Added class documentation.

Author: ajsecord

components/Buttons/src/MDCButton.h

@@ -29,7 +29,7 @@
  All buttons set the exclusiveTouch property to YES by default, which prevents users from
  simultaneously interacting with a button and other UI elements.
  
- @see http://www.google.com/design/spec/components/buttons.html#buttons-main-buttons
+ @see http://www.google.com/design/spec/components/buttons.html
  */
 @interface MDCButton : UIButton
 

components/Buttons/src/MDCFlatButton.h

@@ -18,14 +18,24 @@
 
 #import "MDCButton.h"
 
+/**
+ A "flat" MDCButton.
+ 
+ Flat buttons should be considered the default button. They do not have its own background color
+ and do not raise when touched. This type of button should be used in most situations requiring a
+ button. For layouts with many UI elements in which a flat button might get visually lost,
+ consider using a MDCRaisedButton instead.
+ 
+ @see http://www.google.com/design/spec/components/buttons.html#buttons-flat-buttons
+ */
 @interface MDCFlatButton : MDCButton
 
 /**
- * Use an opaque background color (default is NO).
- *
- * Flat buttons normally have a transparent background and blend seamlessly with their underlying
- * color, but occasionally a flat button with an opaque background will be required. Consider using
- * a raised button instead if possible.
+ Use an opaque background color (default is NO).
+ 
+ Flat buttons normally have a transparent background and blend seamlessly with their underlying
+ color, but occasionally a flat button with an opaque background will be required. Consider using
+ a raised button instead if possible.
  */
 @property(nonatomic) BOOL hasOpaqueBackground;
 

components/Buttons/src/MDCFloatingButton.h

@@ -29,6 +29,15 @@ typedef NS_ENUM(NSInteger, MDCFloatingButtonShape) {
   MDCFloatingButtonShapeMini
 };
 
+/**
+ * A "floating" MDCButton.
+ *
+ * Floating action buttons are circular, float a considerable amount above their parent, have
+ * their own background color, and also raise briefly when touched. Floating action buttons should
+ * only be used rarely, for the main action of a screen.
+ *
+ * @see http://www.google.com/design/spec/components/buttons.html#buttons-main-buttons
+ */
 @interface MDCFloatingButton : MDCButton
 
 /**

components/Buttons/src/MDCRaisedButton.h

@@ -16,5 +16,14 @@
 
 #import "MDCButton.h"
 
+/**
+ A "raised" MDCButton.
+ 
+ Raised buttons have their own background color, float above their parent slightly, and raise
+ briefly when touched. Raised buttons should be used when flat buttons would get lost among other
+ UI elements on the screen.
+ 
+ @see http://www.google.com/design/spec/components/buttons.html#buttons-raised-buttons
+ */
 @interface MDCRaisedButton : MDCButton
 @end