Carla/source/modules/juce_gui_basics/native/juce_ios_UIViewComponentPeer.mm

/*
  ==============================================================================

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2020 - Raw Material Software Limited

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For this technical preview, this file is not subject to commercial licensing.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

class UIViewComponentPeer;

// The way rotation works changed in iOS8..
static bool isUsingOldRotationMethod() noexcept
{
    static bool isPreV8 = ([[[UIDevice currentDevice] systemVersion] compare: @"8.0"
                                                                     options: NSNumericSearch] == NSOrderedAscending);
    return isPreV8;
}

static UIInterfaceOrientation getWindowOrientation()
{
    UIApplication* sharedApplication = [UIApplication sharedApplication];

   #if (defined (__IPHONE_13_0) && __IPHONE_OS_VERSION_MIN_REQUIRED >= __IPHONE_13_0)
    return [[[[sharedApplication windows] firstObject] windowScene] interfaceOrientation];
   #else
    return [sharedApplication statusBarOrientation];
   #endif
}

namespace Orientations
{
    static Desktop::DisplayOrientation convertToJuce (UIInterfaceOrientation orientation)
    {
        switch (orientation)
        {
            case UIInterfaceOrientationPortrait:            return Desktop::upright;
            case UIInterfaceOrientationPortraitUpsideDown:  return Desktop::upsideDown;
            case UIInterfaceOrientationLandscapeLeft:       return Desktop::rotatedClockwise;
            case UIInterfaceOrientationLandscapeRight:      return Desktop::rotatedAntiClockwise;
            case UIInterfaceOrientationUnknown:
            default:                                        jassertfalse; // unknown orientation!
        }

        return Desktop::upright;
    }

    static UIInterfaceOrientation convertFromJuce (Desktop::DisplayOrientation orientation)
    {
        switch (orientation)
        {
            case Desktop::upright:                          return UIInterfaceOrientationPortrait;
            case Desktop::upsideDown:                       return UIInterfaceOrientationPortraitUpsideDown;
            case Desktop::rotatedClockwise:                 return UIInterfaceOrientationLandscapeLeft;
            case Desktop::rotatedAntiClockwise:             return UIInterfaceOrientationLandscapeRight;
            case Desktop::allOrientations:
            default:                                        jassertfalse; // unknown orientation!
        }

        return UIInterfaceOrientationPortrait;
    }

    static CGAffineTransform getCGTransformFor (const Desktop::DisplayOrientation orientation) noexcept
    {
        if (isUsingOldRotationMethod())
        {
            switch (orientation)
            {
                case Desktop::upsideDown:             return CGAffineTransformMake (-1, 0,  0, -1, 0, 0);
                case Desktop::rotatedClockwise:       return CGAffineTransformMake (0, -1,  1,  0, 0, 0);
                case Desktop::rotatedAntiClockwise:   return CGAffineTransformMake (0,  1, -1,  0, 0, 0);
                case Desktop::upright:
                case Desktop::allOrientations:
                default:                              break;
            }
        }

        return CGAffineTransformIdentity;
    }

    static NSUInteger getSupportedOrientations()
    {
        NSUInteger allowed = 0;
        Desktop& d = Desktop::getInstance();

        if (d.isOrientationEnabled (Desktop::upright))              allowed |= UIInterfaceOrientationMaskPortrait;
        if (d.isOrientationEnabled (Desktop::upsideDown))           allowed |= UIInterfaceOrientationMaskPortraitUpsideDown;
        if (d.isOrientationEnabled (Desktop::rotatedClockwise))     allowed |= UIInterfaceOrientationMaskLandscapeLeft;
        if (d.isOrientationEnabled (Desktop::rotatedAntiClockwise)) allowed |= UIInterfaceOrientationMaskLandscapeRight;

        return allowed;
    }
}

struct AsyncBoundsUpdater  : public AsyncUpdater
{
    AsyncBoundsUpdater (UIViewController* vc)
        : viewController (vc)
    {
    }

    ~AsyncBoundsUpdater() override
    {
        cancelPendingUpdate();
    }

    void handleAsyncUpdate() override;

    UIViewController* viewController;
};

//==============================================================================
} // namespace juce

using namespace juce;


@interface JuceUIView : UIView <UITextViewDelegate>
{
@public
    UIViewComponentPeer* owner;
    UITextView* hiddenTextView;
}

- (JuceUIView*) initWithOwner: (UIViewComponentPeer*) owner withFrame: (CGRect) frame;
- (void) dealloc;

- (void) drawRect: (CGRect) r;

- (void) touchesBegan:     (NSSet*) touches  withEvent: (UIEvent*) event;
- (void) touchesMoved:     (NSSet*) touches  withEvent: (UIEvent*) event;
- (void) touchesEnded:     (NSSet*) touches  withEvent: (UIEvent*) event;
- (void) touchesCancelled: (NSSet*) touches  withEvent: (UIEvent*) event;

- (BOOL) becomeFirstResponder;
- (BOOL) resignFirstResponder;
- (BOOL) canBecomeFirstResponder;

- (BOOL) textView: (UITextView*) textView shouldChangeTextInRange: (NSRange) range replacementText: (NSString*) text;
@end

