/*

     File: MyTableViewController.m

 Abstract: The main table view controller of this app.

  Version: 1.6

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 OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.

 IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL

 OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

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 Copyright (C) 2014 Apple Inc. All Rights Reserved.

 */

#import "MyTableViewController.h"

#define kPickerAnimationDuration    0.40   // duration for the animation to slide the date picker into view

#define kDatePickerTag              99     // view tag identifiying the date picker view

#define kTitleKey       @"title"   // key for obtaining the data source item's title

#define kDateKey        @"date"    // key for obtaining the data source item's date value

// keep track of which rows have date cells

#define kDateStartRow   1

#define kDateEndRow     2

static NSString *kDateCellID = @"dateCell";     // the cells with the start or end date

static NSString *kDatePickerID = @"datePicker"; // the cell containing the date picker

static NSString *kOtherCell = @"otherCell";     // the remaining cells at the end

#pragma mark -

@interface MyTableViewController ()

@property (nonatomic, strong) NSArray *dataArray;

@property (nonatomic, strong) NSDateFormatter *dateFormatter;

// keep track which indexPath points to the cell with UIDatePicker

@property (nonatomic, strong) NSIndexPath *datePickerIndexPath;

@property (assign) NSInteger pickerCellRowHeight;

@property (nonatomic, strong) IBOutlet UIDatePicker *pickerView;

// this button appears only when the date picker is shown (iOS 6.1.x or earlier)

@property (nonatomic, strong) IBOutlet UIBarButtonItem *doneButton;

@end

#pragma mark -

@implementation MyTableViewController

/*! Primary view has been loaded for this view controller

 */

- (void)viewDidLoad

{

    [super viewDidLoad];

    // setup our data source

    NSMutableDictionary *itemOne = [@{ kTitleKey : @"Tap a cell to change its date:" } mutableCopy];

    NSMutableDictionary *itemTwo = [@{ kTitleKey : @"Start Date",

                                       kDateKey : [NSDate date] } mutableCopy];

    NSMutableDictionary *itemThree = [@{ kTitleKey : @"End Date",

                                        kDateKey : [NSDate date] } mutableCopy];

    NSMutableDictionary *itemFour = [@{ kTitleKey : @"(other item1)" } mutableCopy];

    NSMutableDictionary *itemFive = [@{ kTitleKey : @"(other item2)" } mutableCopy];

    self.dataArray = @[itemOne, itemTwo, itemThree, itemFour, itemFive];

    self.dateFormatter = [[NSDateFormatter alloc] init];

    [self.dateFormatter setDateStyle:NSDateFormatterShortStyle];    // show short-style date format

    [self.dateFormatter setTimeStyle:NSDateFormatterNoStyle];

    // obtain the picker view cell's height, works because the cell was pre-defined in our storyboard

    UITableViewCell *pickerViewCellToCheck = [self.tableView dequeueReusableCellWithIdentifier:kDatePickerID];

    self.pickerCellRowHeight = CGRectGetHeight(pickerViewCellToCheck.frame);

    // if the local changes while in the background, we need to be notified so we can update the date

    // format in the table view cells

    //

    [[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(localeChanged:)

                                                 name:NSCurrentLocaleDidChangeNotification

                                               object:nil];

}

- (void)dealloc

{

    [[NSNotificationCenter defaultCenter] removeObserver:self

                                                    name:NSCurrentLocaleDidChangeNotification

                                                  object:nil];

}

#pragma mark - Locale

/*! Responds to region format or locale changes.

 */

- (void)localeChanged:(NSNotification *)notif

{

    // the user changed the locale (region format) in Settings, so we are notified here to

    // update the date format in the table view cells

    //

    [self.tableView reloadData];

}

#pragma mark - Utilities

/*! Returns the major version of iOS, (i.e. for iOS 6.1.3 it returns 6)

 */

NSUInteger DeviceSystemMajorVersion()

{

    static NSUInteger _deviceSystemMajorVersion = -1;

    static dispatch_once_t onceToken;

    dispatch_once(&onceToken, ^{

        _deviceSystemMajorVersion =

            [[[[UIDevice currentDevice] systemVersion] componentsSeparatedByString:@"."][0] integerValue];

    });

    return _deviceSystemMajorVersion;

}

#define EMBEDDED_DATE_PICKER (DeviceSystemMajorVersion() >= 7)

/*! Determines if the given indexPath has a cell below it with a UIDatePicker.

 @param indexPath The indexPath to check if its cell has a UIDatePicker below it.

 */

- (BOOL)hasPickerForIndexPath:(NSIndexPath *)indexPath

{

    BOOL hasDatePicker = NO;

    NSInteger targetedRow = indexPath.row;

    targetedRow++;

    UITableViewCell *checkDatePickerCell =

        [self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:targetedRow inSection:0]];

    UIDatePicker *checkDatePicker = (UIDatePicker *)[checkDatePickerCell viewWithTag:kDatePickerTag];

    hasDatePicker = (checkDatePicker != nil);

    return hasDatePicker;

}

/*! Updates the UIDatePicker's value to match with the date of the cell above it.

