Improved performance (partly) by image caching for static images

example/UIBubbleTableViewExample.xcodeproj/project.pbxproj

@@ -7,6 +7,8 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		20489A9519235BF9002CFE85 /* Default-568h@2x.png in Resources */ = {isa = PBXBuildFile; fileRef = 20489A9419235BF9002CFE85 /* Default-568h@2x.png */; };
+		20489A9819236065002CFE85 /* ImageCache.m in Sources */ = {isa = PBXBuildFile; fileRef = 20489A9719236065002CFE85 /* ImageCache.m */; };
 		76687AFD1622039C00707588 /* UIBubbleTypingTableViewCell.m in Sources */ = {isa = PBXBuildFile; fileRef = 76687AFC1622039C00707588 /* UIBubbleTypingTableViewCell.m */; };
 		76687AFF162203AF00707588 /* halloween.jpg in Resources */ = {isa = PBXBuildFile; fileRef = 76687AFE162203AF00707588 /* halloween.jpg */; };
 		76D097CC1621F0E000C17816 /* UIBubbleHeaderTableViewCell.m in Sources */ = {isa = PBXBuildFile; fileRef = 76D097CB1621F0E000C17816 /* UIBubbleHeaderTableViewCell.m */; };
@@ -37,6 +39,9 @@
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
+		20489A9419235BF9002CFE85 /* Default-568h@2x.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "Default-568h@2x.png"; sourceTree = "<group>"; };
+		20489A9619236065002CFE85 /* ImageCache.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = ImageCache.h; path = ../../src/ImageCache.h; sourceTree = "<group>"; };
+		20489A9719236065002CFE85 /* ImageCache.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = ImageCache.m; path = ../../src/ImageCache.m; sourceTree = "<group>"; };
 		76687AFB1622039C00707588 /* UIBubbleTypingTableViewCell.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = UIBubbleTypingTableViewCell.h; path = ../../src/UIBubbleTypingTableViewCell.h; sourceTree = "<group>"; };
 		76687AFC1622039C00707588 /* UIBubbleTypingTableViewCell.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = UIBubbleTypingTableViewCell.m; path = ../../src/UIBubbleTypingTableViewCell.m; sourceTree = "<group>"; };
 		76687AFE162203AF00707588 /* halloween.jpg */ = {isa = PBXFileReference; lastKnownFileType = image.jpeg; path = halloween.jpg; sourceTree = SOURCE_ROOT; };
@@ -94,6 +99,7 @@
 		76ED205315BF096C00E186D3 = {
 			isa = PBXGroup;
 			children = (
+				20489A9419235BF9002CFE85 /* Default-568h@2x.png */,
 				76ED206815BF096C00E186D3 /* UIBubbleTableViewExample */,
 				76ED206115BF096C00E186D3 /* Frameworks */,
 				76ED205F15BF096C00E186D3 /* Products */,
@@ -151,6 +157,8 @@
 		76ED208315BF09AD00E186D3 /* src */ = {
 			isa = PBXGroup;
 			children = (
+				20489A9619236065002CFE85 /* ImageCache.h */,
+				20489A9719236065002CFE85 /* ImageCache.m */,
 				76ED208915BF0BB100E186D3 /* NSBubbleData.h */,
 				76ED208A15BF0BB100E186D3 /* NSBubbleData.m */,
 				76ED208515BF09E300E186D3 /* UIBubbleTableView.h */,
@@ -210,7 +218,7 @@
 		76ED205515BF096C00E186D3 /* Project object */ = {
 			isa = PBXProject;
 			attributes = {
-				LastUpgradeCheck = 0430;
+				LastUpgradeCheck = 0510;
 			};
 			buildConfigurationList = 76ED205815BF096C00E186D3 /* Build configuration list for PBXProject "UIBubbleTableViewExample" */;
 			compatibilityVersion = "Xcode 3.2";
@@ -242,6 +250,7 @@
 				C83B107A15DE43180067DADE /* bubbleMine@2x.png in Resources */,
 				C83B107B15DE43180067DADE /* bubbleSomeone.png in Resources */,
 				C83B107C15DE43180067DADE /* bubbleSomeone@2x.png in Resources */,
+				20489A9519235BF9002CFE85 /* Default-568h@2x.png in Resources */,
 				C83B107D15DE43180067DADE /* typingMine.png in Resources */,
 				C83B107E15DE43180067DADE /* typingMine@2x.png in Resources */,
 				C83B107F15DE43180067DADE /* typingSomeone.png in Resources */,
@@ -267,6 +276,7 @@
 				76ED208B15BF0BB100E186D3 /* NSBubbleData.m in Sources */,
 				76ED209415BF29EE00E186D3 /* UIBubbleTableViewCell.m in Sources */,
 				76D097CC1621F0E000C17816 /* UIBubbleHeaderTableViewCell.m in Sources */,
+				20489A9819236065002CFE85 /* ImageCache.m in Sources */,
 				76687AFD1622039C00707588 /* UIBubbleTypingTableViewCell.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -297,7 +307,12 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				ARCHS = "$(ARCHS_STANDARD_32_BIT)";
+				CLANG_WARN_BOOL_CONVERSION = YES;
+				CLANG_WARN_CONSTANT_CONVERSION = YES;
+				CLANG_WARN_EMPTY_BODY = YES;
+				CLANG_WARN_ENUM_CONVERSION = YES;
+				CLANG_WARN_INT_CONVERSION = YES;
+				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "iPhone Developer";
 				COPY_PHASE_STRIP = NO;
 				GCC_C_LANGUAGE_STANDARD = gnu99;
@@ -309,10 +324,14 @@
 				);
 				GCC_SYMBOLS_PRIVATE_EXTERN = NO;
 				GCC_VERSION = com.apple.compilers.llvm.clang.1_0;
+				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 				GCC_WARN_ABOUT_RETURN_TYPE = YES;
+				GCC_WARN_UNDECLARED_SELECTOR = YES;
 				GCC_WARN_UNINITIALIZED_AUTOS = YES;
+				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 5.1;
+				IPHONEOS_DEPLOYMENT_TARGET = 7.1;
+				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = iphoneos;
 			};
 			name = Debug;
@@ -321,15 +340,23 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
-				ARCHS = "$(ARCHS_STANDARD_32_BIT)";
+				CLANG_WARN_BOOL_CONVERSION = YES;
+				CLANG_WARN_CONSTANT_CONVERSION = YES;
+				CLANG_WARN_EMPTY_BODY = YES;
+				CLANG_WARN_ENUM_CONVERSION = YES;
+				CLANG_WARN_INT_CONVERSION = YES;
+				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "iPhone Developer";
 				COPY_PHASE_STRIP = YES;
 				GCC_C_LANGUAGE_STANDARD = gnu99;
 				GCC_VERSION = com.apple.compilers.llvm.clang.1_0;
+				GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 				GCC_WARN_ABOUT_RETURN_TYPE = YES;
+				GCC_WARN_UNDECLARED_SELECTOR = YES;
 				GCC_WARN_UNINITIALIZED_AUTOS = YES;
+				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 5.1;
+				IPHONEOS_DEPLOYMENT_TARGET = 7.1;
 				OTHER_CFLAGS = "-DNS_BLOCK_ASSERTIONS=1";
 				SDKROOT = iphoneos;
 				VALIDATE_PRODUCT = YES;

