moonlight-ios/Limelight/Input/StreamView.m

//
//  StreamView.m
//  Moonlight
//
//  Created by Cameron Gutman on 10/19/14.
//  Copyright (c) 2014 Moonlight Stream. All rights reserved.
//

#import "StreamView.h"
#include <Limelight.h>
#import "DataManager.h"
#import "ControllerSupport.h"
#import "KeyboardSupport.h"

static const int REFERENCE_WIDTH = 1280;
static const int REFERENCE_HEIGHT = 720;

@implementation StreamView {
    CGPoint touchLocation, originalLocation;
    BOOL touchMoved;
    OnScreenControls* onScreenControls;
    
    BOOL isInputingText;
    BOOL isDragging;
    NSTimer* dragTimer;
    
    float streamAspectRatio;
    
    // iOS 13.4 mouse support
    NSInteger lastMouseButtonMask;
    float lastMouseX;
    float lastMouseY;
    
    // iOS 14 mouse support
    double accumulatedMouseDeltaX;
    double accumulatedMouseDeltaY;
    
#if TARGET_OS_TV
    UIGestureRecognizer* remotePressRecognizer;
    UIGestureRecognizer* remoteLongPressRecognizer;
#endif
    
    id<UserInteractionDelegate> interactionDelegate;
    NSTimer* interactionTimer;
    BOOL hasUserInteracted;
    
    NSDictionary<NSString *, NSNumber *> *dictCodes;
}

- (void) setupStreamView:(ControllerSupport*)controllerSupport
           swipeDelegate:(id<EdgeDetectionDelegate>)swipeDelegate
     interactionDelegate:(id<UserInteractionDelegate>)interactionDelegate
                  config:(StreamConfiguration*)streamConfig {
    self->interactionDelegate = interactionDelegate;
    self->streamAspectRatio = (float)streamConfig.width / (float)streamConfig.height;
    
    TemporarySettings* settings = [[[DataManager alloc] init] getSettings];
    
#if TARGET_OS_TV
    remotePressRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(remoteButtonPressed:)];
    remotePressRecognizer.allowedPressTypes = @[@(UIPressTypeSelect)];
    
    remoteLongPressRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(remoteButtonLongPressed:)];
    remoteLongPressRecognizer.allowedPressTypes = @[@(UIPressTypeSelect)];
    
    [self addGestureRecognizer:remotePressRecognizer];
    [self addGestureRecognizer:remoteLongPressRecognizer];
#else
    onScreenControls = [[OnScreenControls alloc] initWithView:self controllerSup:controllerSupport swipeDelegate:swipeDelegate];
    OnScreenControlsLevel level = (OnScreenControlsLevel)[settings.onscreenControls integerValue];
    if (level == OnScreenControlsLevelAuto) {
        [controllerSupport initAutoOnScreenControlMode:onScreenControls];
    }
    else {
        Log(LOG_I, @"Setting manual on-screen controls level: %d", (int)level);
        [onScreenControls setLevel:level];
    }
    
    if (@available(iOS 14.0, *)) {
        // Use the new GCMouse API on iOS 14
    }
    else if (@available(iOS 13.4, *)) {
        // Use the legacy mouse API on iOS 13.4
        [self addInteraction:[[UIPointerInteraction alloc] initWithDelegate:self]];
        
        UIPanGestureRecognizer *mouseWheelRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(mouseWheelMoved:)];
        mouseWheelRecognizer.allowedScrollTypesMask = UIScrollTypeMaskAll;
        mouseWheelRecognizer.allowedTouchTypes = @[@(UITouchTypeIndirectPointer)];
        [self addGestureRecognizer:mouseWheelRecognizer];
    }
#endif
}

- (void)startInteractionTimer {
    // Restart user interaction tracking
    hasUserInteracted = NO;
    
    BOOL timerAlreadyRunning = interactionTimer != nil;
    
    // Start/restart the timer
    [interactionTimer invalidate];
    interactionTimer = [NSTimer scheduledTimerWithTimeInterval:2.0
                        target:self
                        selector:@selector(interactionTimerExpired:)
                        userInfo:nil
                        repeats:NO];
    
    // Notify the delegate if this was a new user interaction
    if (!timerAlreadyRunning) {
        [interactionDelegate userInteractionBegan];
    }
}

- (void)interactionTimerExpired:(NSTimer *)timer {
    if (!hasUserInteracted) {
        // User has finished touching the screen
        interactionTimer = nil;
        [interactionDelegate userInteractionEnded];
    }
    else {
        // User is still touching the screen. Restart the timer.
        [self startInteractionTimer];
    }
}

