Camera image orientation

I was having a confusing problem where images taken from the iPhone camera were being displayed in the wrong orientation. I would take a photo in portrait and save the data to disk. Later when I retrieved the photo it would show up rotated 90 degrees.

The iPhone knows what orientation a photo is taken, and this orientation depends on how the camera is being held when you snap the photo. You can get the orientation value on a UIImage from the property imageOrientation.

When you save the photo, it is possible that this information could get lost, depending on the way you save it. If it does get lost, the UIImageView will assume the photo was taken as a left-side landscape photo, and display it with that orientation.

I ran into a problem when trying to save the camera image with UIImagePNGRepresentation(). For some reason this loses the orientation info. I switched to UIImageJPEGRepresentation() and all is well now.

So basically if you run into the problem, you have 2 choices: Be sure you use a format that preserves orientation data, or rotate the UIImage data directly before saving it to a file.

Rotating view around arbitrary point the easy way

I have a UIImageView that I want to rotate around a given point. By default, the layer will rotate around the center of the UIImageView. Trying to change this anchor point involves a bit of work, either move at the beginning and reposition all the view elements, or translating the view, rotating, and translating back. The last option works fine, unless you are trying to use core animation to smoothly rotate the view.

I found out a much easier solution to the whole problem. You could call it a workaround, but it works well without disturbing the view you want rotated.

Basically, you create a new UIView. Place the center point where you want the rotation to occur. Change the size of the view so that the view you want rotated will fit inside. Make your view (you want rotated) a subview of the new view. Now, just rotate the new view, and your subview will be rotated correctly.

Example: lets say we have a UIImageView that is 320x480 (the size of the whole iPhone screen). We want it to rotate from the bottom center instead of its middle. Create a new UIView that is 0,0,320,960. This is basically double the height of the screen, positioned so the bottom half is off the screen, which places the center point right where we want it. Now place your UIImageView inside the new UIView in the top half (visible on the screen.) Now when you rotate the UIView, it will pivot on the bottom center of the screen, and your UIImageView will rotate along with it, as expected.

iPhone 2.2.1 available fonts

Here is a list of the fonts available to the iPhone as of SDK 2.2.1:


Family: Courier
Font: Courier
Font: Courier-BoldOblique
Font: Courier-Oblique
Font: Courier-Bold
Family: AppleGothic
Font: AppleGothic
Family: Arial
Font: ArialMT
Font: Arial-BoldMT
Font: Arial-BoldItalicMT
Font: Arial-ItalicMT
Family: STHeiti TC
Font: STHeitiTC-Light
Font: STHeitiTC-Medium
Family: Hiragino Kaku Gothic ProN
Font: HiraKakuProN-W6
Font: HiraKakuProN-W3
Family: Courier New
Font: CourierNewPS-BoldMT
Font: CourierNewPS-ItalicMT
Font: CourierNewPS-BoldItalicMT
Font: CourierNewPSMT
Family: Zapfino
Font: Zapfino
Family: Arial Unicode MS
Font: ArialUnicodeMS
Family: STHeiti SC
Font: STHeitiSC-Medium
Font: STHeitiSC-Light
Family: American Typewriter
Font: AmericanTypewriter
Font: AmericanTypewriter-Bold
Family: Helvetica
Font: Helvetica-Oblique
Font: Helvetica-BoldOblique
Font: Helvetica
Font: Helvetica-Bold
Family: Marker Felt
Font: MarkerFelt-Thin
Family: Helvetica Neue
Font: HelveticaNeue
Font: HelveticaNeue-Bold
Family: DB LCD Temp
Font: DBLCDTempBlack
Family: Verdana
Font: Verdana-Bold
Font: Verdana-BoldItalic
Font: Verdana
Font: Verdana-Italic
Family: Times New Roman
Font: TimesNewRomanPSMT
Font: TimesNewRomanPS-BoldMT
Font: TimesNewRomanPS-BoldItalicMT
Font: TimesNewRomanPS-ItalicMT
Family: Georgia
Font: Georgia-Bold
Font: Georgia
Font: Georgia-BoldItalic
Font: Georgia-Italic
Family: STHeiti J
Font: STHeitiJ-Medium
Font: STHeitiJ-Light
Family: Arial Rounded MT Bold
Font: ArialRoundedMTBold
Family: Trebuchet MS
Font: TrebuchetMS-Italic
Font: TrebuchetMS
Font: Trebuchet-BoldItalic
Font: TrebuchetMS-Bold
Family: STHeiti K
Font: STHeitiK-Medium
Font: STHeitiK-Light


Getting URL from UIWebView

It thought I'd post how to get the current URL string from a UIWebView object. Here you go:

NSString *currentURL
= myWebView.request.URL.absoluteString;

That is assuming myWebView is your UIWebView object.

To open a web page in Safari from a UIWebView, do this:

[[UIApplication sharedApplication]
openURL:myWebView.request.URL];