//==============================================================================
@interface JuceUIViewController : UIViewController
{
@public
    std::unique_ptr<AsyncBoundsUpdater> boundsUpdater;
}

- (JuceUIViewController*) init;

- (NSUInteger) supportedInterfaceOrientations;
- (BOOL) shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation) interfaceOrientation;
- (void) willRotateToInterfaceOrientation: (UIInterfaceOrientation) toInterfaceOrientation duration: (NSTimeInterval) duration;
- (void) didRotateFromInterfaceOrientation: (UIInterfaceOrientation) fromInterfaceOrientation;
- (void) viewWillTransitionToSize: (CGSize) size withTransitionCoordinator: (id<UIViewControllerTransitionCoordinator>) coordinator;
- (BOOL) prefersStatusBarHidden;
- (UIStatusBarStyle) preferredStatusBarStyle;

- (void) viewDidLoad;
- (void) viewWillAppear: (BOOL) animated;
- (void) viewDidAppear: (BOOL) animated;
- (void) viewWillLayoutSubviews;
- (void) viewDidLayoutSubviews;
@end

//==============================================================================
@interface JuceUIWindow : UIWindow
{
@private
    UIViewComponentPeer* owner;
}

- (void) setOwner: (UIViewComponentPeer*) owner;
- (void) becomeKeyWindow;
@end

//==============================================================================
//==============================================================================
namespace juce
{

struct UIViewPeerControllerReceiver
{
    virtual ~UIViewPeerControllerReceiver();
    virtual void setViewController (UIViewController*) = 0;
};

UIViewPeerControllerReceiver::~UIViewPeerControllerReceiver() {}

class UIViewComponentPeer  : public ComponentPeer,
                             public FocusChangeListener,
                             public UIViewPeerControllerReceiver
{
public:
    UIViewComponentPeer (Component&, int windowStyleFlags, UIView* viewToAttachTo);
    ~UIViewComponentPeer() override;

    //==============================================================================
    void* getNativeHandle() const override                  { return view; }
    void setVisible (bool shouldBeVisible) override;
    void setTitle (const String& title) override;
    void setBounds (const Rectangle<int>&, bool isNowFullScreen) override;

    void setViewController (UIViewController* newController) override
    {
        jassert (controller == nullptr);
        controller = [newController retain];
    }

    Rectangle<int> getBounds() const override               { return getBounds (! isSharedWindow); }
    Rectangle<int> getBounds (bool global) const;
    Point<float> localToGlobal (Point<float> relativePosition) override;
    Point<float> globalToLocal (Point<float> screenPosition) override;
    using ComponentPeer::localToGlobal;
    using ComponentPeer::globalToLocal;
    void setAlpha (float newAlpha) override;
    void setMinimised (bool) override                       {}
    bool isMinimised() const override                       { return false; }
    void setFullScreen (bool shouldBeFullScreen) override;
    bool isFullScreen() const override                      { return fullScreen; }
    bool contains (Point<int> localPos, bool trueIfInAChildWindow) const override;
    BorderSize<int> getFrameSize() const override           { return BorderSize<int>(); }
    bool setAlwaysOnTop (bool alwaysOnTop) override;
    void toFront (bool makeActiveWindow) override;
    void toBehind (ComponentPeer* other) override;
    void setIcon (const Image& newIcon) override;
    StringArray getAvailableRenderingEngines() override     { return StringArray ("CoreGraphics Renderer"); }

    void drawRect (CGRect);
    bool canBecomeKeyWindow();

    //==============================================================================
    void viewFocusGain();
    void viewFocusLoss();
    bool isFocused() const override;
    void grabFocus() override;
    void textInputRequired (Point<int>, TextInputTarget&) override;

    BOOL textViewReplaceCharacters (Range<int>, const String&);
    void updateHiddenTextContent (TextInputTarget*);
    void globalFocusChanged (Component*) override;

    void updateTransformAndScreenBounds();

    void handleTouches (UIEvent*, bool isDown, bool isUp, bool isCancel);

    //==============================================================================
    void repaint (const Rectangle<int>& area) override;
    void performAnyPendingRepaintsNow() override;

    //==============================================================================
    UIWindow* window;
    JuceUIView* view;
    UIViewController* controller;
    bool isSharedWindow, fullScreen, insideDrawRect, isAppex;

    static int64 getMouseTime (UIEvent* e) noexcept
    {
        return (Time::currentTimeMillis() - Time::getMillisecondCounter())
                + (int64) ([e timestamp] * 1000.0);
    }

    static Rectangle<int> rotatedScreenPosToReal (const Rectangle<int>& r)
    {
        if (! SystemStats::isRunningInAppExtensionSandbox() && isUsingOldRotationMethod())
        {
            const Rectangle<int> screen (convertToRectInt ([UIScreen mainScreen].bounds));

            switch (getWindowOrientation())
            {
                case UIInterfaceOrientationPortrait:
                    return r;

                case UIInterfaceOrientationPortraitUpsideDown:
                    return Rectangle<int> (screen.getWidth() - r.getRight(), screen.getHeight() - r.getBottom(),
                                           r.getWidth(), r.getHeight());

