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Android Build an Interactive Story App The Rest of the Story Ending the Story

Posted by Joshgun Huseynov
Joshgun Huseynov
1,053 Points

I don't understand the Listeners added to Buttons

We added Listeners to Buttons. When we hit them it takes us to relevant pages (nextPage). But I don't understand how these Buttons know the path which we must go? We have no any methods that update the nextPage variable. Can you please widely explain the process behind the " loadPage(page.getChoice1().getNextPage());" method?

1 Answer

Boban Talevski
Boban Talevski
24,793 Points
Boban Talevski
Boban Talevski
24,793 Points

Check the Story constructor, it's where we are creating all the Page objects. And each Page object has two Choice objects, and each Choice object has a textId and nextPage. The nextPage actually contains the number of the page we should go to for the respective choice. And all that info is filled in the constructor, we copy pasted it from teacher's notes (most of it), which might lead to your confusion that we didn't add this information and getting that "how does the app now where to go?" feeling :).

For example, this line in the Story constructor

pages[0] = new Page(R.drawable.page0,
                R.string.page0,
                new Choice(R.string.page0_choice1, 1),
                new Choice(R.string.page0_choice2, 2));

is creating a new Page object, adding it at index 0 of the pages array, with the 3rd and 4th parameters being Choice objects which we are creating right then and there, and the second parameter for each Choice object is a number which indicates to which page we should go if that choice is selected. So all the information about how to navigate through the story is already entered in the Story constructor.