SDL2/src/video/uikit/SDL_uikitviewcontroller.m

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2023 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/
#include "SDL_internal.h"

#if SDL_VIDEO_DRIVER_UIKIT

#include "../SDL_sysvideo.h"
#include "../../events/SDL_events_c.h"

#include "SDL_uikitviewcontroller.h"
#include "SDL_uikitmessagebox.h"
#include "SDL_uikitevents.h"
#include "SDL_uikitvideo.h"
#include "SDL_uikitmodes.h"
#include "SDL_uikitwindow.h"
#include "SDL_uikitopengles.h"

#if TARGET_OS_TV
static void SDLCALL SDL_AppleTVControllerUIHintChanged(void *userdata, const char *name, const char *oldValue, const char *hint)
{
    @autoreleasepool {
        SDL_uikitviewcontroller *viewcontroller = (__bridge SDL_uikitviewcontroller *)userdata;
        viewcontroller.controllerUserInteractionEnabled = hint && (*hint != '0');
    }
}
#endif

#if !TARGET_OS_TV
static void SDLCALL SDL_HideHomeIndicatorHintChanged(void *userdata, const char *name, const char *oldValue, const char *hint)
{
    @autoreleasepool {
        SDL_uikitviewcontroller *viewcontroller = (__bridge SDL_uikitviewcontroller *)userdata;
        viewcontroller.homeIndicatorHidden = (hint && *hint) ? SDL_atoi(hint) : -1;
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wunguarded-availability-new"
        if ([viewcontroller respondsToSelector:@selector(setNeedsUpdateOfHomeIndicatorAutoHidden)]) {
            [viewcontroller setNeedsUpdateOfHomeIndicatorAutoHidden];
            [viewcontroller setNeedsUpdateOfScreenEdgesDeferringSystemGestures];
        }
#pragma clang diagnostic pop
    }
}
#endif

@implementation SDLUITextField : UITextField
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
{
	if (action == @selector(paste:)) {
		return NO;
	}

	return [super canPerformAction:action withSender:sender];
}
@end

@implementation SDL_uikitviewcontroller
{
    CADisplayLink *displayLink;
    int animationInterval;
    void (*animationCallback)(void *);
    void *animationCallbackParam;

#if SDL_IPHONE_KEYBOARD
    SDLUITextField *textField;
    BOOL hardwareKeyboard;
    BOOL showingKeyboard;
    BOOL rotatingOrientation;
    NSString *committedText;
    NSString *obligateForBackspace;
#endif
}

@synthesize window;

- (instancetype)initWithSDLWindow:(SDL_Window *)_window
{
    if (self = [super initWithNibName:nil bundle:nil]) {
        self.window = _window;

#if SDL_IPHONE_KEYBOARD
        [self initKeyboard];
        hardwareKeyboard = NO;
        showingKeyboard = NO;
        rotatingOrientation = NO;
#endif

#if TARGET_OS_TV
        SDL_AddHintCallback(SDL_HINT_APPLE_TV_CONTROLLER_UI_EVENTS,
                            SDL_AppleTVControllerUIHintChanged,
                            (__bridge void *)self);
#endif

#if !TARGET_OS_TV
        SDL_AddHintCallback(SDL_HINT_IOS_HIDE_HOME_INDICATOR,
                            SDL_HideHomeIndicatorHintChanged,
                            (__bridge void *)self);
#endif
    }
    return self;
}

- (void)dealloc
{
#if SDL_IPHONE_KEYBOARD
    [self deinitKeyboard];
#endif

#if TARGET_OS_TV
    SDL_DelHintCallback(SDL_HINT_APPLE_TV_CONTROLLER_UI_EVENTS,
                        SDL_AppleTVControllerUIHintChanged,
                        (__bridge void *)self);
#endif

#if !TARGET_OS_TV
    SDL_DelHintCallback(SDL_HINT_IOS_HIDE_HOME_INDICATOR,
                        SDL_HideHomeIndicatorHintChanged,
                        (__bridge void *)self);
#endif
}

- (void)setAnimationCallback:(int)interval
                    callback:(void (*)(void *))callback
               callbackParam:(void *)callbackParam
{
    [self stopAnimation];

    animationInterval = interval;
    animationCallback = callback;
    animationCallbackParam = callbackParam;

    if (animationCallback) {
        [self startAnimation];
    }
}

- (void)startAnimation
{
    displayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(doLoop:)];