                case UIInterfaceOrientationLandscapeLeft:
                    return Rectangle<int> (r.getY(), screen.getHeight() - r.getRight(),
                                           r.getHeight(), r.getWidth());

                case UIInterfaceOrientationLandscapeRight:
                    return Rectangle<int> (screen.getWidth() - r.getBottom(), r.getX(),
                                           r.getHeight(), r.getWidth());

                case UIInterfaceOrientationUnknown:
                default: jassertfalse; // unknown orientation!
            }
        }

        return r;
    }

    static Rectangle<int> realScreenPosToRotated (const Rectangle<int>& r)
    {
        if (! SystemStats::isRunningInAppExtensionSandbox() && isUsingOldRotationMethod())
        {
            const Rectangle<int> screen (convertToRectInt ([UIScreen mainScreen].bounds));

            switch (getWindowOrientation())
            {
                case UIInterfaceOrientationPortrait:
                    return r;

                case UIInterfaceOrientationPortraitUpsideDown:
                    return Rectangle<int> (screen.getWidth() - r.getRight(), screen.getHeight() - r.getBottom(),
                                           r.getWidth(), r.getHeight());

                case UIInterfaceOrientationLandscapeLeft:
                    return Rectangle<int> (screen.getHeight() - r.getBottom(), r.getX(),
                                           r.getHeight(), r.getWidth());

                case UIInterfaceOrientationLandscapeRight:
                    return Rectangle<int> (r.getY(), screen.getWidth() - r.getRight(),
                                           r.getHeight(), r.getWidth());

                case UIInterfaceOrientationUnknown:
                default: jassertfalse; // unknown orientation!
            }
        }

        return r;
    }

    static MultiTouchMapper<UITouch*> currentTouches;

private:
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (UIViewComponentPeer)

    class AsyncRepaintMessage  : public CallbackMessage
    {
    public:
        UIViewComponentPeer* const peer;
        const Rectangle<int> rect;

        AsyncRepaintMessage (UIViewComponentPeer* const p, const Rectangle<int>& r)
            : peer (p), rect (r)
        {
        }

        void messageCallback() override
        {
            if (ComponentPeer::isValidPeer (peer))
                peer->repaint (rect);
        }
    };
};

static void sendScreenBoundsUpdate (JuceUIViewController* c)
{
    JuceUIView* juceView = (JuceUIView*) [c view];

    if (juceView != nil && juceView->owner != nullptr)
        juceView->owner->updateTransformAndScreenBounds();
}

void AsyncBoundsUpdater::handleAsyncUpdate()
{
    sendScreenBoundsUpdate ((JuceUIViewController*) viewController);
}

static bool isKioskModeView (JuceUIViewController* c)
{
    JuceUIView* juceView = (JuceUIView*) [c view];
    jassert (juceView != nil && juceView->owner != nullptr);

    return Desktop::getInstance().getKioskModeComponent() == &(juceView->owner->getComponent());
}

MultiTouchMapper<UITouch*> UIViewComponentPeer::currentTouches;

} // namespace juce

//==============================================================================
//==============================================================================
@implementation JuceUIViewController

- (JuceUIViewController*) init
{
    self = [super init];

    boundsUpdater = std::make_unique<AsyncBoundsUpdater> (self);

    return self;
}

- (NSUInteger) supportedInterfaceOrientations
{
    return Orientations::getSupportedOrientations();
}

- (BOOL) shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation) interfaceOrientation
{
    return Desktop::getInstance().isOrientationEnabled (Orientations::convertToJuce (interfaceOrientation));
}

- (void) willRotateToInterfaceOrientation: (UIInterfaceOrientation) toInterfaceOrientation
                                 duration: (NSTimeInterval) duration
{
    ignoreUnused (toInterfaceOrientation, duration);

    [UIView setAnimationsEnabled: NO]; // disable this because it goes the wrong way and looks like crap.
}

- (void) didRotateFromInterfaceOrientation: (UIInterfaceOrientation) fromInterfaceOrientation
{
    ignoreUnused (fromInterfaceOrientation);
    sendScreenBoundsUpdate (self);
    [UIView setAnimationsEnabled: YES];
}

- (void) viewWillTransitionToSize: (CGSize) size withTransitionCoordinator: (id<UIViewControllerTransitionCoordinator>) coordinator
{
    [super viewWillTransitionToSize: size withTransitionCoordinator: coordinator];
    sendScreenBoundsUpdate (self);

    // On some devices the screen-size isn't yet updated at this point, so also trigger another
    // async update to double-check..
    if (boundsUpdater != nullptr)
        boundsUpdater->triggerAsyncUpdate();
}

- (BOOL) prefersStatusBarHidden
{
    return isKioskModeView (self);
}

#if defined (__IPHONE_11_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_11_0
 - (BOOL) prefersHomeIndicatorAutoHidden
 {
     return isKioskModeView (self);
 }
#endif

- (UIStatusBarStyle) preferredStatusBarStyle
{
    return UIStatusBarStyleDefault;
}

- (void) viewDidLoad
{
    sendScreenBoundsUpdate (self);
    [super viewDidLoad];
}

