[MDC/Button] Add rippleEdgeInsets API.

Currently we make the ripple the entire size of the button. This limits clients being able to customize if the ripple is inset or outset on a particular side of the button. Since MDCFloatingButton sets its contentEdgeInsets this API is needed to allow for the two values to be independent.

https://developer.apple.com/documentation/uikit/uibutton/1624036-contentedgeinsets

PiperOrigin-RevId: 322199718

components/Buttons/src/MDCButton.h

@@ -96,6 +96,11 @@
  */
 @property(nonatomic) CGSize inkViewOffset;
 
+/**
+ The inset or outset margins for the rectangle surrounding the button’s ripple.
+ */
+@property(nonatomic, assign) UIEdgeInsets rippleEdgeInsets;
+
 /**
  The minimum size of the button’s alignment rect. If either the height or width are non-positive
  (negative or zero), they will be ignored and that axis will adjust to its content size.

components/Buttons/src/MDCButton.m

@@ -337,6 +337,7 @@ - (void)layoutSubviews {
   } else {
     CGRect bounds = CGRectStandardize(self.bounds);
     bounds = CGRectOffset(bounds, self.inkViewOffset.width, self.inkViewOffset.height);
+    bounds = UIEdgeInsetsInsetRect(bounds, self.rippleEdgeInsets);
     _inkView.frame = bounds;
     self.rippleView.frame = bounds;
   }
@@ -641,6 +642,12 @@ - (void)setInkViewOffset:(CGSize)inkViewOffset {
   [self setNeedsLayout];
 }
 
+- (void)setRippleEdgeInsets:(UIEdgeInsets)rippleEdgeInsets {
+  _rippleEdgeInsets = rippleEdgeInsets;
+
+  [self setNeedsLayout];
+}
+
 - (void)setEnableRippleBehavior:(BOOL)enableRippleBehavior {
   _enableRippleBehavior = enableRippleBehavior;
 

components/Buttons/tests/snapshot/ButtonsRippleSnapshotTests.m

@@ -160,4 +160,14 @@ - (void)testButtonWhenRippleTouchDownAtPointIsCalledGeneratesCorrectImage {
   [self generateSnapshotAndVerifyForView:self.button];
 }
 
+- (void)testButtonRippleWhenContentEdgeInsetsAreSet {
+  // When
+  self.button.rippleEdgeInsets = UIEdgeInsetsMake(1, 2, 3, 4);
+  self.button.rippleView.backgroundColor = UIColor.purpleColor;
+  [self.button layoutIfNeeded];
+
+  // Then
+  [self generateSnapshotAndVerifyForView:self.button];
+}
+
 @end

components/Buttons/tests/unit/MDCButtonRippleTests.m

@@ -182,4 +182,23 @@ - (void)testSettingSelectedUpdatesRippleTheming {
   XCTAssertFalse(self.button.rippleView.isSelected);
 }
 
+- (void)testSettingContentEdgeInsetsUpdatesRipple {
+  // Given
+  self.button.enableRippleBehavior = YES;
+  CGRect buttonFrame = CGRectMake(0, 0, 100, 100);
+  self.button.frame = buttonFrame;
+  UIEdgeInsets buttonRippleInsets = UIEdgeInsetsMake(1, 2, 3, 4);
+
+  // When
+  self.button.rippleEdgeInsets = buttonRippleInsets;
+  [self.button layoutIfNeeded];
+
+  // Then
+  XCTAssertTrue(CGRectEqualToRect(UIEdgeInsetsInsetRect(buttonFrame, buttonRippleInsets),
+                                  self.button.rippleView.frame),
+                @"%@ is not equal to %@",
+                NSStringFromCGRect(UIEdgeInsetsInsetRect(buttonFrame, buttonRippleInsets)),
+                NSStringFromCGRect(self.button.rippleView.frame));
+}
+
 @end