Fix Application.Current null exception

[Jack251970]

Fix this exception:

[Copilot]

Pull Request Overview

This pull request addresses the Application.Current null exception by adding null-checks before invoking Dispatcher methods on Application.Current.

• Updated calls to Dispatcher.Invoke to use a null-conditional operator.
• Adjusted comments to reflect the possibility of Application.Current being null during application exit.

[Jack251970]

Small patch and it is good to me.

[gitstream-cm]

🥷 Code experts: onesounds

Jack251970, onesounds have most 👩‍💻 activity in the files.
Jack251970, onesounds have most 🧠 knowledge in the files.

See details

Flow.Launcher/ViewModel/MainViewModel.cs

Activity based on git-commit:

	Jack251970	onesounds
MAR	483 additions & 435 deletions	293 additions & 201 deletions
FEB	63 additions & 21 deletions	23 additions & 25 deletions
JAN	17 additions & 21 deletions
DEC	59 additions & 63 deletions
NOV	39 additions & 15 deletions
OCT

Knowledge based on git-blame:
Jack251970: 26%
onesounds: 10%

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[gitstream-cm]

Be a legend 🏆 by adding a before and after screenshot of the changes you made, especially if they are around UI/UX.

[coderabbitai]

📝 Walkthrough

Walkthrough

This change updates the MainViewModel class's Show and Hide methods. The update adds a null-conditional check for Application.Current before using the UI dispatcher, preventing potential null reference exceptions during application exit. Additionally, comment text was refined for clarity, including the correction of a typo.

Changes

File(s)	Change Summary
Flow.Launcher/.../MainViewModel.cs	Modified Show and Hide methods to use the null-conditional operator when accessing Application.Current and updated comments for clarity.

Sequence Diagram(s)

sequenceDiagram
    participant VM as MainViewModel
    participant App as Application.Current
    participant UI as Dispatcher/UI Thread

    VM->>App: Check if Application.Current exists (null-conditional)
    alt Application exists
        App->>UI: Invoke UI operation via dispatcher
    else
        VM-->>VM: Skip UI operation (safe exit)
    end

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Possibly related PRs

• Fix Dependency Injection Issue #3275: Related changes in dispatcher handling in the MainViewModel class linked with updates in the PublicAPIInstance.
• Fix application null exception & Remove unused MainWindowOpacity property #3392: Involves modifications to UI visibility management and updates to the MainViewModel's Show and Hide methods.
• Task delay: Beyond Journey's End #3389: Addresses similar null reference exception issues in the MainViewModel methods by refining dispatcher invocation checks.

Suggested reviewers

• jjw24
• taooceros

Poem

I'm a hopping rabbit, glad to say,
Our code now skips the null display,
With safe checks here to guard the run,
No more crashes when the day's done.
Hoppin' with joy, our bugs have fled—
CodeRabbit cheers, and so do I, ahead!
🐰✨

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Reviewing files that changed from the base of the PR and between f07c09f and aec4539.

📒 Files selected for processing (1)

• Flow.Launcher/ViewModel/MainViewModel.cs (2 hunks)

⏰ Context from checks skipped due to timeout of 90000ms (4)

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🔇 Additional comments (2)

Flow.Launcher/ViewModel/MainViewModel.cs (2)

1467-1470: Good addition of null check to prevent NRE!

Adding the null-conditional operator (?.) is a solid defensive coding practice that prevents null reference exceptions when Application.Current is null during application shutdown.

---

1542-1545: Good addition of null check to prevent NRE!

Similar to the change in the Show method, this null check in the Hide method prevents potential null reference exceptions during application shutdown.

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[Copilot]

Pull Request Overview

This pull request addresses the Application.Current null exception by updating UI thread invocations in the Show() and Hide() methods.

• Updated invocation calls to use the null-conditional operator in both Show() and Hide()
• Revised comments to clarify behavior when Application.Current is null during application exit