iPhone Keyboard Covers Text Field

By Josh Highland in iPhone app dev, tutorials

Recently while developing an app, I ran into an issues where the iPhone keyboard was sliding up and covering the text field. I did some quick searching on the on the internet an came across some sample code on StackOverflow (http://stackoverflow.com/questions/1247113/iphone-keyboard-covers-text-field)

I took the code that was given and spun it for my own uses. After placing the code in the project, I linked the hidden textFields ‘Editing Did Begin” and “Editing Did End” events to the “slideFrameUp” and “slideFrameDown” methods.

The end result works great!

-(IBAction) slideFrameUp;
{
[self slideFrame:YES];
}

-(IBAction) slideFrameDown;
{
[self slideFrame:NO];
}

-(void) slideFrame:(BOOL) up
{
const int movementDistance = 50; // tweak as needed
const float movementDuration = 0.3f; // tweak as needed

int movement = (up ? -movementDistance : movementDistance);

[UIView beginAnimations: @"anim" context: nil];
[UIView setAnimationBeginsFromCurrentState: YES];
[UIView setAnimationDuration: movementDuration];
self.view.frame = CGRectOffset(self.view.frame, 0, movement);
[UIView commitAnimations];
}

Don’t use NSLog anymore!

By Josh Highland in iPhone app dev, tutorials

NSLog is a convenient way to output logging information from your iPhone app. NSLog is most commonly used by developers for debugging purposes. The problem with adding NSLog statements in your code is that you have to remove them or comment them out before you can submit your application to the app store. Apps that output data via NSLog will not be approved into the app store.

I would like to show you how I handle this delema. Start by opening the “_Prefix.pch” file.

next, add the following lines to the file

#define DEBUG_MODE

#ifdef DEBUG_MODE
#define DebugLog( s, ... ) NSLog( @"<%@:(%d)> %@", [[NSString stringWithUTF8String:__FILE__] lastPathComponent], __LINE__, [NSString stringWithFormat:(s), ##__VA_ARGS__] )
#else
#define DebugLog( s, ... )
#endif

In your code, replace “NSLog” with “DebugLog”. THATS IT!

DebugLog adds some new functionality to NSLog. It will now output the file name and line number of the Debug statement.

The best part of this is that its very easy to disable when its time to create a release build of your code. Simple comment out the “#define DEBUG_MODE” line im the “_Prefix.pch” file.

How To detect an internet connection with the iPhone SDK

By Josh Highland in iPhone, iPhone app dev, Programming, Tech, tutorials

There are several ways to problematically detect if an iPhone has an internet connection, but most of them cant tell you how the iPhone is connected to the internet.

Apple has sample code to accomplish just this task. The Reachability class is not shipped with the SDK, but is part of a sample project of the same name. http://developer.apple.com/iphone/library/samplecode/Reachability/index.html

Using the reachability class:

Set up:

  • Download the reachability project from Apple
  • Copy Reachability.h and Reachability.m to your project.
  • Add the ‘SystemConfiguration’ framework to your project.

Sample Usage:

Reachability *reachability = [Reachability sharedReachability];
 [reachability setHostName:@"www.JoshHighland.com"];
 NetworkStatus remoteHostStatus = [reachability remoteHostStatus];

if(remoteHostStatus == NotReachable) {
 //no internet connection
 }
 else if (remoteHostStatus == ReachableViaWiFiNetwork) {
 //wifi connection found
 }
 else if (remoteHostStatus == ReachableViaCarrierDataNetwork) {
 //EDGE or 3G connection found
 }