0.4.0

implementation("com.timkrest:underlay:0.4.0")

Added

• liveSnapshot on blurredUnderlay. The host window is captured again every time it draws, one
  capture in flight at a time, so a list scrolling under a popup shows through blurred a couple of
  frames behind instead of frozen. Off by default: it costs a PixelCopy and a blur per host frame
  for as long as the host keeps drawing. SystemBlur is live on its own and ignores it.

Changed

• :sample opens its Popup without taking the touches outside it, so the grid scrolls under an
  open popup, and the panel carries a switch for the live snapshot.

0.3.1

implementation("com.timkrest:underlay:0.3.1")

Fixed

• SystemBlur was reported from the intent to set the window flag, not from the window taking it.
  A Popup whose root view had already left the window manager refused the update, and the overlay
  reported a system blur while the host stayed sharp behind it. A refusal now falls through to a
  snapshot, the same way a device with cross-window blur switched off does.
• On a host window whose width or height is not a multiple of four, PixelCopy captured the whole
  window into a bitmap that could not hold it at a flat quarter scale, while decorView.draw()
  scaled by exactly a quarter. Placement assumes the quarter, so on the PixelCopy path the
  backdrop was shifted, and the last one to three columns or rows of the window had none at all.
  Both paths now cover the largest exact quarter that fits.

Changed

• :sample carries the radius slider inside the overlay card as well as in the panel: a Dialog
  and a Popup swallow the touches outside them, which left re-blurring an open overlay
  unreachable. It also reports whether the device has cross-window blur at all, rather than only
  pointing at Battery Saver once an overlay had already reached SystemBlur.

0.3.0

implementation("com.timkrest:underlay:0.3.0")

Added

• UnderlayState.source: the UnderlaySource the overlay carrying the state draws from, as Compose
  state. Null while no overlay carries it, so a badge outside the overlay clears on dismiss without
  hosting the value from onSourceChange by hand. The callback stays for callers without a state.

Fixed

• The snapshot could spill up to three host pixels past the composable it backs, where its
  placement rounds out to whole snapshot pixels. It is now clipped to the composable.
• On API 31 and above with cross-window blur switched off, opening an overlay captured the host
  window twice: the initial callback of the blur listener repeated the choice start() had already
  made. The source is now chosen only when the system's answer changes.
• A detached node kept its Activity, Configuration and WindowManager until it was collected.

0.2.0

implementation("com.timkrest:underlay:0.2.0")

Added

• UnderlayState and rememberUnderlayState(), passed to Modifier.blurredUnderlay as state.
  refresh() captures the host window again, for content that moves underneath an open overlay.
  The snapshot on screen stays until the new one is ready, so a refresh does not flash.

Changed

• minSdk is 23, down from 24 - the floor Compose itself declares. CI runs the instrumentation
  suite on API 23, 26, 28, 31 and 34.
• A capture waits for the frame it was asked from to reach the screen. UnderlayState.refresh()
  called right after changing the content underneath now captures that change rather than the
  frame before it.
• The CPU blur radius is the one whose three box passes land closest to the requested Gaussian.
  The previous SVG approximation rounded some radii down to no blur and undershot the rest by up
  to 29%.
• A snapshot that covers only part of the composable is drawn at its capture scale over that part
  instead of being stretched across the whole of it.
• The snapshot is blurred with RenderEffect on the GPU from API 31, where the CPU box passes used
  to run. Snapshot is reached when the system switches cross-window blur off, which is usually
  battery saver - the moment CPU is least available. Below API 31 the platform ignores
  RenderEffect, so the box blur stays.
• blurredUnderlay is a Modifier.Node element rather than a @Composable function, so the
  modifier can be hoisted into a val outside composition. Trailing-lambda call sites keep
  compiling; a call that passed onSourceChange as a fourth positional argument does not, because
  that position takes state. Code built against 0.1.0 needs a rebuild either way.

0.1.0

implementation("com.timkrest:underlay:0.1.0")

Added

• Modifier.blurredUnderlay(blurRadius, tint, fallback, onSourceChange) — a blurred backdrop for
  overlays rendered in their own window, on API 24 and above.
• Three-step degradation reported through UnderlaySource: SystemBlur (FLAG_BLUR_BEHIND, API
  31+), Snapshot (PixelCopy of the host window, decorView.draw() below API 26) and Fallback
  (a solid color). A fourth value, Pending, covers the frames where a capture is in flight: only
  the tint is drawn there, so an overlay never flashes an opaque fallback on its way to a snapshot.
• Live fall-through from SystemBlur to Snapshot when the system disables cross-window blur, via
  WindowManager.addCrossWindowBlurEnabledListener.
• Snapshot re-capture when the host window changes size or configuration. Changing only
  blurRadius re-blurs the pixels already captured rather than reading the window back again.
• :sample application covering all four window kinds: Dialog, Popup, a translucent activity
  and a plain in-window overlay.
• Instrumentation coverage of every rung of the ladder, run on API 24, 28, 31 and 34: the software
  decorView draw, PixelCopy, and FLAG_BLUR_BEHIND. The step each test asserts follows what the
  device offers, not the API level, so a device with cross-window blur switched off is covered too.