我正在寻找使用Apple推荐的正确方法向NSOutlineview添加复选框的方法-但是从文档中看不出来。
如何添加允许用户使用的行为,如果我单击父复选框,则它将选择子项,而如果不单击它,它将取消选择该项目的子项?
编辑:我简化了我的问题,并添加了图片以使其更清晰(希望如此)
我的方法: 我一直在使用Code Different提供的出色答案在Mac应用程序中构建“大纲”视图。 https://stackoverflow.com/a/45384599/559760 -我选择使用手动过程而不是使用CocoaBindings填充NSoutLine视图。
我在堆栈视图中添加了一个复选框,这似乎是正确的方法:
我的解决方案包括创建一个数组,以将选定的项保存在viewcontroller中,然后创建用于添加和删除的功能
var selectedItems: [Int]?
@objc func cellWasClicked(sender: NSButton) {
let newCheckBoxState = sender.state
let tag = sender.tag
switch newCheckBoxState {
case NSControl.StateValue.on:
print("adding- \(sender.tag)")
case NSControl.StateValue.off:
print("removing- \(sender.tag)")
default:
print("unhandled button state \(newCheckBoxState)")
}
我通过分配给复选框的标签识别该复选框按钮
答案 0 :(得分:1)
为了将来的Google员工的利益,我将重复我在other answer中编写的内容。此处的区别是,这具有额外的要求,即列是可编辑的,并且我已经改进了该技术。
NSOutlineView
的关键是必须为每行提供一个标识符,可以是字符串,数字或唯一标识该行的对象。 NSOutlineView
将此称为item
。基于此item
,您将查询数据模型以填充轮廓。
在此答案中,我们将设置一个具有两列的轮廓视图:一个可编辑的已选中列和一个不可编辑的标题列。
isSelected
title
isSelectedCell
titleCell
一致性在这里很重要。单元格的标识符应等于其列的标识符+ Cell
。
默认NSTableCellView
包含不可编辑的文本字段。我们需要一个复选框,所以我们必须设计自己的单元格。
import Cocoa
/// A set of methods that `CheckboxCelView` use to communicate changes to another object
protocol CheckboxCellViewDelegate {
func checkboxCellView(_ cell: CheckboxCellView, didChangeState state: NSControl.StateValue)
}
class CheckboxCellView: NSTableCellView {
/// The checkbox button
@IBOutlet weak var checkboxButton: NSButton!
/// The item that represent the row in the outline view
/// We may potentially use this cell for multiple outline views so let's make it generic
var item: Any?
/// The delegate of the cell
var delegate: CheckboxCellViewDelegate?
override func awakeFromNib() {
checkboxButton.target = self
checkboxButton.action = #selector(self.didChangeState(_:))
}
/// Notify the delegate that the checkbox's state has changed
@objc private func didChangeState(_ sender: NSObject) {
delegate?.checkboxCellView(self, didChangeState: checkboxButton.state)
}
}
isSelected
列中的默认文本字段NSTableCellView
并将其类别更改为CheckboxCellView
最后是视图控制器的代码:
import Cocoa
/// A class that represents a row in the outline view. Add as many properties as needed
/// for the columns in your outline view.
class OutlineViewRow {
var title: String
var isSelected: Bool
var children: [OutlineViewRow]
init(title: String, isSelected: Bool, children: [OutlineViewRow] = []) {
self.title = title
self.isSelected = isSelected
self.children = children
}
func setIsSelected(_ isSelected: Bool, recursive: Bool) {
self.isSelected = isSelected
if recursive {
self.children.forEach { $0.setIsSelected(isSelected, recursive: true) }
}
}
}
/// A enum that represents the list of columns in the outline view. Enum is preferred over
/// string literals as they are checked at compile-time. Repeating the same strings over
/// and over again are error-prone. However, you need to make the Column Identifier in
/// Interface Builder with the raw value used here.
enum OutlineViewColumn: String {
case isSelected = "isSelected"
case title = "title"
init?(_ tableColumn: NSTableColumn) {
self.init(rawValue: tableColumn.identifier.rawValue)
}
var cellIdentifier: NSUserInterfaceItemIdentifier {
return NSUserInterfaceItemIdentifier(self.rawValue + "Cell")
}
}
class ViewController: NSViewController {
@IBOutlet weak var outlineView: NSOutlineView!
