fix: broken transparent window styles on resizable change

[zoy-l]

Description of Change

Fix: #4835
Fix #48421

If resizable: false is set during titleBarOverlay initialization, the maximize button is still available.

Reason: When setting up a transparent window during initialization, calling SetCanResize(true) triggers OnSizeConstraintsChanged. The internal check finds CanResize is true, and since we removed the is_translucent_ check, this causes an unintended window-style flag to be set.

Change Description:
Override the internal CanResize function to prevent inconsistencies with Chromium’s internal state.
SetResizable no longer needs to repeatedly trigger OnSizeConstraintsChanged and call SetMaximizable.

Background:
Previous Process

1. Calling SetResizable(true) first triggered OnSizeConstraintsChanged.
2. At that moment, the internal can_resize flag was still false.
3. The canMaximize check (delegate->CanMaximize() && can_resize) evaluated to false, which applied a disabled style.
4. SetMaximizable was then called to restore the correct style.
5. Finally, SetCanResize updated Chromium’s internal state and triggered OnSizeConstraintsChanged again, correctly applying the style.

---

To fix the background material, the !is_translucent_ check for can_resize was removed in HWNDMessageHandler::SizeConstraintsChanged, which exposed this issue. See fix_resolve_dynamic_background_material_update_issue_on_windows_11.patch for reference.

This brings two changes that need to be confirmed.: one is that windows with thickFrame: false can no longer get the maximize button unless implemented manually. The other is that when thickFrame is false, isResizable is always false under normal circumstances.

Note: In previous versions, transparent windows did not support resizing by dragging the borders.

Checklist

• PR description included and stakeholders cc'd
• npm test passes
• tests are changed or added
• relevant API documentation, tutorials, and examples are updated and follow the documentation style guide
• PR release notes describe the change in a way relevant to app developers, and are capitalized, punctuated, and past tense.

Release Notes

Notes: Fixed an issue where changing the resizable property on a window would break the styles of a transparent window.

meant to comment

[codebytere]

@zoy-l the failures are related, see e.g.:

not ok 401 BrowserWindow module window states resizable state does affect maximizability when disabled and enabled

[zoy-l]

@zoy-l the failures are related, see e.g.:

not ok 401 BrowserWindow module window states resizable state does affect maximizability when disabled and enabled

I’ll fix it later.

[zoy-l]

Hmm, this seems a bit off. I need to test it again.😅

[nikwen]

Notes: To fix the background material, the !is_translucent_ check for can_resize was removed in HWNDMessageHandler::SizeConstraintsChanged, which exposed this issue. See fix_resolve_dynamic_background_material_update_issue_on_windows_11.patch for reference.

This brings two changes that need to be confirmed.: one is that windows with thickFrame: false can no longer get the maximize button unless implemented manually. The other is that when thickFrame is false, isResizable is always false under normal circumstances.

The release notes are meant for app developers upgrading their Electron version. They should be relatively simple overall.

Example: "Fixed issue where changing resizable on a window caused <explain bug>."

Could you update them, please?

[zoy-l]

@nikwen 👌