via Cocoa-dev
>>>>>>>> <email@hidden> wrote:
>>>>>>>
>>>>>>> Hi All,
>>>>>>>
>>>>>>> I'm getting reports from users complaining about a strange display
>>>>>>> issue on Catalina with my app.
>>>>>>> My app is a word-processor (not based on the cocoa text system) whose
>>>>>>> main display shows the pages of the document. Every page is a separate
>>>>>>> view and all the pages are subviews of one big view which resides
>>>>>>> inside a scroll view.
>>>>>>>
>>>>>>> The problem is that when with some documents, sometimes, when the user
>>>>>>> scrolls down the document, some pages are not drawn or even partially
>>>>>>> drawn. When the user clicks the place where the page is supposed to
>>>>>>> appear, it shows up.
>>>>>>> Another interesting bit is seems that while the scroll view background
>>>>>>> is drawn, the document views (the view containing the page views)
>>>>>>> drawRect is not called or at least not taking effect, I can tell
>>>>>>> because the pages on this view cast a shadow which is drawn by drawing
>>>>>>> blank squares on the document view with a transparency layer.
>>>>>>> Last bit of info, copiesOnScroll set to NO for this view and I see that
>>>>>>> this property is deprecated on Catalina.
>>>>>>>
>>>>>>> So far I'm struggling with this for a couple of weeks, I wasn't able to
>>>>>>> reproduce this at all on my machine.
>>>>>>> I'm really desperate for an answer and while I'm not expecting anyone
>>>>>>> here to provide me with one (wouldn't object, of course :-)) I would
>>>>>>> love if people reading this might try to speculate to the causes of
>>>>>>> this or perhaps if you have any direction as to what to test on my
>>>>>>> users machines in order to be able to reproduce this.
>>>>>>>
>>>>>>> Thanks
>>>>>>>
>>>>>>> Eyal Redler
>>>>>>> ------------------------------------------------------------------------------------------------
>>>>>>> "If Uri Geller bends spoons with divine powers, then he's doing it the
>>>>>>> hard way."
>>>>>>> --James Randi
>>>>>>> www.eyalredler.com
>>>>>>
>>>>
>>>
>
>
>
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