From af4676ea9faa7264623d79682a16ea3f85c4b63a Mon Sep 17 00:00:00 2001
From: Marco Conti <marcoconti83@gmail.com>
Date: Thu, 1 Mar 2018 09:31:58 +0100
Subject: [PATCH] Ask for confirmation on operations

---
 EasyTables/EasyTableSource.swift            | 39 ++++++++++++++++++---
 EasyTables/ObjectOperation.swift            |  1 +
 EasyTablesExample/TableViewController.swift |  6 ++--
 3 files changed, 39 insertions(+), 7 deletions(-)

diff --git a/EasyTables/EasyTableSource.swift b/EasyTables/EasyTableSource.swift
index 634d90c..4fe6bc7 100644
--- a/EasyTables/EasyTableSource.swift
+++ b/EasyTables/EasyTableSource.swift
@@ -38,6 +38,8 @@ public class EasyTableSource<Object: Equatable> {
         return self.dataSource.table
     }
     
+    public typealias ConfirmationCallback = (Bool)->()
+    
     /// Creates a table configuration and applies it to a table
     /// The configuration needs to be retained as long as the table
     /// is retained
@@ -56,6 +58,7 @@ public class EasyTableSource<Object: Equatable> {
                 contextMenuOperations: [ObjectOperation<Object>],
                 table: NSTableView? = nil,
                 selectionModel: SelectionModel = .singleNative,
+                operationConfirmationCallback: @escaping (ConfirmationCallback, String)->() = ConfirmationAlert.ask,
                 selectionCallback: (([Object])->(Void))? = nil)
         where Objects.Iterator.Element == Object
     {
@@ -72,8 +75,10 @@ public class EasyTableSource<Object: Equatable> {
         
         table.dataSource = self.dataSource
         table.delegate = self.dataSource
-        self.setupTable(columns: columns, selectionModel: selectionModel)
-        self.setupMenu(operations: contextMenuOperations)
+        self.setupTable(columns: columns,
+                        selectionModel: selectionModel)
+        self.setupMenu(operations: contextMenuOperations,
+                       operationConfirmationCallback: operationConfirmationCallback)
     }
     
     /// Content of the table
@@ -119,7 +124,8 @@ extension EasyTableSource {
     
     /// Sets up the contextual menu for the table
     fileprivate func setupMenu(
-        operations: [ObjectOperation<Object>]
+        operations: [ObjectOperation<Object>],
+        operationConfirmationCallback: @escaping (ConfirmationCallback, String)->()
         ) {
         guard !operations.isEmpty else {
             self.table.menu = nil
@@ -131,7 +137,15 @@ extension EasyTableSource {
                 guard let `self` = self else { return }
                 let selectedObjects = self.targetObjectsForContextualOperation
                 guard !selectedObjects.isEmpty else { return }
-                operation.action(selectedObjects)
+                if operation.needsConfirmation {
+                    operationConfirmationCallback({
+                        if $0 {
+                            operation.action(selectedObjects)
+                        }
+                    }, operation.label)
+                } else {
+                    operation.action(selectedObjects)
+                }
             }
             menu.addItem(item)
             item.isEnabled = true
@@ -184,3 +198,20 @@ extension ComparisonResult {
         }
     }
 }
+
+
+public struct ConfirmationAlert {
+    static func OKCancel(message: String) -> Bool {
+        let alert = NSAlert()
+        alert.messageText = message
+        alert.alertStyle = .warning
+        alert.addButton(withTitle: "Yes")
+        alert.addButton(withTitle: "Cancel")
+        return alert.runModal() == .alertFirstButtonReturn
+    }
+    
+    public static func ask(callback: (Bool)->(), operation: String) {
+        let response = OKCancel(message: "\(operation)\nAre you sure?")
+        callback(response)
+    }
+}
diff --git a/EasyTables/ObjectOperation.swift b/EasyTables/ObjectOperation.swift
index dd96b84..9441d36 100644
--- a/EasyTables/ObjectOperation.swift
+++ b/EasyTables/ObjectOperation.swift
@@ -35,3 +35,4 @@ public struct ObjectOperation<Object> {
         self.needsConfirmation = needsConfirmation
     }
 }
+
diff --git a/EasyTablesExample/TableViewController.swift b/EasyTablesExample/TableViewController.swift
index 9383076..c100e77 100644
--- a/EasyTablesExample/TableViewController.swift
+++ b/EasyTablesExample/TableViewController.swift
@@ -56,7 +56,6 @@ class TableViewController: NSViewController {
         
         let (scroll, table) = NSTableView.inScrollView()
         self.createLayoutConstraints(table: scroll, button1: selectButton, button2: filterButton)
-        
         self.createTableSource(for: table)
 
     }
@@ -74,7 +73,7 @@ class TableViewController: NSViewController {
             ],
             contextMenuOperations: [
                 // Remove object from the table
-                ObjectOperation(label: "Remove", action: {
+                ObjectOperation(label: "Remove", needsConfirmation: true, action: {
                     [weak self] (items: [String]) -> Void in
                     guard let `self` = self else { return }
                     items.forEach {
@@ -124,7 +123,6 @@ class TableViewController: NSViewController {
             table.top == b1.bottom + space
         }
     }
-    
 }
 
 extension String {
@@ -134,3 +132,5 @@ extension String {
         return NSAttributedString(string: self, attributes: [NSAttributedStringKey.font: font])
     }
 }
+
+