[T6A1][F09-A4] Poh Yee Heng

doc/DeveloperGuide.md

@@ -74,6 +74,22 @@ Use case ends.
 > 3a1. AddressBook shows an error message <br>
   Use case resumes at step 2
 
+#### Use case: Change theme
+
+ **MSS**
+
+ 1. User requests to change to a new theme
+ 2. AddressBook changes the theme
+ Use case ends.
+
+ **Extensions**
+
+ 1a. The theme to be renamed does not exist
+
+ > 1a1. AddressBook shows an error message <br>
+   Use case ends
+
+
 ## Appendix C : Non Functional Requirements
 
 1. Should work on any [mainstream OS](#mainstream-os) as long as it has Java 8 or higher installed.

doc/UserGuide.md

@@ -99,6 +99,17 @@ Examples:
 Clears all entries from the address book.<br>
 Format: `clear`  
 
+## Changing a theme : `theme`
+ Changes the theme of the app. Irreversible.<br>
+ Format: `theme NEW_THEME`
+
+ > Changes the theme of the app.
+
+ Examples: 
+ * `theme Light`<br>
+   Changes the theme of the app to Light theme.
+
+
 ## Exiting the program : `exit`
 Exits the program.<br>
 Format: `exit`  

src/seedu/addressbook/commands/AddCommand.java

@@ -58,13 +58,17 @@ public ReadOnlyPerson getPerson() {
     }
 
     @Override
-    public CommandResult execute() {
+    public CommandResult execute() throws Exception {
         try {
             addressBook.addPerson(toAdd);
             return new CommandResult(String.format(MESSAGE_SUCCESS, toAdd));
         } catch (UniquePersonList.DuplicatePersonException dpe) {
             return new CommandResult(MESSAGE_DUPLICATE_PERSON);
         }
     }
-
+
+    @Override
+        public boolean isMutating() {
+            return true;
+        }
 }

src/seedu/addressbook/commands/ChangeThemeCommand.java

@@ -0,0 +1,34 @@
+package seedu.addressbook.commands;
+
+import seedu.addressbook.data.AddressBook;
+import seedu.addressbook.ui.Gui;
+
+public class ChangeThemeCommand extends Command {
+
+    public static final String COMMAND_WORD = "theme";
+
+    public static String MESSAGE_USAGE = String.format(COMMAND_WORD + ":\n" 
+            + "Changes theme of the application.\n\t"
+            + "Parameters: NEW_THEME\n\t"
+            + "Themes available: %1$s\n\t"
+            + "Example: " + COMMAND_WORD + " Light", AddressBook.allThemesString());
+
+    public static final String MESSAGE_SUCCESS = "Theme changed successfully";
+    public static final String MESSAGE_FAILED_THEME_DOES_NOT_EXIST = "Theme %1$s does not exist.\n";
+
+    private final String newThemeName;
+
+    public ChangeThemeCommand(String newThemeName) {
+        this.newThemeName = newThemeName;
+    }
+
+    @Override
+    public CommandResult execute() {
+        if (!addressBook.containsTheme(newThemeName)) {
+            return new CommandResult(String.format(MESSAGE_FAILED_THEME_DOES_NOT_EXIST, newThemeName));
+        }
+        Gui.changeTheme(newThemeName);
+        return new CommandResult(MESSAGE_SUCCESS);
+    }
+
+}

src/seedu/addressbook/commands/ClearCommand.java

@@ -19,4 +19,9 @@ public CommandResult execute() {
         addressBook.clear();
         return new CommandResult(MESSAGE_SUCCESS);
     }
+
+    @Override
+        public boolean isMutating() {
+            return true;
+        }
 }

src/seedu/addressbook/commands/Command.java

@@ -38,8 +38,9 @@ public static String getMessageForPersonListShownSummary(List<? extends ReadOnly
 
     /**
      * Executes the command and returns the result.
+     * @throws Exception 
      */
-    public abstract CommandResult execute();
+    public abstract CommandResult execute() throws Exception;
 
     /**
      * Supplies the data the command will operate on.

src/seedu/addressbook/commands/DeleteCommand.java

@@ -38,5 +38,10 @@ public CommandResult execute() {
             return new CommandResult(Messages.MESSAGE_PERSON_NOT_IN_ADDRESSBOOK);
         }
     }
+
+    @Override
+    public boolean isMutating() {
+        return true;
+    }
 
