Homework 2

Let's build an application that allows browsing between a set of plants in a greenhouse.

The app has 2 views:

1. A List of all plants
2. A Detailed view of one plant.

Implementing UI & Navigation

The UI should be implemented using 1 Activity and 2 Fragments.

• One Fragment for List of plants
  • The list should be implemented using RecyclerView
  • Each list item layout should have a TextView and an ImageView
    • By default, the ImageView should not be visible
  • The user should be able to select one plant in the List, which navigates them to the details View of the selected Plant.
    • The movement between the list and detailed view should be implemented using a Navigation Graph (Recall Lab 2)
    • Use Fragment Arguments to pass data to the Details view
• Second Fragment for the Detailed view of one plant. It should include at minimum
  • A TextView for the name of the plant,
  • A TextView for Description of the Plant
  • An ImageView, which will have a default image or be hidden by default (up to you).
  • A Button with the text "Take picture" (see below)

Base project

Use [ this base project ] as a starting point for the app. It provides a Plant data class and a PlantRepository and PlantDataset classes. Use PlantDataset to get the list of plants or fetch a single one by ID / Name or to assign a thumbnail to a plant.

• Use PlantRepository.instance(context) to get an instance of a PlantDataset object.
  • PlantRepository uses the Singleton pattern to ensure that only 1 instance of PlantDataset exists, even if the above is called multiple times, from different Activities, Fragments, etc.
• Use methods of PlantDataset to get a list of all plants from the json. You should use setPlantThumbnail(..) to update the thumbnail
• NB! make sure you test your to ensure the recycling of views during scrolling does not introduce unexpected bugs!
• Your RecyclerView custom Adapter should manage a dataset of the Plant class/type (instead of String as we did in Lab 4).

"Take picture" button

• Clicking the "Take Picture" button brings the user to the Camera app for taking a picture.
• After the picture is taken, the user is returned to the Detail view, and the image is shown in the DetailsView with an ImageView
• Recall how we started new Activities in Lab 2, use Intents, refer to this material to get started
  • You can use the simpler version of image capture that only returns the thumbnail in Intent Extras, handling the full-size image requires some more work, not needed for this homework. See here

Distinguishing plants that have a Pictures in the list

• After a picture has been taken and returning back to the list, listed plants that have a picture taken should have a little Icon next to their name, distinguishing whether or not a picture was taken.
  • Hint: achieve this with View Binding of RecyclerViews, and use the thumbnail attribute of the Plant data class. Use the PlantRepository.instance(context).setPlantThumbnail( .. ) helper method to update the in-memory object.

Note: If the app is closed, the state is lost, we are not requiring storing any long-term state.

Submission

Create a sub-folder particularly for this homework (call it homework2), it should contain the source code of your Android Studio project.

• Create a new Git TAG named homework2 for the last commit related to this homework.
• Update the .MD file at the root of your repository, so it contains a link to the subfolder of this homework.