Merge pull request nus-cs2103-AY2223S2#65 from hongshenggg/master

Add delete-image feature to DeveloperGuide

README.md

@@ -2,7 +2,7 @@
 [![codecov](https://codecov.io/gh/nus-cs2103-AY2223S2/tp/branch/master/graph/badge.svg?token=SNV76O467D)](https://codecov.io/gh/nus-cs2103-AY2223S2/tp)
 ![Ui](docs/images/Ui.png)
 
-* This is BookFace, a university-centered address book application.
+* This is BookFace, an NUS-centered address book application.
   Example usages:
     * Add contacts along with the image of the person
     * Quickly import university related contacts

docs/DeveloperGuide.md

@@ -1,10 +1,10 @@
 **Target user profile**:
 
-University students who need to keep track of their contacts from different classes/ccas/clubs etc.
+Students from the National University of Singapore (NUS) who need to keep track of their contacts from different classes/ccas/clubs etc.
 
 **Value proposition**:
 
-Students often take many classes and meet different people. This application helps them to organise their
+NUS Students often take many classes and meet different people. This application helps them to organise their
 contacts list for an easier way to set up proper communication channels. This makes it easier for students to form
 connections with their peers during their time in University.
 
@@ -168,21 +168,21 @@ The add-image mechanism is facilitated by `AddImageCommand`, `AddImageCommandPar
 - `AddImageCommand` extends `Command`
 - `AddImageCommandParser` extends `Parser`
 
-The `AddImageCommandParser` parses the user input into index of contact and path to an image. 
-It returns a `AddImageCommand` with the 2 information retrieved. 
-`AddImageCommand#execute` copies the image provided by the user via a path and replaces the current image with the new one. 
+The `AddImageCommandParser` parses the user input into index of contact and path to an image.
+It returns a `AddImageCommand` with the 2 information retrieved.
+`AddImageCommand#execute` copies the image provided by the user via a path and replaces the current image with the new one.
 It also saves the file name of the new image to the `model`.
 
 Given below is an example usage scenario and how the add-image mechanism behaves at each step.
 
 Step 1. When user wants to add an image to a contact, they use the `add-image` command.
 
-Step 2. The `LogicManger` receives the command text from the user input and gives it to `AddressBookParser`. `AddressBookParser` calls `AddImageCommandParser` to parse the user input.
+Step 2. The `LogicManager` receives the command text from the user input and gives it to `AddressBookParser`. `AddressBookParser` calls `AddImageCommandParser` to parse the user input.
 
 Step 3. The `AddImageCommandParser` retrieves the contact index as well as the image path and creates a `AddImageCommand`
 
-Step 4. `AddImageCommand#execute` is called. The method calls `ImageUtil#importImage` to copy the image into the "profile_pictures/" directory. 
-Once that is successful, `AddImageCommand#execute` proceeds to call `ImageUtil#deleteImage` to remove the current image. 
+Step 4. `AddImageCommand#execute` is called. The method calls `ImageUtil#importImage` to copy the image into the "profile_pictures/" directory.
+Once that is successful, `AddImageCommand#execute` proceeds to call `ImageUtil#deleteImage` to remove the current image.
 Finally `AddImageCommand#execute` updates the model provided in the arguments.
 
 > **Note**: If the path given is invalid or if the file at the given path is not a png/jpeg image, the command will not be completed.
@@ -207,3 +207,61 @@ The following activity diagram summarizes what happens when a user executes add-
       - Easy to save as only the Path as a string
    - Cons:
       - Path is easily invalidated (e.g. user moves/deletes/renames the image)
+## Delete Image Feature
+### Delete Image Implementation
+The delete-image feature is facilitated by the classes `DeleteImageCommand`, 
+`DeleteImageCommandParser`, `ImageUtil`, and `ParserUtil`.
+The `DeleteImageCommandParser` first parses through the user command to obtain
+the desired index through using `ParserUtil#parseIndex`. Following which an
+instance of a `DeleteImageCommand` containing the desired index is returned.
+`DeleteImageCommand#execute` is then called, which sets the image of the contact
+at the desired index to a default image, and deletes the existing image through
+`ImageUtil#deleteImage`.
+
+Given below is an example usage scenario for how the delete-image mechanism behaves.
+
+Step 1: User starts up the application and sees their list of contacts. Some of
+which have already had an image added.
+
+Step 2: The user decides that the image given to the contact at index 4 is not
+suitable, and wants to delete it. The user inputs `delete-image 4`.
+`DeleteImageCommandParser#parse` is then called to parse this input for the 
+desired index.
+
+> **Note**: If the user inputs an index of a contact which currently does not have
+an image, or if the user inputs an invalid index, an error will be returned to
+the user
+
+Step 3: If the instruction was valid, `Model#deleteImage` is called to set the
+image of the contact to the default image.
+
+Step 4: `ImageUtil#deleteImage` is then called to delete the existing image
+from the program directory.
+
+The following sequence diagram shows how the delete-image operation works.
+
+![DeleteImageSequenceDiagram](images/DeleteImageSequenceDiagram.png)
+
+> **Note**: The lifeline of the `DeleteImageCommandParser` and `DeleteImageCommand`
+> should end at the destroy marker (X) but due to the limitations of PlantUML, the
+> lifeline reaches the end of the diagram.
+
+The following activity diagram summarizes what happens when a user executes a
+delete-image command:
+
+![DeleteImageActivityDiagram](images/DeleteImageActivityDiagram.png)
+
+### Design Considerations:
+- **Alternative 1 (current choice):** Delete the existing image file from program
+directory.
+    - Pros:
+        - Ensures application does not consume excess storage
+    - Cons:
+        - Extra complexity in requiring file i/o operations
+
+- **Alternative 2:** Disregard deleting the image file from program directory.
+    - Pros:
+        - Easier to implement
+    - Cons:
+        - Application will take up increasingly more unnecessary storage during
+          its lifetime of usage

