CupertinoTextField vertical alignment (#34723)

CupertinoTextField now supports vertical alignment via the textAlignVertical parameter.

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

@@ -3576,42 +3576,3 @@ class InputDecorationTheme extends Diagnosticable {
     properties.add(DiagnosticsProperty<bool>('alignLabelWithHint', alignLabelWithHint, defaultValue: defaultTheme.alignLabelWithHint));
   }
 }
-
-/// The vertical alignment of text within an input.
-///
-/// A single [y] value that can range from -1.0 to 1.0. -1.0 aligns to the top
-/// of the input so that the top of the first line of text fits within the input
-/// and its padding. 0.0 aligns to the center of the input. 1.0 aligns so that
-/// the bottom of the last line of text aligns with the bottom interior edge of
-/// the input.
-///
-/// See also:
-///
-///  * [TextField.textAlignVertical], which is passed on to the [InputDecorator].
-///  * [InputDecorator.textAlignVertical], which defines the alignment of
-///    prefix, input, and suffix, within the [InputDecorator].
-class TextAlignVertical {
-  /// Construct TextAlignVertical from any given y value.
-  const TextAlignVertical({
-    @required this.y,
-  }) : assert(y != null),
-       assert(y >= -1.0 && y <= 1.0);
-
-  /// A value ranging from -1.0 to 1.0 that defines the topmost and bottommost
-  /// locations of the top and bottom of the input text box.
-  final double y;
-
-  /// Aligns a TextField's input Text with the topmost location within the
-  /// TextField.
-  static const TextAlignVertical top = TextAlignVertical(y: -1.0);
-  /// Aligns a TextField's input Text to the center of the TextField.
-  static const TextAlignVertical center = TextAlignVertical(y: 0.0);
-  /// Aligns a TextField's input Text with the bottommost location within the
-  /// TextField.
-  static const TextAlignVertical bottom = TextAlignVertical(y: 1.0);
-
-  @override
-  String toString() {
-    return '$runtimeType(y: $y)';
-  }
-}

packages/flutter/lib/src/painting/alignment.dart

@@ -633,3 +633,44 @@ class _MixedAlignment extends AlignmentGeometry {
     return null;
   }
 }
+
+/// The vertical alignment of text within an input box.
+///
+/// A single [y] value that can range from -1.0 to 1.0. -1.0 aligns to the top
+/// of an input box so that the top of the first line of text fits within the
+/// box and its padding. 0.0 aligns to the center of the box. 1.0 aligns so that
+/// the bottom of the last line of text aligns with the bottom interior edge of
+/// the input box.
+///
+/// See also:
+///
+///  * [TextField.textAlignVertical], which is passed on to the [InputDecorator].
+///  * [CupertinoTextField.textAlignVertical], which behaves in the same way as
+///    the parameter in TextField.
+///  * [InputDecorator.textAlignVertical], which defines the alignment of
+///    prefix, input, and suffix within an [InputDecorator].
+class TextAlignVertical {
+  /// Creates a TextAlignVertical from any y value between -1.0 and 1.0.
+  const TextAlignVertical({
+    @required this.y,
+  }) : assert(y != null),
+       assert(y >= -1.0 && y <= 1.0);
+
+  /// A value ranging from -1.0 to 1.0 that defines the topmost and bottommost
+  /// locations of the top and bottom of the input box.
+  final double y;
+
+  /// Aligns a TextField's input Text with the topmost location within a
+  /// TextField's input box.
+  static const TextAlignVertical top = TextAlignVertical(y: -1.0);
+  /// Aligns a TextField's input Text to the center of the TextField.
+  static const TextAlignVertical center = TextAlignVertical(y: 0.0);
+  /// Aligns a TextField's input Text with the bottommost location within a
+  /// TextField.
+  static const TextAlignVertical bottom = TextAlignVertical(y: 1.0);
+
+  @override
+  String toString() {
+    return '$runtimeType(y: $y)';
+  }
+}

packages/flutter/lib/src/rendering/editable.dart

@@ -1252,7 +1252,7 @@ class RenderEditable extends RenderBox {
   double get preferredLineHeight => _textPainter.preferredLineHeight;
 
   double _preferredHeight(double width) {
-    // Lock height to maxLines if needed
+    // Lock height to maxLines if needed.
     final bool lockedMax = maxLines != null && minLines == null;
     final bool lockedBoth = minLines != null && minLines == maxLines;
     final bool singleLine = maxLines == 1;
@@ -1260,7 +1260,7 @@ class RenderEditable extends RenderBox {
       return preferredLineHeight * maxLines;
     }
 
-    // Clamp height to minLines or maxLines if needed
+    // Clamp height to minLines or maxLines if needed.
     final bool minLimited = minLines != null && minLines > 1;
     final bool maxLimited = maxLines != null;
     if (minLimited || maxLimited) {
@@ -1273,7 +1273,7 @@ class RenderEditable extends RenderBox {
       }
     }
 
-    // Set the height based on the content
+    // Set the height based on the content.
     if (width == double.infinity) {
       final String text = _textPainter.text.toPlainText();
       int lines = 1;