- (void) showOnScreenControls {
#if !TARGET_OS_TV
    [onScreenControls show];
    [self becomeFirstResponder];
#endif
}

- (OnScreenControlsLevel) getCurrentOscState {
    if (onScreenControls == nil) {
        return OnScreenControlsLevelOff;
    }
    else {
        return [onScreenControls getLevel];
    }
}

- (BOOL)isConfirmedMove:(CGPoint)currentPoint from:(CGPoint)originalPoint {
    // Movements of greater than 5 pixels are considered confirmed
    return hypotf(originalPoint.x - currentPoint.x, originalPoint.y - currentPoint.y) >= 5;
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    if ([self handleMouseButtonEvent:BUTTON_ACTION_PRESS
                          forTouches:touches
                           withEvent:event]) {
        // If it's a mouse event, we're done
        return;
    }
    
    Log(LOG_D, @"Touch down");
    
    // Notify of user interaction and start expiration timer
    [self startInteractionTimer];
    
    if (![onScreenControls handleTouchDownEvent:touches]) {
        UITouch *touch = [[event allTouches] anyObject];
        originalLocation = touchLocation = [touch locationInView:self];
        touchMoved = false;
        if ([[event allTouches] count] == 1 && !isDragging) {
            dragTimer = [NSTimer scheduledTimerWithTimeInterval:0.650
                                                     target:self
                                                   selector:@selector(onDragStart:)
                                                   userInfo:nil
                                                    repeats:NO];
        }
    }
}

- (void)onDragStart:(NSTimer*)timer {
    if (!touchMoved && !isDragging){
        isDragging = true;
        LiSendMouseButtonEvent(BUTTON_ACTION_PRESS, BUTTON_LEFT);
    }
}

- (BOOL)handleMouseButtonEvent:(int)buttonAction forTouches:(NSSet *)touches withEvent:(UIEvent *)event {
#if !TARGET_OS_TV
    if (@available(iOS 13.4, *)) {
        UITouch* touch = [touches anyObject];
        if (touch.type == UITouchTypeIndirectPointer) {
            if (@available(iOS 14.0, *)) {
                // We'll handle this with GCMouse. Do nothing here.
                return YES;
            }
            else {
                UIEventButtonMask changedButtons = lastMouseButtonMask ^ event.buttonMask;
                            
                for (int i = BUTTON_LEFT; i <= BUTTON_X2; i++) {
                    UIEventButtonMask buttonFlag;
                    
                    switch (i) {
                        // Right and Middle are reversed from what iOS uses
                        case BUTTON_RIGHT:
                            buttonFlag = UIEventButtonMaskForButtonNumber(2);
                            break;
                        case BUTTON_MIDDLE:
                            buttonFlag = UIEventButtonMaskForButtonNumber(3);
                            break;
                            
                        default:
                            buttonFlag = UIEventButtonMaskForButtonNumber(i);
                            break;
                    }
                    
                    if (changedButtons & buttonFlag) {
                        LiSendMouseButtonEvent(buttonAction, i);
                    }
                }
                
                lastMouseButtonMask = event.buttonMask;
                return YES;
            }
        }
    }
#endif
    
    return NO;
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
#if !TARGET_OS_TV
    if (@available(iOS 13.4, *)) {
        UITouch *touch = [touches anyObject];
        if (touch.type == UITouchTypeIndirectPointer) {
            if (@available(iOS 14.0, *)) {
                // We'll handle this with GCMouse. Do nothing here.
                return;
            }
            else {
                // We must handle this event to properly support
                // drags while the middle, X1, or X2 mouse buttons are
                // held down. For some reason, left and right buttons
                // don't require this, but we do it anyway for them too.
                // Cursor movement without a button held down is handled
                // in pointerInteraction:regionForRequest:defaultRegion.
                [self updateCursorLocation:[touch locationInView:self]];
                return;
            }
        }
    }
#endif
    
    hasUserInteracted = YES;
    
    if (![onScreenControls handleTouchMovedEvent:touches]) {
        if ([[event allTouches] count] == 1) {
            UITouch *touch = [[event allTouches] anyObject];
            CGPoint currentLocation = [touch locationInView:self];
            
            if (touchLocation.x != currentLocation.x ||
                touchLocation.y != currentLocation.y)
            {
                int deltaX = (currentLocation.x - touchLocation.x) * (REFERENCE_WIDTH / self.bounds.size.width);
                int deltaY = (currentLocation.y - touchLocation.y) * (REFERENCE_HEIGHT / self.bounds.size.height);
                
                if (deltaX != 0 || deltaY != 0) {
                    LiSendMouseMoveEvent(deltaX, deltaY);
                    touchLocation = currentLocation;
                    
