Related to iPhone apps

Question

can anyone tell how to flip an image or a view from bottom to top vertically (not curlup) in iPhone/iPad app developement.
thanks
devendra kumar singh.

Answer 1

Hello Devendra, I have used this code in the past and kept it as a "snipet" for future use
Dont forget to add -(UIImage*)rotate:(UIImageOrientation)orient to your .h file and thanks to [this|http://www.platinumball.net/blog/2010/01/31/iphone-uiimage-rotation-and-scaling/] blog for the code.
-(UIImage*)rotate:(UIImageOrientation)orient
    CGRect             bnds = CGRectZero;
    UIImage*           copy = nil;
    CGContextRef       ctxt = nil;
    CGRect             rect = CGRectZero;
    CGAffineTransform  tran = CGAffineTransformIdentity;
    bnds.size = self.size;
    rect.size = self.size;
    switch (orient)
        case UIImageOrientationUp:
        return self;
        case UIImageOrientationUpMirrored:
        tran = CGAffineTransformMakeTranslation(rect.size.width, 0.0);
        tran = CGAffineTransformScale(tran, -1.0, 1.0);
        break;
        case UIImageOrientationDown:
        tran = CGAffineTransformMakeTranslation(rect.size.width,
         rect.size.height);
        tran = CGAffineTransformRotate(tran, degreesToRadians(180.0));
        break;
        case UIImageOrientationDownMirrored:
        tran = CGAffineTransformMakeTranslation(0.0, rect.size.height);
        tran = CGAffineTransformScale(tran, 1.0, -1.0);
        break;
        case UIImageOrientationLeft:
        bnds.size = swapWidthAndHeight(bnds.size);
        tran = CGAffineTransformMakeTranslation(0.0, rect.size.width);
        tran = CGAffineTransformRotate(tran, degreesToRadians(-90.0));
        break;
        case UIImageOrientationLeftMirrored:
        bnds.size = swapWidthAndHeight(bnds.size);
        tran = CGAffineTransformMakeTranslation(rect.size.height,
         rect.size.width);
        tran = CGAffineTransformScale(tran, -1.0, 1.0);
        tran = CGAffineTransformRotate(tran, degreesToRadians(-90.0));
        break;
        case UIImageOrientationRight:
        bnds.size = swapWidthAndHeight(bnds.size);
        tran = CGAffineTransformMakeTranslation(rect.size.height, 0.0);
        tran = CGAffineTransformRotate(tran, degreesToRadians(90.0));
        break;
        case UIImageOrientationRightMirrored:
        bnds.size = swapWidthAndHeight(bnds.size);
        tran = CGAffineTransformMakeScale(-1.0, 1.0);
        tran = CGAffineTransformRotate(tran, degreesToRadians(90.0));
        break;
        default:
        // orientation value supplied is invalid
        assert(false);
        return nil;
    UIGraphicsBeginImageContext(bnds.size);
    ctxt = UIGraphicsGetCurrentContext();
    switch (orient)
        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
        CGContextScaleCTM(ctxt, -1.0, 1.0);
        CGContextTranslateCTM(ctxt, -rect.size.height, 0.0);
        break;
        default:
        CGContextScaleCTM(ctxt, 1.0, -1.0);
        CGContextTranslateCTM(ctxt, 0.0, -rect.size.height);
        break;
    CGContextConcatCTM(ctxt, tran);
    CGContextDrawImage(ctxt, rect, self.CGImage);
    copy = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return copy;
Edited by: Paul Aschmann on Oct 25, 2011 1:40 AM