thickness. molecule alignment

MVMCoreUI/Atoms/Buttons/CaretButton.swift

@@ -135,4 +135,8 @@ open class CaretButton: MFCustomButton, MVMCoreUIMoleculeViewProtocol {
     public func needsToBeConstrained() -> Bool {
         return true
     }
+    
+    open func moleculeAlignment() -> UIStackView.Alignment {
+        return UIStackView.Alignment.leading;
+    }
 }

MVMCoreUI/Atoms/Buttons/MFTextButton.m

@@ -145,4 +145,8 @@
     return YES;
 }
 
+- (UIStackViewAlignment)moleculeAlignment {
+    return UIStackViewAlignmentLeading;
+}
+
 @end

MVMCoreUI/Atoms/Views/CaretView.swift

@@ -13,9 +13,15 @@ open class CaretView: MFView {
     // MARK: - Properties
     //------------------------------------------------------
     
+    // Objc can't use float enum.
+    @objc public static let thin: CGFloat = 6.0
+    @objc public static let standard: CGFloat = 2.6
+    @objc public static let thick: CGFloat = 1.5
+    
     private(set) var strokeColor: UIColor?
     private var lineWidth: CGFloat?
-    
+    private var lineThickness: CGFloat?
+
     //------------------------------------------------------
     // MARK: - Initialization
     //------------------------------------------------------
@@ -32,14 +38,19 @@ open class CaretView: MFView {
         super.init(coder: aDecoder)
     }
     
+    /// Can init with a specific line width.
     @objc public init(lineWidth: CGFloat) {
         super.init(frame: CGRect())
-        
         self.lineWidth = lineWidth
     }
     
+    /// Can init with a specific line thickness, scales based on width and height.
+    @objc public init(lineThickness: CGFloat) {
+        super.init(frame: CGRect())
+        self.lineThickness = lineThickness
+    }
+    
     @objc override open func setupView() {
-        
         defaultState()
     }
     
@@ -48,7 +59,6 @@ open class CaretView: MFView {
     //------------------------------------------------------
     
     private func defaultState() {
-        
         isOpaque = false
         isHidden = false
         backgroundColor = .clear
@@ -64,7 +74,7 @@ open class CaretView: MFView {
         let context = UIGraphicsGetCurrentContext()
         context?.clear(rect)
         
-        let lineWidthToDraw: CGFloat = lineWidth ?? frame.size.width / 2.6
+        let lineWidthToDraw: CGFloat = lineWidth ?? frame.size.width / (lineThickness ?? 2.6)
         
         let path = UIBezierPath()
         path.move(to: CGPoint(x: lineWidthToDraw / 2.0, y: 0.0))
@@ -80,7 +90,6 @@ open class CaretView: MFView {
     }
     
     @objc public func setLineColor(_ color: UIColor?) {
-        
         strokeColor = color
         setNeedsDisplay()
     }
@@ -123,4 +132,8 @@ open class CaretView: MFView {
     open override func needsToBeConstrained() -> Bool {
         return true
     }
+    
+    open override func moleculeAlignment() -> UIStackView.Alignment {
+        return UIStackView.Alignment.leading;
+    }
 }

MVMCoreUI/Atoms/Views/MFView.m

@@ -36,7 +36,7 @@
 }
 
 - (void)setupView {
-    
+    self.preservesSuperviewLayoutMargins = YES;
 }
 
 - (void)updateView:(CGFloat)size {

MVMCoreUI/Atoms/Views/ViewConstrainingView.h

@@ -27,7 +27,7 @@
 + (nonnull ViewConstrainingView *)viewConstrainingView:(nonnull UIView *)view;
 
 // Can be initialized with a molecule to constrain
-- (nullable instancetype)initWithMolecule:(nonnull UIView <MVMCoreUIMoleculeViewProtocol>*)molecule;
+- (nullable instancetype)initWithMolecule:(nonnull UIView <MVMCoreUIMoleculeViewProtocol>*)molecule alignment:(UIStackViewAlignment)alignment;
 
