From concept to engineering model
Qt Model/View scales UI data handling by separating storage logic from rendering logic. Correctness depends on consistent model contracts and update notifications.
Key low-level points:
- Model indexes and roles define how views access and present data.
- Structural and data-change signals keep views synchronized with model state.
- Delegates enable presentation and editing customization without polluting model core.
Mathematical relationships worth memorizing
Rough repaint work estimate:
Where:
- : average cell paint time
Applied design scenario
Start with a small custom model and verify each required method deterministically.
Emit correct begin/end and changed signals around mutations.
Test insertion/removal/selection interactions under dynamic updates.
Profile paint and data role paths for larger datasets.
Mistakes to prevent before hardware or runtime tests
Missing or wrong signals lead to stale views and hard-to-trace UI defects.
Invalid index reuse after model changes causes subtle crashes.
Heavy role calculations can bottleneck view responsiveness.
Avoid embedding business logic directly in delegates.
Model/View pays off when data changes remain predictable and render paths remain decoupled from core logic.
