Review changes.

Fixed default elevations and added unit tests.
Removed useless backwards-compatible decoding logic.

Author: ajsecord

components/Buttons/ButtonsTests/ButtonsTests.m

@@ -24,13 +24,6 @@
 // values.
 static const UIControlState kNumUIControlStates = 2 * UIControlStateSelected - 1;
 
-static inline UIColor *MDCColorFromRGB(NSInteger rgbValue) {
-  return [UIColor colorWithRed:((float)((rgbValue & 0xFF0000) >> 16)) / 255.0
-                         green:((float)((rgbValue & 0x00FF00) >> 8)) / 255.0
-                          blue:((float)((rgbValue & 0x0000FF) >> 0)) / 255.0
-                         alpha:1.0];
-}
-
 static CGFloat randomNumber() {
   return arc4random_uniform(100) / (CGFloat)10;
 }
@@ -78,7 +71,7 @@ - (void)testUppercaseTitleYes {
   NSString *originalTitle = @"some Text";
 
   // When
-  button.uppercaseTitle = YES;
+  button.shouldCapitalizeTitle = YES;
   [button setTitle:originalTitle forState:UIControlStateNormal];
 
   // Then
@@ -91,7 +84,7 @@ - (void)testUppercaseTitleNo {
   NSString *originalTitle = @"some Text";
 
   // When
-  button.uppercaseTitle = NO;
+  button.shouldCapitalizeTitle = NO;
   [button setTitle:originalTitle forState:UIControlStateNormal];
 
   // Then
@@ -104,9 +97,9 @@ - (void)testUppercaseTitleNoChangedToYes {
   NSString *originalTitle = @"some Text";
 
   // When
-  button.uppercaseTitle = NO;
+  button.shouldCapitalizeTitle = NO;
   [button setTitle:originalTitle forState:UIControlStateNormal];
-  button.uppercaseTitle = YES;
+  button.shouldCapitalizeTitle = YES;
 
   // Then
   XCTAssertEqualObjects(button.currentTitle, [originalTitle uppercaseStringWithLocale:[NSLocale currentLocale]]);
@@ -161,6 +154,34 @@ - (void)testResetElevationForState {
   }
 }
 
+- (void)testDefaultElevationsForState {
+  // Given
+  MDCButton *button = [[MDCButton alloc] init];
+
+  // When
+
+  // Then
+  XCTAssertEqual([button elevationForState:UIControlStateNormal], 0);
+  XCTAssertEqual([button elevationForState:UIControlStateHighlighted], 0);
+  XCTAssertEqual([button elevationForState:UIControlStateDisabled], 0);
+  XCTAssertEqual([button elevationForState:UIControlStateSelected], 1);
+}
+
+- (void)testDefaultElevationRelationships {
+  // Given
+  MDCButton *button = [[MDCButton alloc] init];
+  CGFloat normalElevation = randomNumber();
+
+  // When
+  [button setElevation:normalElevation forState:UIControlStateNormal];
+
+  // Then
+  XCTAssertEqual([button elevationForState:UIControlStateNormal], normalElevation);
+  XCTAssertEqual([button elevationForState:UIControlStateHighlighted], normalElevation);
+  XCTAssertEqual([button elevationForState:UIControlStateDisabled], normalElevation);
+  XCTAssertEqual([button elevationForState:UIControlStateSelected], 2 * normalElevation);
+}
+
 - (void)testBackgroundColorForState {
   // Given
   MDCButton *button = [[MDCButton alloc] init];

components/Buttons/src/MDCButton.h

@@ -40,7 +40,7 @@
  @param state The state.
  @return The background color.
  */
-- (nonnull UIColor *)backgroundColorForState:(UIControlState)state;
+- (nullable UIColor *)backgroundColorForState:(UIControlState)state;
 
 /**
  A color used as the button's @c backgroundColor.
@@ -51,7 +51,7 @@
 - (void)setBackgroundColor:(nullable UIColor *)backgroundColor forState:(UIControlState)state;
 
 /** The ink color of the button. */
-@property(null_resettable, nonatomic, strong) UIColor *inkColor;
+@property(nonatomic, strong, null_resettable) UIColor *inkColor;
 
 /**
  * A custom title color for the non-disabled states. The default is nil, which means that the button
@@ -77,12 +77,12 @@
 @property(nonatomic) BOOL shouldRaiseOnTouch;
 
 /**
- * Converts the button title to uppercase. Changing this property to NO will not update the current
- * title string.
+ * If true, converts the button title to uppercase. Changing this property to NO will not update the
+ * current title string.
  *
  * Default is YES and is recommended whenever possible.
  */
-@property(nonatomic, getter=isUppercaseTitle) BOOL uppercaseTitle;
+@property(nonatomic) BOOL shouldCapitalizeTitle;
 