#ifdef __IPHONE_10_3
    SDL_WindowData *data = window->driverdata;

    if ([displayLink respondsToSelector:@selector(preferredFramesPerSecond)] && data != nil && data.uiwindow != nil && [data.uiwindow.screen respondsToSelector:@selector(maximumFramesPerSecond)]) {
        displayLink.preferredFramesPerSecond = data.uiwindow.screen.maximumFramesPerSecond / animationInterval;
    } else
#endif
    {
#if __IPHONE_OS_VERSION_MIN_REQUIRED < 100300
        [displayLink setFrameInterval:animationInterval];
#endif
    }

    [displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
}

- (void)stopAnimation
{
    [displayLink invalidate];
    displayLink = nil;
}

- (void)doLoop:(CADisplayLink *)sender
{
    /* Don't run the game loop while a messagebox is up */
    if (!UIKit_ShowingMessageBox()) {
        /* See the comment in the function definition. */
#if SDL_VIDEO_OPENGL_ES || SDL_VIDEO_OPENGL_ES2
        UIKit_GL_RestoreCurrentContext();
#endif

        animationCallback(animationCallbackParam);
    }
}

- (void)loadView
{
    /* Do nothing. */
}

- (void)viewDidLayoutSubviews
{
    const CGSize size = self.view.bounds.size;
    int w = (int)size.width;
    int h = (int)size.height;

    SDL_SendWindowEvent(window, SDL_EVENT_WINDOW_RESIZED, w, h);
}

#if !TARGET_OS_TV
- (NSUInteger)supportedInterfaceOrientations
{
    return UIKit_GetSupportedOrientations(window);
}

- (BOOL)prefersStatusBarHidden
{
    BOOL hidden = (window->flags & (SDL_WINDOW_FULLSCREEN | SDL_WINDOW_BORDERLESS)) != 0;
    return hidden;
}

- (BOOL)prefersHomeIndicatorAutoHidden
{
    BOOL hidden = NO;
    if (self.homeIndicatorHidden == 1) {
        hidden = YES;
    }
    return hidden;
}

- (UIRectEdge)preferredScreenEdgesDeferringSystemGestures
{
    if (self.homeIndicatorHidden >= 0) {
        if (self.homeIndicatorHidden == 2) {
            return UIRectEdgeAll;
        } else {
            return UIRectEdgeNone;
        }
    }

    /* By default, fullscreen and borderless windows get all screen gestures */
    if ((window->flags & (SDL_WINDOW_FULLSCREEN | SDL_WINDOW_BORDERLESS)) != 0) {
        return UIRectEdgeAll;
    } else {
        return UIRectEdgeNone;
    }
}

- (BOOL)prefersPointerLocked
{
    return SDL_GCMouseRelativeMode() ? YES : NO;
}

#endif /* !TARGET_OS_TV */

/*
 ---- Keyboard related functionality below this line ----
 */
#if SDL_IPHONE_KEYBOARD

@synthesize textInputRect;
@synthesize keyboardHeight;
@synthesize keyboardVisible;

/* Set ourselves up as a UITextFieldDelegate */
- (void)initKeyboard
{
    obligateForBackspace = @"                                                                "; /* 64 space */
    textField = [[SDLUITextField alloc] initWithFrame:CGRectZero];
    textField.delegate = self;
    /* placeholder so there is something to delete! */
    textField.text = obligateForBackspace;
    committedText = textField.text;

    /* set UITextInputTrait properties, mostly to defaults */
    textField.autocapitalizationType = UITextAutocapitalizationTypeNone;
    textField.autocorrectionType = UITextAutocorrectionTypeNo;
    textField.enablesReturnKeyAutomatically = NO;
    textField.keyboardAppearance = UIKeyboardAppearanceDefault;
    textField.keyboardType = UIKeyboardTypeDefault;
    textField.returnKeyType = UIReturnKeyDefault;
    textField.secureTextEntry = NO;

    textField.hidden = YES;
    keyboardVisible = NO;

    NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
#if !TARGET_OS_TV
    [center addObserver:self
               selector:@selector(keyboardWillShow:)
                   name:UIKeyboardWillShowNotification
                 object:nil];
    [center addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];
#endif
    [center addObserver:self
               selector:@selector(textFieldTextDidChange:)
                   name:UITextFieldTextDidChangeNotification
                 object:nil];
}