 */

- (void)updateDatePicker

{

    if (self.datePickerIndexPath != nil)

    {

        UITableViewCell *associatedDatePickerCell = [self.tableView cellForRowAtIndexPath:self.datePickerIndexPath];

        UIDatePicker *targetedDatePicker = (UIDatePicker *)[associatedDatePickerCell viewWithTag:kDatePickerTag];

        if (targetedDatePicker != nil)

        {

            // we found a UIDatePicker in this cell, so update it's date value

            //

            NSDictionary *itemData = self.dataArray[self.datePickerIndexPath.row - 1];

            [targetedDatePicker setDate:[itemData valueForKey:kDateKey] animated:NO];

        }

    }

}

/*! Determines if the UITableViewController has a UIDatePicker in any of its cells.

 */

- (BOOL)hasInlineDatePicker

{

    return (self.datePickerIndexPath != nil);

}

/*! Determines if the given indexPath points to a cell that contains the UIDatePicker.

 @param indexPath The indexPath to check if it represents a cell with the UIDatePicker.

 */

- (BOOL)indexPathHasPicker:(NSIndexPath *)indexPath

{

    return ([self hasInlineDatePicker] && self.datePickerIndexPath.row == indexPath.row);

}

/*! Determines if the given indexPath points to a cell that contains the start/end dates.

    @param indexPath The indexPath to check if it represents start/end date cell.

*/

- (BOOL)indexPathHasDate:(NSIndexPath *)indexPath

{

    BOOL hasDate = NO;

    if ((indexPath.row == kDateStartRow) ||

        (indexPath.row == kDateEndRow || ([self hasInlineDatePicker] && (indexPath.row == kDateEndRow + 1))))

    {

        hasDate = YES;

    }

    return hasDate;

}

#pragma mark - UITableViewDataSource

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath

{

    return ([self indexPathHasPicker:indexPath] ? self.pickerCellRowHeight : self.tableView.rowHeight);

}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

{

    if ([self hasInlineDatePicker])

    {

        // we have a date picker, so allow for it in the number of rows in this section

        NSInteger numRows = self.dataArray.count;

        return ++numRows;

    }

    return self.dataArray.count;

}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

{

    UITableViewCell *cell = nil;

    NSString *cellID = kOtherCell;

    if ([self indexPathHasPicker:indexPath])

    {

        // the indexPath is the one containing the inline date picker

        cellID = kDatePickerID;     // the current/opened date picker cell

    }

    else if ([self indexPathHasDate:indexPath])

    {

        // the indexPath is one that contains the date information

        cellID = kDateCellID;       // the start/end date cells

    }

    cell = [tableView dequeueReusableCellWithIdentifier:cellID];

    if (indexPath.row == 0)

    {

        // we decide here that first cell in the table is not selectable (it's just an indicator)

        cell.selectionStyle = UITableViewCellSelectionStyleNone;

    }

    // if we have a date picker open whose cell is above the cell we want to update,

    // then we have one more cell than the model allows

    //

    NSInteger modelRow = indexPath.row;

    if (self.datePickerIndexPath != nil && self.datePickerIndexPath.row <= indexPath.row)

    {

        modelRow--;

    }

    NSDictionary *itemData = self.dataArray[modelRow];

    // proceed to configure our cell

    if ([cellID isEqualToString:kDateCellID])

    {

        // we have either start or end date cells, populate their date field

        //

        cell.textLabel.text = [itemData valueForKey:kTitleKey];

        cell.detailTextLabel.text = [self.dateFormatter stringFromDate:[itemData valueForKey:kDateKey]];

    }

    else if ([cellID isEqualToString:kOtherCell])

    {

        // this cell is a non-date cell, just assign it's text label

        //

        cell.textLabel.text = [itemData valueForKey:kTitleKey];

    }

    return cell;

}

/*! Adds or removes a UIDatePicker cell below the given indexPath.

 @param indexPath The indexPath to reveal the UIDatePicker.

 */

- (void)toggleDatePickerForSelectedIndexPath:(NSIndexPath *)indexPath

{

    [self.tableView beginUpdates];

    NSArray *indexPaths = @[[NSIndexPath indexPathForRow:indexPath.row + 1 inSection:0]];

    // check if 'indexPath' has an attached date picker below it

    if ([self hasPickerForIndexPath:indexPath])

    {

        // found a picker below it, so remove it

        [self.tableView deleteRowsAtIndexPaths:indexPaths

                              withRowAnimation:UITableViewRowAnimationFade];

    }

    else

    {

        // didn't find a picker below it, so we should insert it

        [self.tableView insertRowsAtIndexPaths:indexPaths

                              withRowAnimation:UITableViewRowAnimationFade];

    }

    [self.tableView endUpdates];

}

/*! Reveals the date picker inline for the given indexPath, called by "didSelectRowAtIndexPath".

 @param indexPath The indexPath to reveal the UIDatePicker.