docs/UserGuide.md

@@ -32,16 +32,16 @@ Examples:
 
 ## Delete Image for contacts
 
-Delete image of a contact.
+Delete the image of a contact.
 Format: `delete-image INDEX`
 
-* Delete image of contact specified by `INDEX`
+* Deletes the image of contact specified by `INDEX`
 * The index refers to the index number shown in the displayed person list.
 * The index *must* be a positive integer 1, 2, 3, …
-* The image must be placed in a specific folder for BookFace to locate
 * A default image will be used after it is deleted
-  Example:
-* `delete-image` 2 deletes the image of the 2nd person in the address book.
+
+Example:
+* `delete-image 2` deletes the image of the 2nd person in the address book.
 
 ## Quick Import for admin contacts: `import`
 

docs/diagrams/DeleteImageActivityDiagram.puml

@@ -0,0 +1,18 @@
+@startuml
+start
+:User executes delete-image command;
+'Since the beta syntax does not support placing the condition outside the
+'diamond we place it as the true branch instead.
+
+if () then ([index provided is valid])
+    if () then ([person at index does not have default image])
+    	:Person's image is set to default image;
+    	:Image is deleted from program directory;
+    else ([else])
+    	:Display error message;
+    endif
+else ([else])
+    : Display error message;
+endif
+stop
+@enduml

docs/diagrams/DeleteImageSequenceDiagram.puml

@@ -0,0 +1,79 @@
+@startuml
+!include style.puml
+
+box Logic LOGIC_COLOR_T1
+participant ":LogicManager" as LogicManager LOGIC_COLOR
+participant ":AddressBookParser" as AddressBookParser LOGIC_COLOR
+participant ":DeleteImageCommandParser" as DeleteImageCommandParser LOGIC_COLOR
+participant "d:DeleteImageCommand" as DeleteImageCommand LOGIC_COLOR
+participant "result:CommandResult" as CommandResult LOGIC_COLOR
+participant "<<class>>\nImageUtil" as ImageUtil LOGIC_COLOR
+end box
+
+box Model MODEL_COLOR_T1
+participant ":Model" as Model MODEL_COLOR
+end box
+
+[-> LogicManager : execute("delete-image 1")
+activate LogicManager
+
+LogicManager -> AddressBookParser : parseCommand("delete-image 1")
+activate AddressBookParser
+
+create DeleteImageCommandParser
+AddressBookParser -> DeleteImageCommandParser
+activate DeleteImageCommandParser
+
+DeleteImageCommandParser --> AddressBookParser
+deactivate DeleteImageCommandParser
+
+AddressBookParser -> DeleteImageCommandParser : parse("1")
+activate DeleteImageCommandParser
+
+create DeleteImageCommand
+DeleteImageCommandParser -> DeleteImageCommand
+activate DeleteImageCommand
+
+DeleteImageCommand --> DeleteImageCommandParser : d
+deactivate DeleteImageCommand
+
+DeleteImageCommandParser --> AddressBookParser : d
+deactivate DeleteImageCommandParser
+'Hidden arrow to position the destroy marker below the end of the activation bar.
+DeleteImageCommandParser -[hidden]-> AddressBookParser
+destroy DeleteImageCommandParser
+
+AddressBookParser --> LogicManager : d
+deactivate AddressBookParser
+
+LogicManager -> DeleteImageCommand : execute()
+activate DeleteImageCommand
+
+DeleteImageCommand -> Model : deleteImage(personaAtIndex)
+activate Model
+
+Model --> DeleteImageCommand
+deactivate Model
+
+DeleteImageCommand -> ImageUtil : deleteImage(imageName)
+activate ImageUtil
+
+ImageUtil --> DeleteImageCommand
+deactivate ImageUtil
+
+create CommandResult
+DeleteImageCommand -> CommandResult
+activate CommandResult
+
+CommandResult --> DeleteImageCommand : result
+deactivate CommandResult
+
+DeleteImageCommand --> LogicManager : result
+deactivate DeleteImageCommand
+'Hidden arrow to position the destroy marker below the end of the activation bar.
+DeleteImageCommandParser -[hidden]-> LogicManager
+destroy DeleteImageCommand
+
+[<--LogicManager : result
+deactivate LogicManager
+@enduml