 // Use these to sets the constants, because subclasses may align differently.
 - (void)setPinConstantsWithInsets:(UIEdgeInsets)insets;

MVMCoreUI/Atoms/Views/ViewConstrainingView.m

@@ -9,6 +9,7 @@
 #import "ViewConstrainingView.h"
 @import MVMCore.MVMCoreConstants;
 @import MVMCore.MVMCoreDispatchUtility;
+#import "NSLayoutConstraint+MFConvenience.h"
 #import "MFStyler.h"
 
 @interface ViewConstrainingView ()
@@ -18,10 +19,11 @@
 
 @implementation ViewConstrainingView
 
-- (nullable instancetype)initWithMolecule:(nonnull UIView <MVMCoreUIMoleculeViewProtocol>*)molecule {
+- (nullable instancetype)initWithMolecule:(nonnull UIView <MVMCoreUIMoleculeViewProtocol>*)molecule alignment:(UIStackViewAlignment)alignment {
     if (self = [super init]) {
         if (!molecule.superview) {
-            [self addConstrainedView:molecule];
+            [self addConstrainedView:molecule alignment:alignment];
+            [self setAsMolecule];
         }
         self.molecule = molecule;
     }
@@ -44,23 +46,11 @@
 }
 
 - (void)pinToSuperView {
-
+    NSDictionary *dictionary = [NSLayoutConstraint constraintPinSubviewToSuperview:self];
-    // Align left and right constants.
+    self.leftPin = dictionary[ConstraintLeading];
-    NSLayoutConstraint *leftPin = [NSLayoutConstraint constraintWithItem:self attribute:NSLayoutAttributeLeft relatedBy:NSLayoutRelationEqual toItem:self.superview attribute:NSLayoutAttributeLeft multiplier:1.0 constant:0];
+    self.topPin = dictionary[ConstraintTop];
-    self.leftPin = leftPin;
+    self.bottomPin = dictionary[ConstraintBot];
-    leftPin.active = YES;
+    self.rightPin = dictionary[ConstraintTrailing];
-    
-    NSLayoutConstraint *topPin = [NSLayoutConstraint constraintWithItem:self attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:self.superview attribute:NSLayoutAttributeTop multiplier:1.0 constant:0];
-    self.topPin = topPin;
-    topPin.active = YES;
-    
-    NSLayoutConstraint *bottomPin = [NSLayoutConstraint constraintWithItem:self.superview attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeBottom multiplier:1.0 constant:0];
-    self.bottomPin = bottomPin;
-    bottomPin.active = YES;
-    
-    NSLayoutConstraint *rightPin = [NSLayoutConstraint constraintWithItem:self.superview attribute:NSLayoutAttributeRight relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeRight multiplier:1.0 constant:0];
-    self.rightPin = rightPin;
-    rightPin.active = YES;
 }
     
 - (void)setPinConstantsWithInsets:(UIEdgeInsets)insets {
@@ -106,26 +96,32 @@
     self.backgroundColor = [UIColor clearColor];
 }
 
-- (void)addConstrainedView:(nonnull UIView *)view {
+- (void)addConstrainedView:(nonnull UIView *)view alignment:(UIStackViewAlignment)alignment {
     view.translatesAutoresizingMaskIntoConstraints = NO;
     [self addSubview:view];
     self.constrainedView = view;
     
