> When the initial value of a styleable property is not specified in a
> stylesheet, no transition is started:
>
> .button {
> transition: -fx-opacity 1s;
> }
>
> .button:hover {
> -fx-opacity: 0.5;
> }
>
> The expected behavior is that a transition is started in this case, since the
> default value of `-fx-opacity` is 1.
>
> The reason for this bug is that `StyleableProperty` implementations do not
> start a CSS transition when the value is applied for the first time. The
> intention behind this is that a node that is added to the scene graph should
> not start transitions. CSS transitions should only be started _after_ the
> node has been shown for the first time.
>
> The logic to detect this situation is currently as follows:
>
> // If this.origin == null, we're setting the value for the first time.
> // No transition should be started in this case.
> TransitionDefinition transition = this.origin != null && getBean()
> instanceof Node node ?
> NodeHelper.findTransitionDefinition(node, getCssMetaData()) : null;
>
>
> However, this does not work. When no initial style is specified in the
> stylesheet, `this.origin` will not be set, and thus no transition will be
> started even after the node has been shown. The new logic works like this:
>
> A `Node.initialCssState` flag is added. Initially, this is `true`. Manually
> calling `applyCss` or similar methods will not clear this flag, as we
> consider all manual CSS processing to be part of the "initial CSS state".
> Only at the end of `Scene.doCSSPass` will this flag be cleared on all nodes
> that have expressed their interest. This mechanism ensures that a node will
> be eligible for CSS transitions only after the following conditions have been
> satisfied:
> 1. The node was added to a scene graph
> 2. CSS processing was completed for a scene pulse
Michael Strauß has updated the pull request with a new target base due to a
merge or a rebase. The incremental webrev excludes the unrelated changes
brought in by the merge/rebase. The pull request contains three additional
commits since the last revision:
- Merge branch 'master' into fixes/css-initial-value
- use HashSet instead of IdentityHashMap
- start transitions only when not in initial CSS state
-------------
Changes:
- all: https://git.openjdk.org/jfx/pull/1607/files
- new: https://git.openjdk.org/jfx/pull/1607/files/261da3b8..819952a4
Webrevs:
- full: https://webrevs.openjdk.org/?repo=jfx&pr=1607&range=02
- incr: https://webrevs.openjdk.org/?repo=jfx&pr=1607&range=01-02
Stats: 13037 lines in 311 files changed: 4863 ins; 6082 del; 2092 mod
Patch: https://git.openjdk.org/jfx/pull/1607.diff
Fetch: git fetch https://git.openjdk.org/jfx.git pull/1607/head:pull/1607
PR: https://git.openjdk.org/jfx/pull/1607