 /**
  * Allows the button to detect touches outside of its bounds. A negative value indicates an
@@ -117,6 +117,7 @@
 /**
  * Returns the elevation for a particular control state.
  *
+ * The default values are particular to each subclass of MDCButton.
  * The default value for UIControlStateNormal is 0. The default value for UIControlStateSelected is
  * twice greater than the value of UIControlStateNormal. The default values for all other states is
  * the value of UIControlStateNormal.

components/Buttons/src/MDCButton.m

@@ -36,14 +36,10 @@
     @"MDCButtonDisabledBackgroundColorDarkKey";
 static NSString *const MDCButtonInkViewInkColorKey = @"MDCButtonInkViewInkColorKey";
 static NSString *const MDCButtonShouldRaiseOnTouchKey = @"MDCButtonShouldRaiseOnTouchKey";
-static NSString *const MDCButtonUppercaseTitleKey = @"MDCButtonUppercaseTitleKey";
+static NSString *const MDCButtonShouldCapitalizeTitleKey = @"MDCButtonShouldCapitalizeTitleKey";
 static NSString *const MDCButtonUnderlyingColorKey = @"MDCButtonUnderlyingColorKey";
 static NSString *const MDCButtonUserElevationsKey = @"MDCButtonUserElevationsKey";
 
-// MDCButtonUserZIndicesKey provides backward compatibility with old z-index shadows values.
-// TODO: Remove from MDC, it is only useful for internal clients.
-static NSString *const MDCButtonUserZIndicesKey = @"MDCButtonUserZIndicesKey";
-
 static const NSTimeInterval MDCButtonAnimationDuration = 0.2;
 
 // http://www.google.com/design/spec/components/buttons.html#buttons-main-buttons
@@ -96,13 +92,11 @@ - (instancetype)initWithFrame:(CGRect)frame {
 - (void)commonInit {
   _disabledAlpha = MDCButtonDisabledAlpha;
   _shouldRaiseOnTouch = YES;
-  _uppercaseTitle = YES;
+  _shouldCapitalizeTitle = YES;
   _userElevations = [NSMutableDictionary dictionary];
   _backgroundColors = [NSMutableDictionary dictionary];
   _accessibilityLabelForState = [NSMutableDictionary dictionary];
 
-  [self setElevation:MDCShadowElevationNone forState:UIControlStateDisabled];
-
   // Disable default highlight state.
   self.adjustsImageWhenHighlighted = NO;
   self.showsTouchWhenHighlighted = NO;
@@ -111,12 +105,15 @@ - (void)commonInit {
   self.titleLabel.font = [MDCTypography buttonFont];
   [self updateTitleColor];
   [self updateDisabledTitleColor];
+  [self updateAlphaAndBackgroundColorAnimated:NO];
 
   // Default content insets
   self.contentEdgeInsets = [self defaultContentEdgeInsets];
 
-  self.layer.shadowPath = [self boundingPath].CGPath;
-  self.layer.shadowColor = [UIColor blackColor].CGColor;
+  MDCShadowLayer *shadowLayer = [self shadowLayer];
+  shadowLayer.shadowPath = [self boundingPath].CGPath;
+  shadowLayer.shadowColor = [UIColor blackColor].CGColor;
+  shadowLayer.elevation = [self elevationForState:self.state];
 
   // Set up ink layer.
   _inkView = [[MDCInkView alloc] initWithFrame:self.bounds];
@@ -197,26 +194,18 @@ - (instancetype)initWithCoder:(NSCoder *)aDecoder {
     if ([aDecoder containsValueForKey:MDCButtonShouldRaiseOnTouchKey]) {
       self.shouldRaiseOnTouch = [aDecoder decodeBoolForKey:MDCButtonShouldRaiseOnTouchKey];
     }
-    if ([aDecoder containsValueForKey:MDCButtonUppercaseTitleKey]) {
-      self.uppercaseTitle = [aDecoder decodeBoolForKey:MDCButtonUppercaseTitleKey];
+
+    if ([aDecoder containsValueForKey:MDCButtonShouldCapitalizeTitleKey]) {
+      self.shouldCapitalizeTitle = [aDecoder decodeBoolForKey:MDCButtonShouldCapitalizeTitleKey];
     }
+
     if ([aDecoder containsValueForKey:MDCButtonUnderlyingColorKey]) {
       self.underlyingColor = [aDecoder decodeObjectForKey:MDCButtonUnderlyingColorKey];
     }
 
     if ([aDecoder containsValueForKey:MDCButtonUserElevationsKey]) {
       _userElevations = [aDecoder decodeObjectForKey:MDCButtonUserElevationsKey];
     }
-    // For backward compatibility
-    if ([aDecoder containsValueForKey:MDCButtonUserZIndicesKey]) {
-      NSMutableDictionary *userZIndices = [aDecoder decodeObjectForKey:MDCButtonUserZIndicesKey];
-      NSArray *userZIndicesStates = [userZIndices allKeys];
-      for (NSNumber *stateNum in userZIndicesStates) {
-        NSNumber *zIndex = userZIndices[stateNum];
-        CGFloat elevation = (float)pow(2.f, [zIndex floatValue]);
-        [_userElevations setObject:@(elevation) forKey:stateNum];
-      }
-    }
   }
   return self;
 }
@@ -229,7 +218,7 @@ - (void)encodeWithCoder:(NSCoder *)aCoder {
   }
 