-    NSLayoutConstraint *leftPin = [view.leftAnchor constraintEqualToAnchor:self.leftAnchor];
+    NSLayoutRelation leftRelation;
-    self.leftPin = leftPin;
+    if (alignment == UIStackViewAlignmentFill || alignment == UIStackViewAlignmentLeading || alignment == UIStackViewAlignmentFirstBaseline) {
-    leftPin.active = YES;
+        leftRelation = NSLayoutRelationEqual;
-    
+    } else {
-    NSLayoutConstraint *topPin = [view.topAnchor constraintEqualToAnchor:self.topAnchor];
+        leftRelation = NSLayoutRelationGreaterThanOrEqual;
-    self.topPin = topPin;
+    }
-    topPin.active = YES;
+    NSLayoutRelation rightRelation;
-    
+    if (alignment == UIStackViewAlignmentFill || alignment == UIStackViewAlignmentTrailing || alignment == UIStackViewAlignmentLastBaseline) {
-    NSLayoutConstraint *bottomPin = [self.bottomAnchor constraintEqualToAnchor:view.bottomAnchor];
+        rightRelation = NSLayoutRelationEqual;
-    self.bottomPin = bottomPin;
+    } else {
-    bottomPin.active = YES;
+        rightRelation = NSLayoutRelationGreaterThanOrEqual;
-    
+    }
-    NSLayoutConstraint *rightPin = [self.rightAnchor constraintEqualToAnchor:view.rightAnchor];
+    NSDictionary *dictionary = [NSLayoutConstraint constraintPinSubview:view topRelation:NSLayoutRelationEqual bottomRelation:NSLayoutRelationEqual leftRelation:leftRelation rightRelation:rightRelation];
-    self.rightPin = rightPin;
+    self.leftPin = dictionary[ConstraintLeading];
-    rightPin.active = YES;
+    self.topPin = dictionary[ConstraintTop];
+    self.bottomPin = dictionary[ConstraintBot];
+    self.rightPin = dictionary[ConstraintTrailing];
+}
+
+- (void)addConstrainedView:(nonnull UIView *)view {
+    [self addConstrainedView:view alignment:UIStackViewAlignmentFill];
 }
 
 - (void)setupView {
@@ -153,9 +149,6 @@
 
 - (void)setAsMolecule {
     self.updateViewHorizontalDefaults = YES;
-    if ([self.molecule respondsToSelector:@selector(setAsMolecule)]) {
-        [self.molecule setAsMolecule];
-    }
 }
 
 - (void)setWithJSON:(NSDictionary *)json delegateObject:(DelegateObject *)delegateObject additionalData:(NSDictionary *)additionalData {

MVMCoreUI/Categories/NSLayoutConstraint+MFConvenience.h

@@ -31,8 +31,12 @@ extern NSString * _Nonnull const ConstraintWidth;
 
 + (nullable NSDictionary *)constraintPinSubview:(nullable UIView *)subview pinTop:(BOOL)pinTop pinBottom:(BOOL)pinBottom pinLeft:(BOOL)pinLeft pinRight:(BOOL)pinRight;
 
++ (nullable NSDictionary *)constraintPinSubview:(nullable UIView *)subview topRelation:(NSLayoutRelation)topRelation bottomRelation:(NSLayoutRelation)bottomRelation leftRelation:(NSLayoutRelation)leftRelation rightRelation:(NSLayoutRelation)rightRelation;
+
 + (nullable NSDictionary *)constraintPinSubview:(nullable UIView *)subview pinTop:(BOOL)pinTop topConstant:(CGFloat)topConstant pinBottom:(BOOL)pinBottom bottomConstant:(CGFloat)bottomConstant pinLeft:(BOOL)pinLeft leftConstant:(CGFloat)leftConstant pinRight:(BOOL)pinRight rightConstant:(CGFloat)rightConstant;
 
++ (nullable NSDictionary *)constraintPinSubview:(nullable UIView *)subview pinTop:(BOOL)pinTop topConstant:(CGFloat)topConstant topRelation:(NSLayoutRelation)topRelation pinBottom:(BOOL)pinBottom bottomConstant:(CGFloat)bottomConstant bottomRelation:(NSLayoutRelation)bottomRelation pinLeft:(BOOL)pinLeft leftConstant:(CGFloat)leftConstant leftRelation:(NSLayoutRelation)leftRelation pinRight:(BOOL)pinRight rightConstant:(CGFloat)rightConstant rightRelation:(NSLayoutRelation)rightRelation;
+
 // Pin subview with 1 side
 + (nullable NSDictionary *)constraintPinTopSubview:(nonnull UIView *)subview topConstant:(CGFloat)topConstant;
 + (nullable NSDictionary *)constraintPinBottomSubview:(nonnull UIView *)subview bottomConstant:(CGFloat)bottomConstant;
@@ -57,6 +61,7 @@ extern NSString * _Nonnull const ConstraintWidth;
 
