From 6dfbafe71aba41bdcf8aba331c1c193c88b42561 Mon Sep 17 00:00:00 2001
From: Vitaly Takmazov
Date: Sun, 3 Nov 2013 04:38:05 +0400
Subject: Pull to refresh and infinite scrolling

---
 Juick/MasterViewController.m | 92 +++++++++++++++++++++++++++++---------------
 1 file changed, 60 insertions(+), 32 deletions(-)

(limited to 'Juick/MasterViewController.m')

diff --git a/Juick/MasterViewController.m b/Juick/MasterViewController.m
index 74b4fdc..26035cd 100644
--- a/Juick/MasterViewController.m
+++ b/Juick/MasterViewController.m
@@ -14,42 +14,74 @@
 
 static NSString *CellIdentifier = @"MessageCell";
 
-@interface MasterViewController () {
-    NSMutableArray *messages;
-}
+@interface MasterViewController ();
+
+@property(nonatomic, strong) NSMutableArray *messages;
+@property(nonatomic, assign) Boolean dataLoading;
+
 @end
 
 @implementation MasterViewController
 
+- (void) refreshData:(UIRefreshControl *)refresh {
+    [self.messages removeAllObjects];
+    [self.tableView reloadData];
+    NSURL *url = [NSURL URLWithString:@"https://api.juick.com/messages"];
+    
+    NSArray *next = [Message pullNextFromURL:url];
+    int64_t delayInSeconds = 2.0;
+    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (delayInSeconds * NSEC_PER_SEC));
+    dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
+        [self.tableView beginUpdates];
+        CGPoint offset = self.tableView.contentOffset;
+        for (int i = 0; i < [next count]; i++) {
+            [self.messages addObject:[next objectAtIndex:i]];
+            [self.tableView insertRowsAtIndexPaths:@[[NSIndexPath indexPathForRow:self.messages.count-1 inSection:0]] withRowAnimation:UITableViewRowAnimationNone];
+        }
+        [self.tableView setContentOffset:offset animated:NO];
+        [self.tableView endUpdates];
+        [refresh endRefreshing];
+    });
+}
+
+- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
+    CGPoint pos = scrollView.contentOffset;
+    CGFloat contentHeight = scrollView.contentSize.height - scrollView.contentSize.height / 3;
+    if (pos.y >= contentHeight && !self.dataLoading) {
+        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{
+            self.dataLoading = YES;
+            Message * lastMessage = [self.messages lastObject];
+            NSArray *next = [Message pullNextFromURL:[NSURL URLWithString:[NSString stringWithFormat:@"http://api.juick.com/messages?before_mid=%@", lastMessage.MID]]];
+            int64_t delayInSeconds = 2.0;
+            dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (delayInSeconds * NSEC_PER_SEC));
+            dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
+                [self.tableView beginUpdates];
+                for (int i = 0; i < [next count]; i++) {
+                    [self.messages addObject:[next objectAtIndex:i]];
+                    [self.tableView insertRowsAtIndexPaths:@[[NSIndexPath indexPathForRow:self.messages.count-1 inSection:0]] withRowAnimation:UITableViewRowAnimationNone];
+                }
+                [self.tableView setContentOffset:pos animated:NO];
+                [self.tableView endUpdates];
+                self.dataLoading = NO;
+            });
+        });
+        
+    }
+}
 
 - (void)viewDidLoad
 {
     [super viewDidLoad];
+    self.dataLoading = NO;
     self.title = @"Messages";
-    // Change button color
-    
-    // Set the gesture
-    messages = [[NSMutableArray alloc] init];
-    NSError *error;
-    NSURL *url = [NSURL URLWithString:@"http://api.juick.com/messages"];
-    NSString *data = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncoding error:&error];
-    if (data == nil) {
-        NSLog(@"Download Error: %@", error);
-        return;
-    }
-    NSArray *resultObject = [NSJSONSerialization JSONObjectWithData:[data dataUsingEncoding:NSUTF8StringEncoding] options:kNilOptions error:&error];
-    if (resultObject == nil) {
-        NSLog(@"JSON Error: %@", error);
-        return;
-    }
+    self.messages = [NSMutableArray array];
+    UIRefreshControl *refresh = [[UIRefreshControl alloc] init];
+    [refresh addTarget:self action:@selector(refreshData:) forControlEvents:UIControlEventValueChanged];
+    self.refreshControl = refresh;
     
-    for (NSDictionary *message in resultObject) {
-        Message *msg = [[Message alloc] initWithDictionary:message];
-        [messages addObject:msg];
-    }
     //UINib *cellNib = [UINib nibWithNibName:@"MessageCell" bundle:nil];
     //[self.tableView registerNib:cellNib forCellReuseIdentifier:@"MessageCell"];
-    [self.tableView registerClass:[MessageCell class] forCellReuseIdentifier:CellIdentifier];
+    [self.tableView registerClass:[MessageCell class] forCellReuseIdentifier:CellIdentifier];    
     
 }
 
@@ -83,22 +115,18 @@ static NSString *CellIdentifier = @"MessageCell";
     [self.tableView reloadData];
 }
 
--(void) parserDidEndDocument:(NSXMLParser *)parser {
-    [self.tableView reloadData];
-}
-
 - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
     return 1;
 }
 
 - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
-    return messages.count;
+    return _messages.count;
 }
 
 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
     MessageCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
     [cell updateFonts];
-    Message *msg = [messages objectAtIndex:indexPath.row];
+    Message *msg = [_messages objectAtIndex:indexPath.row];
     cell.titleLabel.text = msg.user;
     cell.bodyLabel.text =  msg.text;
     [cell setNeedsUpdateConstraints];
@@ -112,7 +140,7 @@ static NSString *CellIdentifier = @"MessageCell";
     
     [cell updateFonts];
     
-    Message *msg = [messages objectAtIndex:indexPath.row];
+    Message *msg = [_messages objectAtIndex:indexPath.row];
     cell.titleLabel.text = msg.user;
     cell.bodyLabel.text =  msg.text;
     
@@ -130,7 +158,7 @@ static NSString *CellIdentifier = @"MessageCell";
 
 - (CGFloat)tableView:(UITableView *)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath *)indexPath
 {
-    return 500.0f;
+    return 100.0f;
 }
 
 
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