   [aCoder encodeBool:_shouldRaiseOnTouch forKey:MDCButtonShouldRaiseOnTouchKey];
-  [aCoder encodeBool:_uppercaseTitle forKey:MDCButtonUppercaseTitleKey];
+  [aCoder encodeBool:_shouldCapitalizeTitle forKey:MDCButtonShouldCapitalizeTitleKey];
   if (_underlyingColor) {
     [aCoder encodeObject:_underlyingColor forKey:MDCButtonUnderlyingColorKey];
   }
@@ -308,9 +297,9 @@ - (void)setEnabled:(BOOL)enabled animated:(BOOL)animated {
 
 #pragma mark - Title Uppercasing
 
-- (void)setUppercaseTitle:(BOOL)uppercaseTitle {
-  _uppercaseTitle = uppercaseTitle;
-  if (_uppercaseTitle) {
+- (void)setShouldCapitalizeTitle:(BOOL)shouldCapitalizeTitle {
+  _shouldCapitalizeTitle = shouldCapitalizeTitle;
+  if (_shouldCapitalizeTitle) {
     // This ensures existing titles will get upper cased
     UIControlState allControlStates =
         (UIControlStateHighlighted | UIControlStateDisabled | UIControlStateSelected);
@@ -332,7 +321,7 @@ - (void)setTitle:(NSString *)title forState:(UIControlState)state {
     [_accessibilityLabelForState removeObjectForKey:@(state)];
   }
 
-  if (_uppercaseTitle) {
+  if (_shouldCapitalizeTitle) {
     title = [title uppercaseStringWithLocale:[NSLocale currentLocale]];
   }
   [super setTitle:title forState:state];
@@ -347,7 +336,7 @@ - (void)setAttributedTitle:(NSAttributedString *)title forState:(UIControlState)
     [_accessibilityLabelForState removeObjectForKey:@(state)];
   }
 
-  if (_uppercaseTitle) {
+  if (_shouldCapitalizeTitle) {
     // Store the attributes.
     NSMutableArray *attributes = [NSMutableArray array];
     [title enumerateAttributesInRange:NSMakeRange(0, [title length])
@@ -386,7 +375,7 @@ - (void)setAccessibilityLabel:(NSString *)accessibilityLabel {
 }
 
 - (NSString *)accessibilityLabel {
-  if (!_uppercaseTitle) {
+  if (!_shouldCapitalizeTitle) {
     return [super accessibilityLabel];
   }
 
@@ -463,6 +452,7 @@ - (void)setElevation:(CGFloat)elevation forState:(UIControlState)state {
 
   // The elevation of the normal state controls whether this button is flat or not, and flat buttons
   // have different background color requirements than raised buttons.
+  // TODO(ajsecord): Move to MDCFlatButton and update this comment.
   if (state == UIControlStateNormal) {
     [self updateAlphaAndBackgroundColorAnimated:NO];
     [self updateTitleColor];
@@ -547,7 +537,16 @@ - (UIEdgeInsets)defaultContentEdgeInsets {
 }
 
 - (CGFloat)defaultElevationForState:(UIControlState)state {
-  return 0;
+  if (state == UIControlStateNormal) {
+    return 0;
+  }
+
+  if ((state & UIControlStateSelected) == UIControlStateSelected) {
+    CGFloat normalElevation = [self elevationForState:UIControlStateNormal];
+    return normalElevation > 0 ? 2 * normalElevation : 1;
+  }
+
+  return [self elevationForState:UIControlStateNormal];
 }
 
 - (BOOL)shouldHaveOpaqueBackground {

components/Buttons/src/MDCFloatingButton.m

@@ -51,7 +51,6 @@ - (instancetype)initWithFrame:(CGRect)frame shape:(MDCFloatingButtonShape)shape
   self = [super initWithFrame:frame];
   if (self) {
     _shape = shape;
-    [self setElevation:MDCShadowElevationRaisedButtonResting forState:UIControlStateNormal];
   }
   return self;
 }

components/Buttons/src/MDCRaisedButton.m

@@ -25,14 +25,6 @@
 
 @implementation MDCRaisedButton
 
-- (instancetype)initWithFrame:(CGRect)frame {
-  self = [super initWithFrame:frame];
-  if (self) {
-    [self setElevation:MDCShadowElevationRaisedButtonResting forState:UIControlStateNormal];
-  }
-  return self;
-}
-
 #pragma mark - Subclassing
 
 - (CGFloat)defaultElevationForState:(UIControlState)state {