 #pragma mark - With Margins
 
++ (nonnull NSDictionary <NSString *, NSLayoutConstraint *>*)pinViewToSuperview:(nonnull UIView *)subview useMargins:(BOOL)useMargins;
 + (nonnull NSLayoutConstraint *)pinViewTopToSuperview:(nonnull UIView *)view useMargins:(BOOL)useMargins constant:(CGFloat)constant;
 + (nonnull NSLayoutConstraint *)pinViewLeftToSuperview:(nonnull UIView *)view useMargins:(BOOL)useMargins constant:(CGFloat)constant;
 + (nonnull NSLayoutConstraint *)pinViewRightToSuperview:(nonnull UIView *)view useMargins:(BOOL)useMargins constant:(CGFloat)constant;

MVMCoreUI/Categories/NSLayoutConstraint+MFConvenience.m

@@ -44,29 +44,37 @@ NSString *const ConstraintWidth = @"width";
     return [NSLayoutConstraint constraintPinSubview:subview pinTop:pinTop topConstant:0 pinBottom:pinBottom bottomConstant:0 pinLeft:pinLeft leftConstant:0 pinRight:pinRight rightConstant:0];
 }
 
++ (nullable NSDictionary *)constraintPinSubview:(nullable UIView *)subview topRelation:(NSLayoutRelation)topRelation bottomRelation:(NSLayoutRelation)bottomRelation leftRelation:(NSLayoutRelation)leftRelation rightRelation:(NSLayoutRelation)rightRelation {
+    return [self constraintPinSubview:subview pinTop:YES topConstant:0 topRelation:topRelation pinBottom:YES bottomConstant:0 bottomRelation:bottomRelation pinLeft:YES leftConstant:0 leftRelation:leftRelation pinRight:YES rightConstant:0 rightRelation:rightRelation];
+}
+
 + (NSDictionary *)constraintPinSubview:(UIView *)subview pinTop:(BOOL)pinTop topConstant:(CGFloat)topConstant pinBottom:(BOOL)pinBottom bottomConstant:(CGFloat)bottomConstant pinLeft:(BOOL)pinLeft leftConstant:(CGFloat)leftConstant pinRight:(BOOL)pinRight rightConstant:(CGFloat)rightConstant {
+    return [self constraintPinSubview:subview pinTop:pinTop topConstant:topConstant topRelation:NSLayoutRelationEqual pinBottom:pinBottom bottomConstant:bottomConstant bottomRelation:NSLayoutRelationEqual pinLeft:pinLeft leftConstant:leftConstant leftRelation:NSLayoutRelationEqual pinRight:pinRight rightConstant:rightConstant rightRelation:NSLayoutRelationEqual];
+}
+
++ (NSDictionary *)constraintPinSubview:(UIView *)subview pinTop:(BOOL)pinTop topConstant:(CGFloat)topConstant topRelation:(NSLayoutRelation)topRelation pinBottom:(BOOL)pinBottom bottomConstant:(CGFloat)bottomConstant bottomRelation:(NSLayoutRelation)bottomRelation pinLeft:(BOOL)pinLeft leftConstant:(CGFloat)leftConstant leftRelation:(NSLayoutRelation)leftRelation pinRight:(BOOL)pinRight rightConstant:(CGFloat)rightConstant rightRelation:(NSLayoutRelation)rightRelation {
     UIView *superview = subview.superview;
     NSMutableDictionary *constraintDic = [[NSMutableDictionary alloc] init];
     if (pinTop) {
-        NSLayoutConstraint *top = [NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:superview attribute:NSLayoutAttributeTop multiplier:1 constant:topConstant];
+        NSLayoutConstraint *top = [NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeTop relatedBy:topRelation toItem:superview attribute:NSLayoutAttributeTop multiplier:1 constant:topConstant];
         top.priority = 999;
         top.active = YES;
         [constraintDic setObject:top forKey:ConstraintTop];
     }
     if (pinBottom) {
-        NSLayoutConstraint *bottom = [NSLayoutConstraint constraintWithItem:superview attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:subview attribute:NSLayoutAttributeBottom multiplier:1 constant:bottomConstant];