                    // If we've moved far enough to confirm this wasn't just human/machine error,
                    // mark it as such.
                    if ([self isConfirmedMove:touchLocation from:originalLocation]) {
                        touchMoved = true;
                    }
                }
            }
        } else if ([[event allTouches] count] == 2) {
            CGPoint firstLocation = [[[[event allTouches] allObjects] objectAtIndex:0] locationInView:self];
            CGPoint secondLocation = [[[[event allTouches] allObjects] objectAtIndex:1] locationInView:self];
            
            CGPoint avgLocation = CGPointMake((firstLocation.x + secondLocation.x) / 2, (firstLocation.y + secondLocation.y) / 2);
            if (touchLocation.y != avgLocation.y) {
                LiSendScrollEvent(avgLocation.y - touchLocation.y);
            }

            // If we've moved far enough to confirm this wasn't just human/machine error,
            // mark it as such.
            if ([self isConfirmedMove:firstLocation from:originalLocation]) {
                touchMoved = true;
            }
            
            touchLocation = avgLocation;
        }
    }
    
}

- (void)pressesBegan:(NSSet<UIPress *> *)presses withEvent:(UIPressesEvent *)event {
    BOOL handled = NO;
    
    if (@available(iOS 13.4, tvOS 13.4, *)) {
        for (UIPress* press in presses) {
            // For now, we'll treated it as handled if we handle at least one of the
            // UIPress events inside the set.
            if (press.key != nil && [KeyboardSupport sendKeyEvent:press.key down:YES]) {
                // This will prevent the legacy UITextField from receiving the event
                handled = YES;
            }
        }
    }
    
    if (!handled) {
        [super pressesBegan:presses withEvent:event];
    }
}

- (void)pressesEnded:(NSSet<UIPress *> *)presses withEvent:(UIPressesEvent *)event {
    BOOL handled = NO;
    
    if (@available(iOS 13.4, tvOS 13.4, *)) {
        for (UIPress* press in presses) {
            // For now, we'll treated it as handled if we handle at least one of the
            // UIPress events inside the set.
            if (press.key != nil && [KeyboardSupport sendKeyEvent:press.key down:NO]) {
                // This will prevent the legacy UITextField from receiving the event
                handled = YES;
            }
        }
    }
    
    if (!handled) {
        [super pressesEnded:presses withEvent:event];
    }
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    if ([self handleMouseButtonEvent:BUTTON_ACTION_RELEASE
                          forTouches:touches
                           withEvent:event]) {
        // If it's a mouse event, we're done
        return;
    }
    
    Log(LOG_D, @"Touch up");
    
    hasUserInteracted = YES;
    
    if (![onScreenControls handleTouchUpEvent:touches]) {
        [dragTimer invalidate];
        dragTimer = nil;
        if (isDragging) {
            isDragging = false;
            LiSendMouseButtonEvent(BUTTON_ACTION_RELEASE, BUTTON_LEFT);
        } else if (!touchMoved) {
            if ([[event allTouches] count] == 3) {
                if (isInputingText) {
                    Log(LOG_D, @"Closing the keyboard");
                    [_keyInputField resignFirstResponder];
                    isInputingText = false;
                } else {
                    Log(LOG_D, @"Opening the keyboard");
                    // Prepare the textbox used to capture keyboard events.
                    _keyInputField.delegate = self;
                    _keyInputField.text = @"0";
                    [_keyInputField becomeFirstResponder];
                    [_keyInputField addTarget:self action:@selector(onKeyboardPressed:) forControlEvents:UIControlEventEditingChanged];
                    
                    // Undo causes issues for our state management, so turn it off
                    [_keyInputField.undoManager disableUndoRegistration];
                    
                    isInputingText = true;
                }
            } else if ([[event allTouches] count]  == 2) {
                dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
                    Log(LOG_D, @"Sending right mouse button press");
                    
                    LiSendMouseButtonEvent(BUTTON_ACTION_PRESS, BUTTON_RIGHT);
                    
                    // Wait 100 ms to simulate a real button press
                    usleep(100 * 1000);
                    
