Move progress bar animation init to Loaded event to fix possible null exception of ProgressBar

[Jack251970]

InitProgressbarAnimation is now triggered by the progress bar's Loaded event instead of during main window initialization. This ensures the animation starts only after the progress bar is fully loaded, improving reliability and preventing potential UI timing issues.

Resolve #4311

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Summary by cubic

Moves the progress bar animation init from window load to the ProgressBar Loaded event. This prevents null reference exceptions and ensures the animation starts only after the control is ready.

• Summary of changes
  • Changed: Removed InitProgressbarAnimation() call from MainWindow.OnLoaded; animation now depends on the ProgressBar’s lifecycle.
  • Added: ProgressBar_Loaded event handler in code-behind that calls InitProgressbarAnimation(); wired up in XAML via Loaded="ProgressBar_Loaded".
  • Removed: Early initialization of the progress bar animation during main window initialization.
  • Tests: No unit tests added (UI timing change).
  • Security: No security impact; UI-only change.

^{Written for commit a2f2242. Summary will update on new commits.}

[Copilot]

Pull request overview

Moves progress bar animation initialization to the ProgressBar Loaded event to avoid timing-related null access during main window initialization.

Changes:

• Removed InitProgressbarAnimation() call from MainWindow.OnLoaded.
• Added a ProgressBar_Loaded handler in code-behind to trigger InitProgressbarAnimation().
• Wired the ProgressBar Loaded event in XAML.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
Flow.Launcher/MainWindow.xaml.cs	Removes initialization from window load and introduces ProgressBar_Loaded to init animation when the control is loaded.
Flow.Launcher/MainWindow.xaml	Hooks the ProgressBar Loaded event to call the new handler.

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[coderabbitai]

📝 Walkthrough

Walkthrough

Moves progress bar animation initialization from the main window's Loaded event to the progress bar's own Loaded event handler, ensuring the control is fully initialized before animation setup begins.

Changes

Cohort / File(s)	Summary
ProgressBar Event Binding Flow.Launcher/MainWindow.xaml	Added Loaded event binding to ProgressBar element, wiring it to ProgressBar_Loaded handler for initialization.
ProgressBar Initialization Handler Flow.Launcher/MainWindow.xaml.cs	Added ProgressBar_Loaded event handler to invoke InitProgressbarAnimation and removed the same call from OnLoaded method, changing initialization sequence.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Possibly related PRs

• Fix first-time window flicker & clock panel flicker issue #3391: Modifies MainWindow.xaml.cs's load-time initialization of UI elements.
• Initialize HotKeyMapper after window is loaded & Wait image cache saved before closing main window #3422: Adjusts MainWindow.xaml.cs load-time initialization sequence by moving component initialization into dedicated event handlers.
• Fix startup flicker #3521: Removes initialization calls from MainWindow's OnLoaded method to refactor startup sequence.

Suggested reviewers

• jjw24
• onesounds

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main change: moving progress bar animation initialization to its Loaded event to fix a null exception.
Linked Issues check	✅ Passed	The changes directly address issue #4311 by moving InitProgressbarAnimation from main window initialization to the ProgressBar's Loaded event, preventing null reference exceptions.
Out of Scope Changes check	✅ Passed	All changes are focused on resolving the progress bar initialization timing issue described in issue #4311; no extraneous modifications are present.
Description check	✅ Passed	The description clearly relates to the changeset by explaining why progress bar animation initialization is being moved to the Loaded event to fix timing and null reference issues.

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✨ Finishing Touches

• 📝 Generate docstrings (stacked PR)
• 📝 Generate docstrings (commit on current branch)

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch InitProgressbarAnimation_Null

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[cubic-dev-ai]

No issues found across 2 files

[gitstream-cm]

🥷 Code experts: jjw24

jjw24, Jack251970 have most 👩‍💻 activity in the files.
Jack251970, jjw24 have most 🧠 knowledge in the files.

See details

Flow.Launcher/MainWindow.xaml

Activity based on git-commit:

	jjw24	Jack251970
MAR
FEB
JAN
DEC		1 additions & 1 deletions
NOV
OCT		1 additions & 1 deletions

Knowledge based on git-blame:
jjw24: 100%

Flow.Launcher/MainWindow.xaml.cs

Activity based on git-commit:

	jjw24	Jack251970
MAR
FEB
JAN
DEC
NOV		1 additions & 1 deletions
OCT		8 additions & 7 deletions

Knowledge based on git-blame:
Jack251970: 100%

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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.

[jjw24]

Do we know if this actually solves the issue?

[Jack251970]

Do we know if this actually solves the issue?

It is very hard to reproduce this issue since this issue happens only if the ProgressBar is not loaded when window is loaded (You need a computer with high computation speed and good gpu performance). We can only analyze the root reason of the issue.