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iosuser-interfaceuitabbar

centralizing the central tab bar button

How is that done? that dome effect for a central tab bar button? is it a simple projection of the dome image on top of the regularly central shaped tab button? or is there anything more to it?

Solution

  • You can achieve this by,

        UIButton* button = [UIButton buttonWithType:UIButtonTypeCustom];
    button.frame = CGRectMake(0.0, 0.0, buttonImage.size.width, buttonImage.size.height);
    [button setBackgroundImage:buttonImage forState:UIControlStateNormal];
    [button setBackgroundImage:highlightImage forState:UIControlStateHighlighted];

    CGFloat heightDifference = buttonImage.size.height - self.tabBar.frame.size.height;
    if (heightDifference < 0)
      button.center = self.tabBar.center;
    else
    {
      CGPoint center = self.tabBar.center;
      center.y = center.y - heightDifference/2.0;
      button.center = center;
    }

    [self.view addSubview:button];

    Please check these links: http://idevrecipes.com/2010/12/16/raised-center-tab-bar-button/

    You will get the full source code at https://github.com/boctor/idev-recipes/tree/master/RaisedCenterTabBar