Make LinkPreviewView reusable.

Signal/src/ViewControllers/ConversationView/Cells/OWSMessageBubbleView.h

@@ -1,5 +1,5 @@
 //
-//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2019 Open Whisper Systems. All rights reserved.
 //
 
 NS_ASSUME_NONNULL_BEGIN
@@ -10,6 +10,7 @@ NS_ASSUME_NONNULL_BEGIN
 @protocol ConversationViewItem;
 
 @class OWSContact;
+@class OWSLinkPreview;
 @class OWSQuotedReplyModel;
 @class TSAttachmentPointer;
 @class TSAttachmentStream;
@@ -21,6 +22,7 @@ typedef NS_ENUM(NSUInteger, OWSMessageGestureLocation) {
     OWSMessageGestureLocation_OversizeText,
     OWSMessageGestureLocation_Media,
     OWSMessageGestureLocation_QuotedReply,
+    OWSMessageGestureLocation_LinkPreview,
 };
 
 extern const UIDataDetectorTypes kOWSAllowedDataDetectorTypes;
@@ -46,6 +48,8 @@ extern const UIDataDetectorTypes kOWSAllowedDataDetectorTypes;
                                  quotedReply:(OWSQuotedReplyModel *)quotedReply
     failedThumbnailDownloadAttachmentPointer:(TSAttachmentPointer *)attachmentPointer;
 
+- (void)didTapConversationItem:(id<ConversationViewItem>)viewItem linkPreview:(OWSLinkPreview *)linkPreview;
+
 - (void)didTapContactShareViewItem:(id<ConversationViewItem>)viewItem;
 
 - (void)didTapSendMessageToContactShare:(ContactShareViewModel *)contactShare

Signal/src/ViewControllers/ConversationView/Cells/OWSMessageBubbleView.m

@@ -40,6 +40,8 @@ const UIDataDetectorTypes kOWSAllowedDataDetectorTypes
 
 @property (nonatomic, nullable) UIView *bodyMediaView;
 
+@property (nonatomic, nullable) LinkPreviewView *linkPreviewView;
+
 // Should lazy-load expensive view contents (images, etc.).
 // Should do nothing if view is already loaded.
 @property (nonatomic, nullable) dispatch_block_t loadCellContentBlock;
@@ -1158,6 +1160,13 @@ const UIDataDetectorTypes kOWSAllowedDataDetectorTypes
         }
     }
 
+    if (self.viewItem.linkPreview) {
+        CGSize linkPreviewSize = [LinkPreviewView measureWithConversationViewItem:self.viewItem];
+        linkPreviewSize.width = MIN(linkPreviewSize.width, self.conversationStyle.maxMessageWidth);
+        cellSize.width = MAX(cellSize.width, linkPreviewSize.width);
+        cellSize.height += linkPreviewSize.height;
+    }
+
     NSValue *_Nullable bodyTextSize = [self bodyTextSize];
     if (bodyTextSize) {
         [textViewSizes addObject:bodyTextSize];
@@ -1284,6 +1293,9 @@ const UIDataDetectorTypes kOWSAllowedDataDetectorTypes
 
     [self.contactShareButtonsView removeFromSuperview];
     self.contactShareButtonsView = nil;
+
+    [self.linkPreviewView removeFromSuperview];
+    self.linkPreviewView = nil;
 }
 
 #pragma mark - Gestures
@@ -1338,6 +1350,13 @@ const UIDataDetectorTypes kOWSAllowedDataDetectorTypes
                 OWSFailDebug(@"Missing quoted message.");
             }
             break;
+        case OWSMessageGestureLocation_LinkPreview:
+            if (self.viewItem.linkPreview) {
+                [self.delegate didTapConversationItem:self.viewItem linkPreview:self.viewItem.linkPreview];
+            } else {
+                OWSFailDebug(@"Missing link preview.");
+            }
+            break;
     }
 }
 
@@ -1426,6 +1445,17 @@ const UIDataDetectorTypes kOWSAllowedDataDetectorTypes
         }
     }
 