+        NSLayoutConstraint *bottom = [NSLayoutConstraint constraintWithItem:superview attribute:NSLayoutAttributeBottom relatedBy:bottomRelation toItem:subview attribute:NSLayoutAttributeBottom multiplier:1 constant:bottomConstant];
         bottom.priority = 999;
         bottom.active = YES;
         [constraintDic setObject:bottom forKey:ConstraintBot];
     }
     if (pinLeft) {
-        NSLayoutConstraint *leading = [NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeLeading relatedBy:NSLayoutRelationEqual toItem:superview attribute:NSLayoutAttributeLeading multiplier:1 constant:leftConstant];
+        NSLayoutConstraint *leading = [NSLayoutConstraint constraintWithItem:subview attribute:NSLayoutAttributeLeading relatedBy:leftRelation toItem:superview attribute:NSLayoutAttributeLeading multiplier:1 constant:leftConstant];
         leading.priority = 999;
         leading.active = YES;
         [constraintDic setObject:leading forKey:ConstraintLeading];
     }
     if (pinRight) {
-        NSLayoutConstraint *trailing = [NSLayoutConstraint constraintWithItem:superview attribute:NSLayoutAttributeTrailing relatedBy:NSLayoutRelationEqual toItem:subview attribute:NSLayoutAttributeTrailing multiplier:1 constant:rightConstant];
+        NSLayoutConstraint *trailing = [NSLayoutConstraint constraintWithItem:superview attribute:NSLayoutAttributeTrailing relatedBy:rightRelation toItem:subview attribute:NSLayoutAttributeTrailing multiplier:1 constant:rightConstant];
         trailing.priority = 999;
         trailing.active = YES;
         [constraintDic setObject:trailing forKey:ConstraintTrailing];
@@ -152,6 +160,14 @@ NSString *const ConstraintWidth = @"width";
 
 #pragma mark - With Margins
 
++ (nonnull NSDictionary *)pinViewToSuperview:(nonnull UIView *)subview useMargins:(BOOL)useMargins {
+    return @{ConstraintTop:[self pinViewTopToSuperview:subview useMargins:useMargins constant:0],
+                                           ConstraintLeading:[self pinViewLeftToSuperview:subview useMargins:useMargins constant:0],
+                                           ConstraintTrailing:[self pinViewRightToSuperview:subview useMargins:useMargins constant:0],
+                                           ConstraintBot:[self pinViewBottomToSuperview:subview useMargins:useMargins constant:0],
+                                           };
+}
+
 + (NSLayoutConstraint *)pinViewTopToSuperview:(UIView *)view useMargins:(BOOL)useMargins constant:(CGFloat)constant {
     return [view.topAnchor constraintEqualToAnchor:(useMargins ? view.superview.layoutMarginsGuide.topAnchor : view.superview.topAnchor) constant:constant];
 }

MVMCoreUI/Molecules/MoleculeStackView.swift

@@ -57,8 +57,7 @@ public class MoleculeStackView: MFView {
         // Create the molecules and set the json.
         var moleculesArray = [] as [UIView]
         for moleculeJSON in molecules {
-            if let name = moleculeJSON.optionalStringForKey("moleculeName"), let molecule = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForName(name) {
+            if let molecule = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForStack(withJSON: moleculeJSON, delegateObject: delegateObject) {
-                molecule.setWithJSON(moleculeJSON, delegateObject: delegateObject, additionalData: additionalData)
                 moleculesArray.append(molecule)
             }
         }

