Merge pull request #1 from Kobot7/branch-Level-9

Add find task feature

src/main/java/kobot/command/Command.java

@@ -8,7 +8,7 @@ public abstract class Command {
     protected TaskList taskList;
 
     Command(TaskList taskList) {
-        canExecute = false;
+        this.canExecute = false;
         this.taskList = taskList;
     }
     public abstract void execute();

src/main/java/kobot/command/FindCommand.java

@@ -0,0 +1,39 @@
+package kobot.command;
+
+import kobot.task.TaskList;
+import kobot.task.Task;
+import kobot.ui.Ui;
+
+public class FindCommand extends Command {
+    private String keyword;
+
+    public FindCommand(TaskList tasklist, String keyword) {
+        super(tasklist);
+        parseArguments(keyword);
+    }
+
+    public void parseArguments(String keyword) {
+        try {
+            this.keyword = keyword.trim();
+        } catch (NullPointerException exception) {
+            Ui.printMissingArgumentErrorMessage();
+            Ui.printFindCommandUsage();
+            return;
+        }
+
+        if (this.keyword.isEmpty()) {
+            Ui.printEmptyArgumentErrorMessage();
+            Ui.printFindCommandUsage();
+            return;
+        }
+
+        this.canExecute = true;
+    }
+    public void execute() {
+        if (!canExecute) {
+            return;
+        }
+
+        taskList.findTasks(keyword);
+    }
+}

src/main/java/kobot/command/Parser.java

@@ -7,6 +7,7 @@ public class Parser {
     private static final String EXIT_COMMAND = "exit";
     private static final String BYE_COMMAND = "bye";
     private static final String LIST_COMMAND = "list";
+    private static final String FIND_COMMAND = "find";
     private static final String TODO_COMMAND = "todo";
     private static final String DEADLINE_COMMAND = "deadline";
     private static final String EVENT_COMMAND = "event";
@@ -65,6 +66,8 @@ public Command prepareCommand(TaskList taskList) {
         case BYE_COMMAND:
             exit();
             return null;
+        case FIND_COMMAND:
+            return new FindCommand(taskList, this.arguments);
         case LIST_COMMAND:
             return new ListCommand(taskList);
         case TODO_COMMAND:

src/main/java/kobot/task/TaskList.java

@@ -70,7 +70,7 @@ public void printTaskList() {
             index++;
         }
     }
-
+    
     /**
      * Marks a specified task as done.
      *
@@ -148,4 +148,17 @@ public String toStorageFormat() {
 
         return String.valueOf(storage);
     }
+
+    public void findTasks(String keyword) {
+        System.out.println("Tasks containing \"" + keyword + "\":");
+
+        int index = 1;
+        for (Task task:taskList) {
+            if (task.getDescription().contains(keyword)) {
+                System.out.print(index + ". ");
+                System.out.println(task);
+                index++;
+            }
+        }
+    }
 }

src/main/java/kobot/ui/Ui.java

@@ -26,6 +26,7 @@ public class Ui {
     private static final String MARK_TASK_COMMAND_FORMAT = "mark <task index>";
     private static final String UNMARK_TASK_COMMAND_FORMAT = "unmark <task index>";
     private static final String DELETE_TASK_COMMAND_FORMAT = "delete <task index>";
+    private static final String FIND_TASK_COMMAND_FORMAT = "find <keyword>";
 
     private static final String INVALID_COMMAND_ERROR = "Invalid command. Please try again.";
     private static final String EMPTY_ARGUMENT_ERROR = "Empty or whitespace-only fields are not allowed.";
@@ -124,4 +125,9 @@ public static void printDeleteCommandUsage() {
         System.out.println("Command to delete task:");
         System.out.println(DELETE_TASK_COMMAND_FORMAT);
     }
+
+    public static void printFindCommandUsage() {
+        System.out.println("Command to find tasks:");
+        System.out.println(FIND_TASK_COMMAND_FORMAT);
+    }
 }