Best practice to calculate view size within loadView method

Question

What is the best practice to calculate the view size in the loadView method (in an UIViewController) without a XIB file?

Here is my solution:

- (void)loadView {

  //Calculate Screensize
  BOOL statusBarHidden = [[UIApplication sharedApplication] isStatusBarHidden ];
  BOOL navigationBarHidden = [self.navigationController isNavigationBarHidden];
  BOOL tabBarHidden = [self.tabBarController.tabBar isHidden];

  CGRect frame = [[UIScreen mainScreen] bounds];

  if (!statusBarHidden) {
    frame.size.height -= [[UIApplication sharedApplication] statusBarFrame].size.height; 
  }
  if (!navigationBarHidden) {
    frame.size.height -= self.navigationController.navigationBar.frame.size.height; 
  }
  if (!tabBarHidden) {
    frame.size.height -= self.tabBarController.tabBar.frame.size.height; 
  }

  UIView *v = [[UIView alloc] initWithFrame: frame];
  [v setBackgroundColor: [UIColor whiteColor] ];
  [v setAutoresizingMask: UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight ];
  [self setView: v ];
  [v release];      
}

Is this code okay, or should I edit something?

score 6 · Accepted Answer · answered Feb 06 '12 at 10:45

6

The docs recommend using [[UIScreen mainScreen] applicationFrame] to get the screen bounds without the status bar

answered Feb 06 '12 at 10:45

wattson12

11,176
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thx, here are the docs for anyone who is interested: https://developer.apple.com/library/IOs/documentation/UIKit/Reference/UIScreen_Class/Reference/UIScreen.html#//apple_ref/occ/instp/UIScreen/applicationFrame – CarlJ Feb 06 '12 at 10:55
[i can](https://developer.apple.com/library/IOs/#documentation/UIKit/Reference/UIScreen_Class/Reference/UIScreen.html) – wattson12 Feb 06 '12 at 10:56
What do you base this claim on? Do you have a reference? – lhunath Nov 16 '17 at 20:32

score 1 · Answer 2 · answered Oct 25 '12 at 12:34

so for anyone who want to know a best practice example:

#pragma mark -
#pragma mark LoadView Methods
- (void)loadView {

  //Calculate Screensize
  BOOL statusBarHidden = [[UIApplication sharedApplication] isStatusBarHidden ];
  BOOL navigationBarHidden = [self.navigationController isNavigationBarHidden];
  BOOL tabBarHidden = [self.tabBarController.tabBar isHidden];
  BOOL toolBarHidden = [self.navigationController isToolbarHidden];

  CGRect frame = [[UIScreen mainScreen] applicationFrame];

  //check if you should rotate the view, e.g. change width and height of the frame
  BOOL rotate = NO;
  if ( UIInterfaceOrientationIsLandscape( [UIApplication sharedApplication].statusBarOrientation ) ) {
    if (frame.size.width < frame.size.height) {
      rotate = YES;
    }
  }

  if ( UIInterfaceOrientationIsPortrait( [UIApplication sharedApplication].statusBarOrientation ) ) {
    if (frame.size.width > frame.size.height) {
      rotate = YES;
    }
  }

  if (rotate) {
    CGFloat tmp = frame.size.height;
    frame.size.height = frame.size.width;
    frame.size.width = tmp;
  }


  if (statusBarHidden) {
    frame.size.height -= [[UIApplication sharedApplication] statusBarFrame].size.height;
  }
  if (!navigationBarHidden) {
    frame.size.height -= self.navigationController.navigationBar.frame.size.height;
  }
  if (!tabBarHidden) {
    frame.size.height -= self.tabBarController.tabBar.frame.size.height;
  }
  if (!toolBarHidden) {
    frame.size.height -= self.navigationController.toolbar.frame.size.height;
  }

  UIView *v = [[UIView alloc] initWithFrame: frame];
  v.backgroundColor = [UIColor whiteColor];
  v.autoresizingMask  = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

  self.view = v;
  [v release]; //depends on your ARC configuration
}

score 0 · Answer 3 · answered Feb 06 '12 at 09:56

0

You are adjusting the height depend on the status bar and navigation bars.. But you have not done anything with respect to the origin of the view.

answered Feb 06 '12 at 09:56

Ilanchezhian

17,426
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yes the origin is always {0, 0}. An if the navBar is visible the point 0,0 is under the navBar. or I'm wrong? – CarlJ Feb 06 '12 at 10:10

Best practice to calculate view size within loadView method

3 Answers3