IPDFMacSheet.m

//
//  IPDFMacSheet.m
//  InstaPDF for Mac
//
//  Created by mmackh on 13.10.19.
//  Copyright © 2019 mackh ag. All rights reserved.
//

#import "IPDFMacSheet.h"

@interface NSWindow_Catalyst : NSObject

- (void)beginSheet:(id)sheet completionHandler:(id)completionHandler;
@property id contentView;
@property CGSize contentSize;

@end

@interface IPDFMacSheetToolbarItemState : NSObject

@property (nonatomic,weak) NSToolbarItem *toolbarItem;
@property (nonatomic) BOOL enabled;
@property (nonatomic) BOOL autovalidates;

@end @implementation IPDFMacSheetToolbarItemState @end

@interface IPDFMacSheet ()

@property (nonatomic) UIView *backgroundView;

@end

@interface IPDFMacSheet ()

+ (void)setDisableToolbar:(BOOL)toolbar;

@end

@implementation IPDFMacSheet

+ (UIWindow *)targetWindow
{
    UIWindow *targetWindow = nil;
    
    for (UIWindow *window in [UIApplication sharedApplication].windows)
    {
        if (window.isKeyWindow)
        {
            targetWindow = window;
            break;
        }
    }
    
    return targetWindow;
}

+ (instancetype)showSheetWithSizeHandler:(CGSize(^)(CGRect windowBounds))sizeHandler viewConfigurationHandler:(void(^)(UIView *contentView))viewConfigurationHandler
{
    
    UIWindow *targetWindow = [self targetWindow];
    
    IPDFMacSheet *sheet = [[self class] new];
    
    UIEdgeInsets safeAreaInsets = targetWindow.safeAreaInsets;
    
    CGRect windowBounds = targetWindow.frame;
    windowBounds.origin.y = safeAreaInsets.top;
    windowBounds.size.height -= safeAreaInsets.top;
    
    CGRect backgroundViewFrame = windowBounds;
    IPDFMacSheet *possibleParentSheet = [IPDFMacSheet currentSheet];
    if (possibleParentSheet)
    {
        // Avoid compounding white background that turns more opaque the more sheets are stacked
        backgroundViewFrame = possibleParentSheet.frame;
    }
    
    sheet.backgroundView = [[UIView alloc] initWithFrame:backgroundViewFrame];
    sheet.backgroundView.backgroundColor = [UIColor clearColor];
    sheet.backgroundView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    [targetWindow addSubview:sheet.backgroundView];
    
    sheet.sizeHandler = sizeHandler;
    
    CGSize sheetSize = sizeHandler(windowBounds);
    CGRect targetSheetFrame = windowBounds;
    targetSheetFrame.size = sheetSize;
    targetSheetFrame.origin.x = windowBounds.size.width / 2 - sheetSize.width/2;
    targetSheetFrame.origin.y = -targetSheetFrame.size.height;
    sheet.frame = targetSheetFrame;
    sheet.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    targetSheetFrame.origin.y = safeAreaInsets.top - 1;

    UIVisualEffectView *backgroundBlurView = [[UIVisualEffectView alloc] initWithEffect:[UIBlurEffect effectWithStyle:UIBlurEffectStyleSystemThickMaterial]];
    backgroundBlurView.frame = sheet.bounds;
    backgroundBlurView.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
    [sheet addSubview:backgroundBlurView];
    
    sheet.layer.borderColor = [UIColor colorWithRed:0.74 green:0.74 blue:0.74 alpha:1.00].CGColor;
    sheet.layer.borderWidth = 1.0;
    
    sheet.layer.shadowColor = [UIColor colorWithWhite:0.3 alpha:1.0].CGColor;
    sheet.layer.shadowRadius = 8;
    sheet.layer.shadowOffset = CGSizeZero;
    sheet.layer.shadowOpacity = 0.5;
    
    [targetWindow addSubview:sheet];
    
    if (viewConfigurationHandler) viewConfigurationHandler(sheet);
    