                    LiSendMouseButtonEvent(BUTTON_ACTION_RELEASE, BUTTON_RIGHT);
                });
            } else if ([[event allTouches] count]  == 1) {
                dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
                    if (!self->isDragging){
                        Log(LOG_D, @"Sending left mouse button press");
                        
                        LiSendMouseButtonEvent(BUTTON_ACTION_PRESS, BUTTON_LEFT);
                        
                        // Wait 100 ms to simulate a real button press
                        usleep(100 * 1000);
                    }
                    self->isDragging = false;
                    LiSendMouseButtonEvent(BUTTON_ACTION_RELEASE, BUTTON_LEFT);
                });
            }
        }
        
        // We we're moving from 2+ touches to 1. Synchronize the current position
        // of the active finger so we don't jump unexpectedly on the next touchesMoved
        // callback when finger 1 switches on us.
        if ([[event allTouches] count] - [touches count] == 1) {
            NSMutableSet *activeSet = [[NSMutableSet alloc] initWithCapacity:[[event allTouches] count]];
            [activeSet unionSet:[event allTouches]];
            [activeSet minusSet:touches];
            touchLocation = [[activeSet anyObject] locationInView:self];
            
            // Mark this touch as moved so we don't send a left mouse click if the user
            // right clicks without moving their other finger.
            touchMoved = true;
        }
    }
}

- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {
    [dragTimer invalidate];
    dragTimer = nil;
    if (isDragging) {
        isDragging = false;
        LiSendMouseButtonEvent(BUTTON_ACTION_RELEASE, BUTTON_LEFT);
    }
    [self handleMouseButtonEvent:BUTTON_ACTION_RELEASE
                      forTouches:touches
                       withEvent:event];
}

#if TARGET_OS_TV
- (void)remoteButtonPressed:(id)sender {
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
        Log(LOG_D, @"Sending left mouse button press");
        
        // Mark this as touchMoved to avoid a duplicate press on touch up
        self->touchMoved = true;
        
        LiSendMouseButtonEvent(BUTTON_ACTION_PRESS, BUTTON_LEFT);
        
        // Wait 100 ms to simulate a real button press
        usleep(100 * 1000);
            
        LiSendMouseButtonEvent(BUTTON_ACTION_RELEASE, BUTTON_LEFT);
    });
}
- (void)remoteButtonLongPressed:(id)sender {
    Log(LOG_D, @"Holding left mouse button");
    
    isDragging = true;
    LiSendMouseButtonEvent(BUTTON_ACTION_PRESS, BUTTON_LEFT);
}
#else
- (void) updateCursorLocation:(CGPoint)location {
    // These are now relative to the StreamView, however we need to scale them
    // further to make them relative to the actual video portion.
    float x = location.x - self.bounds.origin.x;
    float y = location.y - self.bounds.origin.y;
    
    // For some reason, we don't seem to always get to the bounds of the window
    // so we'll subtract 1 pixel if we're to the left/below of the origin and
    // and add 1 pixel if we're to the right/above. It should be imperceptible
    // to the user but it will allow activation of gestures that require contact
    // with the edge of the screen (like Aero Snap).
    if (x < self.bounds.size.width / 2) {
        x--;
    }
    else {
        x++;
    }
    if (y < self.bounds.size.height / 2) {
        y--;
    }
    else {
        y++;
    }
    
    // This logic mimics what iOS does with AVLayerVideoGravityResizeAspect
    CGSize videoSize;
    CGPoint videoOrigin;
    if (self.bounds.size.width > self.bounds.size.height * streamAspectRatio) {
        videoSize = CGSizeMake(self.bounds.size.height * streamAspectRatio, self.bounds.size.height);
    } else {
        videoSize = CGSizeMake(self.bounds.size.width, self.bounds.size.width / streamAspectRatio);
    }
    videoOrigin = CGPointMake(self.bounds.size.width / 2 - videoSize.width / 2,
                              self.bounds.size.height / 2 - videoSize.height / 2);
    
    // Confine the cursor to the video region. We don't just discard events outside
    // the region because we won't always get one exactly when the mouse leaves the region.
    x = MIN(MAX(x, videoOrigin.x), videoOrigin.x + videoSize.width);
    y = MIN(MAX(y, videoOrigin.y), videoOrigin.y + videoSize.height);
    
