From 39938a76c4dcb6311f92c2a39b38eefbda62583f Mon Sep 17 00:00:00 2001
From: giomfo <giom@matrix.org>
Date: Tue, 14 Oct 2014 22:50:24 +0200
Subject: [PATCH] Handle back pagination in room details

---
 .../syMessaging/Base.lproj/Main.storyboard    |  6 +++
 syMessaging/syMessaging/RoomViewController.m  | 41 ++++++++++++++++++-
 2 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/syMessaging/syMessaging/Base.lproj/Main.storyboard b/syMessaging/syMessaging/Base.lproj/Main.storyboard
index c58d74cfa..3a6391220 100644
--- a/syMessaging/syMessaging/Base.lproj/Main.storyboard
+++ b/syMessaging/syMessaging/Base.lproj/Main.storyboard
@@ -182,6 +182,9 @@
                                     <constraint firstAttribute="centerY" secondItem="cfF-YG-Cvg" secondAttribute="centerY" id="ugG-2r-MsO"/>
                                 </constraints>
                             </view>
+                            <activityIndicatorView hidden="YES" opaque="NO" contentMode="scaleToFill" horizontalHuggingPriority="750" verticalHuggingPriority="750" hidesWhenStopped="YES" style="gray" translatesAutoresizingMaskIntoConstraints="NO" id="dvT-c5-Ymf">
+                                <rect key="frame" x="290" y="100" width="20" height="20"/>
+                            </activityIndicatorView>
                         </subviews>
                         <color key="backgroundColor" white="1" alpha="1" colorSpace="calibratedWhite"/>
                         <constraints>
@@ -189,13 +192,16 @@
                             <constraint firstItem="6fM-aJ-d0M" firstAttribute="leading" secondItem="1BF-nV-MTf" secondAttribute="leading" id="7eH-ST-BbY"/>
                             <constraint firstItem="nNf-bE-8dQ" firstAttribute="top" secondItem="6fM-aJ-d0M" secondAttribute="bottom" id="C5t-bm-3s8"/>
                             <constraint firstAttribute="bottom" secondItem="meV-kn-sxo" secondAttribute="bottom" constant="44" id="Cos-M5-WHG"/>
+                            <constraint firstItem="dvT-c5-Ymf" firstAttribute="top" secondItem="it4-Tc-q7z" secondAttribute="bottom" constant="36" id="FV3-P0-ekh"/>
                             <constraint firstItem="meV-kn-sxo" firstAttribute="top" secondItem="1BF-nV-MTf" secondAttribute="top" id="OWt-4M-1DF"/>
                             <constraint firstItem="meV-kn-sxo" firstAttribute="leading" secondItem="1BF-nV-MTf" secondAttribute="leading" id="ext-xr-eNx"/>
+                            <constraint firstAttribute="centerX" secondItem="dvT-c5-Ymf" secondAttribute="centerX" id="u9d-Bd-6Ci"/>
                             <constraint firstAttribute="trailing" secondItem="meV-kn-sxo" secondAttribute="trailing" id="vBl-Ri-4Hb"/>
                         </constraints>
                     </view>
                     <navigationItem key="navigationItem" title="Room title" id="3Zt-Wl-J6o"/>
                     <connections>
+                        <outlet property="activityIndicator" destination="dvT-c5-Ymf" id="F6h-Al-Vw6"/>
                         <outlet property="controlView" destination="6fM-aJ-d0M" id="13g-Wl-z5n"/>
                         <outlet property="controlViewBottomConstraint" destination="C5t-bm-3s8" id="Ks1-Z5-mzO"/>
                         <outlet property="messageTextField" destination="k2m-aY-U73" id="fSA-Eg-duj"/>
diff --git a/syMessaging/syMessaging/RoomViewController.m b/syMessaging/syMessaging/RoomViewController.m
index 2ed594dbb..557ad897d 100644
--- a/syMessaging/syMessaging/RoomViewController.m
+++ b/syMessaging/syMessaging/RoomViewController.m
@@ -49,6 +49,7 @@
 @property (weak, nonatomic) IBOutlet UITextField *messageTextField;
 @property (weak, nonatomic) IBOutlet UIButton *sendBtn;
 @property (weak, nonatomic) IBOutlet NSLayoutConstraint *controlViewBottomConstraint;
+@property (weak, nonatomic) IBOutlet UIActivityIndicatorView *activityIndicator;
 
 @property (strong, nonatomic) MXRoomData *mxRoomData;
 
@@ -135,6 +136,7 @@
     
     [self scrollToBottomAnimated:YES];
     
+    // Move up control view
     // Don't forget the offset related to tabBar
     _controlViewBottomConstraint.constant = insets.bottom - [AppDelegate theDelegate].masterTabBarController.tabBar.frame.size.height;
 }
@@ -203,6 +205,43 @@
     [self dismissKeyboard];
 }
 
+// Detect vertical bounce at the top of the tableview to trigger pagination
+- (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset {
+    if (scrollView == self.tableView) {
+        // paginate ?
+        if ((scrollView.contentOffset.y < -64) && (_activityIndicator.isAnimating == NO))
+        {
+            if (self.mxRoomData.canPaginate)
+            {
+                [_activityIndicator startAnimating];
+                
+                [self.mxRoomData paginateBackMessages:20 success:^(NSArray *messages) {
+                    // Update room data
+                    self.mxRoomData = [[[MatrixHandler sharedHandler] mxData] getRoomData:self.roomId];
+                    
+                    // Refresh display
+                    [self.tableView beginUpdates];
+                    NSMutableArray *indexPaths = [NSMutableArray arrayWithCapacity:messages.count];
+                    for (NSUInteger index = 0; index < messages.count; index++) {
+                        [indexPaths addObject:[NSIndexPath indexPathForRow:index inSection:0]];
+                    }
+                    [self.tableView insertRowsAtIndexPaths:indexPaths withRowAnimation:UITableViewRowAnimationNone];
+                    [self.tableView endUpdates];
+                    
+                    // Maintain the current message in visible area
+                    [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:(messages.count - 1) inSection:0] atScrollPosition:UITableViewScrollPositionMiddle animated:YES];
+                    [_activityIndicator stopAnimating];
+                } failure:^(NSError *error) {
+                    [_activityIndicator stopAnimating];
+                    NSLog(@"Failed to paginate back: %@", error);
+                    //Alert user
+                    [[AppDelegate theDelegate] showErrorAsAlert:error];
+                }];
+            }
+        }
+    }
+}
+
 #pragma mark - UITextField delegate
 
 - (void)onTextFieldChange:(NSNotification *)notif {
@@ -240,7 +279,7 @@
         }];
     } else if (sender == _optionBtn) {
         [self dismissKeyboard];
-        //TODO
+        //TODO: display option menu (Attachments...)
     }
 }
 @end