DP44/enriched-qwen3-coder-next/Common/DTS.CommonCore/Interface/DownloadEvent.md

source_files, generated_at, model, schema_version, sha256

source_files	generated_at	model	schema_version	sha256
Common/DTS.CommonCore/Interface/DownloadEvent/IDownloadEvent.cs	2026-04-16T02:20:00.100876+00:00	Qwen/Qwen3-Coder-Next-FP8	1	089f2c1bff740fce

DownloadEvent

Purpose

This module defines the IDownloadEvent interface, which represents a single download event in a multiple-download system. It serves as a contract for objects that model downloadable content units (e.g., media segments, files, or tasks), exposing metadata and state necessary for UI binding and orchestration—such as identification, enablement status, defaultness, and duration—while supporting data binding via INotifyPropertyChanged.

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Public Interface

• int EventNumber { get; set; }
  Gets or sets a numeric identifier for the download event. Used for ordering or referencing the event programmatically.

• string EventNumberDisplay { get; set; }
  Gets or sets a user-facing string representation of the event number (e.g., "1", "A", "001"), allowing formatting distinct from EventNumber.

• bool IsEnabled { get; set; }
  Gets or sets whether the event is active and可 downloaded. When false, the event should be skipped or ignored during download operations.

• bool IsReadonly { get; set; }
  Gets or sets whether the event’s properties (e.g., EventNumber, IsEnabled) are immutable in the UI or via programmatic modification. A true value indicates the event is locked for editing.

• bool IsDefault { get; }
  Gets a read-only flag indicating whether this event is the default selection (e.g., pre-selected for download). Cannot be set—implementation-determined.

• TimeSpan EventLength { get; set; }
  Gets or sets the total duration of the downloadable content for this event (e.g., video/audio length). Represents available content length, not necessarily downloaded.

• bool ShouldDisplayLength { get; set; }
  Gets or sets whether the EventLength should be rendered in the UI. Allows conditional visibility of duration (e.g., hide for non-time-based downloads).

All properties raise PropertyChanged notifications via INotifyPropertyChanged when modified (as required by the interface inheritance).

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Invariants

• IsDefault is read-only (get only); its value must be determined and fixed by the implementing type and cannot be altered externally.
• EventLength represents available content duration, not actual downloaded bytes or progress—its semantics are temporal, not volumetric.
• IsReadonly and IsEnabled may be set independently, but UI behavior should ensure IsReadonly = true implies IsEnabled cannot be toggled by user action (though programmatic changes remain possible).
• EventNumberDisplay is not required to match EventNumber.ToString(); implementations may format it arbitrarily (e.g., localized, padded, or symbolic).

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Dependencies

• Depends on:
  • System (core types like TimeSpan, EventHandler)
  • System.ComponentModel (INotifyPropertyChanged)
• Depended on by:
  • UI layers (e.g., WPF/WinForms view models) that bind to download event lists
  • Download orchestration logic that filters or prioritizes events based on IsEnabled, IsDefault, or EventNumber
  • Serialization/deserialization logic (e.g., for persisting download configurations)

No other internal module dependencies are visible in this file.

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Gotchas

• EventLength is named descriptively as “total length available for download event” in XML doc, but the property itself does not distinguish between total available vs. downloaded—consumers must infer semantics from naming and context.
• IsDefault is read-only but has no documentation on how it is determined (e.g., by position, metadata, or configuration). Its behavior is implementation-specific.
• ShouldDisplayLength is a UI hint only; it does not affect EventLength’s value or behavior in non-UI logic. Misusing it as a data filter may cause inconsistencies.
• No validation rules are enforced by the interface (e.g., EventNumber may be negative; EventLength may be TimeSpan.Zero or negative unless guarded by implementation).
• The file header comment //FB 6399 suggests a feature/bug reference, but no context is provided—this may be relevant for historical debugging.

None identified beyond the above.