* renames RoomTooltip to be a generic Tooltip (which it is)
* hooks it into Field to show validation results
* adds onValidate to Field to let Field instances call an arbitrary validation function
Rebased from @ara4n's https://github.com/matrix-org/matrix-react-sdk/pull/2550
by @jryans. Subsequent commits revise and adapt this work.
This allows Webpack to insert the proper image URL after builds steps like
adding a hash and so on. The path you supply to `require` is relative to the JS
source file, just like any other would be.
The benefits of this:
- One code path for determining spinner/placeholder and it's position
for loading images/stickers. This includes spinner used in e2e
decryption of images.
- Very small definition for MStickerBody, only overriding the minimal
differences is has from MImageBody.
The disadvantages:
- Slightly more complicated MImageBody, but hopefully not less
readable.
fixupHeight was the only thing actually fixing the size of the
sticker image to be the size we want it rather than the pixel size
of the image, and this was only getting run after the image loaded,
causing a flash of 2x image.
