[TextFields] Implement some UIView overrides in MDCBaseTextField (mat…

…erial-components#8494)

This PR adds a bit some UIView overrides to MDCBaseTextField with some additional minor cleanup and wiring, and a disabled snapshot test :D

Related to #6942.

components/TextFields/src/ContainedInputView/MDCBaseTextField.m

@@ -99,8 +99,19 @@ - (void)layoutSubviews {
   [self postLayoutSubviews];
 }
 
+// UITextField's sizeToFit calls this method and then also calls setNeedsLayout.
+// When the system calls this method the size parameter is the view's current size.
+- (CGSize)sizeThatFits:(CGSize)size {
+  return [self preferredSizeWithWidth:size.width];
+}
+
+- (CGSize)intrinsicContentSize {
+  return [self preferredSizeWithWidth:CGRectGetWidth(self.bounds)];
+}
+
 - (void)traitCollectionDidChange:(UITraitCollection *)previousTraitCollection {
   [super traitCollectionDidChange:previousTraitCollection];
+
   self.layoutDirection = self.mdf_effectiveUserInterfaceLayoutDirection;
 }
 
@@ -193,8 +204,20 @@ - (CGFloat)clearButtonSideLengthWithTextFieldSize:(CGSize)textFieldSize {
   return systemPlaceholderRect.size.height;
 }
 
+- (CGSize)preferredSizeWithWidth:(CGFloat)width {
+  CGSize fittingSize = CGSizeMake(width, CGFLOAT_MAX);
+  MDCBaseTextFieldLayout *layout = [self calculateLayoutWithTextFieldSize:fittingSize];
+  return CGSizeMake(width, layout.calculatedHeight);
+}
+
 #pragma mark UITextField Accessor Overrides
 
+- (void)setEnabled:(BOOL)enabled {
+  [super setEnabled:enabled];
+
+  [self setNeedsLayout];
+}
+
 - (void)setLeftViewMode:(UITextFieldViewMode)leftViewMode {
   NSLog(@"Setting leftViewMode is not recommended. Consider setting leadingViewMode and "
         @"trailingViewMode instead.");

components/TextFields/src/ContainedInputView/private/MDCBaseTextFieldLayout.h

@@ -31,6 +31,9 @@
 @property(nonatomic, assign) CGRect leftViewFrame;
 @property(nonatomic, assign) CGRect rightViewFrame;
 
+@property(nonatomic, readonly) CGFloat calculatedHeight;
+@property(nonatomic, assign) CGFloat containerHeight;
+
 - (nonnull instancetype)initWithTextFieldSize:(CGSize)textFieldSize
                          positioningReference:
                              (nonnull id<MDCContainerStyleVerticalPositioningReference>)

components/TextFields/src/ContainedInputView/private/MDCBaseTextFieldLayout.m

@@ -229,6 +229,7 @@ - (void)calculateLayoutWithTextFieldSize:(CGSize)textFieldSize
   self.labelFrameNormal = labelFrameNormal;
   self.leftViewHidden = !displaysLeftView;
   self.rightViewHidden = !displaysRightView;
+  self.containerHeight = positioningReference.containerHeight;
 }
 
 - (CGFloat)minYForSubviewWithHeight:(CGFloat)height centerY:(CGFloat)centerY {
@@ -342,4 +343,8 @@ - (CGFloat)textHeightWithFont:(UIFont *)font {
   return (CGFloat)ceil((double)font.lineHeight);
 }
 
+- (CGFloat)calculatedHeight {
+  return self.containerHeight;
+}
+
 @end

components/TextFields/tests/snapshot/MDCBaseTextFieldSnapshotTests.m

@@ -182,4 +182,16 @@ - (void)testFloatingLabelWithCustomColorWhileEditing {
   [self validateTextField:textField];
 }
 
+- (void)testDisabledTextField {
+  // Given
+  MDCBaseTextField *textField = self.textField;
+
+  // When
+  textField.label.text = @"Floating label text";
+  textField.text = @"Text";
+  textField.enabled = NO;
+
+  // Then
+  [self validateTextField:textField];
+}
 @end

components/TextFields/tests/unit/ContainedInputView/MDCBaseTextFieldTests.m

@@ -248,4 +248,19 @@ - (void)testTextColorAccessors {
                         [textField textColorForState:MDCTextControlStateDisabled]);
 }
 
+- (void)testSizeThatFits {
+  // Given
+  CGRect largeTextFieldFrame = CGRectMake(0, 0, 130, 300);
+  MDCBaseTextField *textField = [[MDCBaseTextField alloc] initWithFrame:largeTextFieldFrame];
+
+  // When
+  textField.text = @"text";
+  [textField sizeToFit];
+
+  // Then
+  CGSize newSize = textField.frame.size;
+  CGSize correctSize = CGSizeMake(130, 50);
+  XCTAssertTrue(CGSizeEqualToSize(newSize, correctSize));
+}
+
 @end