Previously, the start time for a transition could be slightly different for
different elements, even when the transition was created at the same time. This
commit allows timers to be created with an explicit reference time (then),
allowing a transition to be temporaly consistent across elements.
They weren't being invoked with the correct syntax (being passed the data and
index, with the current node as the context). This commit also removes the
d3_array wrapper, which does not appear to be necessary; I've forgotten why it
was there in the first place.
This also fixes a few bugs in the new implementation, restoring support for the
offset between the mouse and the dragged element by reporting a delta rather
than an absolute offset. Also, this fixes an infinite loop when an element is
removed from the DOM.
I'm including the axis component in the core build because it should be useful
in many different visualization types, similar to the other svg components. The
chart module contains a hodgepodge of more obscure visualization types, and
there's no reason to pull those in for more common visualizations. Perhaps most
importantly, the axis component isn't a chart type!
This means that you can now extend D3's selections and transitions with custom
functionality! Also, you can use now instanceof to see whether something is an
instanceof d3.selection or d3.transition.
Also fix a bug where it would be possible for an earlier to transition to become
the lock owner. We now guarantee that the lock owner can only increase while
transitions are scheduled on an element.
This caught a couple bugs in the previous commit. First, I wasn't sending the
correct index (i) to the "end" event listeners, because it was being masked by
a local variable. Second, the transition lock was being incorrectly deleted when
a transition is inherited on the same node and there is zero delay and
d3.timer.flush is called. There was potentially a related bug where the active
field was not being cleared on the transition lock. Yay tests!
This changes the core implementation of selections and transitions to use
prototype injection rather than direct extension. This offers better performance
by eliminating per-instance overhead from closures and assignment. On browsers
that don't support prototype injection, we fall back to direct extension.
This commit isn't just about performance, though; the code ends up being a lot
cleaner and more separable if we force methods to rely solely on `this`, rather
than capturing surrounding variables with closures.
Most importantly, transitions are now "transparent", like selections. Rather
than opaque objects, transitions are now arrays of nodes, similar to selections.
The nodes are wrapped in an object that stores the delay and duration, which
means you can now inspect the computed delay and duration. (This was the
original motivation for this commit, and will allow chart components to be
call'd on transitions as well as selections.)
Transitions now support the `each` operator with one argument, which has the
same behavior as on selections. The `each` operator now passes a third argument
containing the group index (`j`). Transitions now also support a `tween`
operator, which is a generic mechanism for doing things during a transition; use
this in place of a "tick" event.
This commit also fixes a few bugs. The enter selection now supports the empty
operator; we can add other operators in the future more easily, if we so choose.
Transition's attr operator now supports namespaced attributes. Selection's
property operator no longer parses property namespaces.
This returns a copy of the scale, such that future modifications to the scale's
domain or range (or other attributes) are isolated from the copy. This is useful
for transitions where you may want to make a copy of a scale before it changes,
such that entering elements can be initialized using the previous copy.
Mike Bostock
Jason Davies