example/UIBubbleTableViewExample/ViewController.m

@@ -82,7 +82,7 @@ - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interface
 
 #pragma mark - UIBubbleTableViewDataSource implementation
 
-- (NSInteger)rowsForBubbleTable:(UIBubbleTableView *)tableView
+- (NSUInteger)rowsForBubbleTable:(UIBubbleTableView *)tableView
 {
     return [bubbleData count];
 }

src/ImageCache.h

@@ -0,0 +1,24 @@
+//
+//  ImageCache.h
+//  InstrumentsTutorial
+//
+//  Created by Matt Galloway on 06/09/2012.
+//  Copyright (c) 2012 Swipe Stack Ltd. All rights reserved.
+//  Modified by Lubos Ilcik on 14/05/2014.
+//
+
+#import <Foundation/Foundation.h>
+
+typedef void(^ImageCacheDownloadCompletionHandler)(UIImage *image);
+
+@interface ImageCache : NSObject
+
++ (id)sharedInstance;
+
+- (UIImage*)imageForKey:(NSString*)key;
+- (void)setImage:(UIImage*)image forKey:(NSString*)key;
+- (void)downloadImageAtURL:(NSURL*)url completionHandler:(ImageCacheDownloadCompletionHandler)completion;
+- (UIImage*)imageNamed:(NSString*)name;
+- (UIImage *)imageNamed:(NSString*)name stretchableWithLeftCapWidth:(NSInteger)leftCapWidth topCapHeight:(NSInteger)topCapHeight;
+
+@end

