Implements an alternative technique for dragging the keyboard on iOS 9

Source/SLKInputAccessoryView.m

@@ -20,14 +20,11 @@
 
 @implementation SLKInputAccessoryView
 
-
 #pragma mark - Super Overrides
 
 - (void)willMoveToSuperview:(UIView *)newSuperview
 {
-    if (!SLK_IS_IOS9_AND_HIGHER) {
-        _keyboardViewProxy = newSuperview;
-    }
+    _keyboardViewProxy = newSuperview;
 }
 
 @end

Source/SLKTextInputbar.h

@@ -122,6 +122,19 @@ typedef NS_ENUM(NSUInteger, SLKCounterPosition) {
  */
 - (void)endTextEdition;
 
+/**
+ Shows a keyboard snapshot placeholder, replacing the system keyboard.
+ The snapshot is being added as a subview, aligned at the same position the keyboard is, before hiding it momentarily.
+
+ @param view The view where the snapshot is taken for, for aligning purposes.
+ */
+- (void)prepareKeyboardPlaceholderFromView:(UIView *)view;
+
+/**
+ Hides the visible keyboard snapshot placeholder, if applicable.
+ */
+- (void)showKeyboardPlaceholder:(BOOL)show;
+
 
 #pragma mark - Text Counting
 ///------------------------------------------------

Source/SLKTextInputbar.m

@@ -39,6 +39,7 @@ @interface SLKTextInputbar ()
 @property (nonatomic, strong) NSArray *charCountLabelVCs;
 
 @property (nonatomic, strong) UILabel *charCountLabel;
+@property (nonatomic, strong) UIView *keyboardPlaceholderView;
 
 @property (nonatomic) CGPoint previousOrigin;
 
@@ -538,6 +539,65 @@ - (void)slk_updateCounter
 }
 
 
+#pragma mark - Keyboard Snapshot Placeholder
+
+- (void)prepareKeyboardPlaceholderFromView:(UIView *)view
+{
+    UIWindow *keyboardWindow = [self slk_keyboardWindow];
+
+    if (!_keyboardPlaceholderView && keyboardWindow) {
+        // Takes a snapshot of the keyboard's window
+        UIView *snapshotView = [keyboardWindow snapshotViewAfterScreenUpdates:NO];
+
+        CGRect screenBounds = [UIScreen mainScreen].bounds;
+
+        // Shifts the snapshot up to fit to the bottom
+        CGRect snapshowFrame = snapshotView.frame;
+        snapshowFrame.origin.y = CGRectGetHeight(self.inputAccessoryView.keyboardViewProxy.frame) - CGRectGetHeight(screenBounds);
+        snapshotView.frame = snapshowFrame;
+
+        CGRect keyboardFrame = self.inputAccessoryView.keyboardViewProxy.frame;
+        keyboardFrame.origin.y = CGRectGetHeight(self.frame);
+
+        self.keyboardPlaceholderView = [[UIView alloc] initWithFrame:keyboardFrame];
+        self.keyboardPlaceholderView.backgroundColor = [UIColor clearColor];
+        [self.keyboardPlaceholderView addSubview:snapshotView];
+    }
+}
+
+- (void)showKeyboardPlaceholder:(BOOL)show
+{
+    UIWindow *keyboardWindow = [self slk_keyboardWindow];
+
+    if (show && self.keyboardPlaceholderView && keyboardWindow) {
+
+        // Adds the placeholder view to the input bar, so when it looks they are sticked together.
+        [self addSubview:self.keyboardPlaceholderView];
+
+        // Let's delay hiding the keyboard's window to avoid noticeable glitches
+        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.01 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
+            keyboardWindow.hidden = YES;
+        });
+    }
+    else if (!show && _keyboardPlaceholderView && keyboardWindow) {
+
+        [_keyboardPlaceholderView removeFromSuperview];
+        _keyboardPlaceholderView = nil;
+
+        keyboardWindow.hidden = NO;
+    }
+}
+
+- (UIWindow *)slk_keyboardWindow
+{
+    NSArray *array = [[UIApplication sharedApplication] windows];
+
+    // NOTE: This is risky, since the order may change in the future.
+    // But it is the only way of looking up for the keyboard window without using private APIs.
+    return [array lastObject];
+}
+
+
 #pragma mark - Notification Events
 
