Merge pull request #26 from CS2103-AY1819S2-W13-3/master

merge

docs/DeveloperGuide.adoc

@@ -269,6 +269,35 @@ Step 3. The user executes `restore 1` and only one entry will be deleted, which
 * **Alternative 2 (current choice):** Using Json Managers and DeletedSources in the Model
 // end::restore[]
 
+// tag::panic[]
+=== Panic Mode feature
+The panic mode feature allows the user to temporarily hide user data and replace it with dummy data.
+
+==== Overview
+The user's original data is replaced by dummy data for the duration that panic mode is enabled.
+Enabling panic mode can be thought of as "stashing" the user's data temporarily in memory.
+This is reflected both on-screen and on-disk.
+On the screen, the list of sources is replaced by an empty dummy list.
+On disk, the contents of the JSON file storing the user's sources is replaced by dummy content that tracks and reflects the dummy data.
+
+==== Implementation
+This is implemented by "swapping" the source manager with an empty dummy source manager.
+This "swap" is carried out by storing the original source manager in a private variable `sourceManagerBackup`, and then resetting the original source manager with a new empty source manager instance.
+We also set the boolean variable `panicMode = true`.
+
+When the user disables panic mode, we restore the original source manager, and reset `panicMode = false`.
+
+==== Elaboration
+We use a boolean variable `panicMode` to keep track of whether panic mode has been activated.
+This is to guard against the scenario of entering panic mode while already in panic mode, which results in permanent data loss.
+
+This is because when panic mode is activated, we store the original source manager in the private variable `sourceManagerBackup`, and reset the original source manager, as described above.
+
+Therefore, should panic mode be activated while already in panic mode, `sourceManagerBackup` will now store the dummy source manager, and the original source manager will be deallocated and eventually purged from memory by Java's garbage collector.
+
+Since the JSON file on disk automatically tracks the source manager through the observer pattern, it automatically updates to track and reflect the data in the dummy source manager.
+
+
 // tag::alias[]
 === Command Alias feature
 The command alias feature allows users to use shorthand commands to rapidly "get things done", for instance using `a` instead of `add`, or `c` instead of `count`.

docs/UserGuide.adoc

@@ -350,16 +350,38 @@ The `redo` command fails as there are no `undo` commands executed previously.
 `redo` (reapplies the `clear` command) +
 // end::undoredo[]
 
+// tag::panic[]
 === Enabling panic mode : `panic`
 
-Allows user to temporarily hide data. +
+Allows the user to temporarily hide data. +
 Format: `panic`
 
-=== Enabling panic mode : `unpanic`
+Research data may be sensitive.
+Panic mode is a privacy-focused feature that swaps out the user's data store with an empty dummy data store.
 
-Restores user data. +
+When it is enabled, the application window replaces the original list of sources with an empty list.
+This change is reflected on disk too; the JSON file of sources is replaced by an empty dummy file that tracks the dummy data store.
+The original data store exists only in memory, until panic mode is disabled.
+
+In panic mode, the dummy data store behaves exactly like a real one.
+Therefore, all commands (e.g. add, remove, etc.) mutate the dummy data store (and the dummy JSON file), **without affecting the actual data store.**
+
+[NOTE]
+====
+If the user exits the application in panic mode (using the `exit` command), the application automatically restores the user's original data from memory and saves it to disk before exiting, to prevent permanent data loss.
+
+However, if the application is closed directly **while in panic mode**, **permanent data loss** will occur.
+====
+
+// tag::unpanic[]
+=== Disabling panic mode : `unpanic`
+
+Restores the user's original data. +
 Format: `unpanic`
 
+This reverses the effect of panic mode by restoring the user's original data.
+The restorated is reflected on the disk too; the JSON file is reset to its original state and will now track the original data store.
+
 === Clearing all entries : `clear`
 
 Clears all entries from the source manager and all the deleted sources as well. +