Interactive/Cancelable slide left for details

// FREEBIE

Signal.xcodeproj/project.pbxproj

@@ -147,6 +147,8 @@
 		4521C3C01F59F3BA00B4C582 /* TextFieldHelper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4521C3BF1F59F3BA00B4C582 /* TextFieldHelper.swift */; };
 		4521C3C11F59F3BA00B4C582 /* TextFieldHelper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4521C3BF1F59F3BA00B4C582 /* TextFieldHelper.swift */; };
 		4523149C1F7D7F81003A428C /* OWSMessagesBubbleImageFactory.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4523149B1F7D7F81003A428C /* OWSMessagesBubbleImageFactory.swift */; };
+		4523149E1F7E916B003A428C /* SlideOffAnimatedTransition.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4523149D1F7E916B003A428C /* SlideOffAnimatedTransition.swift */; };
+		452314A01F7E9E18003A428C /* DirectionalPanGestureRecognizer.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4523149F1F7E9E18003A428C /* DirectionalPanGestureRecognizer.swift */; };
 		452C468F1E427E200087B011 /* OutboundCallInitiator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 452C468E1E427E200087B011 /* OutboundCallInitiator.swift */; };
 		452C46901E427E200087B011 /* OutboundCallInitiator.swift in Sources */ = {isa = PBXBuildFile; fileRef = 452C468E1E427E200087B011 /* OutboundCallInitiator.swift */; };
 		452D1EE81DCA90D100A57EC4 /* MesssagesBubblesSizeCalculatorTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 452D1EE71DCA90D100A57EC4 /* MesssagesBubblesSizeCalculatorTest.swift */; };
@@ -615,6 +617,8 @@
 		4520D8D41D417D8E00123472 /* Photos.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Photos.framework; path = System/Library/Frameworks/Photos.framework; sourceTree = SDKROOT; };
 		4521C3BF1F59F3BA00B4C582 /* TextFieldHelper.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = TextFieldHelper.swift; sourceTree = "<group>"; };
 		4523149B1F7D7F81003A428C /* OWSMessagesBubbleImageFactory.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = OWSMessagesBubbleImageFactory.swift; sourceTree = "<group>"; };
+		4523149D1F7E916B003A428C /* SlideOffAnimatedTransition.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = SlideOffAnimatedTransition.swift; path = UserInterface/SlideOffAnimatedTransition.swift; sourceTree = "<group>"; };
+		4523149F1F7E9E18003A428C /* DirectionalPanGestureRecognizer.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = DirectionalPanGestureRecognizer.swift; sourceTree = "<group>"; };
 		452C468E1E427E200087B011 /* OutboundCallInitiator.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = OutboundCallInitiator.swift; sourceTree = "<group>"; };
 		452D1EE71DCA90D100A57EC4 /* MesssagesBubblesSizeCalculatorTest.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = MesssagesBubblesSizeCalculatorTest.swift; path = Models/MesssagesBubblesSizeCalculatorTest.swift; sourceTree = "<group>"; };
 		452EA09D1EA7ABE00078744B /* AttachmentPointerView.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = AttachmentPointerView.swift; sourceTree = "<group>"; };
@@ -1211,6 +1215,7 @@
 				34B3F8331E8DF1700035BE1A /* ViewControllers */,
 				76EB052B18170B33006006FC /* Views */,
 				4523149B1F7D7F81003A428C /* OWSMessagesBubbleImageFactory.swift */,
+				4523149D1F7E916B003A428C /* SlideOffAnimatedTransition.swift */,
 			);
 			name = UserInterface;
 			sourceTree = "<group>";
@@ -1519,6 +1524,7 @@
 				45A6DAD51EBBF85500893231 /* ReminderView.swift */,
 				450D19111F85236600970622 /* RemoteVideoView.h */,
 				450D19121F85236600970622 /* RemoteVideoView.m */,
+				4523149F1F7E9E18003A428C /* DirectionalPanGestureRecognizer.swift */,
 			);
 			name = Views;
 			path = views;
@@ -2283,6 +2289,7 @@
 				76EB068618170B34006006FC /* ContactTableViewCell.m in Sources */,
 				3497DBEF1ECE2E4700DB2605 /* DomainFrontingCountryViewController.m in Sources */,
 				34B3F8881E8DF1700035BE1A /* OversizeTextMessageViewController.swift in Sources */,
+				452314A01F7E9E18003A428C /* DirectionalPanGestureRecognizer.swift in Sources */,
 				34330AA31E79686200DF2FB9 /* OWSProgressView.m in Sources */,
 				34B3F8A21E8EA6040035BE1A /* ViewControllerUtils.m in Sources */,
 				34CA1C271F7156F300E51C51 /* MessageMetadataViewController.swift in Sources */,
@@ -2317,6 +2324,7 @@
 				34B3F8911E8DF1710035BE1A /* ShowGroupMembersViewController.m in Sources */,
 				4539B5861F79348F007141FF /* PushRegistrationManager.swift in Sources */,
 				45FBC5D11DF8592E00E9B410 /* SignalCall.swift in Sources */,
+				4523149E1F7E916B003A428C /* SlideOffAnimatedTransition.swift in Sources */,
 				452C468F1E427E200087B011 /* OutboundCallInitiator.swift in Sources */,
 				45F170BB1E2FC5D3003FC1F2 /* CallAudioService.swift in Sources */,
 				34B3F8711E8DF1700035BE1A /* AboutTableViewController.m in Sources */,