 - (void)slk_didChangeTextViewText:(NSNotification *)notification

Source/SLKTextViewController.h

@@ -80,9 +80,12 @@ NS_CLASS_AVAILABLE_IOS(7_0) @interface SLKTextViewController : UIViewController
 /** A single tap gesture used to dismiss the keyboard. SLKTextViewController is its delegate. */
 @property (nonatomic, readonly) UIGestureRecognizer *singleTapGesture;
 
-/** A vertical pan gesture used for bringing the keyboard from the bottom. SLKTextViewController is its delegate. */
+/** A vertical pan gesture used for moving the keyboard up and bottom. SLKTextViewController is its delegate. */
 @property (nonatomic, readonly) UIPanGestureRecognizer *verticalPanGesture;
 
+/** A vertical swipe gesture used for bringing the keyboard from the bottom. SLKTextViewController is its delegate. */
+@property (nonatomic, readonly) UISwipeGestureRecognizer *verticalSwipeGesture;
+
 /** YES if animations should have bouncy effects. Default is YES. */
 @property (nonatomic, assign) BOOL bounces;
 
@@ -91,9 +94,6 @@ NS_CLASS_AVAILABLE_IOS(7_0) @interface SLKTextViewController : UIViewController
 
 /**
  YES if keyboard can be dismissed gradually with a vertical panning gesture. Default is YES.
-
- This feature doesn't work on iOS 9 due to no legit alternatives to detect the keyboard view.
- Open Radar: http://openradar.appspot.com/radar?id=5021485877952512
  */
 @property (nonatomic, assign, getter = isKeyboardPanningEnabled) BOOL keyboardPanningEnabled;
 
@@ -558,6 +558,7 @@ NS_CLASS_AVAILABLE_IOS(7_0) @interface SLKTextViewController : UIViewController
 
 /** UIGestureRecognizerDelegate */
 - (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer NS_REQUIRES_SUPER;
+- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer NS_REQUIRES_SUPER;
 
 /** UIAlertViewDelegate */
 #ifndef __IPHONE_8_0

Source/SLKTextViewController.m

@@ -19,9 +19,6 @@
 
 #import "UIResponder+SLKAdditions.h"
 
-/** Feature flagged while waiting to implement a more reliable technique. */
-#define SLKBottomPanningEnabled 0
-
 #define kSLKAlertViewClearTextTag [NSStringFromClass([SLKTextViewController class]) hash]
 
 NSString * const SLKKeyboardWillShowNotification =      @"SLKKeyboardWillShowNotification";
@@ -323,8 +320,12 @@ - (SLKTextInputbar *)textInputbar
 
         _verticalPanGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(slk_didPanTextInputBar:)];
         _verticalPanGesture.delegate = self;
-
         [_textInputbar addGestureRecognizer:self.verticalPanGesture];
+
+        _verticalSwipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(slk_didSwipeTextInputBar:)];
+        _verticalSwipeGesture.direction = UISwipeGestureRecognizerDirectionUp;
+        _verticalSwipeGesture.delegate = self;
+        [_textInputbar addGestureRecognizer:self.verticalSwipeGesture];
     }
     return _textInputbar;
 }
@@ -909,26 +910,20 @@ - (void)setTextInputbarHidden:(BOOL)hidden animated:(BOOL)animated
 
 #pragma mark - Private Methods
 
-- (void)slk_didPanTextInputBar:(UIPanGestureRecognizer *)gesture
+- (void)slk_didSwipeTextInputBar:(UISwipeGestureRecognizer *)gesture
 {
-    // Textinput dragging isn't supported when
-    if (!self.view.window || !self.keyboardPanningEnabled ||
-        [self ignoreTextInputbarAdjustment] || self.isPresentedInPopover) {
-        return;
+    if (gesture.state == UIGestureRecognizerStateEnded) {
+        if (!self.isPresentedInPopover && ![self ignoreTextInputbarAdjustment]) {
+            [self presentKeyboard:YES];
+        }
     }
-
-    dispatch_async(dispatch_get_main_queue(), ^{
-        [self slk_handlePanGestureRecognizer:gesture];
-    });
 }
 
