Various docs easy fixes (#10797)

packages/flutter/lib/src/animation/curves.dart

@@ -175,6 +175,8 @@ class Threshold extends Curve {
 /// ![](https://flutter.github.io/assets-for-api-docs/animation/curve_ease_in.png)
 /// ![](https://flutter.github.io/assets-for-api-docs/animation/curve_ease_out.png)
 /// ![](https://flutter.github.io/assets-for-api-docs/animation/curve_ease_in_out.png)
+///
+/// The [Cubic] class implements third-order Bézier curves.
 class Cubic extends Curve {
   /// Creates a cubic curve.
   ///

packages/flutter/lib/src/gestures/recognizer.dart

@@ -23,11 +23,15 @@ export 'pointer_router.dart' show PointerRouter;
 /// anonymous functions that return objects of particular types.
 typedef T RecognizerCallback<T>();
 
-/// The base class that all GestureRecognizers should inherit from.
+/// The base class that all gesture recognizers inherit from.
 ///
 /// Provides a basic API that can be used by classes that work with
 /// gesture recognizers but don't care about the specific details of
 /// the gestures recognizers themselves.
+///
+/// See also:
+///
+///  * [GestureDetector], the widget that is used to detect gestures.
 abstract class GestureRecognizer extends GestureArenaMember {
   /// Registers a new pointer that might be relevant to this gesture
   /// detector.

packages/flutter/lib/src/material/ink_well.dart

@@ -21,23 +21,45 @@ import 'theme.dart';
 /// For a variant of this widget that is specialized for rectangular areas that
 /// always clip splashes, see [InkWell].
 ///
+/// An [InkResponse] widget does two things when responding to a tap:
+///
+///  * It starts to animate a _highlight_. The shape of the highlight is
+///    determined by [highlightShape]. If it is a [BoxShape.circle], the
+///    default, then the highlight is a circle of fixed size centered in the
+///    [InkResponse]. If it is [BoxShape.rectangle], then the highlight is a box
+///    the size of the [InkResponse] itself, unless [getRectCallback] is
+///    provided, in which case that callback defines the rectangle. The color of
+///    the highlight is set by [highlightColor].
+///
+///  * Simultaneously, it starts to animate a _splash_. This is a growing circle
+///    initially centered on the tap location. If this is a [containedInkWell],
+///    the splash grows to the [radius] while remaining centered at the tap
+///    location. Otherwise, the splash migrates to the center of the box as it
+///    grows.
+///
 /// The following two diagrams show how [InkResponse] looks when tapped if the
 /// [highlightShape] is [BoxShape.circle] (the default) and [containedInkWell]
-/// is false (also the default). The first diagram shows how it looks if the
-/// [InkResponse] is relatively large, the second shows how it looks if it is
-/// small. The main thing to notice is that the splashes happily exceed the
-/// bounds of the widget (because [containedInkWell] is false).
+/// is false (also the default).
+///
+/// The first diagram shows how it looks if the [InkResponse] is relatively
+/// large:
 ///
 /// ![The highlight is a disc centered in the box, smaller than the child widget.](https://flutter.github.io/assets-for-api-docs/material/ink_response_large.png)
+///
+/// The second diagram shows how it looks if the [InkResponse] is small:
+///
 /// ![The highlight is a disc overflowing the box, centered on the child.](https://flutter.github.io/assets-for-api-docs/material/ink_response_small.png)
 ///
+/// The main thing to notice from these diagrams is that the splashes happily
+/// exceed the bounds of the widget (because [containedInkWell] is false).
+///
 /// The following diagram shows the effect when the [InkResponse] has a
 /// [highlightShape] of [BoxShape.rectangle] with [containedInkWell] set to
 /// true. These are the values used by [InkWell].
 ///
 /// ![The highlight is a rectangle the size of the box.](https://flutter.github.io/assets-for-api-docs/material/ink_well.png)
 ///
-/// The [InkResponse] widbget must have a [Material] widget as an ancestor. The
+/// The [InkResponse] widget must have a [Material] widget as an ancestor. The
 /// [Material] widget is where the ink reactions are actually painted. This
 /// matches the material design premise wherein the [Material] is what is
 /// actually reacting to touches by spreading ink.
@@ -76,7 +98,7 @@ class InkResponse extends StatefulWidget {
   /// The widget below this widget in the tree.
   final Widget child;
 