 */

- (void)displayInlineDatePickerForRowAtIndexPath:(NSIndexPath *)indexPath

{

    // display the date picker inline with the table content

    [self.tableView beginUpdates];

    BOOL before = NO;   // indicates if the date picker is below "indexPath", help us determine which row to reveal

    if ([self hasInlineDatePicker])

    {

        before = self.datePickerIndexPath.row < indexPath.row;

    }

    BOOL sameCellClicked = (self.datePickerIndexPath.row - 1 == indexPath.row);

    // remove any date picker cell if it exists

    if ([self hasInlineDatePicker])

    {

        [self.tableView deleteRowsAtIndexPaths:@[[NSIndexPath indexPathForRow:self.datePickerIndexPath.row inSection:0]]

                              withRowAnimation:UITableViewRowAnimationFade];

        self.datePickerIndexPath = nil;

    }

    if (!sameCellClicked)

    {

        // hide the old date picker and display the new one

        NSInteger rowToReveal = (before ? indexPath.row - 1 : indexPath.row);

        NSIndexPath *indexPathToReveal = [NSIndexPath indexPathForRow:rowToReveal inSection:0];

        [self toggleDatePickerForSelectedIndexPath:indexPathToReveal];

        self.datePickerIndexPath = [NSIndexPath indexPathForRow:indexPathToReveal.row + 1 inSection:0];

    }

    // always deselect the row containing the start or end date

    [self.tableView deselectRowAtIndexPath:indexPath animated:YES];

    [self.tableView endUpdates];

    // inform our date picker of the current date to match the current cell

    [self updateDatePicker];

}

/*! Reveals the UIDatePicker as an external slide-in view, iOS 6.1.x and earlier, called by "didSelectRowAtIndexPath".

 @param indexPath The indexPath used to display the UIDatePicker.

 */

- (void)displayExternalDatePickerForRowAtIndexPath:(NSIndexPath *)indexPath

{

    // first update the date picker's date value according to our model

    NSDictionary *itemData = self.dataArray[indexPath.row];

    [self.pickerView setDate:[itemData valueForKey:kDateKey] animated:YES];

    // the date picker might already be showing, so don't add it to our view

    if (self.pickerView.superview == nil)

    {

        CGRect startFrame = self.pickerView.frame;

        CGRect endFrame = self.pickerView.frame;

        // the start position is below the bottom of the visible frame

        startFrame.origin.y = CGRectGetHeight(self.view.frame);

        // the end position is slid up by the height of the view

        endFrame.origin.y = startFrame.origin.y - CGRectGetHeight(endFrame);

        self.pickerView.frame = startFrame;

        [self.view addSubview:self.pickerView];

        // animate the date picker into view

        [UIView animateWithDuration:kPickerAnimationDuration animations: ^{ self.pickerView.frame = endFrame; }

                         completion:^(BOOL finished) {

                             // add the "Done" button to the nav bar

                             self.navigationItem.rightBarButtonItem = self.doneButton;

                         }];

    }

}

#pragma mark - UITableViewDelegate

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath

{

    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];

    if (cell.reuseIdentifier == kDateCellID)

    {

        if (EMBEDDED_DATE_PICKER)

            [self displayInlineDatePickerForRowAtIndexPath:indexPath];

        else

            [self displayExternalDatePickerForRowAtIndexPath:indexPath];

    }

    else

    {

        [tableView deselectRowAtIndexPath:indexPath animated:YES];

    }

}

#pragma mark - Actions

/*! User chose to change the date by changing the values inside the UIDatePicker.

 @param sender The sender for this action: UIDatePicker.

 */

- (IBAction)dateAction:(id)sender

{

    NSIndexPath *targetedCellIndexPath = nil;

    if ([self hasInlineDatePicker])

    {

        // inline date picker: update the cell's date "above" the date picker cell

        //

        targetedCellIndexPath = [NSIndexPath indexPathForRow:self.datePickerIndexPath.row - 1 inSection:0];

    }

    else

    {

        // external date picker: update the current "selected" cell's date

        targetedCellIndexPath = [self.tableView indexPathForSelectedRow];

    }

    UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:targetedCellIndexPath];

    UIDatePicker *targetedDatePicker = sender;

    // update our data model

    NSMutableDictionary *itemData = self.dataArray[targetedCellIndexPath.row];

    [itemData setValue:targetedDatePicker.date forKey:kDateKey];

    // update the cell's date string

    cell.detailTextLabel.text = [self.dateFormatter stringFromDate:targetedDatePicker.date];

}

/*! User chose to finish using the UIDatePicker by pressing the "Done" button

    (used only for "non-inline" date picker, iOS 6.1.x or earlier)

 @param sender The sender for this action: The "Done" UIBarButtonItem

 */

- (IBAction)doneAction:(id)sender

{

    CGRect pickerFrame = self.pickerView.frame;

    pickerFrame.origin.y = CGRectGetHeight(self.view.frame);

    // animate the date picker out of view

    [UIView animateWithDuration:kPickerAnimationDuration animations: ^{ self.pickerView.frame = pickerFrame; }

                     completion:^(BOOL finished) {

                         [self.pickerView removeFromSuperview];

                     }];

    // remove the "Done" button in the navigation bar

    self.navigationItem.rightBarButtonItem = nil;

    // deselect the current table cell

    NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];

    [self.tableView deselectRowAtIndexPath:indexPath animated:YES];

}

@end