-- (void)slk_handlePanGestureRecognizer:(UIPanGestureRecognizer *)gesture
+- (void)slk_didPanTextInputBar:(UIPanGestureRecognizer *)gesture
 {
-    // Local variables
     static CGPoint startPoint;
     static CGRect originalFrame;
     static BOOL dragging = NO;
-    static BOOL presenting = NO;
 
     __block UIView *keyboardView = [_textInputbar.inputAccessoryView keyboardViewProxy];
 
@@ -944,78 +939,44 @@ - (void)slk_handlePanGestureRecognizer:(UIPanGestureRecognizer *)gesture
     CGFloat keyboardMaxY = CGRectGetHeight(SLKKeyWindowBounds());
     CGFloat keyboardMinY = keyboardMaxY - CGRectGetHeight(keyboardView.frame);
 
-
-    // Skips this if it's not the expected textView.
-    // Checking the keyboard height constant helps to disable the view constraints update on iPad when the keyboard is undocked.
-    // Checking the keyboard status allows to keep the inputAccessoryView valid when still reacing the bottom of the screen.
-    if (![self.textView isFirstResponder] || (self.keyboardHC.constant == 0 && self.keyboardStatus == SLKKeyboardStatusDidHide)) {
-#if SLKBottomPanningEnabled
-        if ([gesture.view isEqual:self.scrollViewProxy]) {
-            if (gestureVelocity.y > 0) {
-                return;
-            }
-            else if ((self.isInverted && ![self.scrollViewProxy slk_isAtTop]) || (!self.isInverted && ![self.scrollViewProxy slk_isAtBottom])) {
-                return;
-            }
-        }
-
-        presenting = YES;
-#else
-        if ([gesture.view isEqual:_textInputbar] && gestureVelocity.y < 0) {
-            [self presentKeyboard:YES];
-        }
-        return;
-#endif
-    }
-
     switch (gesture.state) {
         case UIGestureRecognizerStateBegan: {
 
             startPoint = CGPointZero;
             dragging = NO;
 
-            if (presenting) {
-                // Let's first present the keyboard without animation
-                [self presentKeyboard:NO];
-
-                // So we can capture the keyboard's view
-                keyboardView = [_textInputbar.inputAccessoryView keyboardViewProxy];
-
-                originalFrame = keyboardView.frame;
-                originalFrame.origin.y = CGRectGetMaxY(self.view.frame);
-
-                // And move the keyboard to the bottom edge
-                // TODO: Fix an occasional layout glitch when the keyboard appears for the first time.
-                keyboardView.frame = originalFrame;
+            // Because the keyboard is on its own view hierarchy since iOS 9,
+            // we instead show a snapshot of the keyboard and hide it
+            // to give the illusion that the keyboard is being moved by the user.
+            if (SLK_IS_IOS9_AND_HIGHER && gestureVelocity.y > 0) {
+                [self.textInputbar prepareKeyboardPlaceholderFromView:self.view];
             }
 
             break;
         }
         case UIGestureRecognizerStateChanged: {
 
-            if (CGRectContainsPoint(_textInputbar.frame, gestureLocation) || dragging || presenting){
-
+            if (CGRectContainsPoint(_textInputbar.frame, gestureLocation) || dragging){
                 if (CGPointEqualToPoint(startPoint, CGPointZero)) {
                     startPoint = gestureLocation;
                     dragging = YES;
 
-                    if (!presenting) {
-                        originalFrame = keyboardView.frame;
+                    // Because the keyboard is on its own view hierarchy since iOS 9,
+                    // we instead show a snapshot of the keyboard and hide it
+                    // to give the illusion that the keyboard is being moved by the user.
+                    if (SLK_IS_IOS9_AND_HIGHER && gestureVelocity.y > 0) {
+                        [self.textInputbar showKeyboardPlaceholder:YES];
                     }
+
+                    originalFrame = keyboardView.frame;
                 }
 
                 self.movingKeyboard = YES;
 
                 CGPoint transition = CGPointMake(gestureLocation.x - startPoint.x, gestureLocation.y - startPoint.y);
 