MVMCoreUI/Molecules/MoleculeTableViewCell.swift

@@ -10,11 +10,42 @@ import UIKit
 
 @objcMembers open class MoleculeTableViewCell: UITableViewCell, MVMCoreViewProtocol, MVMCoreUIMoleculeViewProtocol {
     var molecule: (UIView & MVMCoreUIMoleculeViewProtocol)?
+    
+    public override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
+        super.init(style: style, reuseIdentifier: reuseIdentifier)
+        setupView()
+    }
+    
+    public required init?(coder aDecoder: NSCoder) {
+        super.init(coder: aDecoder)
+        setupView()
+    }
+    
+    // For the accessory view convenience.
+    var caretView: CaretView?
+    private var caretViewWidthSizeObject: MFSizeObject?
+    private var caretViewHeightSizeObject: MFSizeObject?
 
     public func updateView(_ size: CGFloat) {
+        MFStyler.setDefaultMarginsFor(self, size: size)
+        if #available(iOS 11.0, *) {
+            contentView.directionalLayoutMargins = directionalLayoutMargins
+        } else {
+            contentView.layoutMargins = layoutMargins
+        }
+        
         if let molecule = molecule as? MVMCoreViewProtocol {
             molecule.updateView(size)
         }
+        if let _ = accessoryView, let caretView = caretView, let widthObject = caretViewWidthSizeObject, let heightObject = caretViewHeightSizeObject {
+            caretView.frame = CGRect(x: 0, y: 0, width: widthObject.getValueBased(onSize: size), height: heightObject.getValueBased(onSize: size))
+        }
+    }
+    
+    public func setupView() {
+        preservesSuperviewLayoutMargins = false
+        contentView.preservesSuperviewLayoutMargins = false
+        selectionStyle = .none
     }
     
     public func setWithJSON(_ json: [AnyHashable : Any]?, delegateObject: DelegateObject?, additionalData: [AnyHashable : Any]?) {
@@ -22,13 +53,28 @@ import UIKit
             return
         }
         if molecule == nil {
-            if let moleculeView = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForJSON(json, delegateObject: delegateObject) {
+            if let moleculeView = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForStack(withJSON: json, delegateObject: delegateObject) {
-                addSubview(moleculeView)
+                contentView.addSubview(moleculeView)
-                NSLayoutConstraint.constraintPinSubview(toSuperview: moleculeView)
+                NSLayoutConstraint.activate(Array(NSLayoutConstraint.pinView(toSuperview: moleculeView, useMargins: moleculeView.needsToBeConstrained?() ?? false).values))
                 molecule = moleculeView
             }
         } else {
             molecule?.setWithJSON(json, delegateObject: delegateObject, additionalData: additionalData)
         }
+        backgroundColor = molecule?.backgroundColor
+    }
+    
+    // MARK- Convenience
+    public func addCaretViewAccessory() {
+        guard accessoryView == nil else {
+            return
+        }
+        let width: CGFloat = 6
+        let height: CGFloat = 10
+        caretView = CaretView(lineThickness: CaretView.thin)
+        caretView?.frame = CGRect(x: 0, y: 0, width: width, height: height)
+        caretViewWidthSizeObject = MFSizeObject(scalingStandardSize: width)
+        caretViewHeightSizeObject = MFSizeObject(scalingStandardSize: height)
+        accessoryView = caretView
     }
 }

MVMCoreUI/Molecules/Protocols/MVMCoreUIMoleculeViewProtocol.h

@@ -22,6 +22,12 @@
 // Notifies the creator that the view needs to be constrained in a view.
 - (BOOL)needsToBeConstrained;
 
+// The alignment for the molecule if constrained.
+- (UIStackViewAlignment)moleculeAlignment;
+
+// For the molecule list to load more efficiently.
++ (CGFloat)estimatedHeightForRow;
+
 @end
 
