---
source_files:
  - Common/DTS.Common/obj/x86/Debug/Themes/CommonStyles.g.i.cs
  - Common/DTS.Common/obj/x86/Debug/Themes/CommonStyles.g.cs
generated_at: "2026-04-16T02:57:35.324519+00:00"
model: "Qwen/Qwen3-Coder-Next-FP8"
schema_version: 1
sha256: "2e2061c5c6af1d0a"
---

# Themes

## Documentation: `DTS.Common.CommonStyles`

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### 1. Purpose

This module defines a WPF `ResourceDictionary` subclass (`CommonStyles`) that encapsulates shared UI styles and event handlers for tooltips across the application. It is auto-generated from `Themes/CommonStyles.xaml` during the build process and serves as the runtime entry point for loading those styles into the WPF resource system. Its primary role is to ensure consistent tooltip behavior—specifically, attaching a common `ToolTipOpening` event handler (`ToolTipEventHandler`) to multiple named styles defined in the XAML source—without requiring manual wiring in application code.

---

### 2. Public Interface

The class `CommonStyles` is a partial class inheriting from `System.Windows.ResourceDictionary` and implementing `IComponentConnector` and `IStyleConnector`. It exposes only one *public* method:

- **`void InitializeComponent()`**  
  Initializes the component by loading the embedded XAML resource dictionary from `/DTS.Common;component/themes/commonstyles.xaml`. This method is idempotent: it checks `_contentLoaded` and returns early on subsequent calls. It must be called before the dictionary is used (typically invoked automatically by the WPF framework or in the constructor of a consuming class).

> **Note**: All other methods (`Connect(int, object)` for `IComponentConnector` and `IStyleConnector`) are *explicit interface implementations* and are not intended for direct public consumption. They are invoked internally by the WPF build/runtime infrastructure.

---

### 3. Invariants

- `_contentLoaded` is `false` initially and set to `true` on first call to `InitializeComponent()` or `IComponentConnector.Connect()`. Once `true`, it is never reset.
- `InitializeComponent()` must be called **exactly once** per instance before the dictionary is used; otherwise, styles may not be loaded.
- The `IStyleConnector.Connect()` implementation assumes exactly 12 styles (connection IDs 1–12) in `CommonStyles.xaml` each define a `ToolTipOpening` event handler. If the XAML changes (e.g., adds/removes styles), the generated code and XAML must be regenerated together to maintain correctness.
- All event setters attach to `FrameworkElement.ToolTipOpeningEvent` using the same handler: `this.ToolTipEventHandler`. The handler itself is not defined in this file—its implementation resides in the *other* partial part of `CommonStyles` (likely in `CommonStyles.xaml.cs`), which is not provided here.

---

### 4. Dependencies

- **Dependencies *of* this module**:
  - `System.Windows.Application.LoadComponent()` — used to load the embedded XAML resource.
  - `System.Windows.ResourceDictionary` — base type.
  - `System.Windows.Markup.IComponentConnector`, `IStyleConnector` — required for WPF’s build-time code generation contract.
  - `System.Windows.Controls.ToolTipEventHandler` — delegate type for tooltip events.
  - `System.Windows.EventSetter` — used to attach event handlers to styles.
  - `Microsoft.Windows.Controls` — likely indicates dependency on Microsoft’s WPF Toolkit or similar (e.g., `Microsoft.Windows.Controls.DataVisualization` or `Charting`).

- **Dependencies *on* this module**:
  - Any WPF application or library referencing `DTS.Common` that uses styles defined in `CommonStyles.xaml`.
  - The `CommonStyles.xaml` file itself (source) — this generated code is tightly coupled to it. Changes to the XAML require regeneration.

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### 5. Gotchas

- **Auto-generated code**: This file is auto-generated by `PresentationBuildTasks` (WPF build tasks). **Manual edits will be overwritten** on rebuild. Always modify `CommonStyles.xaml` (and its code-behind, if any) instead.
- **Missing handler definition**: The `ToolTipEventHandler` method is referenced but not defined in this file. Its implementation is assumed to exist in the corresponding `CommonStyles.xaml.cs` (not provided), which must be present at runtime—otherwise, a `MissingMethodException` will occur.
- **Hardcoded connection IDs**: The `IStyleConnector.Connect()` switch statement uses numeric IDs (1–12) that correspond to style definitions in `CommonStyles.xaml`. If styles are reordered, added, or removed in the XAML without regenerating, the event handlers may be attached to the wrong styles or not at all.
- **No public style keys exposed**: This module does not expose any public constants or properties for style keys (e.g., `x:Key="MyStyle"`). Consumers must know or inspect the XAML to reference styles.
- **No validation of `target` type**: The `IStyleConnector.Connect()` method casts `target` to `Style` without checking—passing a non-`Style` object will cause a runtime `InvalidCastException`.

> **None identified from source alone** beyond the above.

--- 

**Note**: Since the actual `CommonStyles.xaml` and `CommonStyles.xaml.cs` files are not provided, details about the specific styles, their keys, or the logic inside `ToolTipEventHandler` are inferred only from the generated code’s structure and line references.