- (void) viewWillAppear: (BOOL) animated
{
    sendScreenBoundsUpdate (self);
    [super viewWillAppear:animated];
}

- (void) viewDidAppear: (BOOL) animated
{
    sendScreenBoundsUpdate (self);
    [super viewDidAppear:animated];
}

- (void) viewWillLayoutSubviews
{
    sendScreenBoundsUpdate (self);
}

- (void) viewDidLayoutSubviews
{
    sendScreenBoundsUpdate (self);
}

@end

@implementation JuceUIView

- (JuceUIView*) initWithOwner: (UIViewComponentPeer*) peer
                    withFrame: (CGRect) frame
{
    [super initWithFrame: frame];
    owner = peer;

    hiddenTextView = [[UITextView alloc] initWithFrame: CGRectZero];
    [self addSubview: hiddenTextView];
    hiddenTextView.delegate = self;

    hiddenTextView.autocapitalizationType = UITextAutocapitalizationTypeNone;
    hiddenTextView.autocorrectionType = UITextAutocorrectionTypeNo;

    return self;
}

- (void) dealloc
{
    [hiddenTextView removeFromSuperview];
    [hiddenTextView release];

    [super dealloc];
}

//==============================================================================
- (void) drawRect: (CGRect) r
{
    if (owner != nullptr)
        owner->drawRect (r);
}

//==============================================================================
- (void) touchesBegan: (NSSet*) touches withEvent: (UIEvent*) event
{
    ignoreUnused (touches);

    if (owner != nullptr)
        owner->handleTouches (event, true, false, false);
}

- (void) touchesMoved: (NSSet*) touches withEvent: (UIEvent*) event
{
    ignoreUnused (touches);

    if (owner != nullptr)
        owner->handleTouches (event, false, false, false);
}

- (void) touchesEnded: (NSSet*) touches withEvent: (UIEvent*) event
{
    ignoreUnused (touches);

    if (owner != nullptr)
        owner->handleTouches (event, false, true, false);
}

- (void) touchesCancelled: (NSSet*) touches withEvent: (UIEvent*) event
{
    if (owner != nullptr)
        owner->handleTouches (event, false, true, true);

    [self touchesEnded: touches withEvent: event];
}

//==============================================================================
- (BOOL) becomeFirstResponder
{
    if (owner != nullptr)
        owner->viewFocusGain();

    return true;
}

- (BOOL) resignFirstResponder
{
    if (owner != nullptr)
        owner->viewFocusLoss();

    return [super resignFirstResponder];
}

- (BOOL) canBecomeFirstResponder
{
    return owner != nullptr && owner->canBecomeKeyWindow();
}

- (BOOL) textView: (UITextView*) textView shouldChangeTextInRange: (NSRange) range replacementText: (NSString*) text
{
    ignoreUnused (textView);
    return owner->textViewReplaceCharacters (Range<int> ((int) range.location, (int) (range.location + range.length)),
                                             nsStringToJuce (text));
}

@end

//==============================================================================
@implementation JuceUIWindow

- (void) setOwner: (UIViewComponentPeer*) peer
{
    owner = peer;
}

- (void) becomeKeyWindow
{
    [super becomeKeyWindow];

    if (owner != nullptr)
        owner->grabFocus();
}

@end

//==============================================================================
//==============================================================================
namespace juce
{

bool KeyPress::isKeyCurrentlyDown (int)
{
    return false;
}

Point<float> juce_lastMousePos;

//==============================================================================
UIViewComponentPeer::UIViewComponentPeer (Component& comp, const int windowStyleFlags, UIView* viewToAttachTo)
    : ComponentPeer (comp, windowStyleFlags),
      window (nil),
      view (nil),
      controller (nil),
      isSharedWindow (viewToAttachTo != nil),
      fullScreen (false),
      insideDrawRect (false),
      isAppex (SystemStats::isRunningInAppExtensionSandbox())
{
    CGRect r = convertToCGRect (component.getBounds());

    view = [[JuceUIView alloc] initWithOwner: this withFrame: r];

    view.multipleTouchEnabled = YES;
    view.hidden = true;
    view.opaque = component.isOpaque();
    view.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent: 0];
    view.transform = CGAffineTransformIdentity;

    if (isSharedWindow)
    {
        window = [viewToAttachTo window];
        [viewToAttachTo addSubview: view];
    }
    else
    {
        r = convertToCGRect (rotatedScreenPosToReal (component.getBounds()));
        r.origin.y = [UIScreen mainScreen].bounds.size.height - (r.origin.y + r.size.height);

        window = [[JuceUIWindow alloc] initWithFrame: r];
        [((JuceUIWindow*) window) setOwner: this];

        controller = [[JuceUIViewController alloc] init];
        controller.view = view;
        window.rootViewController = controller;

        window.hidden = true;
        window.transform = Orientations::getCGTransformFor (Desktop::getInstance().getCurrentOrientation());
        window.opaque = component.isOpaque();
        window.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent: 0];

        if (component.isAlwaysOnTop())
            window.windowLevel = UIWindowLevelAlert;

        view.frame = CGRectMake (0, 0, r.size.width, r.size.height);

