oh my … where to begin ?
Let’s start with Fig 7.6 0 a high level view of the application.
For one, CrimeActivity (uh, the MainActivity) is King !!! … this starts everything …
… making CrimeFragment a small graphic in that figure would be appropriate.
Why? … because you need to understand what the OS is doing.
In AdroidManifest, the OS is directed to CrimeActivity, and
does what it specifies - i.e. creating a java object out of the
activity_crime.xml ViewGroup. … which happens to be empty
… but whatever ! … that what’s it doing!
then, we create the FragmentManager … skip from page 128 to 148 to follow this.
oh my… now what do we have?
Of the 2 ways to create fragments (via xml, or via java classes - not explained), we’re going to use
methods in the java fragment class to add views (ie. fragment views) to that empty ViewGroup.
Views are objects that the OS will eventually use (i.e. way down the LifeCycle) to display.
… that’s Chapter 7… I’m skipping over creation of the Fragment Class,etc, … but do
you understand this much? … if so, re-read Chapter 7, and it will make more sense.