This fix causes several unit tests to fail.
________________________________
From: David Grieve <david.gri...@microsoft.com>
Sent: Tuesday, March 10, 2020 12:48 PM
To: David Grieve <david.gri...@microsoft.com>; Danny Gonzalez
<danny.gonza...@screamingfrog.co.uk>
Cc: openjfx-dev@openjdk.java.net <openjfx-dev@openjdk.java.net>
Subject: RE: JDK-8177945 : Single cell selection flickers when adding data to
TableView
The flickering is happening because of the way VirtualFlow reuses cells. The
selected state gets cleared and reset, which is the flicker.
This change fixed the flickering for me. I'm not sure why the index of a cell
was being set to -1, but the effect of doing so is that when the
cell is pulled out of the pile, it looks like a new cell that has to have its
index set, selected state set, etc, etc. By commenting out the
updateIndex(-1), VirtualFlow can reuse the cell - setting the index, selected
state, etc turns into noops (more or less).
Again, there may have been a good reason for setting index to -1 in this
condition. More investigation needs to be done.
diff --git
a/modules/javafx.controls/src/main/java/javafx/scene/control/skin/VirtualFlow.java
b/modules/javafx.controls/src/main/java/javafx/scene/control/skin/VirtualFlow.java
index 728e7c5513..a58859bd05 100644
---
a/modules/javafx.controls/src/main/java/javafx/scene/control/skin/VirtualFlow.java
+++
b/modules/javafx.controls/src/main/java/javafx/scene/control/skin/VirtualFlow.java
@@ -991,9 +991,9 @@ public class VirtualFlow<T extends IndexedCell> extends
Region {
lastWidth = -1;
lastHeight = -1;
releaseCell(accumCell);
- for (int i = 0, max = cells.size(); i < max; i++) {
- cells.get(i).updateIndex(-1);
- }
+// for (int i = 0, max = cells.size(); i < max; i++) {
+// cells.get(i).updateIndex(-1);
+// }
addAllToPile();
releaseAllPrivateCells();
} else if (needsReconfigureCells) {
> -----Original Message-----
> From: openjfx-dev <openjfx-dev-boun...@openjdk.java.net> On Behalf Of
> David Grieve
> Sent: Friday, March 6, 2020 9:29 AM
> To: Danny Gonzalez <danny.gonza...@screamingfrog.co.uk>
> Cc: openjfx-dev@openjdk.java.net
> Subject: RE: JDK-8177945 : Single cell selection flickers when adding data to
> TableView
>
> This might fix the issue, but I’d like to understand better what the root of
> the
> problem is. My concern is that this fix might cause a performance regression.
> I’m using the code in JDK-8177945. I want to look at what TableView does
> when it adds a cell. Is there something about the selected state that
> changes? Or is this just the CSS implementation recalculating styles and un-
> necessarily clearing old values? Some debugging is in order.
>
> From: Danny Gonzalez <danny.gonza...@screamingfrog.co.uk>
> Sent: Wednesday, March 4, 2020 4:34 AM
> To: David Grieve <david.gri...@microsoft.com>
> Cc: openjfx-dev@openjdk.java.net
> Subject: [EXTERNAL] Re: JDK-8177945 : Single cell selection flickers when
> adding data to TableView
>
> Hi David,
>
> Just wanted to add some more information.
>
> The cell selection flashing issue goes away If I put back the following code
> in
> the layout function in Parent.java:
>
> //
> // One idiom employed by developers is to, during the layout
> pass,
> // add or remove nodes from the scene. For example, a
> ScrollPane
> // might add scroll bars to itself if it determines during
> layout
> // that it needs them, or a ListView might add cells to
> itself if
> // it determines that it needs to. In such situations we must
> // apply the CSS immediately and not add it to the scene's
> queue
> // for deferred action.
> //
> // Note that we only call processCSS if the flag is update.
> If the
> // flag is DIRTY_BRANCH, then the whatever children need
> UPDATE
> // will be visited during this layout anyway. On the next
> pulse,
> // doCSSPass will clean up the DIRTY_BRANCH nodes.
