All examples now have at least the required `+catalogBreadcrumbs` and `+catalogIsPrimaryDemo`. All examples in the same breadcrumbs path have only one primary demo. There should be only one `-catalogDescription` attached to the primary demo.
Closes#1897
* MDCTabBarViewController - like UITabBarViewController, but uses Material Design's MDCTabBar
* MDCTabBarViewController Interface Builder example
It's integrated into the Catalog app as a Tab example. Also demonstrates moving the tab bar from the unselected state to the selected state. Note: this reveals a bug with the unselected state that https://github.com/material-components/material-components-ios/pull/1441 fixes.
* Copyright date is 2017 for these TabBarViewController files. Fix white space issues.
* Add <UITabBarItem *> to local variable in updateTabBarItems
* Address Brian Moore's comments: ran clang-format -style=file on these files,
Modified tabBar delegate protocol: tabBar:willSelectItem: becomes tabBar:shouldSelectItem:
so that MDCTabBarViewController can have a 'shouldSelect' delegate.
* comment correction of ViewController to view controller.
* Add new API to MDCItemBar in preparation for deprecating willSelect: from the delegate protocol, replacing it with shouldSelect:. Revert changes to comment lines that appear to be a mis-configuration at my end to 80 columns.
* Tested more thoroughly, verified that the class still works.
* Restore the delegate willSelect method that we intended in favor of shouldSelect:
* Simplify private/MDCItemBar's delegate protocol, write MDCTabBar public protocol in terms of it, as Brian asked.
* Comment fixes.
* Address Brian Moore's May 31 comments. Adjust color of TabBar in Interface builder example.
* Update README.md
