Adds OAStackViewProxy to support native UIStackView in iOS 9

Pod/Classes/OAStackViewProxy.h

@@ -0,0 +1,35 @@
+//
+//  OAStackViewProxy.h
+//  Pods
+//
+//  Created by Natan Rolnik on 8/5/15.
+//
+//
+
+#import <UIKit/UIKit.h>
+
+@interface OAStackViewProxy : UIView
+
+@property(nonatomic,readonly,copy) NSArray<__kindof UIView *> *arrangedSubviews;
+
+- (instancetype)initWithArrangedSubviews:(NSArray *)arrangedSubviews;
+
+- (void)addArrangedSubview:(UIView *)view;
+
+- (void)removeArrangedSubview:(UIView *)view;
+
+- (void)insertArrangedSubview:(UIView *)view atIndex:(NSUInteger)stackIndex;
+
+@property(nonatomic) UILayoutConstraintAxis axis;
+
+@property(nonatomic) UIStackViewDistribution distribution;
+
+@property(nonatomic) UIStackViewAlignment alignment;
+
+@property(nonatomic) CGFloat spacing;
+
+@property(nonatomic,getter=isBaselineRelativeArrangement) BOOL baselineRelativeArrangement;
+
+@property(nonatomic,getter=isLayoutMarginsRelativeArrangement) BOOL layoutMarginsRelativeArrangement;
+
+@end

Pod/Classes/OAStackViewProxy.m

@@ -0,0 +1,167 @@
+//
+//  OAStackViewProxy.m
+//  Pods
+//
+//  Created by Natan Rolnik on 8/5/15.
+//
+//
+
+#import "OAStackView.h"
+#import "OAStackViewProxy.h"
+
+@interface OAStackViewProxy()
+
+@property (nonatomic, strong) UIView *stackView;
+@property (nonatomic, strong) NSArray<UIView *> *initialArrangedSubviews;
+
+@property (nonatomic, strong) UIStackView *nativeStackView;
+@property (nonatomic, strong) OAStackView *backwardsCompatibleStackView;
+
+@end
+
+@implementation OAStackViewProxy
+
++ (BOOL)nativeStackViewAvailable
+{
+    return NSClassFromString(@"UIStackView") != nil;
+}
+
+#pragma mark - Initializers
+
+- (instancetype)init
+{
+    self = [self initWithArrangedSubviews:nil];
+
+    [self commonInit];
+
+    return self;
+}
+
+- (instancetype)initWithFrame:(CGRect)frame
+{
+    self = [super initWithFrame:frame];
+
+    [self commonInit];
+
+    return self;
+}
+
+- (instancetype)initWithCoder:(nonnull NSCoder *)aDecoder
+{
+    self = [super initWithCoder:aDecoder];
+
+    [self commonInit];
+
+    return self;
+}
+
+- (instancetype)initWithArrangedSubviews:(NSArray *)arrangedSubviews
+{
+    self = [super initWithFrame:CGRectZero];
+
+    self.initialArrangedSubviews = arrangedSubviews;
+
+    [self commonInit];
+
+    return self;
+}
+
+- (void)commonInit
+{
+    [self createStackView];
+    [self addSubview:self.stackView];
+}
+
+- (void)createStackView
+{
+    if (!self.stackView) {
+        if ([OAStackViewProxy nativeStackViewAvailable]) {
+            self.nativeStackView = [[UIStackView alloc] initWithArrangedSubviews:self.initialArrangedSubviews];
+            self.stackView = self.nativeStackView;
+        }
+        else {
+            self.backwardsCompatibleStackView = [[OAStackView alloc] initWithArrangedSubviews:self.initialArrangedSubviews];
+            self.stackView = self.backwardsCompatibleStackView;
+        }
+    }
+}
+
+#pragma mark - Runtime
+
+- (NSMethodSignature*)methodSignatureForSelector:(SEL)selector
+{
+    NSMethodSignature *signature = [super methodSignatureForSelector:selector];
+
+    if (!signature) {
+        signature = [self.stackView methodSignatureForSelector:selector];
+    }
+
+    return signature;
+}
+
+- (void)forwardInvocation:(NSInvocation *)anInvocation
+{
+    if ([self.stackView respondsToSelector:[anInvocation selector]]) {
+        [anInvocation invokeWithTarget:self.stackView];
+    }
+    else {
+        [super forwardInvocation:anInvocation];
+    }
+}
+
+#pragma mark - Setters
+
+- (void)setFrame:(CGRect)frame
+{
+    [super setFrame:frame];
+
+    self.stackView.frame = self.bounds;
+}
+
+- (void)setAxis:(UILayoutConstraintAxis)axis
+{
+    _axis = axis;
+
+    self.nativeStackView.axis = axis;
+    self.backwardsCompatibleStackView.axis = axis;
+}
+
+- (void)setDistribution:(UIStackViewDistribution)distribution
+{
+    _distribution = distribution;
+
+    self.nativeStackView.distribution = distribution;
+    self.backwardsCompatibleStackView.distribution = distribution;
+}
+
+- (void)setAlignment:(UIStackViewAlignment)alignment
+{
+    _alignment = alignment;
+
+    self.nativeStackView.alignment = alignment;
+    self.backwardsCompatibleStackView.alignment = alignment;
+}
+
+- (void)setSpacing:(CGFloat)spacing
+{
+    _spacing = spacing;
+
+    self.nativeStackView.spacing = spacing;
+    self.backwardsCompatibleStackView.spacing = spacing;
+}
+
+- (void)setBaselineRelativeArrangement:(BOOL)baselineRelativeArrangement
+{
+    _baselineRelativeArrangement = baselineRelativeArrangement;
+
+    self.nativeStackView.baselineRelativeArrangement = baselineRelativeArrangement;
+}
+
+- (void)setLayoutMarginsRelativeArrangement:(BOOL)layoutMarginsRelativeArrangement
+{
+    _layoutMarginsRelativeArrangement = layoutMarginsRelativeArrangement;
+
+    self.nativeStackView.layoutMarginsRelativeArrangement = layoutMarginsRelativeArrangement;
+}
+
+@end