#5488 Drag and Drop Images

Signal/ConversationView/ConversationInputTextView.swift

@@ -5,8 +5,12 @@
 
 public import SignalServiceKit
 import SignalUI
+import UIKit
+import MobileCoreServices
+import UniformTypeIdentifiers
 
 public protocol ConversationInputTextViewDelegate: AnyObject {
+    func didAttemptToDropAttachments(_ attachments: [SignalAttachment])
     func didAttemptAttachmentPaste()
     func inputTextViewSendMessagePressed()
     func textViewDidChange(_ textView: UITextView)
@@ -46,6 +50,10 @@ class ConversationInputTextView: BodyRangesTextView {
 
         contentMode = .redraw
         dataDetectorTypes = []
+
+        //Drop Interaction for images
+        let dropInteraction = UIDropInteraction(delegate: self)
+        addInteraction(dropInteraction)
 
         placeholderView.text = OWSLocalizedString(
             "INPUT_TOOLBAR_MESSAGE_PLACEHOLDER",
@@ -221,3 +229,25 @@ class ConversationInputTextView: BodyRangesTextView {
         textViewToolbarDelegate?.textViewDidChange(self)
     }
 }
+
+extension ConversationInputTextView : UIDropInteractionDelegate {
+
+    func dropInteraction(_ interaction: UIDropInteraction, canHandle session: any UIDropSession) -> Bool {
+        let inputUtiTypes = Array(MimeTypeUtil.supportedInputImageUtiTypes)
+        return session.hasItemsConforming(toTypeIdentifiers: inputUtiTypes)
+    }
+
+    func dropInteraction(_ interaction: UIDropInteraction, sessionDidUpdate session: any UIDropSession) -> UIDropProposal {
+        return UIDropProposal(operation: .copy)
+    }
+
+    func dropInteraction(_ interaction: UIDropInteraction, performDrop session: any UIDropSession) {
+        //session.loadObject automatically runs on the main thread as per documentation
+        session.loadObjects(ofClass: SignalAttachment.self) { attachmentItems in
+            if let attachments = attachmentItems as? [SignalAttachment] {
+                self.inputTextViewDelegate?.didAttemptToDropAttachments(attachments)
+            }
+        }
+    }
+
+}

Signal/ConversationView/ConversationViewController+Delegates.swift

@@ -223,6 +223,19 @@ extension ConversationViewController: ConversationHeaderViewDelegate {
 // MARK: -
 
 extension ConversationViewController: ConversationInputTextViewDelegate {
+
+    public func didAttemptToDropAttachments(_ attachments: [SignalAttachment]) {
+        //We only want one attachment (image for now)
+        if let firstAttachment = attachments.first {
+            if firstAttachment.isBorderless {
+                tryToSendAttachments([ firstAttachment ], messageBody: nil)
+            } else {
+                dismissKeyBoard()
+                showApprovalDialog(forAttachment: firstAttachment)
+            }
+        }
+    }
+
     public func didAttemptAttachmentPaste() {
         ModalActivityIndicatorViewController.present(fromViewController: self) { modal in
             let attachment: SignalAttachment? = await SignalAttachment.attachmentFromPasteboard()

Signal/ConversationView/ConversationViewController.swift

@@ -5,6 +5,7 @@
 
 public import SignalServiceKit
 public import SignalUI
+import UIKit
 
 public enum ConversationUIMode: UInt {
     case normal
@@ -223,6 +224,9 @@ public final class ConversationViewController: OWSViewController {
         loadCoordinator.viewDidLoad()
 
         self.startReloadTimer()
+
+        let dropInteraction = UIDropInteraction(delegate: self)
+        self.view.addInteraction(dropInteraction)
     }
 
     private func createContents() {
@@ -683,3 +687,31 @@ extension ConversationViewController: ContactsViewHelperObserver {
         loadCoordinator.enqueueReload(canReuseInteractionModels: true, canReuseComponentStates: false)
     }
 }
+
+extension ConversationViewController: UIDropInteractionDelegate {
+
+    public func dropInteraction(_ interaction: UIDropInteraction, canHandle session: any UIDropSession) -> Bool {
+        let inputUtiTypes = Array(MimeTypeUtil.supportedInputImageUtiTypes)
+        return session.hasItemsConforming(toTypeIdentifiers: inputUtiTypes) && uiMode == .normal
+    }
+
+    public func dropInteraction(_ interaction: UIDropInteraction, sessionDidUpdate session: any UIDropSession) -> UIDropProposal {
+        return UIDropProposal(operation: .copy)
+    }
+
+    public func dropInteraction(_ interaction: UIDropInteraction, performDrop session: any UIDropSession) {
+        //session.loadObject automatically runs on the main thread as per documentation
+        session.loadObjects(ofClass: SignalAttachment.self) { [weak self] attachmentItems in
+            if let attachments = attachmentItems as? [SignalAttachment], let firstAttachment = attachments.first {
+                //MARK: Perhaps if we're using this code block so much, it should be refactored into its own function somewhere.
+                if firstAttachment.isBorderless {
+                    self?.tryToSendAttachments([ firstAttachment ], messageBody: nil)
+                } else {
+                    self?.dismissKeyBoard()
+                    self?.showApprovalDialog(forAttachment: firstAttachment)
+                }
+            }
+        }
+    }
+
+}

SignalServiceKit/Attachments/SignalAttachment.swift

@@ -1387,3 +1387,17 @@ public class SignalAttachment: NSObject {
         return attachment
     }
 }
+
+
+extension SignalAttachment : NSItemProviderReading {
+
+    public static var readableTypeIdentifiersForItemProvider: [String] {
+        return Array(inputImageUTISet) //Only support images for now
+    }
+
+    public static func object(withItemProviderData data: Data, typeIdentifier: String) throws -> Self {
+        let dataSource = DataSourceValue(data, utiType: typeIdentifier)
+        return imageAttachment(dataSource: dataSource, dataUTI: typeIdentifier, isBorderless: dataSource?.hasStickerLikeProperties ?? false) as! Self
+    }
+
+}