 

MVMCoreUI/OtherHandlers/MVMCoreUIMoleculeMappingObject.h

@@ -22,4 +22,7 @@
 - (nullable UIView <MVMCoreUIMoleculeViewProtocol>*)getMoleculeForName:(nonnull NSString *)name;
 - (nullable UIView <MVMCoreUIMoleculeViewProtocol>*)getMoleculeForJSON:(nonnull NSDictionary *)json delegateObject:(nullable DelegateObject *)delegateObject;
 
+// Similar to above but also checks if the molecule needs to be constrained for a stack.
+- (nullable UIView <MVMCoreUIMoleculeViewProtocol>*)getMoleculeForStackWithJSON:(nonnull NSDictionary *)json delegateObject:(nullable DelegateObject *)delegateObject;
+
 @end

MVMCoreUI/OtherHandlers/MVMCoreUIMoleculeMappingObject.m

@@ -45,20 +45,17 @@
 
 - (nullable UIView <MVMCoreUIMoleculeViewProtocol>*)getMoleculeForName:(nonnull NSString *)name {
     Class class = [self.moleculeMapping objectForKey:name];
-    if (class) {
+    if (!class) {
-        UIView <MVMCoreUIMoleculeViewProtocol>*view = [[class alloc] init];
+        return nil;
-        if ([view respondsToSelector:@selector(needsToBeConstrained)] && [view needsToBeConstrained]) {
-            view = [[ViewConstrainingView alloc] initWithMolecule:view];
-        }
-        if ([view respondsToSelector:@selector(setAsMolecule)]) {
-            [view setAsMolecule];
-        }
-        return view;
     }
-    return nil;
+    UIView <MVMCoreUIMoleculeViewProtocol>*molecule = [[class alloc] init];
+    if ([molecule respondsToSelector:@selector(setAsMolecule)]) {
+        [molecule setAsMolecule];
+    }
+    return molecule;
 }
 
-- (nullable UIView <MVMCoreUIMoleculeViewProtocol>*)getMoleculeForJSON:(nonnull NSDictionary *)json delegateObject:(nullable MVMCoreUIDelegateObject *)delegateObject {
+- (nullable UIView <MVMCoreUIMoleculeViewProtocol>*)getMoleculeForJSON:(nonnull NSDictionary *)json delegateObject:(nullable DelegateObject *)delegateObject {
     NSString *moleculeName = [json string:@"moleculeName"];
     if (!moleculeName) {
         return nil;
@@ -69,4 +66,17 @@
 }
 
 
+- (nullable UIView <MVMCoreUIMoleculeViewProtocol>*)getMoleculeForStackWithJSON:(nonnull NSDictionary *)json delegateObject:(nullable DelegateObject *)delegateObject {
+    NSString *moleculeName = [json string:@"moleculeName"];
+    if (!moleculeName) {
+        return nil;
+    }
+    UIView <MVMCoreUIMoleculeViewProtocol>*molecule = [self getMoleculeForName:moleculeName];
+    if ([molecule respondsToSelector:@selector(needsToBeConstrained)] && [molecule needsToBeConstrained]) {
+        molecule = [[ViewConstrainingView alloc] initWithMolecule:molecule alignment:[molecule respondsToSelector:@selector(moleculeAlignment)] ? [molecule moleculeAlignment] : UIStackViewAlignmentFill];
+    }
+    [molecule setWithJSON:json delegateObject:delegateObject additionalData:nil];
+    return molecule;
+}
+
 @end