 }

src/seedu/addressbook/commands/ExitCommand.java

@@ -15,5 +15,9 @@ public class ExitCommand extends Command {
     public CommandResult execute() {
         return new CommandResult(MESSAGE_EXIT_ACKNOWEDGEMENT);
     }
-
+
+    @Override
+    public boolean isMutating() {
+        return false;
+    }
 }

src/seedu/addressbook/commands/FindCommand.java

@@ -52,5 +52,10 @@ private List<ReadOnlyPerson> getPersonsWithNameContainingAnyKeyword(Set<String>
         }
         return matchedPersons;
     }
+
+    @Override
+    public boolean isMutating() {
+        return false;
+    }
 
 }

src/seedu/addressbook/commands/HelpCommand.java

@@ -19,12 +19,18 @@ public class HelpCommand extends Command {
             + "\n" + ViewCommand.MESSAGE_USAGE
             + "\n" + ViewAllCommand.MESSAGE_USAGE
             + "\n" + HelpCommand.MESSAGE_USAGE
-            + "\n" + ExitCommand.MESSAGE_USAGE;
+            + "\n" + ExitCommand.MESSAGE_USAGE
+    		+ "\n" + ChangeThemeCommand.MESSAGE_USAGE;
 
     public HelpCommand() {}
 
     @Override
     public CommandResult execute() {
         return new CommandResult(MESSAGE_ALL_USAGES);
     }
+
+    @Override
+    public boolean isMutating() {
+        return false;
+    }
 }

src/seedu/addressbook/commands/IncorrectCommand.java

@@ -16,5 +16,10 @@ public IncorrectCommand(String feedbackToUser){
     public CommandResult execute() {
         return new CommandResult(feedbackToUser);
     }
+
+    @Override
+    public boolean isMutating() {
+        return false;
+    }
 
 }

src/seedu/addressbook/commands/ListCommand.java

@@ -22,4 +22,9 @@ public CommandResult execute() {
         List<ReadOnlyPerson> allPersons = addressBook.getAllPersons().immutableListView();
         return new CommandResult(getMessageForPersonListShownSummary(allPersons), allPersons);
     }
+
+    @Override
+    public boolean isMutating() {
+        return false;
+    }
 }

src/seedu/addressbook/commands/ViewAllCommand.java

@@ -37,4 +37,9 @@ public CommandResult execute() {
             return new CommandResult(Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX);
         }
     }
+
+    @Override
+    public boolean isMutating() {
+        return false;
+    }
 }

src/seedu/addressbook/commands/ViewCommand.java

@@ -37,5 +37,10 @@ public CommandResult execute() {
             return new CommandResult(Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX);
         }
     }
+
+    @Override
+    public boolean isMutating() {
+        return false;
+    }
 
 }

src/seedu/addressbook/data/AddressBook.java

@@ -19,7 +19,7 @@ public class AddressBook {
 
     private final UniquePersonList allPersons;
     private final UniqueTagList allTags; // can contain tags not attached to any person
-
+    private final static String[] allThemes = {"Dark", "Light", "Mocha", "Grape"};
     public static AddressBook empty() {
         return new AddressBook();
     }
@@ -106,6 +106,27 @@ public boolean containsTag(Tag key) {
     }
 
     /**
+         * Checks if provided theme name exists
+         * */
+
+        public boolean containsTheme(String theme) {
+            for (String th : allThemes) {
+                if (th.equals(theme)) {
+                    return true;
+                }
+            }
+            return false;
+        }
+
+        /**
+         * Returns all themes as a string, for use of help command.
+         * */
+        public static String allThemesString() {
+            return String.join(", ", allThemes);
+        }
+
+    /**
+
      * Removes the equivalent person from the address book.
      *
      * @throws PersonNotFoundException if no such Person could be found.

src/seedu/addressbook/logic/Logic.java

@@ -85,7 +85,10 @@ public CommandResult execute(String userCommandText) throws Exception {
     private CommandResult execute(Command command) throws Exception {
         command.setData(addressBook, lastShownList);
         CommandResult result = command.execute();
-        storage.save(addressBook);
+        if (command.isMutating()) {
+        	 storage.save(addressBook);
+
+        }
         return result;
     }