reapplyCss() Is called too many times when adding a node hierarchy to the Scene
david.grieve at oracle.com
Fri Mar 11 22:33:50 UTC 2016
There is (was?) some code in Node or Parent that was supposed to prevent
Namely, I thought I had it so CSS was applied from the parent before
applying to the children.
It may also depend on how you add the nodes to the scene.
On 3/11/16 5:18 PM, Scott Palmer wrote:
> I think I've discovered a significant performance issue with CSS
> Adding a Node hierarchy to a Scene leads to
> javafx.scene.node.setScenes(Scene, SubScene) being called. This leads a
> walk down the Node hierarchy like so:
> -> invalidatedScenes
> -> scenesChanged
> -> setScenes // on child Nodes -- recursion
> -> impl_reapplyCSS()
> loops over children calling reapplyCss() on each - recursive
> The thing to note there is:
> * invalidatedScenes decides if it is going to call impl_reapplyCSS()
> * invalidatedScenes calls scenesChanged which calls setScenes on all
> children which leads to invalidateScenes being called recursively on the
> node hierarchy
> * invalidatedScenes calls impl_reapplyCSS()
> As the setScene call walks down the node hierarchy it gets to a leaf node
> and then calls impl_reapplyCSS() which will call reapplyCss() recursively.
> Since when reapplyCss() returns the cssFlag for the node will be set back
> to UPDATE, so when the parent calls impl_reapplyCSS() the CSS is
> recursively applied to the Nodes that just had CSS applied!
> Am I missing something?
> I made a quick test case where I add a VBox containing another VBox
> containing a Rectangle to the Scene when I press a button. I can confirm
> that reapplyCss() is called THREE times for the Rectangle, twice for the
> "middle" VBox, and once on the "top" VBox.
> Obviously the deeper the hierarchy the worse this gets.
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