src/ImageCache.m

@@ -0,0 +1,84 @@
+//
+//  ImageCache.m
+//  InstrumentsTutorial
+//
+//  Created by Matt Galloway on 06/09/2012.
+//  Copyright (c) 2012 Swipe Stack Ltd. All rights reserved.
+//  Modified by Lubos Ilcik on 14/05/2014.
+//
+
+#import "ImageCache.h"
+
+@interface ImageCache () {
+    NSMutableDictionary *_cache;
+}
+@end
+
+@implementation ImageCache
+
++ (id)sharedInstance {
+    static ImageCache *sharedInstance = nil;
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        sharedInstance = [[[self class] alloc] init];
+    });
+    return sharedInstance;
+}
+
+- (id)init {
+    if ((self = [super init])) {
+        _cache = [NSMutableDictionary new];
+         [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(memoryWarning:) name:UIApplicationDidReceiveMemoryWarningNotification object:nil];
+    }
+    return self;
+}
+
+- (UIImage*)imageForKey:(NSString*)key {
+    return [_cache objectForKey:key];
+}
+
+- (void)setImage:(UIImage*)image forKey:(NSString*)key {
+    [_cache setObject:image forKey:key];
+}
+
+- (void)downloadImageAtURL:(NSURL*)url completionHandler:(ImageCacheDownloadCompletionHandler)completion {
+    UIImage *cachedImage = [self imageForKey:[url absoluteString]];
+    if (cachedImage) {
+        completion(cachedImage);
+    } else {
+        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
+            NSData *data = [NSData dataWithContentsOfURL:url];
+            UIImage *image = [UIImage imageWithData:data];
+            [self setImage:image forKey:[url absoluteString]];
+            dispatch_async(dispatch_get_main_queue(), ^{
+                completion(image);
+            });
+        });
+    }
+}
+
+- (UIImage*)imageNamed:(NSString*)name {
+    UIImage *image;
+    if (!(image = [self imageForKey:name])) {
+        image = [UIImage imageNamed:name];
+        [self setImage:image forKey:name];
+    }
+    return image;
+}
+
+- (UIImage *)imageNamed:(NSString*)name stretchableWithLeftCapWidth:(NSInteger)leftCapWidth topCapHeight:(NSInteger)topCapHeight {
+    UIImage *image;
+    if (!(image = [self imageForKey:name])) {
+        image = [[UIImage imageNamed:name] stretchableImageWithLeftCapWidth:leftCapWidth topCapHeight:topCapHeight];
+        [self setImage:image forKey:name];
+    }
+    return image;
+}
+
+#pragma mark - Private
+
+- (void)memoryWarning:(NSNotification*)note {
+    [_cache removeAllObjects];
+}
+
+@end

src/NSBubbleData.m

@@ -54,9 +54,14 @@ + (id)dataWithText:(NSString *)text date:(NSDate *)date type:(NSBubbleType)type
 - (id)initWithText:(NSString *)text date:(NSDate *)date type:(NSBubbleType)type
 {
     UIFont *font = [UIFont systemFontOfSize:[UIFont systemFontSize]];
-    CGSize size = [(text ? text : @"") sizeWithFont:font constrainedToSize:CGSizeMake(220, 9999) lineBreakMode:NSLineBreakByWordWrapping];
-
-    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, size.width, size.height)];
+    CGSize size = [(text ? text : @"") boundingRectWithSize: CGSizeMake(220, 9999) options: NSStringDrawingUsesLineFragmentOrigin attributes: @{ NSFontAttributeName:font }context: nil].size;
+    /* 
+     documention mentions
+     "In iOS 7 and later, this method returns fractional sizes (in the size component of the returned CGRect); to use a returned size to size views, you must use raise its value to the nearest higher integer using the ceil function."
+     */
+    CGFloat height = ceilf(size.height);
+    CGFloat width  = ceilf(size.width);
+    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, width, height)];
     label.numberOfLines = 0;
     label.lineBreakMode = NSLineBreakByWordWrapping;
     label.text = (text ? text : @"");