        [window addSubview: view];
    }

    setTitle (component.getName());
    setVisible (component.isVisible());

    Desktop::getInstance().addFocusChangeListener (this);
}

UIViewComponentPeer::~UIViewComponentPeer()
{
    currentTouches.deleteAllTouchesForPeer (this);
    Desktop::getInstance().removeFocusChangeListener (this);

    ((JuceUIViewController*) controller)->boundsUpdater = nullptr;

    view->owner = nullptr;
    [view removeFromSuperview];
    [view release];
    [controller release];

    if (! isSharedWindow)
    {
        [((JuceUIWindow*) window) setOwner: nil];
        [window release];
    }
}

//==============================================================================
void UIViewComponentPeer::setVisible (bool shouldBeVisible)
{
    if (! isSharedWindow)
        window.hidden = ! shouldBeVisible;

    view.hidden = ! shouldBeVisible;
}

void UIViewComponentPeer::setTitle (const String&)
{
    // xxx is this possible?
}

void UIViewComponentPeer::setBounds (const Rectangle<int>& newBounds, const bool isNowFullScreen)
{
    fullScreen = isNowFullScreen;

    if (isSharedWindow)
    {
        CGRect r = convertToCGRect (newBounds);

        if (view.frame.size.width != r.size.width || view.frame.size.height != r.size.height)
            [view setNeedsDisplay];

        view.frame = r;
    }
    else
    {
        window.frame = convertToCGRect (rotatedScreenPosToReal (newBounds));
        view.frame = CGRectMake (0, 0, (CGFloat) newBounds.getWidth(), (CGFloat) newBounds.getHeight());

        handleMovedOrResized();
    }
}

Rectangle<int> UIViewComponentPeer::getBounds (const bool global) const
{
    CGRect r = view.frame;

    if (global && view.window != nil)
    {
        r = [view convertRect: r toView: view.window];
        r = [view.window convertRect: r toWindow: nil];

        return realScreenPosToRotated (convertToRectInt (r));
    }

    return convertToRectInt (r);
}

Point<float> UIViewComponentPeer::localToGlobal (Point<float> relativePosition)
{
    return relativePosition + getBounds (true).getPosition().toFloat();
}

Point<float> UIViewComponentPeer::globalToLocal (Point<float> screenPosition)
{
    return screenPosition - getBounds (true).getPosition().toFloat();
}

void UIViewComponentPeer::setAlpha (float newAlpha)
{
    [view.window setAlpha: (CGFloat) newAlpha];
}

void UIViewComponentPeer::setFullScreen (bool shouldBeFullScreen)
{
    if (! isSharedWindow)
    {
        Rectangle<int> r (shouldBeFullScreen ? Desktop::getInstance().getDisplays().getMainDisplay().userArea
                                             : lastNonFullscreenBounds);

        if ((! shouldBeFullScreen) && r.isEmpty())
            r = getBounds();

        // (can't call the component's setBounds method because that'll reset our fullscreen flag)
        if (! r.isEmpty())
            setBounds (ScalingHelpers::scaledScreenPosToUnscaled (component, r), shouldBeFullScreen);

        component.repaint();
    }
}

void UIViewComponentPeer::updateTransformAndScreenBounds()
{
    Desktop& desktop = Desktop::getInstance();
    const Rectangle<int> oldArea (component.getBounds());
    const Rectangle<int> oldDesktop (desktop.getDisplays().getMainDisplay().userArea);

    const_cast<Displays&> (desktop.getDisplays()).refresh();

    window.transform = Orientations::getCGTransformFor (desktop.getCurrentOrientation());
    view.transform = CGAffineTransformIdentity;

    if (fullScreen)
    {
        fullScreen = false;
        setFullScreen (true);
    }
    else if (! isSharedWindow)
    {
        // this will re-centre the window, but leave its size unchanged
        const float centreRelX = oldArea.getCentreX() / (float) oldDesktop.getWidth();
        const float centreRelY = oldArea.getCentreY() / (float) oldDesktop.getHeight();

        const Rectangle<int> newDesktop (desktop.getDisplays().getMainDisplay().userArea);

        const int x = ((int) (newDesktop.getWidth()  * centreRelX)) - (oldArea.getWidth()  / 2);
        const int y = ((int) (newDesktop.getHeight() * centreRelY)) - (oldArea.getHeight() / 2);

        component.setBounds (oldArea.withPosition (x, y));
    }

    [view setNeedsDisplay];
}

bool UIViewComponentPeer::contains (Point<int> localPos, bool trueIfInAChildWindow) const
{
    {
        Rectangle<int> localBounds =
            ScalingHelpers::scaledScreenPosToUnscaled (component, component.getLocalBounds());

        if (! localBounds.contains (localPos))
            return false;
    }

    UIView* v = [view hitTest: convertToCGPoint (localPos)
                    withEvent: nil];

    if (trueIfInAChildWindow)
        return v != nil;

    return v == view;
}

bool UIViewComponentPeer::setAlwaysOnTop (bool alwaysOnTop)
{
    if (! isSharedWindow)
        window.windowLevel = alwaysOnTop ? UIWindowLevelAlert : UIWindowLevelNormal;

