feat(PdfReader): add rotate function

[ArgoZhang]

Link issues

fixes #712

Summary By Copilot

Regression?

• Yes
• No

Risk

• High
• Medium
• Low

Verification

• Manual (required)
• Automated

Packaging changes reviewed?

• Yes
• No
• N/A

☑️ Self Check before Merge

⚠️ Please check all items below before review. ⚠️

• Doc is updated/provided or not needed
• Demo is updated/provided or not needed
• Merge the latest code from the main branch

Summary by Sourcery

Add bidirectional page rotation controls to the PdfReader component and wire them to a new client-side rotation implementation.

New Features:

• Expose RotateLeft and RotateRight actions on the PdfReader toolbar to rotate the current PDF view in 90-degree steps.

Enhancements:

• Replace the previous element-based rotation logic with a viewer-level pagesRotation-based implementation in the PdfReader JavaScript.

[sourcery-ai]

Reviewer's Guide

Adds client- and server-side support for rotating PDF pages in the PdfReader component, wiring new toolbar buttons to a JavaScript rotation function and deprecating the old rotation path via pdf.js.

Sequence diagram for new PDF rotation interactions in PdfReader

sequenceDiagram
    actor "User"
    participant "PdfReader (Razor Component)"
    participant "Blazor JSRuntime"
    participant "PdfReader.razor.js"
    participant "pdfViewer (pdf.js viewer instance)"

    "User" ->> "PdfReader (Razor Component)": "Click rotate-left toolbar button"
    "PdfReader (Razor Component)" ->> "Blazor JSRuntime": "InvokeVoidAsync(\"rotate\", Id, -90)"
    "Blazor JSRuntime" ->> "PdfReader.razor.js": "Call rotate(id, -90)"
    "PdfReader.razor.js" ->> "pdfViewer (pdf.js viewer instance)": "Lookup via Data.get(id)"
    "PdfReader.razor.js" ->> "pdfViewer (pdf.js viewer instance)": "Update pagesRotation with offset -90 (mod 360)"

    "User" ->> "PdfReader (Razor Component)": "Click rotate-right toolbar button"
    "PdfReader (Razor Component)" ->> "Blazor JSRuntime": "InvokeVoidAsync(\"rotate\", Id, 90)"
    "Blazor JSRuntime" ->> "PdfReader.razor.js": "Call rotate(id, 90)"
    "PdfReader.razor.js" ->> "pdfViewer (pdf.js viewer instance)": "Lookup via Data.get(id)"
    "PdfReader.razor.js" ->> "pdfViewer (pdf.js viewer instance)": "Update pagesRotation with offset 90 (mod 360)"

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File-Level Changes

Change	Details	Files
Introduce a new JavaScript-side rotate helper that adjusts pdf.js viewer pagesRotation based on an offset.	Add rotate(id, offset) export that looks up the pdfViewer from Data, adjusts pagesRotation by the given offset, and normalizes it using modulo 360. Use a default starting rotation value when pagesRotation is not yet set to ensure rotation always has a base value.	src/components/BootstrapBlazor.PdfReader/PdfReader.razor.js
Deprecate the old rotation implementation that directly manipulated a pdf object’s rotation and re-rendered a page.	Comment out the previous rotate(invoke, elementId, rotation) function that validated a fixed rotation value and set pdf.rotation followed by queueRenderPage. Retain the function in comments for reference but stop using it in favor of the new viewer-based rotation mechanism.	src/components/BootstrapBlazor.PdfReader/PdfReader.razor.js
Expose rotation actions from the PdfReader Razor component and bind them to toolbar buttons.	Add RotateLeft and RotateRight async methods that invoke the JavaScript rotate function with -90 and +90 degree offsets respectively, using the component’s Id. Wire the existing left-rotation toolbar icon to call RotateLeft on click, and introduce a new right-rotation toolbar icon that calls RotateRight. Keep existing fit-to-page and fit-to-width behavior unchanged while extending the toolbar with rotation controls.	src/components/BootstrapBlazor.PdfReader/PdfReader.razor.cs src/components/BootstrapBlazor.PdfReader/PdfReader.razor

Assessment against linked issues

Issue	Objective	Addressed	Explanation
#712	Add a rotate function to the PdfReader component that allows rotating the displayed PDF pages (e.g., via UI controls and corresponding JS interop).	✅

Possibly linked issues

• feat(PdfReader): add rotate function #712: PR adds PdfReader rotate methods and toolbar buttons, directly implementing the requested rotate function feature.

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[sourcery-ai]

Hey there - I've reviewed your changes - here's some feedback:

• In PdfReader.razor.js, the rotation baseline let rotate = pdfViewer.pagesRotation || 360; will treat an existing 0° rotation as falsy and reset to 360°; consider using a null/undefined check (e.g., ?? 0) so 0 remains a valid rotation state.
• It may be worth validating the offset parameter in the new rotate JS function (e.g., ensuring it is a multiple of 90) to avoid ending up with non-standard rotation angles if the API is misused.

Prompt for AI Agents

Please address the comments from this code review:

## Overall Comments
- In PdfReader.razor.js, the rotation baseline `let rotate = pdfViewer.pagesRotation || 360;` will treat an existing 0° rotation as falsy and reset to 360°; consider using a null/undefined check (e.g., `?? 0`) so 0 remains a valid rotation state.
- It may be worth validating the `offset` parameter in the new `rotate` JS function (e.g., ensuring it is a multiple of 90) to avoid ending up with non-standard rotation angles if the API is misused.

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[Copilot]

Pull request overview

This PR adds page rotation functionality to the PdfReader component, allowing users to rotate PDF pages left and right by 90-degree increments. The implementation replaces an older, unused rotation function with a new approach that leverages the pdf.js viewer's built-in pagesRotation property.

Key Changes

• Added RotateLeft() and RotateRight() public methods in C# that rotate pages by -90° and +90° respectively
• Implemented a new rotate(id, offset) JavaScript function that manipulates the pagesRotation property of the PDFViewer
• Added UI buttons in the toolbar for both rotation directions with Font Awesome icons

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

File	Description
PdfReader.razor.js	Added new rotate() function using pdf.js viewer API; commented out old rotation implementation
PdfReader.razor.cs	Added RotateLeft() and RotateRight() public async methods with version bump
PdfReader.razor	Added two rotation button elements to toolbar with click handlers
BootstrapBlazor.PdfReader.csproj	Updated version to 10.0.1-beta01; includes commented PackageReference

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