+    if (self.linkPreviewView) {
+        // Treat this as a "quoted reply" gesture if:
+        //
+        // * There is a "quoted reply" view.
+        // * The gesture occured within or above the "quoted reply" view.
+        CGPoint location = [self convertPoint:locationInMessageBubble toView:self.linkPreviewView];
+        if (CGRectContainsPoint(self.linkPreviewView.bounds, location)) {
+            return OWSMessageGestureLocation_LinkPreview;
+        }
+    }
+
     if (self.bodyMediaView) {
         // Treat this as a "body media" gesture if:
         //

Signal/src/ViewControllers/ConversationView/Cells/OWSMessageCell.m

@@ -1,5 +1,5 @@
 //
-//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2019 Open Whisper Systems. All rights reserved.
 //
 
 #import "OWSMessageCell.h"
@@ -438,7 +438,8 @@ NS_ASSUME_NONNULL_BEGIN
     CGPoint locationInMessageBubble = [sender locationInView:self.messageBubbleView];
     switch ([self.messageBubbleView gestureLocationForLocation:locationInMessageBubble]) {
         case OWSMessageGestureLocation_Default:
-        case OWSMessageGestureLocation_OversizeText: {
+        case OWSMessageGestureLocation_OversizeText:
+        case OWSMessageGestureLocation_LinkPreview: {
             [self.delegate conversationCell:self
                            shouldAllowReply:shouldAllowReply
                    didLongpressTextViewItem:self.viewItem];

Signal/src/ViewControllers/ConversationView/ConversationInputToolbar.m

@@ -765,7 +765,8 @@ const CGFloat kMaxTextViewHeight = 98;
 
     [self clearLinkPreviewView];
 
-    LinkPreviewView *linkPreviewView = [[LinkPreviewView alloc] initWithState:state delegate:self];
+    LinkPreviewView *linkPreviewView = [[LinkPreviewView alloc] initWithDelegate:self];
+    linkPreviewView.state = state;
     self.linkPreviewView = linkPreviewView;
     // TODO: Revisit once we have a separate quoted reply view.
     [self.contentRows insertArrangedSubview:linkPreviewView atIndex:0];

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -2338,6 +2338,13 @@ typedef enum : NSUInteger {
     // TODO: Highlight the quoted message?
 }
 
+- (void)didTapConversationItem:(id<ConversationViewItem>)viewItem linkPreview:(OWSLinkPreview *)linkPreview
+{
+    OWSAssertIsOnMainThread();
+
+    // TODO:
+}
+
 - (void)showDetailViewForViewItem:(id<ConversationViewItem>)conversationItem
 {
     OWSAssertIsOnMainThread();

Signal/src/ViewControllers/MessageDetailViewController.swift

@@ -1,5 +1,5 @@
 //
-//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2019 Open Whisper Systems. All rights reserved.
 //
 
 import Foundation
@@ -710,6 +710,12 @@ class MessageDetailViewController: OWSViewController, MediaGalleryDataSourceDele
         // no - op
     }
 
+    func didTapConversationItem(_ viewItem: ConversationViewItem, linkPreview: OWSLinkPreview) {
+        // no - op
+
+        // TODO:
+    }
+
     @objc func didLongPressSent(sender: UIGestureRecognizer) {
         guard sender.state == .began else {
             return

Signal/src/views/LinkPreviewView.swift

@@ -197,7 +197,16 @@ public protocol LinkPreviewViewDelegate {
 @objc
 public class LinkPreviewView: UIStackView {
     private weak var delegate: LinkPreviewViewDelegate?
-    private let state: LinkPreviewState
+
+    @objc
+    public var state: LinkPreviewState? {
+        didSet {
+            AssertIsOnMainThread()
+            assert(oldValue == nil)
+
+            updateContents()
+        }
+    }
 
     @available(*, unavailable, message:"use other constructor instead.")
     required init(coder aDecoder: NSCoder) {
@@ -209,30 +218,44 @@ public class LinkPreviewView: UIStackView {
         notImplemented()
     }
 