    return true;
}

void UIViewComponentPeer::toFront (bool makeActiveWindow)
{
    if (isSharedWindow)
        [[view superview] bringSubviewToFront: view];

    if (makeActiveWindow && window != nil && component.isVisible())
        [window makeKeyAndVisible];
}

void UIViewComponentPeer::toBehind (ComponentPeer* other)
{
    if (UIViewComponentPeer* const otherPeer = dynamic_cast<UIViewComponentPeer*> (other))
    {
        if (isSharedWindow)
        {
            [[view superview] insertSubview: view belowSubview: otherPeer->view];
        }
        else
        {
            // don't know how to do this
        }
    }
    else
    {
        jassertfalse; // wrong type of window?
    }
}

void UIViewComponentPeer::setIcon (const Image& /*newIcon*/)
{
    // to do..
}

//==============================================================================
static float getMaximumTouchForce (UITouch* touch) noexcept
{
   #if defined (__IPHONE_9_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_9_0
    if ([touch respondsToSelector: @selector (maximumPossibleForce)])
        return (float) touch.maximumPossibleForce;
   #endif

    ignoreUnused (touch);
    return 0.0f;
}

static float getTouchForce (UITouch* touch) noexcept
{
   #if defined (__IPHONE_9_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_9_0
    if ([touch respondsToSelector: @selector (force)])
        return (float) touch.force;
   #endif

    ignoreUnused (touch);
    return 0.0f;
}

void UIViewComponentPeer::handleTouches (UIEvent* event, const bool isDown, const bool isUp, bool isCancel)
{
    NSArray* touches = [[event touchesForView: view] allObjects];

    for (unsigned int i = 0; i < [touches count]; ++i)
    {
        UITouch* touch = [touches objectAtIndex: i];
        const float maximumForce = getMaximumTouchForce (touch);

        if ([touch phase] == UITouchPhaseStationary && maximumForce <= 0)
            continue;

        CGPoint p = [touch locationInView: view];
        const Point<float> pos (static_cast<float> (p.x), static_cast<float> (p.y));
        juce_lastMousePos = pos + getBounds (true).getPosition().toFloat();

        const int64 time = getMouseTime (event);
        const int touchIndex = currentTouches.getIndexOfTouch (this, touch);

        ModifierKeys modsToSend (ModifierKeys::currentModifiers);

        if (isDown)
        {
            if ([touch phase] != UITouchPhaseBegan)
                continue;

            ModifierKeys::currentModifiers = ModifierKeys::currentModifiers.withoutMouseButtons().withFlags (ModifierKeys::leftButtonModifier);
            modsToSend = ModifierKeys::currentModifiers;

            // this forces a mouse-enter/up event, in case for some reason we didn't get a mouse-up before.
            handleMouseEvent (MouseInputSource::InputSourceType::touch, pos, modsToSend.withoutMouseButtons(),
                              MouseInputSource::invalidPressure, MouseInputSource::invalidOrientation, time, {}, touchIndex);

            if (! isValidPeer (this)) // (in case this component was deleted by the event)
                return;
        }
        else if (isUp)
        {
            if (! ([touch phase] == UITouchPhaseEnded || [touch phase] == UITouchPhaseCancelled))
                continue;

            modsToSend = modsToSend.withoutMouseButtons();
            currentTouches.clearTouch (touchIndex);

            if (! currentTouches.areAnyTouchesActive())
                isCancel = true;
        }

        if (isCancel)
        {
            currentTouches.clearTouch (touchIndex);
            modsToSend = ModifierKeys::currentModifiers = ModifierKeys::currentModifiers.withoutMouseButtons();
        }

        // NB: some devices return 0 or 1.0 if pressure is unknown, so we'll clip our value to a believable range:
        float pressure = maximumForce > 0 ? jlimit (0.0001f, 0.9999f, getTouchForce (touch) / maximumForce)
                                          : MouseInputSource::invalidPressure;

        handleMouseEvent (MouseInputSource::InputSourceType::touch, pos, modsToSend, pressure,
                          MouseInputSource::invalidOrientation, time, { }, touchIndex);

        if (! isValidPeer (this)) // (in case this component was deleted by the event)
            return;

        if (isUp || isCancel)
        {
            handleMouseEvent (MouseInputSource::InputSourceType::touch, MouseInputSource::offscreenMousePos, modsToSend,
                              MouseInputSource::invalidPressure, MouseInputSource::invalidOrientation, time, {}, touchIndex);

            if (! isValidPeer (this))
                return;
        }
    }
}

//==============================================================================
static UIViewComponentPeer* currentlyFocusedPeer = nullptr;

void UIViewComponentPeer::viewFocusGain()
{
    if (currentlyFocusedPeer != this)
    {
        if (ComponentPeer::isValidPeer (currentlyFocusedPeer))
            currentlyFocusedPeer->handleFocusLoss();

        currentlyFocusedPeer = this;

        handleFocusGain();
    }
}

void UIViewComponentPeer::viewFocusLoss()
{
    if (currentlyFocusedPeer == this)
    {
        currentlyFocusedPeer = nullptr;
        handleFocusLoss();
    }
}

