I want to know in detail how deal with toolbars for macos26 using Liquid Glass and all the options we have

To effectively deal with toolbars in macOS 26 using Liquid Glass, you have several options and techniques available. Here's a detailed overview based on the sessions from WWDC 2025:

Liquid Glass Overview

Liquid Glass is a new design material that provides a translucent, glass-like effect, enhancing the visual depth and focus on your app's content. It adapts to the brightness of the content behind it, switching between light and dark appearances as needed.

Toolbars with Liquid Glass

1. Automatic Grouping: AppKit automatically groups multiple toolbar buttons together on one piece of glass. Different types of controls, such as segmented controls and pop-up buttons, are separated into their own glass elements. This grouping is based on the type of each item's control view. You can override this behavior using NSToolbarItemGroup to group items or insert spacers to separate them.

2. Adaptive Material: The Liquid Glass material is adaptive, reacting intelligently to its context. It changes its appearance to suit the brightness of the content behind it, ensuring that toolbar items remain legible.

3. Customization Options:

   • Use the NSToolbarItem style property to specify a prominent style, which tints the glass using the accent color. This is useful for displaying state or emphasizing important actions.
   • The NSItemBadge API can be used to indicate new or pending content, such as unread messages or notifications.

4. Visual Effects: The toolbar glass will switch between light and dark appearances based on the scrolled content's brightness. This change is communicated using the NSAppearance system, so any work done to support dark mode applies here as well.

5. Toolbar Spacer API: This API allows you to create fixed or flexible spaces between toolbar items, providing visual clarity and grouping related actions together.

Implementing Liquid Glass in Toolbars

• Start with Xcode 26: Build your app with Xcode 26 to automatically adopt the new design. Extend your content edge-to-edge and adapt to new control sizes by auditing your app for hard-coded control heights or inflexible layout constraints.
• Use Glass Effect Container: Create an NSGlassEffectContainerView and set your stack view as its content view. This allows you to integrate the Liquid Glass material seamlessly into your existing layout.

For more detailed guidance, you can refer to the session Build an AppKit app with the new design (01:23) and Build a SwiftUI app with the new design (07:49) for specific implementation techniques and examples.