Signal/src/UserInterface/SlideOffAnimatedTransition.swift

@@ -0,0 +1,51 @@
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
+
+import UIKit
+
+@objc
+class SlideOffAnimatedTransition: NSObject, UIViewControllerAnimatedTransitioning {
+
+    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
+
+        let containerView = transitionContext.containerView
+        guard let fromView = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.from)?.view else {
+            owsFail("No fromView")
+            return
+        }
+        guard let toView = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.to)?.view else {
+            owsFail("No toView")
+            return
+        }
+
+        let width = containerView.frame.width
+        let offsetLeft = fromView.frame.offsetBy(dx: -width, dy: 0)
+        toView.frame = fromView.frame
+
+        fromView.layer.shadowRadius = 15.0
+        fromView.layer.shadowOpacity = 1.0
+        toView.layer.opacity = 0.9
+
+        containerView.insertSubview(toView, belowSubview: fromView)
+        UIView.animate(withDuration: transitionDuration(using: transitionContext), delay:0, options: .curveLinear, animations: {
+            fromView.frame = offsetLeft
+
+            toView.layer.opacity = 1.0
+            fromView.layer.shadowOpacity = 0.1
+        }, completion: { _ in
+            toView.layer.opacity = 1.0
+            toView.layer.shadowOpacity = 0
+
+            fromView.layer.opacity = 1.0
+            fromView.layer.shadowOpacity = 0
+
+            transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
+        })
+    }
+
+    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
+        return 0.3
+    }
+
+}

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

@@ -24,6 +24,8 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)didTapFailedIncomingAttachment:(ConversationViewItem *)viewItem
                      attachmentPointer:(TSAttachmentPointer *)attachmentPointer;
 - (void)didTapFailedOutgoingMessage:(TSOutgoingMessage *)message;
+- (void)didPanWithGestureRecognizer:(UIPanGestureRecognizer *)gestureRecognizer
+                           viewItem:(ConversationViewItem *)conversationItem;
 
 - (void)showMetadataViewForMessage:(TSMessage *)message;
 

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

@@ -162,6 +162,12 @@ NS_ASSUME_NONNULL_BEGIN
     UILongPressGestureRecognizer *longPress =
         [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPressGesture:)];
     [self addGestureRecognizer:longPress];
+
+    PanDirectionGestureRecognizer *panGesture =
+        [[PanDirectionGestureRecognizer alloc] initWithDirection:PanDirectionHorizontal
+                                                          target:self
+                                                          action:@selector(handlePanGesture:)];
+    [self addGestureRecognizer:panGesture];
 }
 