- (NSArray *)keyCommands
{
    NSMutableArray *commands = [[NSMutableArray alloc] init];
    [commands addObject:[UIKeyCommand keyCommandWithInput:UIKeyInputUpArrow modifierFlags:kNilOptions action:@selector(handleCommand:)]];
    [commands addObject:[UIKeyCommand keyCommandWithInput:UIKeyInputDownArrow modifierFlags:kNilOptions action:@selector(handleCommand:)]];
    [commands addObject:[UIKeyCommand keyCommandWithInput:UIKeyInputLeftArrow modifierFlags:kNilOptions action:@selector(handleCommand:)]];
    [commands addObject:[UIKeyCommand keyCommandWithInput:UIKeyInputRightArrow modifierFlags:kNilOptions action:@selector(handleCommand:)]];
    [commands addObject:[UIKeyCommand keyCommandWithInput:UIKeyInputEscape modifierFlags:kNilOptions action:@selector(handleCommand:)]];
    return [NSArray arrayWithArray:commands];
}

- (void)handleCommand:(UIKeyCommand *)keyCommand
{
    SDL_Scancode scancode = SDL_SCANCODE_UNKNOWN;
    NSString *input = keyCommand.input;

    if (input == UIKeyInputUpArrow) {
        scancode = SDL_SCANCODE_UP;
    } else if (input == UIKeyInputDownArrow) {
        scancode = SDL_SCANCODE_DOWN;
    } else if (input == UIKeyInputLeftArrow) {
        scancode = SDL_SCANCODE_LEFT;
    } else if (input == UIKeyInputRightArrow) {
        scancode = SDL_SCANCODE_RIGHT;
    } else if (input == UIKeyInputEscape) {
        scancode = SDL_SCANCODE_ESCAPE;
    }

    if (scancode != SDL_SCANCODE_UNKNOWN) {
        SDL_SendKeyboardKeyAutoRelease(0, scancode);
    }
}

- (void)setView:(UIView *)view
{
    [super setView:view];

    [view addSubview:textField];

    if (keyboardVisible) {
        [self showKeyboard];
    }
}

- (void)viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator
{
    [super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];
    rotatingOrientation = YES;
    [coordinator
        animateAlongsideTransition:^(id<UIViewControllerTransitionCoordinatorContext> context) {
        }
        completion:^(id<UIViewControllerTransitionCoordinatorContext> context) {
          self->rotatingOrientation = NO;
        }];
}

- (void)deinitKeyboard
{
    NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
#if !TARGET_OS_TV
    [center removeObserver:self
                      name:UIKeyboardWillShowNotification
                    object:nil];
    [center removeObserver:self name:UIKeyboardWillHideNotification object:nil];
#endif
    [center removeObserver:self
                      name:UITextFieldTextDidChangeNotification
                    object:nil];
}

/* reveal onscreen virtual keyboard */
- (void)showKeyboard
{
    keyboardVisible = YES;
    if (textField.window) {
        showingKeyboard = YES;
        [textField becomeFirstResponder];
        showingKeyboard = NO;
    }
}

/* hide onscreen virtual keyboard */
- (void)hideKeyboard
{
    keyboardVisible = NO;
    [textField resignFirstResponder];
}

- (void)keyboardWillShow:(NSNotification *)notification
{
#if !TARGET_OS_TV
    CGRect kbrect = [[notification userInfo][UIKeyboardFrameEndUserInfoKey] CGRectValue];

    /* The keyboard rect is in the coordinate space of the screen/window, but we
     * want its height in the coordinate space of the view. */
    kbrect = [self.view convertRect:kbrect fromView:nil];

    [self setKeyboardHeight:(int)kbrect.size.height];
#endif
}

- (void)keyboardWillHide:(NSNotification *)notification
{
    if (!showingKeyboard && !rotatingOrientation) {
        SDL_StopTextInput();
    }
    [self setKeyboardHeight:0];
}

- (void)textFieldTextDidChange:(NSNotification *)notification
{
    if (textField.markedTextRange == nil) {
        NSUInteger compareLength = SDL_min(textField.text.length, committedText.length);
        NSUInteger matchLength;