    [UIView animateWithDuration:0.35 animations:^
    {
        sheet.backgroundView.backgroundColor = [[UIColor systemBackgroundColor] colorWithAlphaComponent:0.15];
        sheet.frame = targetSheetFrame;
    }];
    
    if ([IPDFMacSheet currentSheets].count == 1)
    {
        [IPDFMacSheet setDisableToolbar:YES];
    }
    
    return sheet;
}

+ (instancetype)currentSheet
{
    return [IPDFMacSheet currentSheets].lastObject;
}

+ (NSArray *)currentSheets
{
    NSMutableArray *sheetsMutable = [NSMutableArray new];
    
    UIWindow *targetWindow = [self targetWindow];
    for (UIView *subview in targetWindow.subviews)
    {
        if ([subview isKindOfClass:[IPDFMacSheet class]])
        {
            [sheetsMutable addObject:subview];
        }
    }
    return sheetsMutable;
}

- (void)dismiss
{
    [self dismissWithCompletionHandler:nil];
}

- (void)dismissWithCompletionHandler:(void (^)(void))completionHandler
{
    self.sizeHandler = nil;
    
    CGRect targetSheetFrame = self.frame;
    targetSheetFrame.origin.y = -targetSheetFrame.size.height;
    
    [UIView animateWithDuration:0.4 animations:^
    {
        self.frame = targetSheetFrame;
        self.backgroundView.backgroundColor = [UIColor clearColor];
    }
    completion:^(BOOL finished)
    {
        if (completionHandler) completionHandler();

        if ([IPDFMacSheet currentSheets].count == 1)
        {
            [IPDFMacSheet setDisableToolbar:NO];
            toolbarItemStates = nil;
        }
        
        for (UIView *subview in self.subviews) {
            [subview removeFromSuperview];
        }
        
        [self.backgroundView removeFromSuperview];
        [self removeFromSuperview];
    }];
}

- (void)layoutSubviews
{
    [super layoutSubviews];
    
    if (!self.sizeHandler) return;
    
    CGSize targetSize = self.sizeHandler(self.superview.bounds);
    CGRect targetFrame = self.frame;
    targetFrame.origin.x = self.superview.bounds.size.width / 2 - targetSize.width/2;
    targetFrame.size = targetSize;
    
    self.frame = targetFrame;
}

+ (BOOL)dismissableWithESCKey
{
    return YES;
}

static NSMutableArray<IPDFMacSheetToolbarItemState *> *toolbarItemStates;

+ (void)changeStateForToolbarItem:(NSToolbarItem *)toolbarItem stateAfterDismissal:(BOOL)stateAfterDismissal
{
    for (IPDFMacSheetToolbarItemState *state in toolbarItemStates)
    {
        if (state.toolbarItem != toolbarItem) continue;
        
        state.enabled = stateAfterDismissal;
    }
}

+ (void)setDisableToolbar:(BOOL)disableToolbar
{
    if (!toolbarItemStates)
    {
        toolbarItemStates = [NSMutableArray new];
    }
    
    UIWindowScene *scene = [IPDFMacSheet currentSheet].window.windowScene;
    [scene.titlebar.toolbar setDisplayMode:NSToolbarDisplayModeIconAndLabel];
    
    if (!disableToolbar)
    {
        for (IPDFMacSheetToolbarItemState *state in toolbarItemStates)
        {
            NSToolbarItem *item = state.toolbarItem;
            item.autovalidates = state.autovalidates;
            item.enabled = state.enabled;
        }
        
        return;
    }
    
    for (NSToolbarItem *toolbarItem in scene.titlebar.toolbar.items)
    {
        BOOL autovalidates = NO;
        BOOL enabled = NO;
        
        IPDFMacSheetToolbarItemState *state = [IPDFMacSheetToolbarItemState new];
        state.autovalidates = toolbarItem.autovalidates;
        state.enabled = toolbarItem.enabled;
        state.toolbarItem = toolbarItem;
        [toolbarItemStates addObject:state];
        
        toolbarItem.autovalidates = autovalidates;
        toolbarItem.enabled = enabled;
    }
}

@end