 + (NSString *)cellReuseIdentifier
@@ -1029,6 +1035,13 @@ NS_ASSUME_NONNULL_BEGIN
     }
 }
 
+- (void)handlePanGesture:(UIPanGestureRecognizer *)panRecognizer
+{
+    OWSAssert(self.delegate);
+
+    [self.delegate didPanWithGestureRecognizer:panRecognizer viewItem:self.viewItem];
+}
+
 #pragma mark - UIMenuController
 
 - (void)showMenuController:(CGPoint)fromLocation

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -136,6 +136,10 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
     ConversationInputToolbarDelegate,
     GifPickerViewControllerDelegate>
 
+// Show message info animation
+@property (nullable, nonatomic) UIPercentDrivenInteractiveTransition *showMessageDetailsTransition;
+@property (nullable, nonatomic) UIPanGestureRecognizer *currentShowMessageDetailsPanGesture;
+
 @property (nonatomic) TSThread *thread;
 @property (nonatomic) YapDatabaseConnection *editingDatabaseConnection;
 
@@ -988,9 +992,14 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
 
     [super viewWillDisappear:animated];
 
-    self.isViewVisible = NO;
-
     [self.inputToolbar viewWillDisappear:animated];
+}
+
+- (void)viewDidDisappear:(BOOL)animated
+{
+    [super viewDidDisappear:animated];
+    self.userHasScrolled = NO;
+    self.isViewVisible = NO;
 
     [self.audioAttachmentPlayer stop];
     self.audioAttachmentPlayer = nil;
@@ -1005,12 +1014,6 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
     self.isUserScrolling = NO;
 }
 
-- (void)viewDidDisappear:(BOOL)animated
-{
-    [super viewDidDisappear:animated];
-    self.userHasScrolled = NO;
-}
-
 #pragma mark - Initiliazers
 
 - (void)setNavigationTitle
@@ -4036,6 +4039,110 @@ typedef NS_ENUM(NSInteger, MessagesRangeSizeMode) {
     return cell;
 }
 