                 CGRect keyboardFrame = originalFrame;
-
-                if (presenting) {
-                    keyboardFrame.origin.y += transition.y;
-                }
-                else {
-                    keyboardFrame.origin.y += MAX(transition.y, 0.0);
-                }
+                keyboardFrame.origin.y += MAX(transition.y, 0.0);
 
                 // Makes sure they keyboard is always anchored to the bottom
                 if (CGRectGetMinY(keyboardFrame) < keyboardMinY) {
@@ -1055,22 +1016,21 @@ - (void)slk_handlePanGestureRecognizer:(UIPanGestureRecognizer *)gesture
         case UIGestureRecognizerStateFailed: {
 
             if (!dragging) {
+                if (SLK_IS_IOS9_AND_HIGHER) {
+                    [self.textInputbar showKeyboardPlaceholder:NO];
+                }
+
                 break;
             }
 
             CGPoint transition = CGPointMake(0.0, fabs(gestureLocation.y - startPoint.y));
-
             CGRect keyboardFrame = originalFrame;
 
-            if (presenting) {
-                keyboardFrame.origin.y = keyboardMinY;
-            }
-
             // The velocity can be changed to hide or show the keyboard based on the gesture
             CGFloat minVelocity = 20.0;
             CGFloat minDistance = CGRectGetHeight(keyboardFrame)/2.0;
 
-            BOOL hide = (gestureVelocity.y > minVelocity) || (presenting && transition.y < minDistance) || (!presenting && transition.y > minDistance);
+            BOOL hide = (gestureVelocity.y > minVelocity) || (transition.y > minDistance);
 
             if (hide) keyboardFrame.origin.y = keyboardMaxY;
 
@@ -1093,9 +1053,12 @@ - (void)slk_handlePanGestureRecognizer:(UIPanGestureRecognizer *)gesture
                                  startPoint = CGPointZero;
                                  originalFrame = CGRectZero;
                                  dragging = NO;
-                                 presenting = NO;
 
                                  self.movingKeyboard = NO;
+
+                                 if (SLK_IS_IOS9_AND_HIGHER) {
+                                     [self.textInputbar showKeyboardPlaceholder:NO];
+                                 }
                              }];
 
             break;
@@ -1113,11 +1076,6 @@ - (void)slk_didTapScrollView:(UIGestureRecognizer *)gesture
     }
 }
 
-- (void)slk_didPanTextView:(UIGestureRecognizer *)gesture
-{
-    [self presentKeyboard:YES];
-}
-
 - (void)slk_performRightAction
 {
     NSArray *actions = [self.rightButton actionsForTarget:self forControlEvent:UIControlEventTouchUpInside];
@@ -2135,10 +2093,38 @@ - (void)scrollViewDidScroll:(UIScrollView *)scrollView
 - (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gesture
 {
     if ([gesture isEqual:self.singleTapGesture]) {
-        return [self.textView isFirstResponder] && ![self ignoreTextInputbarAdjustment];
+        // Tap to dismiss isn't supported when
+        if (![self.textView isFirstResponder] && [self ignoreTextInputbarAdjustment]) {
+            return NO;
+        }
+
+        return YES;
+    }
+    else if ([gesture isEqual:self.verticalSwipeGesture]) {
+        // TextInput swipping isn't supported when
+        if (!self.view.window || [self.textView isFirstResponder] || [self ignoreTextInputbarAdjustment] || self.isPresentedInPopover) {
+            return NO;
+        }
+
+        return YES;
     }
     else if ([gesture isEqual:self.verticalPanGesture]) {
-        return self.keyboardPanningEnabled && ![self ignoreTextInputbarAdjustment];
+        // TextInput dragging isn't supported when
+        if (!self.view.window || !self.keyboardPanningEnabled || [self ignoreTextInputbarAdjustment] || self.isPresentedInPopover) {
+            return NO;
+        }
+
+        return YES;
+    }
+
+    return NO;
+}
+
+- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
+{
+    if ([otherGestureRecognizer isKindOfClass:[UISwipeGestureRecognizer class]] &&
+        [gestureRecognizer isEqual:self.verticalPanGesture] && [otherGestureRecognizer isEqual:self.verticalSwipeGesture]) {
+        return YES;
     }
 
     return NO;