src/UIBubbleHeaderTableViewCell.m

@@ -49,6 +49,7 @@ - (void)setDate:(NSDate *)value
     self.label.shadowColor = [UIColor whiteColor];
     self.label.textColor = [UIColor darkGrayColor];
     self.label.backgroundColor = [UIColor clearColor];
+    self.label.autoresizingMask = UIViewAutoresizingFlexibleWidth;
     [self addSubview:self.label];
 }
 

src/UIBubbleTableView.m

@@ -13,6 +13,10 @@
 #import "UIBubbleHeaderTableViewCell.h"
 #import "UIBubbleTypingTableViewCell.h"
 
+static NSString * const kBubbleTypingCell = @"tblBubbleTypingCell";
+static NSString * const kBubbleHeaderCell = @"tblBubbleHeaderCell";
+static NSString * const kBubbleCell = @"tblBubbleCell";
+
 @interface UIBubbleTableView ()
 
 @property (nonatomic, retain) NSMutableArray *bubbleSection;
@@ -44,6 +48,12 @@ - (void)initializator
 
     self.snapInterval = 120;
     self.typingBubble = NSBubbleTypingTypeNobody;
+
+    // cell class must be registered otherwise dequeueReusableCellWithIdentifier: returns nill!
+    [self registerClass:[UIBubbleTableViewCell class] forCellReuseIdentifier:kBubbleCell];
+    [self registerClass:[UIBubbleHeaderTableViewCell class] forCellReuseIdentifier:kBubbleHeaderCell];
+    [self registerClass:[UIBubbleTypingTableViewCell class] forCellReuseIdentifier:kBubbleTypingCell];
+
 }
 
 - (id)init
@@ -95,7 +105,7 @@ - (void)reloadData
 	self.bubbleSection = nil;
 
     // Loading new data
-    int count = 0;
+    NSUInteger count = 0;
 #if !__has_feature(objc_arc)
     self.bubbleSection = [[[NSMutableArray alloc] init] autorelease];
 #else
@@ -156,7 +166,7 @@ - (void)reloadData
 
 - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
 {
-    int result = [self.bubbleSection count];
+    NSInteger result = [self.bubbleSection count];
     if (self.typingBubble != NSBubbleTypingTypeNobody) result++;
     return result;
 }
@@ -169,7 +179,7 @@ - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger
     return [[self.bubbleSection objectAtIndex:section] count] + 1;
 }
 
-- (float)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
+- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
 {
     // Now typing
 	if (indexPath.section >= [self.bubbleSection count])
@@ -192,8 +202,7 @@ - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(N
     // Now typing
 	if (indexPath.section >= [self.bubbleSection count])
     {
-        static NSString *cellId = @"tblBubbleTypingCell";
-        UIBubbleTypingTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellId];
+        UIBubbleTypingTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:kBubbleTypingCell];
 
         if (cell == nil) cell = [[UIBubbleTypingTableViewCell alloc] init];
 
@@ -206,8 +215,7 @@ - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(N
     // Header with date and time
     if (indexPath.row == 0)
     {
-        static NSString *cellId = @"tblBubbleHeaderCell";
-        UIBubbleHeaderTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellId];
+        UIBubbleHeaderTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:kBubbleHeaderCell];
         NSBubbleData *data = [[self.bubbleSection objectAtIndex:indexPath.section] objectAtIndex:0];
 
         if (cell == nil) cell = [[UIBubbleHeaderTableViewCell alloc] init];
@@ -218,8 +226,7 @@ - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(N
     }
 
     // Standard bubble    
-    static NSString *cellId = @"tblBubbleCell";
-    UIBubbleTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellId];
+    UIBubbleTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:kBubbleCell];
     NSBubbleData *data = [[self.bubbleSection objectAtIndex:indexPath.section] objectAtIndex:indexPath.row - 1];
 
     if (cell == nil) cell = [[UIBubbleTableViewCell alloc] init];