Implement function to setHidden for left button at TextInputBar

Source/SLKTextInputbar.h

@@ -48,6 +48,9 @@ NS_ASSUME_NONNULL_BEGIN
 /** The right action button action. */
 @property (nonatomic, strong) UIButton *rightButton;
 
+/** YES if the right button should be hidden animatedly in case the text view has no text in it. Default is YES. */
+@property (nonatomic, readwrite) BOOL leftButtonIsHidden;
+
 /** YES if the right button should be hidden animatedly in case the text view has no text in it. Default is YES. */
 @property (nonatomic, readwrite) BOOL autoHideRightButton;
 
@@ -119,6 +122,11 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (void)endTextEdition;
 
+/**
+ Set hidden state for left button.
+ */
+- (void)setLeftButtonHidden:(BOOL)isHidden;
+
 
 #pragma mark - Text Counting
 ///------------------------------------------------

Source/SLKTextInputbar.m

@@ -81,6 +81,7 @@ - (void)slk_commonInit
     self.charCountLabelWarningColor = [UIColor redColor];
 
     self.autoHideRightButton = YES;
+    self.leftButtonIsHidden = YES;
     self.editorContentViewHeight = 38.0;
     self.contentInset = UIEdgeInsetsMake(5.0, 8.0, 5.0, 8.0);
 
@@ -517,6 +518,13 @@ - (void)setCounterPosition:(SLKCounterPosition)counterPosition
     [self addConstraints:self.charCountLabelVCs];
 }
 
+- (void)setLeftButtonHidden:(BOOL)isHidden
+{
+    self.leftButtonIsHidden = isHidden;
+    CGFloat leftButtonWidth = isHidden ? 0 : [self.rightButton intrinsicContentSize].width;
+    self.leftButton.hidden = isHidden;
+    self.leftButtonWC.constant = leftButtonWidth;
+}
 
 #pragma mark - Text Editing
 
@@ -713,8 +721,13 @@ - (void)slk_updateConstraintConstants
             self.leftButtonBottomMarginC.constant = roundf((self.intrinsicContentSize.height - leftButtonSize.height) / 2.0) + self.slk_contentViewHeight / 2.0;
         }
 
-        self.leftButtonWC.constant = roundf(leftButtonSize.width);
-        self.leftMarginWC.constant = (leftButtonSize.width > 0) ? self.contentInset.left : zero;
+        if (self.leftButtonIsHidden) {
+            self.leftButtonWC.constant = 0;
+            self.leftMarginWC.constant = zero;
+        } else {
+            self.leftButtonWC.constant = roundf(leftButtonSize.width);
+            self.leftMarginWC.constant = (leftButtonSize.width > 0) ? self.contentInset.left : zero;
+        }
 
         self.rightButtonWC.constant = [self slk_appropriateRightButtonWidth];
         self.rightMarginWC.constant = [self slk_appropriateRightButtonMargin];

Source/SLKTextViewController.h

@@ -348,9 +348,6 @@ NS_CLASS_AVAILABLE_IOS(7_0) @interface SLKTextViewController : UIViewController
 /// @name Text Input Bar Adjustment
 ///------------------------------------------------
 
-/** YES if the text inputbar is hidden. Default is NO. */
-@property (nonatomic, getter=isTextInputbarHidden) BOOL textInputbarHidden;
-
 /**
  Changes the visibility of the text input bar.
  Calling this method with the animated parameter set to NO is equivalent to setting the value of the toolbarHidden property directly.
@@ -360,6 +357,7 @@ NS_CLASS_AVAILABLE_IOS(7_0) @interface SLKTextViewController : UIViewController
  */
 - (void)setTextInputbarHidden:(BOOL)hidden animated:(BOOL)animated;
 
+- (BOOL)isTextInputBarHidden;
 
 #pragma mark - Text Edition
 ///------------------------------------------------

Source/SLKTextViewController.m

@@ -52,6 +52,8 @@ @interface SLKTextViewController ()
 // YES if the view controller's view's size is changing by its parent (i.e. when its window rotates or is resized)
 @property (nonatomic, getter = isTransitioning) BOOL transitioning;
 
+    @property (nonatomic, readwrite) BOOL _isTextInputBarHidden;
+
 // Optional classes to be used instead of the default ones.
 @property (nonatomic, strong) Class textViewClass;
 @property (nonatomic, strong) Class typingIndicatorViewClass;
@@ -155,7 +157,8 @@ - (void)slk_commonInit
     self.keyboardPanningEnabled = YES;
     self.shouldClearTextAtRightButtonPress = YES;
     self.shouldScrollToBottomAfterKeyboardShows = NO;
-
+    self._isTextInputBarHidden = NO;
+
     self.automaticallyAdjustsScrollViewInsets = YES;
     self.extendedLayoutIncludesOpaqueBars = YES;
 }
@@ -901,11 +904,12 @@ - (void)setTextInputbarHidden:(BOOL)hidden
 
 - (void)setTextInputbarHidden:(BOOL)hidden animated:(BOOL)animated
 {
-    if (self.isTextInputbarHidden == hidden) {
+    if (self._isTextInputBarHidden == hidden) {
         return;
     }
-    
+
     _textInputbar.hidden = hidden;
+    self._isTextInputBarHidden = hidden;
 
     if (@available(iOS 11.0, *)) {
         [self viewSafeAreaInsetsDidChange];
@@ -2276,7 +2280,9 @@ - (void)slk_setupViewConstraints
 
 - (void)slk_updateViewConstraints
 {
-    self.textInputbarHC.constant = self.textInputbar.minimumInputbarHeight;
+    if (!self._isTextInputBarHidden)  {
+        self.textInputbarHC.constant = self.textInputbar.minimumInputbarHeight;
+    }
     self.scrollViewHC.constant = [self slk_appropriateScrollViewHeight];
     self.keyboardHC.constant = [self slk_appropriateKeyboardHeightFromRect:CGRectNull];