        /* Backspace over characters that are no longer in the string */
        for (matchLength = 0; matchLength < compareLength; ++matchLength) {
            if ([committedText characterAtIndex:matchLength] != [textField.text characterAtIndex:matchLength]) {
                break;
            }
        }
        if (matchLength < committedText.length) {
            size_t deleteLength = SDL_utf8strlen([[committedText substringFromIndex:matchLength] UTF8String]);
            while (deleteLength > 0) {
                /* Send distinct down and up events for each backspace action */
                SDL_SendKeyboardKey(0, SDL_PRESSED, SDL_SCANCODE_BACKSPACE);
                SDL_SendKeyboardKey(0, SDL_RELEASED, SDL_SCANCODE_BACKSPACE);
                --deleteLength;
            }
        }

        if (matchLength < textField.text.length) {
            NSString *pendingText = [textField.text substringFromIndex:matchLength];
            if (!SDL_HardwareKeyboardKeyPressed()) {
                /* Go through all the characters in the string we've been sent and
                 * convert them to key presses */
                NSUInteger i;
                for (i = 0; i < pendingText.length; i++) {
                    SDL_SendKeyboardUnicodeKey(0, [pendingText characterAtIndex:i]);
                }
            }
            SDL_SendKeyboardText([pendingText UTF8String]);
        }
        committedText = textField.text;
    }
}

- (void)updateKeyboard
{
    CGAffineTransform t = self.view.transform;
    CGPoint offset = CGPointMake(0.0, 0.0);
    CGRect frame = UIKit_ComputeViewFrame(window, self.view.window.screen);

    if (self.keyboardHeight) {
        int rectbottom = self.textInputRect.y + self.textInputRect.h;
        int keybottom = self.view.bounds.size.height - self.keyboardHeight;
        if (keybottom < rectbottom) {
            offset.y = keybottom - rectbottom;
        }
    }

    /* Apply this view's transform (except any translation) to the offset, in
     * order to orient it correctly relative to the frame's coordinate space. */
    t.tx = 0.0;
    t.ty = 0.0;
    offset = CGPointApplyAffineTransform(offset, t);

    /* Apply the updated offset to the view's frame. */
    frame.origin.x += offset.x;
    frame.origin.y += offset.y;

    self.view.frame = frame;
}

- (void)setKeyboardHeight:(int)height
{
    keyboardVisible = height > 0;
    keyboardHeight = height;
    [self updateKeyboard];
}

/* UITextFieldDelegate method.  Invoked when user types something. */
- (BOOL)textField:(UITextField *)_textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    if (textField.markedTextRange == nil) {
        if (textField.text.length < 16) {
            textField.text = obligateForBackspace;
            committedText = textField.text;
        }
    }
    return YES;
}

/* Terminates the editing session */
- (BOOL)textFieldShouldReturn:(UITextField *)_textField
{
    SDL_SendKeyboardKeyAutoRelease(0, SDL_SCANCODE_RETURN);
    if (keyboardVisible &&
        SDL_GetHintBoolean(SDL_HINT_RETURN_KEY_HIDES_IME, SDL_FALSE)) {
        SDL_StopTextInput();
    }
    return YES;
}

#endif

@end

/* iPhone keyboard addition functions */
#if SDL_IPHONE_KEYBOARD

static SDL_uikitviewcontroller *GetWindowViewController(SDL_Window *window)
{
    if (!window || !window->driverdata) {
        SDL_SetError("Invalid window");
        return nil;
    }

    SDL_WindowData *data = window->driverdata;

    return data.viewcontroller;
}

SDL_bool
UIKit_HasScreenKeyboardSupport(_THIS)
{
    return SDL_TRUE;
}

void UIKit_ShowScreenKeyboard(_THIS, SDL_Window *window)
{
    @autoreleasepool {
        SDL_uikitviewcontroller *vc = GetWindowViewController(window);
        [vc showKeyboard];
    }
}

void UIKit_HideScreenKeyboard(_THIS, SDL_Window *window)
{
    @autoreleasepool {
        SDL_uikitviewcontroller *vc = GetWindowViewController(window);
        [vc hideKeyboard];
    }
}

SDL_bool
UIKit_IsScreenKeyboardShown(_THIS, SDL_Window *window)
{
    @autoreleasepool {
        SDL_uikitviewcontroller *vc = GetWindowViewController(window);
        if (vc != nil) {
            return vc.keyboardVisible;
        }
        return SDL_FALSE;
    }
}

int UIKit_SetTextInputRect(_THIS, const SDL_Rect *rect)
{
    @autoreleasepool {
        SDL_uikitviewcontroller *vc = GetWindowViewController(SDL_GetFocusWindow());
        if (vc != nil) {
            vc.textInputRect = *rect;

            if (vc.keyboardVisible) {
                [vc updateKeyboard];
            }
        }
    }
    return 0;
}

#endif /* SDL_IPHONE_KEYBOARD */

#endif /* SDL_VIDEO_DRIVER_UIKIT */