> //
> if (cssFlag == CssFlags.UPDATE) {
> processCSS();
> }
>
> This code was originally added in in the following commit:
>
> commit e76b5755d4d2752037cc95eb75cb2615a740cc30
> Author: David Grieve
> <dgri...@openjdk.org<mailto:dgri...@openjdk.org>>
> Date: Thu Apr 10 15:40:34 2014 -0400
>
> RT-36559: Some css optimizations: 1 - on impl_reapplyCSS, do not reapply
> css to child nodes if nothing has changed. 2 - on applyCss, only look for
> ancestor node with css state = UPDATE. 3 - only recalculate checksum of css
> file if the file has been removed from a scene or parent
>
>
> It was reverted out in this commit:
>
> commit 05afad6b528e871d607b76aea2642cf788b417fe
> Author: David Grieve
> <dgri...@openjdk.org<mailto:dgri...@openjdk.org>>
> Date: Tue Apr 15 11:51:38 2014 -0400
>
> RT-36672: move code to process css during layout back to impl_reapplyCSS,
> which is where it was priort to RT-36559
>
>
>
>
> This was the point at which the cell selection flashing appeared.
>
>
> Thanks
>
>
> Danny
>
>
>
> On 3 Mar 2020, at 16:50, David Grieve
> <david.gri...@microsoft.com<mailto:david.gri...@microsoft.com>>
> wrote:
>
> The importance of 05afad6 Is there in the commit itself:
>
> + //
> + // One idiom employed by developers is to, during the layout pass,
> + // add or remove nodes from the scene. For example, a ScrollPane
> + // might add scroll bars to itself if it determines during layout
> + // that it needs them, or a ListView might add cells to itself if
> + // it determines that it needs to. In such situations we must
> + // apply the CSS immediately and not add it to the scene's queue
> + // for deferred action.
> +
>
> If you revert 05afad6, you'll break this.
>
> This is the first time I've become aware of this flickering issue. I'll have
> to look
> at it.
> I wonder if the fix for
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugs.openjdk.java.net%2Fbrowse%2FJDK-&data=02%7C01%7CDavid.Grieve%40microsoft.com%7C037e24d8c7a04b55302908d7c512db63%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637194557096877039&sdata=SVf8aTwumI0cSp8WQExMJaXZRV7JVxywHXqYt6ye4gI%3D&reserved=0
> 8193445<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2
> F%2Fbugs.openjdk.java.net%2Fbrowse%2FJDK-
> 8193445&data=02%7C01%7CDavid.Grieve%40microsoft.com%7C9148c860ff5
> 24a32ac3208d7c01f2523%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%
> 7C637189112753556661&sdata=mZrjldSw%2Fjbd0ita58XMU%2BaKM2GlvObq
> 3aaQmQb5Poc%3D&reserved=0> has any impact on this.
>
>
> -----Original Message-----
> From: openjfx-dev <openjfx-dev-
> boun...@openjdk.java.net<mailto:openjfx-dev-
> boun...@openjdk.java.net>> On Behalf Of Danny Gonzalez
> Sent: Tuesday, March 3, 2020 11:14 AM
> To: openjfx-dev@openjdk.java.net<mailto:openjfx-dev@openjdk.java.net>
> Subject: [EXTERNAL] JDK-8177945 : Single cell selection flickers when adding
> data to TableView
>
>
> There is currently an open bug to do with the issue of selection flickering
> when using single cell selection and when adding data to a TableView.
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugs
> .java.com%2Fbugdatabase%2Fview_bug.do%3Fbug_id%3D8177945&da
> ta=02%7C01%7Cdavid.grieve%40microsoft.com%7C91a16d9ab05340719f3008
> d7bf8e3410%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C63718848
> 9816399816&sdata=wdPRh3VnN%2BfJw%2BatKOyBi9%2Ba2%2FidMJJb
> 8AwcRXVrfLo%3D&reserved=0
>
> This bug seems to be low priority because it hasn’t been looked at since I
> submitted it at the start of 2017.
>
> This is quite a major issue for us so I have narrowed down when the issue
> was first introduced.
>
> Here is the changeset:
>
> commit 05afad6b528e871d607b76aea2642cf788b417fe
> Author: David Grieve
> <dgri...@openjdk.org<mailto:dgri...@openjdk.org<mailto:dgrieve@open
> jdk.org%3cmailto:dgri...@openjdk.org>>>
> Date: Tue Apr 15 11:51:38 2014 -0400
>
> RT-36672: move code to process css during layout back to impl_reapplyCSS,
> which is where it was priort to RT-36559
>
>
> I can’t search the bug database for this bug ID as I believe it was submitted
> when a previous bug tracking system was in use.
>
> Does anyone have any knowledge as to why this fix was needed and what
> the repercussions would be if I reverted it out for our local OpenJFX build.
>
> Alternatively I would be glad to receive any suggestions of how to fix the
> flickering issue if this changeset is important to leave in.
>
> Thanks
>
> Danny
