Aligns polyfill with spec changes.

Initial value of lastReportedSize changed from 0, 0 to -1, -1 allowing for consistent notifications to be triggered when an element is observed for the first time.

const el = document.createElement('div');
const ro = new ResizeObserver(() => { ... });
ro.observe(el); // Will now notify with size `0, 0`.

https://github.com/w3c/csswg-drafts/issues/3664#issuecomment-1218270926

• Fixes an issue where isElement sometimes returns false on elements within an iFrame. Thanks @JayaKrishnaNamburu!

• Reports readonly ResizeObserverSize[] to the observer callback
• Exposes ResizeObserverSize

• Fixes issue where calling disconnect would prevent the observer from being used to observe again (#104).
• Uses time instead of frame counts to capture certain events.
• Replaces Map with WeakMap

• Fixes issue with older versions of chromium. No notifications were fired due to differences in MutationObserver implementation.

Tested: Chromium 45.0.2454.0 (64-bit)

• Add missing device-pixel-content-box option to readme.

• Fixes issue where elements observed inside of an IFrame could not be unobserved.

• Support observing elements from other documents (#97)
• Adds ResizeObserverEntry.toJSON()

const elFromIFrame = iframe.contentDocument.querySelector('body');
const ro = new ResizeObserver(() => {
 ...
});
ro.observe(elFromIFrame);

• Removed next tag
• Tagged in npm as latest

Updates library to follow the latest specification. This includes some breaking changes from 2.x.

Breaking changes from 2.x:

• Updates ResizeObserverEntry to return a sequence of sizes, for future fragment support (#84)
• Removes default exports and now returns ResizeObserver and ResizeObserverEntry

Notable improvements:

• Adds UMD bundle for SSR and other CJS loaders (Jest)
• Adds new box option device-pixel-content-box (#85)
• Observes CSS box of root SVG elements (#72)

Other improvements:

• Fix circular dependency - thanks @kei-ito!
• Fix this rewritten to undefined warning in rollup.

• Adds type=module to package.json.
• Adds types field to package.json to explicitly locate declaration files.
• Improves TypeScript usage, when setting observer box option.
• Improvements to readme.

• Removes RAF overrides
• Uses micro tasks to schedule recalculations

• Adds safe global object
• Removes window references
• Supports loading of library in non-browser environments

• Remove IE transpilation wording from readme

This version includes fixes for many of the Web Platform Tests and pre-transpiles code so that no polyfills or conversion is needed for IE11 and other older browsers.

• No longer observes non-replaced inline elements (#57).
• Supports different writing modes and returns correct values for inline/block sizes (#59).
• Scope change: observer.callback.this = observer (#58).
• Library is now pre-transpiled to ES5. Modules are still ESM (#39).

• Add module field to package.json

• Republished version to npm as lib folder was missing. Thanks to @mvsde for spotting this!

Update the shape of the ResizeObserverEntry to match the latest version of the spec.

entry = {
  target: <element>,
  contentRect: { /* v1 backwards compat */ },
  borderBoxSize: { inlineSize, blockSize },
  contentBoxSize: { inlineSize, blockSize }
}

• Removes support for scroll-box.
• Removes support for device-pixel-border-box. This will be added when/if defined in the spec.
• Updates contentSize to contentBoxSize.

Fixes issues where animations/transitions were not initially being noticed.

• Update box demo link in docs.

• Fixes an issue that was introduced in v1.1.0 where calculations couldn't initially be scheduled if a requestAnimationFrame loop was being used.

This version improves animation and transition event performance, by removing listeners during processing and calculation checks.

• Updated docs to include box demo
• Description and keywords updated for npm

• Fixes issue with resize loop errors on element removal.
• Adds scrollbar width support, enabling correct size information when element has scrollbars.
• Improves function names for debugging.

• Removes inline default exports

• Throws type errors for arguments.
• Modifies requestAnimationFrame to fire observations at the correct time.
• Fixes #6, #16 and #28

• Removed ./src folder from npm release

• Code styling rules applied
• Added explicit license

Fixes:

• Support adding script in head of document

Includes fixes for: #11, #12, #13

• Tests separated out into groups
• Test coverage for initial observations in different element states

Supports latest draft specification https://drafts.csswg.org/resize-observer-1

• Supports observing different box sizes