Cold-start splash

Kapow plays a short animation in the logo’s language the first time the process is launched. It never plays when the app resumes from the background, when the activity is recreated, or when a comic is opened through a VIEW intent.

How it plays

1. System splash (Theme.Kapow.Starting, core-splashscreen): the launcher icon inside its 192 dp circle on black, drawn by the OS while the process starts. MainActivity calls installSplashScreen() and hands over to Theme.Kapow.
2. Compose overlay (core/ui/splash/SplashOverlay.kt), drawn on top of KapowRoot from the first frame. Its first frame repaints exactly the same icon at the same place and size, so the handover from the system splash is invisible, and the icon never disappears: it becomes the animation. After three warm-up frames (the library composes underneath during them) a linear 1 300 ms clock drives the sequence:
   • 0–620 ms: the icon’s circle opens until it covers the screen while the page inside grows to full size; the panels that were hidden outside the circle draw their keylines in white (dash-phase stroke, staggered 30 ms) and fill in cascade, turning to ink at 700 ms. The four panels already visible in the icon stay as they are.
   • 300–760 ms: the bubble and the K grow from icon size to hero size with squash & stretch and overshoot, followed by a burst of impact lines.
   • 1 000–1 300 ms: a diagonal wipe with a white edge reveals the app.

Every shape and colour comes from LogoShapes.kt, the same values as tools/store_assets/icon.py, so the splash and the icon are one object. The timing lives in SplashTimeline.kt as pure functions of the clock.

The splash is always the blue stage. Theme.Kapow.Starting names @mipmap/ic_launcher and belongs to .MainActivity, not to the activity-alias the launcher icon picker switches (docs/release.md), and LogoShapes hardcodes the blue palette — so choosing another launcher icon does not repaint the splash.

Gating

ColdStartSplash.claim(context) returns true once per process and only when the system animator scale is above zero, so “Remove animations” skips straight to the app. MainActivity also skips it when it was started with a VIEW intent.

Verifying

Record a cold start and inspect the frames:

adb -s <device> shell am force-stop com.sanchezpaco.kapow.debug
adb -s <device> shell "screenrecord --time-limit 12 /sdcard/splash.mp4" &
adb -s <device> shell monkey -p com.sanchezpaco.kapow.debug -c android.intent.category.LAUNCHER 1

Then ffmpeg -i splash.mp4 -vf fps=30 %03d.png and drop the frames identical to the previous one: a healthy run shows twenty or more distinct frames for the 1.3 s sequence (the Z Fold cover screen shows about thirty). On the emulators the OS splash itself lingers for several seconds before the process starts; that is the emulator, not the app.