It turns out in CSS 3D, the order in which you specify for example
the rotateX(), rotateY() and rotateZ() transformations matter.
Each rotation is relative to the objects then-current position.
Impress.js being hardwired to always do rotateX->rotateY->rotateZ
was therefore limiting, and in fact there are some positions that
can never be reached with an xyz order. The new data-rotate-order=""
attribute allows to specify the order as a permutation of the 3
letters x, y, z, thus relaxing this limitation.
See http://openlife.cc/blogs/2016/october/3d-rotations-css-and-impressjs
for (much) more details.
Unlike impress:stepenter, we emit impress:steprefresh event also
when the "entered" step is the current step. This allows plugins
to reload or redraw objects if needed.
(Note that resize plugin already calls goto() on the active element
for similar purposes when it sees a window resize event. Emitting
impress:steprefresh allows other plugins to join in such a refresh,
and also others can call goto() if a refresh is needed.)
The Mobile plugin adds CSS classes body.impress-mobile and
div.prev, div.next. These can be used in CSS to hide non-active
steps completely, in order to reduce memory consumption on
small mobile devices.
This allows plugins to register to be executed at the beginning of
impress().init() and impress().goto() respectively. By returning false,
a plugin can also cancel the event.
Also adds 3 plugins that use this: rel, goto and stop.
- Libraries are under src/lib/
- Added to build.js as usual, before plugins.
- See src/lib/README.md for details
gc library implements a "garbage collector" library, which allows
both the core and plugins to store elements and listeners to a list,
and when impress().lib.gc.teardown() is called, to have all of them
removed from the DOM. It also allows plugins to register their own
callback functions, which are called at teardown.
Commentary:
This work is based on copying the src/lib/gc.js from impressionist. While it was
useful, it turns out on the impress.js side there was much more a need to reset
attributes rather than delete elements. For now, this means lots of plugins do this
via their own lib.gc.addCallback() functions. Probably it would be nicer to add
some generic lib.gc.resetAttributes() functionality for this particular case.
I'll return to this in a future patch.
extras/ are not supported for impress().tear(). What can I say, they're extras.
Maybe in the future I'll support them, for now I can live without.
* Source files are under src/
* js/impress.js is now generated, but remains part of the repo (so it just works)
* npm run build
* build.js uses buildify node module
* Break out navigation and resize plugins from core src/impress.js file
Henrik Ingo