Technical mental model

A first Qt app should establish a reliable event-loop baseline and a clean project/toolchain setup. This foundation determines how quickly later UI issues can be diagnosed.

Key low-level points:

• The event loop is the runtime core; blocking it directly degrades UI responsiveness.
• QObject parent/child ownership affects memory lifecycle and cleanup behavior.
• Build-kit consistency (compiler, Qt version, debugger) is part of runtime correctness.

Equations and constraints that drive decisions

Frame-time budgeting concept for perceived smoothness:

Where:

• At 60 FPS, target is about 16.7 ms per frame.

Implementation walkthrough

Create minimal window app and verify startup, render, and clean shutdown path.

Confirm debugger attach and breakpoint reliability before feature work.

Keep first interaction path simple (one signal, one state update).

Record baseline startup and interaction latency for future regressions.

Validation and debugging checklist

Long operations in UI thread should be moved to worker paths.

Kit mismatch can look like code bugs; validate environment first.

Ownership assumptions should be explicit when allocating widgets dynamically.

Always keep a known-good minimal window path during refactors.

Once the baseline is stable, later architecture and UI complexity becomes easier to add without losing control of behavior.