# Dynamic performance issues related to Pane's ResizeArea

we can use DynamicModule's variables to reduce the time spent on updating GUI elements as they are owned by the FrontEnd and it does not have call Kernel to get their values.

Let's extend example given in that tutorial

DynamicModule[{x = 0}, Table[Slider[Dynamic[x]], 500]]


to show a feature I'm struggling with:

Synchronized Panes' sizes get hickups when changed via "ResizeArea"

    DynamicModule[{x = {100, 100}},
Table[
Pane[
Slider2D[Dynamic[x], {100, 200}], ImageSize -> Dynamic[x],
AppearanceElements->"ResizeArea"
],
1000
]
]


Resizing with Slider2D works smoothly.

Maybe it is not a major issue here, for 100 panes, but it also affect lower amount of panes with more complicated Dynamic content. This was just easier to show.

Can this be fixed or resized differently?

Maybe not a bug but something worth investigation:

CASE:3698549

[...] I reproduced the same issue on my machine. [...] I have forwarded an incident report to our developers with the information you provided. [...]

• I cannot reproduce this problem in 10.1.0 under Windows 7 x64. – Mr.Wizard Aug 29 '16 at 16:33
• @Mr.Wizard what if you increase number of panes to e.g. 1100? – Kuba Aug 29 '16 at 16:45
• I had to use Table[..., 5000] to get behavior as sluggish as what your .GIF appears to show. However at that point moving the Slider2D is equally sluggish. Example (2) has no apparent lag on my system. – Mr.Wizard Aug 29 '16 at 23:57
• @Mr.Wizard Those standalone cases don't seem real word cases but I think thay are the cause of the problems I have with single Pane resizing with Dynamic content. p.s. the second one is now off topic since the reason why FE calls the Kernel is it can't display a list alone, x[[1]] is fine because it is a number. – Kuba Aug 30 '16 at 6:22