Incallui - ~repack~

If you’ve ever built a VoIP or carrier-grade calling app for Android, you’ve likely cursed the black box known as InCallUI . It’s the system-level interface that pops up when you receive or make a phone call—the screen with the accept, decline, speakerphone, and keypad buttons.

The InCallUI activity requires an absurdly fast start-up time. Telecom starts a "warm-up" process pre-emptively. If your InCallActivity takes longer than ~200ms to inflate its layout or bind to InCallService , the system times out. The call connects, but the UI never appears. incallui

But here’s the catch: For a long time, InCallUI was a tightly guarded, OEM-specific application. With the introduction of the Telecom framework and ConnectionService APIs, Google attempted to standardize it. Yet, the reality remains messy. If you’ve ever built a VoIP or carrier-grade

Trying to overlay a Dialog on top of the system InCallUI. This never works reliably due to SYSTEM_ALERT_WINDOW restrictions and the fact that the system InCallUI has the highest priority ( TYPE_APPLICATION_OVERLAY is lower than TYPE_PHONE ). Telecom starts a "warm-up" process pre-emptively