bool UIViewComponentPeer::isFocused() const
{
    if (isAppex)
        return true;

    return isSharedWindow ? this == currentlyFocusedPeer
                          : (window != nil && [window isKeyWindow]);
}

void UIViewComponentPeer::grabFocus()
{
    if (window != nil)
    {
        [window makeKeyWindow];
        viewFocusGain();
    }
}

void UIViewComponentPeer::textInputRequired (Point<int>, TextInputTarget&)
{
}

static bool isIOS4_1() noexcept
{
    return [[[UIDevice currentDevice] systemVersion] doubleValue] >= 4.1;
}

static UIKeyboardType getUIKeyboardType (TextInputTarget::VirtualKeyboardType type) noexcept
{
    switch (type)
    {
        case TextInputTarget::textKeyboard:          return UIKeyboardTypeAlphabet;
        case TextInputTarget::numericKeyboard:       return isIOS4_1() ? UIKeyboardTypeNumberPad  : UIKeyboardTypeNumbersAndPunctuation;
        case TextInputTarget::decimalKeyboard:       return isIOS4_1() ? UIKeyboardTypeDecimalPad : UIKeyboardTypeNumbersAndPunctuation;
        case TextInputTarget::urlKeyboard:           return UIKeyboardTypeURL;
        case TextInputTarget::emailAddressKeyboard:  return UIKeyboardTypeEmailAddress;
        case TextInputTarget::phoneNumberKeyboard:   return UIKeyboardTypePhonePad;
        default:                                     jassertfalse; break;
    }

    return UIKeyboardTypeDefault;
}

void UIViewComponentPeer::updateHiddenTextContent (TextInputTarget* target)
{
    view->hiddenTextView.keyboardType = getUIKeyboardType (target->getKeyboardType());
    view->hiddenTextView.text = juceStringToNS (target->getTextInRange (Range<int> (0, target->getHighlightedRegion().getStart())));
    view->hiddenTextView.selectedRange = NSMakeRange ((NSUInteger) target->getHighlightedRegion().getStart(), 0);
}

BOOL UIViewComponentPeer::textViewReplaceCharacters (Range<int> range, const String& text)
{
    if (TextInputTarget* const target = findCurrentTextInputTarget())
    {
        const Range<int> currentSelection (target->getHighlightedRegion());

        if (range.getLength() == 1 && text.isEmpty()) // (detect backspace)
            if (currentSelection.isEmpty())
                target->setHighlightedRegion (currentSelection.withStart (currentSelection.getStart() - 1));

        if (text == "\r" || text == "\n" || text == "\r\n")
            handleKeyPress (KeyPress::returnKey, text[0]);
        else
            target->insertTextAtCaret (text);

        updateHiddenTextContent (target);
    }

    return NO;
}

void UIViewComponentPeer::globalFocusChanged (Component*)
{
    if (TextInputTarget* const target = findCurrentTextInputTarget())
    {
        Component* comp = dynamic_cast<Component*> (target);

        Point<int> pos (component.getLocalPoint (comp, Point<int>()));
        view->hiddenTextView.frame = CGRectMake (pos.x, pos.y, 0, 0);

        updateHiddenTextContent (target);
        [view->hiddenTextView becomeFirstResponder];
    }
    else
    {
        [view->hiddenTextView resignFirstResponder];
    }
}


//==============================================================================
void UIViewComponentPeer::drawRect (CGRect r)
{
    if (r.size.width < 1.0f || r.size.height < 1.0f)
        return;

    CGContextRef cg = UIGraphicsGetCurrentContext();

    if (! component.isOpaque())
        CGContextClearRect (cg, CGContextGetClipBoundingBox (cg));

    CGContextConcatCTM (cg, CGAffineTransformMake (1, 0, 0, -1, 0, getComponent().getHeight()));

    // NB the CTM on iOS already includes a factor for the display scale, so
    // we'll tell the context that the scale is 1.0 to avoid it using it twice
    CoreGraphicsContext g (cg, getComponent().getHeight(), 1.0f);

    insideDrawRect = true;
    handlePaint (g);
    insideDrawRect = false;
}

bool UIViewComponentPeer::canBecomeKeyWindow()
{
    return (getStyleFlags() & juce::ComponentPeer::windowIgnoresKeyPresses) == 0;
}

//==============================================================================
void Desktop::setKioskComponent (Component* kioskModeComp, bool enableOrDisable, bool /*allowMenusAndBars*/)
{
    displays->refresh();

    if (ComponentPeer* peer = kioskModeComp->getPeer())
    {
        if (UIViewComponentPeer* uiViewPeer = dynamic_cast<UIViewComponentPeer*> (peer))
            [uiViewPeer->controller setNeedsStatusBarAppearanceUpdate];

        peer->setFullScreen (enableOrDisable);
    }
}

void Desktop::allowedOrientationsChanged()
{
    // if the current orientation isn't allowed anymore then switch orientations
    if (! isOrientationEnabled (getCurrentOrientation()))
    {
        DisplayOrientation orientations[] = { upright, upsideDown, rotatedClockwise, rotatedAntiClockwise };

        const int n = sizeof (orientations) / sizeof (DisplayOrientation);
        int i;

        for (i = 0; i < n; ++i)
            if (isOrientationEnabled (orientations[i]))
                break;