/// The rows of the outline view
let rows: [OutlineViewRow] = {
var child1 = OutlineViewRow(title: "p1-child1", isSelected: true)
var child2 = OutlineViewRow(title: "p1-child2", isSelected: true)
var child3 = OutlineViewRow(title: "p1-child3", isSelected: true)
let parent1 = OutlineViewRow(title: "parent1", isSelected: true, children: [child1, child2, child3])
child1 = OutlineViewRow(title: "p2-child1", isSelected: true)
child2 = OutlineViewRow(title: "p2-child2", isSelected: true)
child3 = OutlineViewRow(title: "p2-child3", isSelected: true)
let parent2 = OutlineViewRow(title: "parent2", isSelected: true, children: [child1, child2, child3])
child1 = OutlineViewRow(title: "p3-child1", isSelected: true)
child2 = OutlineViewRow(title: "p3-child2", isSelected: true)
child3 = OutlineViewRow(title: "p3-child3", isSelected: true)
let parent3 = OutlineViewRow(title: "parent3", isSelected: true, children: [child1, child2, child3])
child3 = OutlineViewRow(title: "p4-child3", isSelected: true)
child2 = OutlineViewRow(title: "p4-child2", isSelected: true, children: [child3])
child1 = OutlineViewRow(title: "p4-child1", isSelected: true, children: [child2])
let parent4 = OutlineViewRow(title: "parent4", isSelected: true, children: [child1])
return [parent1, parent2, parent3, parent4]
}()
override func viewDidLoad() {
super.viewDidLoad()
outlineView.dataSource = self
outlineView.delegate = self
}
}
extension ViewController: NSOutlineViewDataSource, NSOutlineViewDelegate {
/// Returns how many children a row has. `item == nil` means the root row (not visible)
func outlineView(_ outlineView: NSOutlineView, numberOfChildrenOfItem item: Any?) -> Int {
switch item {
case nil: return rows.count
case let row as OutlineViewRow: return row.children.count
default: return 0
}
}
/// Returns the object that represents the row. `NSOutlineView` calls this the `item`
func outlineView(_ outlineView: NSOutlineView, child index: Int, ofItem item: Any?) -> Any {
switch item {
case nil: return rows[index]
case let row as OutlineViewRow: return row.children[index]
default: return NSNull()
}
}
/// Returns whether the row can be expanded
func outlineView(_ outlineView: NSOutlineView, isItemExpandable item: Any) -> Bool {
switch item {
case nil: return !rows.isEmpty
case let row as OutlineViewRow: return !row.children.isEmpty
default: return false
}
}
/// Returns the view that display the content for each cell of the outline view
func outlineView(_ outlineView: NSOutlineView, viewFor tableColumn: NSTableColumn?, item: Any) -> NSView? {
guard let item = item as? OutlineViewRow, let column = OutlineViewColumn(tableColumn!) else { return nil }
switch column {
case .isSelected:
let cell = outlineView.makeView(withIdentifier: column.cellIdentifier, owner: self) as! CheckboxCellView
cell.checkboxButton.state = item.isSelected ? .on : .off
cell.delegate = self
cell.item = item
return cell
case .title:
let cell = outlineView.makeView(withIdentifier: column.cellIdentifier, owner: self) as! NSTableCellView
cell.textField?.stringValue = item.title
return cell
}
}
}
extension ViewController: CheckboxCellViewDelegate {
/// A delegate function where we can act on update from the checkbox in the "Is Selected" column
func checkboxCellView(_ cell: CheckboxCellView, didChangeState state: NSControl.StateValue) {
guard let item = cell.item as? OutlineViewRow else { return }
// The row and its children are selected if state == .on
item.setIsSelected(state == .on, recursive: true)
// This is more efficient than calling reload on every child since collapsed children are
// not reloaded. They will be reloaded when they become visible
outlineView.reloadItem(item, reloadChildren: true)
}
}