    // Send the mouse position relative to the video region if it has changed
    //
    // NB: It is important for functionality (not just optimization) to only
    // send it if the value has changed. We will receive one of these events
    // any time the user presses a modifier key, which can result in errant
    // mouse motion when using a Citrix X1 mouse.
    if (x != lastMouseX || y != lastMouseY) {
        if (lastMouseX != 0 || lastMouseY != 0) {
            LiSendMousePositionEvent(x - videoOrigin.x, y - videoOrigin.y,
                                     videoSize.width, videoSize.height);
        }
        
        lastMouseX = x;
        lastMouseY = y;
    }
}

- (UIPointerRegion *)pointerInteraction:(UIPointerInteraction *)interaction
                       regionForRequest:(UIPointerRegionRequest *)request
                          defaultRegion:(UIPointerRegion *)defaultRegion API_AVAILABLE(ios(13.4)) {
    // This logic mimics what iOS does with AVLayerVideoGravityResizeAspect
    CGSize videoSize;
    CGPoint videoOrigin;
    if (self.bounds.size.width > self.bounds.size.height * streamAspectRatio) {
        videoSize = CGSizeMake(self.bounds.size.height * streamAspectRatio, self.bounds.size.height);
    } else {
        videoSize = CGSizeMake(self.bounds.size.width, self.bounds.size.width / streamAspectRatio);
    }
    videoOrigin = CGPointMake(self.bounds.size.width / 2 - videoSize.width / 2,
                              self.bounds.size.height / 2 - videoSize.height / 2);
    
    // Move the cursor on the host if no buttons are pressed.
    // Motion with buttons pressed in handled in touchesMoved:
    if (lastMouseButtonMask == 0) {
        [self updateCursorLocation:request.location];
    }
    
    // The pointer interaction should cover the video region only
    return [UIPointerRegion regionWithRect:CGRectMake(videoOrigin.x, videoOrigin.y, videoSize.width, videoSize.height) identifier:nil];
}

- (UIPointerStyle *)pointerInteraction:(UIPointerInteraction *)interaction styleForRegion:(UIPointerRegion *)region  API_AVAILABLE(ios(13.4)) {
    // Always hide the mouse cursor over our stream view
    return [UIPointerStyle hiddenPointerStyle];
}

- (void)mouseWheelMoved:(UIPanGestureRecognizer *)gesture {
    switch (gesture.state) {
        case UIGestureRecognizerStateBegan:
        case UIGestureRecognizerStateChanged:
        case UIGestureRecognizerStateEnded:
            break;
            
        default:
            // Ignore recognition failure and other states
            return;
    }

    CGPoint velocity = [gesture velocityInView:self];
    if ((short)velocity.y != 0) {
        LiSendHighResScrollEvent((short)velocity.y);
    }
}

#endif

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
    // Disable all gesture recognizers to prevent them from eating our touches.
    // This can happen on iOS 13 where the 3 finger tap gesture is taken over for
    // displaying custom edit controls.
    return NO;
}

- (BOOL)textFieldShouldReturn:(UITextField *)textField {
    // This method is called when the "Return" key is pressed.
    LiSendKeyboardEvent(0x0d, KEY_ACTION_DOWN, 0);
    usleep(50 * 1000);
    LiSendKeyboardEvent(0x0d, KEY_ACTION_UP, 0);
    return NO;
}

- (void)onKeyboardPressed:(UITextField *)textField {
    NSString* inputText = textField.text;
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
        // If the text became empty, we know the user pressed the backspace key.
        if ([inputText isEqual:@""]) {
            LiSendKeyboardEvent(0x08, KEY_ACTION_DOWN, 0);
            usleep(50 * 1000);
            LiSendKeyboardEvent(0x08, KEY_ACTION_UP, 0);
        } else {
            // Character 0 will be our known sentinel value
            for (int i = 1; i < [inputText length]; i++) {
                struct KeyEvent event = [KeyboardSupport translateKeyEvent:[inputText characterAtIndex:i] withModifierFlags:0];
                if (event.keycode == 0) {
                    // If we don't know the code, don't send anything.
                    Log(LOG_W, @"Unknown key code: [%c]", [inputText characterAtIndex:i]);
                    continue;
                }
                [self sendLowLevelEvent:event];
            }
        }
    });
    
    // Reset text field back to known state
    textField.text = @"0";
    
    // Move the insertion point back to the end of the text box
    UITextRange *textRange = [textField textRangeFromPosition:textField.endOfDocument toPosition:textField.endOfDocument];
    [textField setSelectedTextRange:textRange];
}

- (void)specialCharPressed:(UIKeyCommand *)cmd {
    struct KeyEvent event = [KeyboardSupport translateKeyEvent:0x20 withModifierFlags:[cmd modifierFlags]];
    event.keycode = [[dictCodes valueForKey:[cmd input]] intValue];
    [self sendLowLevelEvent:event];
}

