MenuItem gets updated when IconImageSource changes - Fix 17210

[jm-goldacker]

Description of Change

I added an event handler method that subscribes to the SourceChanged event of the MenuItem's IconImageSource.

When this event occurs, subscribers will be notified that the IconImageSourceProperty of the MenuItem changed - so the UI will update.

Issues Fixed

Fixes #17210

examples from public reproduction project repository, before swapping icons:

after swapping icons:

The examples can be found in the Maui.Controls.Sample project.

[ghost]

Hey there @jm-goldacker! Thank you so much for your PR! Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[jm-goldacker]

The issue mentions "Binding does not work with glyph."

This is the corresponding code in the reproduction project:
<MenuFlyoutItem.IconImageSource> <FontImageSource Glyph="{Binding Icon1}" FontFamily="IconsFont" Color="Blue"/> </MenuFlyoutItem.IconImageSource>

That code will not render the glyph. The problem is the binding.

I solved it by referencing the binding source:
<MenuFlyoutItem.IconImageSource> <FontImageSource Glyph="{Binding BindingContext.Icon1, Source={x:Reference menuBarSamplePage}}" FontFamily="IconsFont"/> </MenuFlyoutItem.IconImageSource>

Is it intended to work like that?
If not, I will still have to put some work into this issue 😅

[mattleibow]

Thanks for this PR! The fix looks right, but I think the issue you pointed out with the weird binding context may be because we are not properly propagating the context to menu items.

Are you still able to look at this PR? I know it has been a day or year... Let me know. I will try and be more responsive. Back in 2023, things were more crazy - now we got time to look at PRs :P

Some questions for the binding issue:

• Does binding things like text work?
• I wonder if you rebase things will be better - it has been over a year now
• Are you able to add a UI test to verify the menu has changed? This PR has a UI test for menu items that you can reference: [Windows] Fix for MenuFlyoutItems programmatically added to MenuFlyoutSubItems are not visible #26886

Let me know if you still feel like working on this issue.

[mattleibow]

I had a quick look at a rebase, and saw this conflict:

		public static readonly BindableProperty IconImageSourceProperty = BindableProperty.Create(nameof(IconImageSource), typeof(ImageSource), typeof(MenuItem), default(ImageSource),
<<<<<<< fix-17210
			propertyChanging: OnImageSourceChanging, propertyChanged: OnImageSourceChanged);
=======
			propertyChanged: (bindable, oldValue, newValue) =>
			{
				((MenuItem)bindable).AddRemoveLogicalChildren(oldValue, newValue);
			}
		);
>>>>>>> main

Basically, the code in main now propagates the binding context. I think if you were to rebase, the old bindings would work and the issue would be to just add a UI test.

[jm-goldacker]

Hi,
thanks for looking into the PR.

I would indeed like to continue working on this issue.