+#pragma mark - swipe to show message details
+
+- (void)didPanWithGestureRecognizer:(UIPanGestureRecognizer *)gestureRecognizer
+                           viewItem:(ConversationViewItem *)conversationItem
+{
+    self.currentShowMessageDetailsPanGesture = gestureRecognizer;
+
+    const CGFloat leftTranslation = -1 * [gestureRecognizer translationInView:self.view].x;
+    const CGFloat percent = MAX(leftTranslation, 0) / self.view.frame.size.width;
+
+    switch (gestureRecognizer.state) {
+        case UIGestureRecognizerStateBegan: {
+            TSInteraction *interaction = conversationItem.interaction;
+            if ([interaction isKindOfClass:[TSIncomingMessage class]] ||
+                [interaction isKindOfClass:[TSOutgoingMessage class]]) {
+
+                // Canary check in case we later have another reason to set navigationController.delegate - we don't
+                // want to inadvertently clobber it here.
+                OWSAssert(self.navigationController.delegate == nil) self.navigationController.delegate = self;
+                TSMessage *message = (TSMessage *)interaction;
+                MessageMetadataViewController *view = [[MessageMetadataViewController alloc] initWithMessage:message];
+                [self.navigationController pushViewController:view animated:YES];
+            } else {
+                OWSFail(@"%@ Can't show message metadata for message of type: %@", self.tag, [interaction class]);
+            }
+            break;
+        }
+        case UIGestureRecognizerStateChanged: {
+            UIPercentDrivenInteractiveTransition *transition = self.showMessageDetailsTransition;
+            if (!transition) {
+                DDLogVerbose(@"%@ transition not set up yet", self.tag);
+                return;
+            }
+            [transition updateInteractiveTransition:percent];
+            break;
+        }
+        case UIGestureRecognizerStateEnded: {
+            const CGFloat velocity = [gestureRecognizer velocityInView:self.view].x;
+
+            UIPercentDrivenInteractiveTransition *transition = self.showMessageDetailsTransition;
+            if (!transition) {
+                DDLogVerbose(@"%@ transition not set up yet", self.tag);
+                return;
+            }
+
+            // Complete the transition if moved sufficiently far or fast
+            // Note this is trickier for incoming, since you are already on the left, and have less space.
+            if (percent > 0.3 || velocity < -800) {
+                [transition finishInteractiveTransition];
+            } else {
+                [transition cancelInteractiveTransition];
+            }
+            break;
+        }
+        case UIGestureRecognizerStateCancelled:
+        case UIGestureRecognizerStateFailed: {
+            UIPercentDrivenInteractiveTransition *transition = self.showMessageDetailsTransition;
+            if (!transition) {
+                DDLogVerbose(@"%@ transition not set up yet", self.tag);
+                return;
+            }
+
+            [transition cancelInteractiveTransition];
+            break;
+        }
+        default:
+            break;
+    }
+}
+
+- (nullable id<UIViewControllerAnimatedTransitioning>)navigationController:
+                                                          (UINavigationController *)navigationController
+                                           animationControllerForOperation:(UINavigationControllerOperation)operation
+                                                        fromViewController:(UIViewController *)fromVC
+                                                          toViewController:(UIViewController *)toVC
+{
+    return [SlideOffAnimatedTransition new];
+}
+
+- (nullable id<UIViewControllerInteractiveTransitioning>)
+                       navigationController:(UINavigationController *)navigationController
+interactionControllerForAnimationController:(id<UIViewControllerAnimatedTransitioning>)animationController
+{
+    // We needed to be the navigation controller delegate to specify the interactive "slide left for message details"
+    // animation But we may not want to be the navigation controller delegate permanently.
+    self.navigationController.delegate = nil;
+
+    DDLogInfo(@"%@ >>>> in %s", self.tag, __PRETTY_FUNCTION__);
+    UIPanGestureRecognizer *recognizer = self.currentShowMessageDetailsPanGesture;
+    if (recognizer == nil) {
+        OWSFail(@"currentShowMessageDetailsPanGesture was unexpectedly nil");
+        return nil;
+    }
+
+    if (recognizer.state == UIGestureRecognizerStateBegan) {
+        self.showMessageDetailsTransition = [UIPercentDrivenInteractiveTransition new];
+        self.showMessageDetailsTransition.completionCurve = UIViewAnimationCurveEaseOut;
+    } else {
+        self.showMessageDetailsTransition = nil;
+    }
+
+    return self.showMessageDetailsTransition;
+}
+
 #pragma mark - UICollectionViewDelegate
 
 - (void)collectionView:(UICollectionView *)collectionView

Signal/src/views/DirectionalPanGestureRecognizer.swift

@@ -0,0 +1,38 @@
+//
+//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//
+
+import UIKit.UIGestureRecognizerSubclass
+
+@objc
+enum PanDirection: Int {
+    case vertical
+    case horizontal
+}
+
+@objc
+class PanDirectionGestureRecognizer: UIPanGestureRecognizer {
+
+    let direction: PanDirection
+
+    init(direction: PanDirection, target: AnyObject, action: Selector) {
+        self.direction = direction
+        super.init(target: target, action: action)
+    }
+
+    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
+        super.touchesMoved(touches, with: event)
+
+        if state == .began {
+            let vel = velocity(in: view)
+            switch direction {
+            case .horizontal where fabs(vel.y) > fabs(vel.x):
+                state = .cancelled
+            case .vertical where fabs(vel.x) > fabs(vel.y):
+                state = .cancelled
+            default:
+                break
+            }
+        }
+    }
+}