added constraints with ios8 support

Author: Vitaliy G

QMChatViewController/Views/CustomUI/InputToolBar/QMInputToolbar.m

@@ -133,11 +133,9 @@ - (void)toggleButtons {
 
         if (!self.audioRecordButtonItem.superview) {
             [self.contentView.rightBarButtonContainerView addSubview:[self audioRecordButtonItem]];
-            [self audioRecordButtonItem].translatesAutoresizingMaskIntoConstraints = false;
-            
-            [[[self audioRecordButtonItem].centerXAnchor constraintEqualToAnchor:self.contentView.rightBarButtonContainerView.centerXAnchor] setActive:YES];
 
-            [[[self audioRecordButtonItem].centerYAnchor constraintEqualToAnchor:self.contentView.rightBarButtonContainerView.centerYAnchor] setActive:YES];
+            [self audioRecordButtonItem].translatesAutoresizingMaskIntoConstraints = false;
+            [self addCenterConstraintsToItem:self.contentView.rightBarButtonContainerView];
         }
     }
     else {
@@ -147,12 +145,33 @@ - (void)toggleButtons {
 
         if (!self.audioRecordButtonItem.superview) {
             [self.contentView.leftBarButtonContainerView addSubview:[self audioRecordButtonItem]];
+            [self audioRecordButtonItem].translatesAutoresizingMaskIntoConstraints = false;
+            [self addCenterConstraintsToItem:self.contentView.leftBarButtonContainerView];
         }
     }
 
     self.audioRecordButtonItem.hidden = hasDataToSend;
 }
 
+- (void)addCenterConstraintsToItem:(UIView *)itemToAdd {
+    
+    [[NSLayoutConstraint constraintWithItem:self.audioRecordButtonItem
+                                  attribute:NSLayoutAttributeCenterX
+                                  relatedBy:NSLayoutRelationEqual
+                                     toItem:itemToAdd
+                                  attribute:NSLayoutAttributeCenterX
+                                 multiplier:1.0f
+                                   constant:0.0f] setActive:YES];;
+    
+    [[NSLayoutConstraint constraintWithItem:self.audioRecordButtonItem
+                                  attribute:NSLayoutAttributeCenterY
+                                  relatedBy:NSLayoutRelationEqual
+                                     toItem:itemToAdd
+                                  attribute:NSLayoutAttributeCenterY
+                                 multiplier:1.0f
+                                   constant:0.0f] setActive:YES];
+}
+
 - (void)toggleSendButtonEnabled {
 
     if (self.audioRecordingIsEnabled) {