Update behavior of recursive constraint removal method to exclude int…

…rinsic content size constraints

Expose a new method which allows ALL constraints (including intrinsic content size constraints) to be removed.

Source/UIView+AutoLayout.h

@@ -57,9 +57,14 @@ typedef void(^ALConstraintsBlock)(void);    // a block of method calls to the UI
 /** Removes the given constraints from the views they have been added to. */
 + (void)removeConstraints:(NSArray *)constraints;
 
-/** Recursively removes all constraints from the view and its subviews. */
+/** Recursively removes all layout constraints from the view and its subviews.
+    NOTE: This method preserves low-priority intrinsic content size constraints, which you usually do not want to remove. */
 - (void)removeAllConstraintsFromViewAndSubviews;
 
+/** Recursively removes all constraints from the view and its subviews, optionally including intrinsic content size constraints.
+    WARNING: Intrinsic content size constraints are auto-generated lower priority constraints, and you usually do not want to remove these. */
+- (void)removeAllConstraintsFromViewAndSubviewsIncludingIntrinsicContentSizeConstraints:(BOOL)shouldRemoveIntrinsicContentSizeConstraints;
+
 
 /** Centers the view in its superview. */
 - (NSArray *)autoCenterInSuperview;

Source/UIView+AutoLayout.m

@@ -103,13 +103,33 @@ + (void)removeConstraints:(NSArray *)constraints
 }
 
 /**
- Recursively removes all constraints from the view and its subviews.
+ Recursively removes all layout constraints from the view and its subviews.
+ NOTE: This method preserves low-priority intrinsic content size constraints, which you usually do not want to remove.
  */
 - (void)removeAllConstraintsFromViewAndSubviews
 {
-    [UIView removeConstraints:self.constraints];
+    [self removeAllConstraintsFromViewAndSubviewsIncludingIntrinsicContentSizeConstraints:NO];
+}
+
+/** 
+ Recursively removes all constraints from the view and its subviews, optionally including intrinsic content size constraints.
+ WARNING: Intrinsic content size constraints are auto-generated lower priority constraints that attempt to keep a view at its
+ intrinsic content size (by hugging its content & resisting compression), and you usually do not want to remove these.
+ 
+ @param shouldRemoveIntrinsicContentSizeConstraints Whether intrinsic content size constraints should be removed or skipped.
+ */
+- (void)removeAllConstraintsFromViewAndSubviewsIncludingIntrinsicContentSizeConstraints:(BOOL)shouldRemoveIntrinsicContentSizeConstraints
+{
+    NSMutableArray *constraintsToRemove = [NSMutableArray new];
+    for (NSLayoutConstraint *constraint in self.constraints) {
+        BOOL isIntrinsicContentSizeConstraint = [NSStringFromClass([constraint class]) isEqualToString:@"NSContentSizeLayoutConstraint"];
+        if (shouldRemoveIntrinsicContentSizeConstraints || !isIntrinsicContentSizeConstraint) {
+            [constraintsToRemove addObject:constraint];
+        }
+    }
+    [UIView removeConstraints:constraintsToRemove];
     for (UIView *subview in self.subviews) {
-        [subview removeAllConstraintsFromViewAndSubviews];
+        [subview removeAllConstraintsFromViewAndSubviewsIncludingIntrinsicContentSizeConstraints:shouldRemoveIntrinsicContentSizeConstraints];
     }
 }