- (void)keyPressed:(UIKeyCommand *)cmd {
    struct KeyEvent event = [KeyboardSupport translateKeyEvent:[[cmd input] characterAtIndex:0] withModifierFlags:[cmd modifierFlags]];
    [self sendLowLevelEvent:event];
}

- (void)sendLowLevelEvent:(struct KeyEvent)event {
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
        // When we want to send a modified key (like uppercase letters) we need to send the
        // modifier ("shift") seperately from the key itself.
        if (event.modifier != 0) {
            LiSendKeyboardEvent(event.modifierKeycode, KEY_ACTION_DOWN, event.modifier);
        }
        LiSendKeyboardEvent(event.keycode, KEY_ACTION_DOWN, event.modifier);
        usleep(50 * 1000);
        LiSendKeyboardEvent(event.keycode, KEY_ACTION_UP, event.modifier);
        if (event.modifier != 0) {
            LiSendKeyboardEvent(event.modifierKeycode, KEY_ACTION_UP, event.modifier);
        }
    });
}

- (BOOL)canBecomeFirstResponder {
    return YES;
}

- (NSArray<UIKeyCommand *> *)keyCommands
{
    NSString *charset = @"qwertyuiopasdfghjklzxcvbnm1234567890\t§[]\\'\"/.,`<>-´ç+`¡'º;ñ= ";
    
    NSMutableArray<UIKeyCommand *> * commands = [NSMutableArray<UIKeyCommand *> array];
    dictCodes = [[NSDictionary alloc] initWithObjectsAndKeys: [NSNumber numberWithInt: 0x0d], @"\r", [NSNumber numberWithInt: 0x08], @"\b", [NSNumber numberWithInt: 0x1b], UIKeyInputEscape, [NSNumber numberWithInt: 0x28], UIKeyInputDownArrow, [NSNumber numberWithInt: 0x26], UIKeyInputUpArrow, [NSNumber numberWithInt: 0x25], UIKeyInputLeftArrow, [NSNumber numberWithInt: 0x27], UIKeyInputRightArrow, nil];
    
    [charset enumerateSubstringsInRange:NSMakeRange(0, charset.length)
                                options:NSStringEnumerationByComposedCharacterSequences
                             usingBlock:^(NSString *substring, NSRange substringRange, NSRange enclosingRange, BOOL *stop) {
                                 [commands addObject:[UIKeyCommand keyCommandWithInput:substring modifierFlags:0 action:@selector(keyPressed:)]];
                                 [commands addObject:[UIKeyCommand keyCommandWithInput:substring modifierFlags:UIKeyModifierShift action:@selector(keyPressed:)]];
                                 [commands addObject:[UIKeyCommand keyCommandWithInput:substring modifierFlags:UIKeyModifierControl action:@selector(keyPressed:)]];
                                 [commands addObject:[UIKeyCommand keyCommandWithInput:substring modifierFlags:UIKeyModifierAlternate action:@selector(keyPressed:)]];
                             }];
    
    for (NSString *c in [dictCodes keyEnumerator]) {
        [commands addObject:[UIKeyCommand keyCommandWithInput:c
                                                modifierFlags:0
                                                       action:@selector(specialCharPressed:)]];
        [commands addObject:[UIKeyCommand keyCommandWithInput:c
                                                modifierFlags:UIKeyModifierShift
                                                       action:@selector(specialCharPressed:)]];
        [commands addObject:[UIKeyCommand keyCommandWithInput:c
                                                modifierFlags:UIKeyModifierShift | UIKeyModifierAlternate
                                                       action:@selector(specialCharPressed:)]];
        [commands addObject:[UIKeyCommand keyCommandWithInput:c
                                                modifierFlags:UIKeyModifierShift | UIKeyModifierControl
                                                       action:@selector(specialCharPressed:)]];
        [commands addObject:[UIKeyCommand keyCommandWithInput:c
                                                modifierFlags:UIKeyModifierControl
                                                       action:@selector(specialCharPressed:)]];
        [commands addObject:[UIKeyCommand keyCommandWithInput:c
                                                modifierFlags:UIKeyModifierControl | UIKeyModifierAlternate
                                                       action:@selector(specialCharPressed:)]];
        [commands addObject:[UIKeyCommand keyCommandWithInput:c
                                                modifierFlags:UIKeyModifierAlternate
                                                       action:@selector(specialCharPressed:)]];
    }
    
    return commands;
}

@end