MVMCoreUI/Templates/MoleculeListTemplate.swift

@@ -23,14 +23,14 @@ public class MoleculeListTemplate: ThreeLayerTableViewController {
     }
     
     public override func viewForTop() -> UIView {
-        guard let moleculeJSON = loadObject?.pageJSON?.optionalDictionaryForKey("header"), let molecule = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForJSON(moleculeJSON, delegateObject: delegateObject()) else {
+        guard let moleculeJSON = loadObject?.pageJSON?.optionalDictionaryForKey("header"), let molecule = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForStack(withJSON: moleculeJSON, delegateObject: delegateObject()) else {
             return super.viewForTop()
         }
         return molecule
     }
     
     override public func viewForBottom() -> UIView {
-        guard let moleculeJSON = loadObject?.pageJSON?.optionalDictionaryForKey("footer"), let molecule = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForJSON(moleculeJSON, delegateObject: delegateObject()) else {
+        guard let moleculeJSON = loadObject?.pageJSON?.optionalDictionaryForKey("footer"), let molecule = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForStack(withJSON: moleculeJSON, delegateObject: delegateObject()) else {
             return viewForBottom()
         }
         return molecule
@@ -41,6 +41,14 @@ public class MoleculeListTemplate: ThreeLayerTableViewController {
         registerWithTable()
     }
     
+    public override func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
+        if let moleculeName = loadObject?.pageJSON?.stringOptionalWithChainOfKeysOrIndexes(["molecules",indexPath.row,"moleculeName"]), let theClass = MVMCoreUIMoleculeMappingObject.shared()?.moleculeMapping?[moleculeName] as? MVMCoreUIMoleculeViewProtocol.Type,
+            let estimatedHeightForRow = theClass.estimatedHeightForRow {
+            return estimatedHeightForRow()
+        }
+        return 0
+    }
+    
     public override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
         return loadObject?.pageJSON?.arrayForKey("molecules").count ?? 0
     }

MVMCoreUI/Templates/MoleculeStackCenteredTemplate.swift

@@ -18,7 +18,7 @@ public class MoleculeStackCenteredTemplate: ThreeLayerViewController {
 
     public override func viewForTop() -> UIView? {
         guard let moleculeJSON = loadObject?.pageJSON?.optionalDictionaryForKey("header"),
-            let molecule = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForJSON(moleculeJSON, delegateObject: delegateObject()) else {
+            let molecule = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForStack(withJSON: moleculeJSON, delegateObject: delegateObject()) else {
             return nil
         }
         return molecule
@@ -26,7 +26,7 @@ public class MoleculeStackCenteredTemplate: ThreeLayerViewController {
     
     override public func viewForBottom() -> UIView? {
         guard let moleculeJSON = loadObject?.pageJSON?.optionalDictionaryForKey("footer"),
-            let molecule = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForJSON(moleculeJSON, delegateObject: delegateObject()) else {
+            let molecule = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForStack(withJSON: moleculeJSON, delegateObject: delegateObject()) else {
             return nil
         }
         return molecule

MVMCoreUI/Templates/MoleculeStackTemplate.swift

@@ -16,7 +16,7 @@ public class MoleculeStackTemplate: ThreeLayerViewController {
     }
     
     public override func viewForTop() -> UIView? {
-        guard let moleculeJSON = loadObject?.pageJSON?.optionalDictionaryForKey("header"), let molecule = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForJSON(moleculeJSON, delegateObject: delegateObject()) else {
+        guard let moleculeJSON = loadObject?.pageJSON?.optionalDictionaryForKey("header"), let molecule = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForStack(withJSON: moleculeJSON, delegateObject: delegateObject()) else {
             return nil
         }
         return molecule
@@ -30,7 +30,7 @@ public class MoleculeStackTemplate: ThreeLayerViewController {
     }
     
     override public func viewForBottom() -> UIView? {
-        guard let moleculeJSON = loadObject?.pageJSON?.optionalDictionaryForKey("footer"), let molecule = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForJSON(moleculeJSON, delegateObject: delegateObject()) else {
+        guard let moleculeJSON = loadObject?.pageJSON?.optionalDictionaryForKey("footer"), let molecule = MVMCoreUIMoleculeMappingObject.shared()?.getMoleculeForStack(withJSON: moleculeJSON, delegateObject: delegateObject()) else {
             return nil
         }
         return molecule