MyPickerView

MyPickerView.h

#import <UIKit/UIKit.h>

@interface MyPickerView : UIView
<UIPickerViewDataSource, UIPickerViewDelegate>
{
    UIToolbar *toolbar;
    UIPickerView *picker;

    void (^completion)(NSString *selected);

    NSArray *items;
}
- (void)setSelectedRow:(NSInteger)row;
- (NSInteger)selectedRow;
- (void)setItems:(NSArray *)array;

- (void)showInWindow:(UIWindow *)window completion:(void (^)(NSString *selected))aCompletion;
- (void)hide;

@end

MyPickerView.m

#import "MyPickerView.h"

@implementation MyPickerView

- (id)init
{
    self = [super initWithFrame:[UIScreen mainScreen].bounds];
    if (self) {
        self.backgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:0.4];

        picker = [[UIPickerView alloc] init];
        picker.showsSelectionIndicator = YES;
        picker.delegate = self;
        picker.dataSource = self;
        CGRect f = picker.frame;
        f.origin.y = 480 - f.size.height;
        picker.frame = f;
        [self addSubview:picker];

        toolbar = [[UIToolbar alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];
        toolbar.barStyle = UIBarStyleBlack;
        toolbar.translucent = YES;
        f = toolbar.frame;
        f.origin.y = picker.frame.origin.y - 44;
        toolbar.frame = f;
        [self addSubview:toolbar];

        UIBarButtonItem *doneItem =
            [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone
                                                          target:self
                                                          action:@selector(doneTapped:)];
        [doneItem autorelease];

        UIBarButtonItem *cancelItem =
            [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCancel
                                                          target:self
                                                          action:@selector(hide)];
        [cancelItem autorelease];
        NSArray *buttonItems = [NSArray arrayWithObjects:
          cancelItem,
          [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace
                                                         target:nil
                                                         action:nil] autorelease],
          doneItem, nil];
        [toolbar setItems:buttonItems animated:NO];
        items = [[NSArray array] retain];
    }
    return self;
}

- (void)setDelegate:(id)aDelegate
{
    picker.delegate = aDelegate;
}

- (void)setSelectedRow:(NSInteger)row
{
    [picker selectRow:row inComponent:0 animated:NO];
}

- (NSInteger)selectedRow
{
    return [picker selectedRowInComponent:0];
}

- (void)setItems:(NSArray *)array
{
    if (items) {
        [items release]; items = nil;
    }
    items = [array retain];
}

#pragma mark UIPickerViewDataSource

- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
    return 1;
}

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
    return [items count];
}

#pragma mark -
#pragma mark UIPickerViewDelegate

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
    return [items objectAtIndex:row];
}

#pragma mark -

- (void)showInWindow:(UIWindow *)window completion:(void (^)(NSString *selected))aCompletion;
{
    completion = [aCompletion copy];

    [picker reloadAllComponents];

    CGRect f = toolbar.frame;
    f.origin.y += 480;
    toolbar.frame = f;

    f = picker.frame;
    f.origin.y += 480;
    picker.frame = f;

    [window addSubview:self];

    [UIView animateWithDuration:0.3
                     animations:^{
                         CGRect frame = toolbar.frame;
                         frame.origin.y -= 480;
                         toolbar.frame = frame;

                         frame = picker.frame;
                         frame.origin.y -= 480;
                         picker.frame = frame;
                     }];
}

- (void)hide
{
    [completion release];
    completion = nil;
    [UIView animateWithDuration:0.3
                     animations:^{
                         CGRect frame = toolbar.frame;
                         frame.origin.y += 480;
                         toolbar.frame = frame;

                         frame = picker.frame;
                         frame.origin.y += 480;
                         picker.frame = frame;
                     }
                     completion:^ (BOOL finished) {
                                    [self removeFromSuperview];

                                    CGRect f = toolbar.frame;
                                    f.origin.y -= 480;
                                    toolbar.frame = f;

                                    f = picker.frame;
                                    f.origin.y -= 480;
                                    picker.frame = f;
                                }];
}

- (void)doneTapped:(id)sender
{
    completion([items objectAtIndex:[picker selectedRowInComponent:0]]);
    [self hide];
}

- (void)dealloc
{
    [toolbar release];
    [picker release];
    [completion release];
    [items release];
    [super dealloc];
}

@end