What methods can be used to automatically detect delays in the user interface rendering process?

To automatically detect delays in the user interface rendering process on Android, the following methods can be used:

• Choreographer API: Allows tracking frames and measuring their rendering time, identifying frame skips (jank).
• Systrace: A profiling tool that shows how long each frame takes to render and where delays occur.
• Profile GPU Rendering: Enabled in developer settings, displays a graph of rendering times for each frame.
• FrameMetrics API (starting from Android 7.0): Collects detailed statistics on frame rendering times.
• StrictMode with main thread monitoring enabled to detect long operations blocking the UI.

Example of using Choreographer to measure time between frames:

val choreographer = Choreographer.getInstance()
choreographer.postFrameCallback(object : Choreographer.FrameCallback {
    var lastFrameTimeNanos = 0L
    override fun doFrame(frameTimeNanos: Long) {
        if (lastFrameTimeNanos != 0L) {
            val frameDurationMs = (frameTimeNanos - lastFrameTimeNanos) / 1_000_000
            if (frameDurationMs > 16) { // 16ms ~ 60fps
                Log.w("FrameDelay", "Frame took $frameDurationMs ms")
            }
        }
        lastFrameTimeNanos = frameTimeNanos
        choreographer.postFrameCallback(this)
    }
})