        // you need to support at least one orientation
        jassert (i < n);
        i = jmin (n - 1, i);

        NSNumber *value = [NSNumber numberWithInt: (int) Orientations::convertFromJuce (orientations[i])];
        [[UIDevice currentDevice] setValue:value forKey:@"orientation"];
        [value release];
    }
}

//==============================================================================
void UIViewComponentPeer::repaint (const Rectangle<int>& area)
{
    if (insideDrawRect || ! MessageManager::getInstance()->isThisTheMessageThread())
        (new AsyncRepaintMessage (this, area))->post();
    else
        [view setNeedsDisplayInRect: convertToCGRect (area)];
}

void UIViewComponentPeer::performAnyPendingRepaintsNow()
{
}

ComponentPeer* Component::createNewPeer (int styleFlags, void* windowToAttachTo)
{
    return new UIViewComponentPeer (*this, styleFlags, (UIView*) windowToAttachTo);
}

//==============================================================================
const int KeyPress::spaceKey        = ' ';
const int KeyPress::returnKey       = 0x0d;
const int KeyPress::escapeKey       = 0x1b;
const int KeyPress::backspaceKey    = 0x7f;
const int KeyPress::leftKey         = 0x1000;
const int KeyPress::rightKey        = 0x1001;
const int KeyPress::upKey           = 0x1002;
const int KeyPress::downKey         = 0x1003;
const int KeyPress::pageUpKey       = 0x1004;
const int KeyPress::pageDownKey     = 0x1005;
const int KeyPress::endKey          = 0x1006;
const int KeyPress::homeKey         = 0x1007;
const int KeyPress::deleteKey       = 0x1008;
const int KeyPress::insertKey       = -1;
const int KeyPress::tabKey          = 9;
const int KeyPress::F1Key           = 0x2001;
const int KeyPress::F2Key           = 0x2002;
const int KeyPress::F3Key           = 0x2003;
const int KeyPress::F4Key           = 0x2004;
const int KeyPress::F5Key           = 0x2005;
const int KeyPress::F6Key           = 0x2006;
const int KeyPress::F7Key           = 0x2007;
const int KeyPress::F8Key           = 0x2008;
const int KeyPress::F9Key           = 0x2009;
const int KeyPress::F10Key          = 0x200a;
const int KeyPress::F11Key          = 0x200b;
const int KeyPress::F12Key          = 0x200c;
const int KeyPress::F13Key          = 0x200d;
const int KeyPress::F14Key          = 0x200e;
const int KeyPress::F15Key          = 0x200f;
const int KeyPress::F16Key          = 0x2010;
const int KeyPress::F17Key          = 0x2011;
const int KeyPress::F18Key          = 0x2012;
const int KeyPress::F19Key          = 0x2013;
const int KeyPress::F20Key          = 0x2014;
const int KeyPress::F21Key          = 0x2015;
const int KeyPress::F22Key          = 0x2016;
const int KeyPress::F23Key          = 0x2017;
const int KeyPress::F24Key          = 0x2018;
const int KeyPress::F25Key          = 0x2019;
const int KeyPress::F26Key          = 0x201a;
const int KeyPress::F27Key          = 0x201b;
const int KeyPress::F28Key          = 0x201c;
const int KeyPress::F29Key          = 0x201d;
const int KeyPress::F30Key          = 0x201e;
const int KeyPress::F31Key          = 0x201f;
const int KeyPress::F32Key          = 0x2020;
const int KeyPress::F33Key          = 0x2021;
const int KeyPress::F34Key          = 0x2022;
const int KeyPress::F35Key          = 0x2023;
const int KeyPress::numberPad0      = 0x30020;
const int KeyPress::numberPad1      = 0x30021;
const int KeyPress::numberPad2      = 0x30022;
const int KeyPress::numberPad3      = 0x30023;
const int KeyPress::numberPad4      = 0x30024;
const int KeyPress::numberPad5      = 0x30025;
const int KeyPress::numberPad6      = 0x30026;
const int KeyPress::numberPad7      = 0x30027;
const int KeyPress::numberPad8      = 0x30028;
const int KeyPress::numberPad9      = 0x30029;
const int KeyPress::numberPadAdd            = 0x3002a;
const int KeyPress::numberPadSubtract       = 0x3002b;
const int KeyPress::numberPadMultiply       = 0x3002c;
const int KeyPress::numberPadDivide         = 0x3002d;
const int KeyPress::numberPadSeparator      = 0x3002e;
const int KeyPress::numberPadDecimalPoint   = 0x3002f;
const int KeyPress::numberPadEquals         = 0x30030;
const int KeyPress::numberPadDelete         = 0x30031;
const int KeyPress::playKey         = 0x30000;
const int KeyPress::stopKey         = 0x30001;
const int KeyPress::fastForwardKey  = 0x30002;
const int KeyPress::rewindKey       = 0x30003;

} // namespace juce