iPhone how to check that a string is numeric only

static bool TextIsValidValue( NSString* newText, double &value )
{
    bool result = false;

    if ( [newText isMatchedByRegex:@"^(?:|0|[1-9]\\d*)(?:\\.\\d*)?$"] ) {
        result = true;
        value = [newText doubleValue];
    }
    return result;
}

- (IBAction) doTextChanged:(id)sender;
{
    double value;
    if ( TextIsValidValue( [i_pause stringValue], value ) ) {
        [i_pause setTextColor:[NSColor blackColor]];
        // do something with the value
    } else {
        [i_pause setTextColor:[NSColor redColor]];
    }
}

Detecting direction of a swipe

Detecting direction of a swipe

MainView.h
Code:

#import
#import

@interface MainView : UIView {
IBOutlet UILabel *whataction;
CGPoint gestureStartPoint;
}

@end

MainView.m
Code:

#import "MainView.h"

@implementation MainView

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
gestureStartPoint = [touch locationInView:self];
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint currentPosition = [touch locationInView:self];
if (currentPosition.x - 30 > gestureStartPoint.x) {
[whataction setText:@"FAR RIGHT"];
}
else if (currentPosition.x > gestureStartPoint.x) {
[whataction setText:@"RIGHT"];
}
if (currentPosition.x + 30 < gestureStartPoint.x) {
[whataction setText:@"FAR LEFT"];
}
else if (currentPosition.x < gestureStartPoint.x) {
[whataction setText:@"LEFT"];
}
if (currentPosition.y - 30 > gestureStartPoint.y) {
[whataction setText:@"FAR DOWN"];
}
else if (currentPosition.y > gestureStartPoint.y) {
[whataction setText:@"DOWN"];
}
if (currentPosition.y + 30 < gestureStartPoint.y) {
[whataction setText:@"FAR UP"];
}
else if (currentPosition.y < gestureStartPoint.y) {
[whataction setText:@"UP"];
}
}
@end

Cocos2d Menu

Menus

CCMenu * myMenu = [CCMenu menuWithItems:nil];

• CCMenuItemAtlasFont
• CCMenuItemFont
• CCMenuItemImage
• CCMenuItemLabel
• CCMenuItemSprite
• CCMenuItemToggle

 CCMenuItemImage *menuItem1 = [CCMenuItemImage itemFromNormalImage:@"myFirstButton.png"
               selectedImage: @"myFirstButton_selected.png"
               target:self
               selector:@selector(doSomething:)];

[myMenu addChild:menuItem1];

[myMenu alignItemsVertically];

[self addChild:myMenu];

- (void) doSomething: (CCMenuItem  *) menuItem
{
 NSLog(@"The  doSomething menu was called");
}

Cocos2d Basic and Scene Transition

Start From Here
http://cocos2d-iphone.org/wiki/doku.php/prog_guide:lesson_1._install_test

Api List
http://www.cocos2d-iphone.org/api-ref/latest-stable/index.html

Push Pop Scene

[[CCDirector sharedDirector] runWithScene: [HelloWorld scene]];

[[CCDirector sharedDirector] replaceScene: [SomeOtherScene scene]];

Fancy Transition List
[[CCDirector sharedDirector] replaceScene:
  [CCTransitionFade transitionWithDuration:0.5f scene:[SomeOtherScene scene]]];

• CCTransitionFade
• CCTransitionFlipAngular
• CCTransitionShrinkGrow
• CCTransitionMoveInB
• CCTransitionMoveInT
• CCTransitionMoveInL
• CCTransitionMoveInR
• CCTransitionFadeTR
• CCTransitionFadeUp
• CCTransitionFlipX
• CCTransitionFlipY
• CCTransitionPageTurn
• CCTransitionCrossFade

Creating Basic Animations on iPhone

[UIView beginAnimations:@"MoveAndStrech" context:nil];
[UIView setAnimationDuration:1];
[UIView setAnimationBeginsFromCurrentState:YES];

[UIView commitAnimations];

http://www.switchonthecode.com/tutorials/creating-basic-animations-on-iphone

Camera Iphone

UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];

// Set source to the camera
imagePicker.sourceType =  UIImagePickerControllerSourceTypeCamera;

// Delegate is self
imagePicker.delegate = self;

// Allow editing of image ?
imagePicker.allowsImageEditing = NO;

// Show image picker
[self presentModalViewController:imagePicker animated:YES];

- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
 // Access the uncropped image from info dictionary
 UIImage *image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];

 // Save image
 UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);

 [picker release];
}

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
 UIAlertView *alert;

 // Unable to save the image  
 if (error)
   alert = [[UIAlertView alloc] initWithTitle:@"Error"
                           message:@"Unable to save image to Photo Album."
                           delegate:self cancelButtonTitle:@"Ok"
                           otherButtonTitles:nil];
 else // All is well
   alert = [[UIAlertView alloc] initWithTitle:@"Success"
                           message:@"Image saved to Photo Album."
                           delegate:self cancelButtonTitle:@"Ok"
                           otherButtonTitles:nil];
 [alert show];
 [alert release];
}

Iphone database samples

http://www.iphonesdkarticles.com/2008/10/sqlite-tutorial-selecting-data.html