-    private let imageView = UIImageView()
+    private var cancelButton: UIButton?
-    private let titleLabel = UILabel()
+    private var layoutConstraints = [NSLayoutConstraint]()
-    private let domainLabel = UILabel()
 
     @objc
-    public init(state: LinkPreviewState,
+    public init(delegate: LinkPreviewViewDelegate?) {
-                delegate: LinkPreviewViewDelegate?) {
-        self.state = state
         self.delegate = delegate
 
         super.init(frame: .zero)
 
-        createContents()
+        self.isUserInteractionEnabled = true
+        self.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(wasTapped)))
     }
 
     private var isApproval: Bool {
         return delegate != nil
     }
 
-    private func createContents() {
+    private func resetContents() {
+        for subview in subviews {
+            subview.removeFromSuperview()
+        }
+        self.axis = .horizontal
+        self.alignment = .center
+        self.distribution = .fill
+        self.spacing = 0
 
-        self.isUserInteractionEnabled = true
+        cancelButton = nil
-        self.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(wasTapped)))
 
+        NSLayoutConstraint.deactivate(layoutConstraints)
+        layoutConstraints = []
+    }
+
+    private func updateContents() {
+        resetContents()
+
+        guard let state = state else {
+            return
+        }
         guard state.isLoaded() else {
             createLoadingContents()
             return
@@ -241,7 +264,7 @@ public class LinkPreviewView: UIStackView {
             createMessageContents()
             return
         }
-        createApprovalContents()
+        createApprovalContents(state: state)
     }
 
     private func createMessageContents() {
@@ -250,9 +273,7 @@ public class LinkPreviewView: UIStackView {
 
     private let approvalHeight: CGFloat = 76
 
-    private var cancelButton: UIButton?
+    private func createApprovalContents(state: LinkPreviewState) {
-
-    private func createApprovalContents() {
         self.axis = .horizontal
         self.alignment = .fill
         self.distribution = .equalSpacing
@@ -260,7 +281,7 @@ public class LinkPreviewView: UIStackView {
 
         // Image
 
-        if let imageView = createImageView() {
+        if let imageView = createImageView(state: state) {
             imageView.contentMode = .scaleAspectFill
             imageView.autoPinToSquareAspectRatio()
             let imageSize = approvalHeight
@@ -346,7 +367,7 @@ public class LinkPreviewView: UIStackView {
         strokeView.autoSetDimension(.height, toSize: CGHairlineWidth())
     }
 
-    private func createImageView() -> UIImageView? {
+    private func createImageView(state: LinkPreviewState) -> UIImageView? {
         guard state.isLoaded() else {
             owsFailDebug("State not loaded.")
             return nil
@@ -367,7 +388,7 @@ public class LinkPreviewView: UIStackView {
     private func createLoadingContents() {
         self.axis = .vertical
         self.alignment = .center
-        self.autoSetDimension(.height, toSize: approvalHeight)
+        self.layoutConstraints.append(self.autoSetDimension(.height, toSize: approvalHeight))
 
         let activityIndicator = UIActivityIndicatorView(activityIndicatorStyle: .gray)
         activityIndicator.startAnimating()
@@ -379,6 +400,9 @@ public class LinkPreviewView: UIStackView {
     // MARK: Events
 
     @objc func wasTapped(sender: UIGestureRecognizer) {
+        guard let state = state else {
+            return
+        }
         guard sender.state == .recognized else {
             return
         }
@@ -392,7 +416,15 @@ public class LinkPreviewView: UIStackView {
                 return
             }
         }
-        self.delegate?.linkPreviewDidTap?(urlString: self.state.urlString())
+        self.delegate?.linkPreviewDidTap?(urlString: state.urlString())
+    }
+
+    // MARK: Measurement
+
+    @objc
+    public class func measure(withConversationViewItem item: ConversationViewItem) -> CGSize {
+        // TODO:
+        return CGSize.zero
     }
 
     @objc func didTapCancel(sender: UIButton) {