将 NSToolbarItems 与 NSSplitView 列对齐

Question

Finder 和 Notes 有一种我正在寻求重现的特殊行为。NSToolbar 中的“灵活空间”似乎考虑了拆分视图的尺寸。例如，第一组按钮在侧边栏的左侧与右侧对齐。第二组图标与第一列的右侧对齐。当我加宽侧边栏时，工具栏项目随之移动。

有没有可能重现这个？

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解决方案

使用@KenThomases 提供的解决方案，我实现了如下：

final class MainWindowController: NSWindowController {
    override func windowDidLoad() {
        super.windowDidLoad()
        window?.toolbar?.delegate = self
        // Make sure that tracking is enabled when the toolbar is completed
        DispatchQueue.main.async {
            self.trackSplitViewForFirstFlexibleToolbarItem()
        }
    }
}

extension MainWindowController: NSToolbarDelegate {
    func toolbarWillAddItem(_ notification: Notification) {
        // Make sure that tracking is evaluated only after the item was added
        DispatchQueue.main.async {
            self.trackSplitViewForFirstFlexibleToolbarItem()
        }
    }

    func toolbarDidRemoveItem(_ notification: Notification) {
        trackSplitViewForFirstFlexibleToolbarItem()
    }

    /// - Warning: This is a private Apple method and may break in the future.
    func toolbarDidReorderItem(_ notification: Notification) {
        trackSplitViewForFirstFlexibleToolbarItem()
    }

    /// - Warning: This method uses private Apple methods that may break in the future.
    fileprivate func trackSplitViewForFirstFlexibleToolbarItem() {
        guard var toolbarItems = self.window?.toolbar?.items, let splitView = (contentViewController as? NSSplitViewController)?.splitView else {
            return
        }

        // Add tracking to the first flexible space and remove it from the group
        if let firstFlexibleToolbarItem = toolbarItems.first, firstFlexibleToolbarItem.itemIdentifier == NSToolbarFlexibleSpaceItemIdentifier {
            _ = firstFlexibleToolbarItem.perform(Selector(("setTrackedSplitView:")), with: splitView)
            toolbarItems.removeFirst()
        }

        // Remove tracking from other flexible spaces
        for flexibleToolbarItem in toolbarItems.filter({ $0.itemIdentifier == NSToolbarFlexibleSpaceItemIdentifier }) {
            _ = flexibleToolbarItem.perform(Selector(("setTrackedSplitView:")), with: nil)
        }
    }
}

Answer 1

使用 macOS 11 或更高版本时，您可以将NSTrackingSeparatorToolbarItem项目插入到工具栏，这会将工具栏分成几个部分，并与对象的分隔线对齐NSSplitView。

此示例将新的分隔符项添加到已包含其余按钮（在 Interface Builder 或代码中配置）的工具栏中。目标分割视图涉及 3 个分割视图的标准配置，包括侧边栏面板。

class WindowController: NSWindowController, NSToolbarDelegate {

    let mainPanelSeparatorIdentifier = NSToolbarItem.Identifier(rawValue: "MainPanel")

    override func windowDidLoad() {
        super.windowDidLoad()

        self.window?.toolbar?.delegate = self
    
        // Calling the inserts async gives more time to bind with the split viewer, and prevents crashes
        DispatchQueue.main.async {

            // The .sidebarTrackingSeparator is a built-in tracking separator which always aligns with the sidebar splitview
            self.window?.toolbar?.insertItem(withItemIdentifier: .sidebarTrackingSeparator, at: 0)
        
            // Example of a custom mainPanelSeparatorIdentifier
            // Index at '3' means that there are 3 toolbar items at the left side
            // of this separator, including the first tracking separator
            self.window?.toolbar?.insertItem(withItemIdentifier: mainPanelSeparatorIdentifier at: 3)
        }
    }

    func toolbar(_ toolbar: NSToolbar, itemForItemIdentifier itemIdentifier: NSToolbarItem.Identifier, willBeInsertedIntoToolbar flag: Bool) -> NSToolbarItem? {
    
        if let splitView = (self.contentViewController as? NSSplitViewController)?.splitView {
        
            // You must implement this for custom separator identifiers, to connect the separator with a split view divider
            if itemIdentifier == mainPanelSeparatorIdentifier {
                return NSTrackingSeparatorToolbarItem(identifier: itemIdentifier, splitView: splitView, dividerIndex: 1)
            }
        }
        return nil
    }
}

如果要添加额外的分隔符（例如，为检查器面板），只需将附加的工具栏项目标识符插入到工具栏，然后将额外的分隔符分配NSTrackingSeparatorToolbarItem给委托函数中的另一个分隔符即可itemForItemIdentifier。