CS492 Assignment 1 Solution

In this assignment, we'll get our toes wet in the pond of Android development by writing the beginnings of a simple weather app. To do this, we'll start working with RecyclerView, which is the best way to write efficient and scalable dynamic list-based user interfaces. The parts of the assignment are outlined below. This screen capture depicts roughly what the app should look like (though you don't have to exactly match the styling here) and how it should behave:

1. Sign up for Campuswire
We'll be using Campuswire as our main communication platform for the course. Campuswire has both a StackOverflow-style Q&A forum, called the “class feedâ€, as well as live chat rooms, so it should hopefully fulfill all of our course communication needs. For this reason, please use Campuswire exclusively for questions you have about the course. I (Hess) and the TAs will be on Campuswire, just like you and your fellow students, so you can feel confident about getting the answers you need there.
I strongly encourage you to also spend time answering your fellow classmates’ questions on Campuswire. This will not only enable everyone to get help quickly, but it will also help you improve your understanding of the material, since teaching someone else is the best way to learn something. As an extra incentive to answer questions on Campuswire, extra credit will be awarded to the most active Campuswire participants at the end of the course (based on Campuswire’s reputation score).
2. Write a basic app to display dummy weather data
This repository contains an initial template for an Android app. Currently, the app contains one extremely basic "hello world" activity. Your job in this assignment is to modify this activity to create the beginnings of a basic weather app. Here's what you need to do to accomplish this:
Create a custom Kotlin class to represent the weather forecast for a specific day or other period of time. This class should have properties to represent the following forecast data (at a minimum; feel free to include more forecast data if you want):
The high and low temperatures for the forecast period.
The probability of precipitation associated with the forecast period (e.g. 75%).
A short description of the weather associated with the forecast period (e.g. "Sunny and warm").
A longer version of the weather description (e.g. "Cloudless and generally warm, with a high of 75F and a low of 57F. Some high clouds late in the day.").
Allocate a list of 10-15 objects of the custom class you just created, and initialize it with some hard-coded, dummy weather data.
Use the RecyclerView framework to display the entire array of forecast data as a scrollable vertical list of cards. To accomplish this, you'll need to do the following:
Add a RecyclerView widget to the main activity's layout.
Create a new layout defining a card that depicts a single forecast element in your array. This card should display all of the information contained in the forecast object except the long version of the forecast, which we'll use later. Try to make your card look as good as you can. For example, add margins, borders, and padding as appropriate to create space inside and around the card and its elements, and try to organize the information displayed in each card in an intuitive and visually appealing way. If you like, try to use some of the principles from the following articles when you're styling your card:
Android styling: themes vs styles
Android styling: common theme attributes
Write a class that extends RecyclerView.Adapter. Within this class, you will:
Implement an inner class that extends RecyclerView.ViewHolder. Objects of this class will represent individual items in your forecast list.
Within your main activity's onCreate() method, create a new layout manager and connect it to the RecyclerView. Then, create a new object of your adapter class and attach that to the RecyclerView. Make sure to store your dummy weather forecast data in the adapter.
Importantly, the app you write should not have any extraneous components. For example, you should not include a text entry box and/or a button like we did in the app we wrote in lecture, since the user will not have to provide any input for this app.
3. Handle user clicks on items in the weather list
Finally, you should add functionality that handles clicks on weather forecast elements in your RecyclerView list. Specifically, modify your main activity and/or adapter class so that, when the user clicks on one of the weather forecast elements in your list, a Snackbar is displayed that contains the longer version of the forecast description corresponding to the list item that was clicked. Note that to do this, you'll have to listen for clicks on the RecyclerView view holders themselves (specifically to the View associated with the view holder). You can attach a click listener to these elements in much the same way we attached one to a button in lecture.
Submission
Grading criteria
The assignment is worth 100 total points, broken down as follows:
20 points: Signed up for Campuswire
80 points: Basic weather app implemented as described above
50 points: correctly uses the RecyclerView framework to display dummy weather forecast data on screen in a scrollable list of nicely-styled cards
10 points: interface does not contain extraneous elements (e.g. buttons, text entry boxes, etc.)
20 points: successfully displays detailed weather forecast in a Snackbar in response to user clicks on forecast items in the list, as described above