-  /// Called when the user taps this part of the material
+  /// Called when the user taps this part of the material.
   final GestureTapCallback onTap;
 
   /// Called when the user double taps this part of the material.
@@ -85,7 +107,8 @@ class InkResponse extends StatefulWidget {
   /// Called when the user long-presses on this part of the material.
   final GestureLongPressCallback onLongPress;
 
-  /// Called when this part of the material either becomes highlighted or stops behing highlighted.
+  /// Called when this part of the material either becomes highlighted or stops
+  /// being highlighted.
   ///
   /// The value passed to the callback is true if this part of the material has
   /// become highlighted and false if this part of the material has stopped
@@ -93,12 +116,46 @@ class InkResponse extends StatefulWidget {
   final ValueChanged<bool> onHighlightChanged;
 
   /// Whether this ink response should be clipped its bounds.
+  ///
+  /// This flag also controls whether the splash migrates to the center of the
+  /// [InkResponse] or not. If [containedInkWell] is true, the splash remains
+  /// centered around the tap location. If it is false, the splash migrates to
+  /// the center of the [InkResponse] as it grows.
+  ///
+  /// See also:
+  ///
+  ///  * [highlightShape], which determines the shape of the highlight.
+  ///  * [borderRadius], which controls the corners when the box is a rectangle.
+  ///  * [getRectCallback], which controls the size and position of the box when
+  ///    it is a rectangle.
   final bool containedInkWell;
 
-  /// The shape (e.g., circle, rectangle) to use for the highlight drawn around this part of the material.
+  /// The shape (e.g., circle, rectangle) to use for the highlight drawn around
+  /// this part of the material.
+  ///
+  /// If the shape is [BoxShape.circle], then the highlight is centered on the
+  /// [InkResponse]. If the shape is [BoxShape.rectangle], then the highlight
+  /// fills the [InkResponse], or the rectangle provided by [getRectCallback] if
+  /// the callback is specified.
+  ///
+  /// See also:
+  ///
+  ///  * [containedInkWell], which controls clipping behavior.
+  ///  * [borderRadius], which controls the corners when the box is a rectangle.
+  ///  * [highlightColor], the color of the highlight.
+  ///  * [getRectCallback], which controls the size and position of the box when
+  ///    it is a rectangle.
   final BoxShape highlightShape;
 
   /// The radius of the ink splash.
+  ///
+  /// Splashes grow up to this size. By default, this size is determined from
+  /// the size of the rectangle provided by [getRectCallback], or the size of
+  /// the [InkResponse] itself.
+  ///
+  /// See also:
+  ///
+  ///  * [splashColor], the color of the splash.
   final double radius;
 
   /// The clipping radius of the containing rect.
@@ -106,10 +163,20 @@ class InkResponse extends StatefulWidget {
 
   /// The highlight color of the ink response. If this property is null then the
   /// highlight color of the theme will be used.
+  ///
+  /// See also:
+  ///
+  ///  * [highlightShape], the shape of the highlight.
+  ///  * [splashColor], the color of the splash.
   final Color highlightColor;
 
   /// The splash color of the ink response. If this property is null then the
   /// splash color of the theme will be used.
+  ///
+  /// See also:
+  ///
+  ///  * [radius], the (maximum) size of the ink splash.
+  ///  * [highlightColor], the color of the highlight.
   final Color splashColor;
 
   /// The rectangle to use for the highlight effect and for clipping
@@ -293,7 +360,7 @@ class _InkResponseState<T extends InkResponse> extends State<T> {
 ///
 /// ![The highlight is a rectangle the size of the box.](https://flutter.github.io/assets-for-api-docs/material/ink_well.png)
 ///
-/// The [InkResponse] widbget must have a [Material] widget as an ancestor. The
+/// The [InkResponse] widget must have a [Material] widget as an ancestor. The
 /// [Material] widget is where the ink reactions are actually painted. This
 /// matches the material design premise wherein the [Material] is what is
 /// actually reacting to touches by spreading ink.