Erase InkHUD settings on factory reset

src/graphics/Screen.cpp

@@ -2840,9 +2840,6 @@ int Screen::handleInputEvent(const InputEvent *event)
 
 int Screen::handleAdminMessage(const meshtastic_AdminMessage *arg)
 {
-    // Note: only selected admin messages notify this observer
-    // If you wish to handle a new type of message, you should modify AdminModule.cpp first
-
     switch (arg->which_payload_variant) {
     // Node removed manually (i.e. via app)
     case meshtastic_AdminMessage_remove_by_nodenum_tag:

src/graphics/niche/FlashData.h

@@ -135,6 +135,29 @@ template <typename T> class FlashData
     }
 };
 
+// Erase contents of the NicheGraphics data directory
+inline void clearFlashData()
+{
+
+#ifdef FSCom
+    File dir = FSCom.open("/NicheGraphics"); // Open the directory
+    File file = dir.openNextFile();          // Attempt to open the first file in the directory
+
+    // While the directory still contains files
+    while (file) {
+        std::string path = "/NicheGraphics/";
+        path += file.name();
+        LOG_DEBUG("Erasing %s", path.c_str());
+        file.close();
+        FSCom.remove(path.c_str());
+
+        file = dir.openNextFile();
+    }
+#else
+    LOG_ERROR("ERROR: Filesystem not implemented\n");
+#endif
+}
+
 } // namespace NicheGraphics
 
 #endif

src/graphics/niche/InkHUD/Events.cpp

@@ -8,6 +8,7 @@
 
 #include "./Applet.h"
 #include "./SystemApplet.h"
+#include "graphics/niche/FlashData.h"
 
 using namespace NicheGraphics;
 
@@ -25,6 +26,9 @@ void InkHUD::Events::begin()
     deepSleepObserver.observe(&notifyDeepSleep);
     rebootObserver.observe(&notifyReboot);
     textMessageObserver.observe(textMessageModule);
+#if !MESHTASTIC_EXCLUDE_ADMIN
+    adminMessageObserver.observe(adminModule);
+#endif
 #ifdef ARCH_ESP32
     lightSleepObserver.observe(&notifyLightSleep);
 #endif
@@ -117,8 +121,13 @@ int InkHUD::Events::beforeReboot(void *unused)
         sa->onReboot();
     }
 
-    inkhud->persistence->saveSettings();
-    inkhud->persistence->saveLatestMessage();
+    // Save settings to flash, or erase if factory reset in progress
+    if (!eraseOnReboot) {
+        inkhud->persistence->saveSettings();
+        inkhud->persistence->saveLatestMessage();
+    } else {
+        NicheGraphics::clearFlashData();
+    }
 
     // Note: no forceUpdate call here
     // We don't have any final screen to draw, although LogoApplet::onReboot did already display a "rebooting" screen
@@ -171,6 +180,23 @@ int InkHUD::Events::onReceiveTextMessage(const meshtastic_MeshPacket *packet)
     return 0; // Tell caller to continue notifying other observers. (No reason to abort this event)
 }
 
+int InkHUD::Events::onAdminMessage(const meshtastic_AdminMessage *message)
+{
+    switch (message->which_payload_variant) {
+    // Factory reset
+    // Two possible messages. One preserves BLE bonds, other wipes. Both should clear InkHUD data.
+    case meshtastic_AdminMessage_factory_reset_device_tag:
+    case meshtastic_AdminMessage_factory_reset_config_tag:
+        eraseOnReboot = true;
+        break;
+
+    default:
+        break;
+    }
+
+    return 0; // Tell caller to continue notifying other observers. (No reason to abort this event)
+}
+
 #ifdef ARCH_ESP32
 // Callback for lightSleepObserver
 // Make sure the display is not partway through an update when we begin light sleep

src/graphics/niche/InkHUD/Events.h

@@ -13,6 +13,7 @@ however this class handles general events which concern InkHUD as a whole, e.g.
 
 #include "configuration.h"
 
+#include "Modules/AdminModule.h"
 #include "Observer.h"
 
 #include "./InkHUD.h"
@@ -33,6 +34,7 @@ class Events
     int beforeDeepSleep(void *unused);                             // Prepare for shutdown
     int beforeReboot(void *unused);                                // Prepare for reboot
     int onReceiveTextMessage(const meshtastic_MeshPacket *packet); // Store most recent text message
+    int onAdminMessage(const meshtastic_AdminMessage *message);    // Handle incoming admin messages
 #ifdef ARCH_ESP32
     int beforeLightSleep(void *unused); // Prepare for light sleep
 #endif
@@ -52,10 +54,17 @@ class Events
     CallbackObserver<Events, const meshtastic_MeshPacket *> textMessageObserver =
         CallbackObserver<Events, const meshtastic_MeshPacket *>(this, &Events::onReceiveTextMessage);
 
+    // Get notified of incoming admin messages, and handle any which are relevant to InkHUD
+    CallbackObserver<Events, const meshtastic_AdminMessage *> adminMessageObserver =
+        CallbackObserver<Events, const meshtastic_AdminMessage *>(this, &Events::onAdminMessage);
+
 #ifdef ARCH_ESP32
     // Get notified when the system is entering light sleep
     CallbackObserver<Events, void *> lightSleepObserver = CallbackObserver<Events, void *>(this, &Events::beforeLightSleep);
 #endif
+
+    // If set, InkHUD's data will be erased during onReboot
+    bool eraseOnReboot = false;
 };
 
 } // namespace NicheGraphics::InkHUD

src/graphics/niche/InkHUD/docs/README.md

@@ -502,6 +502,10 @@ Applets themselves do also listen separately for various events, but for the pur
 
 Button input is sometimes handled by a system applet. `InkHUD::Events` determines whether the button should be handled by a specific system applet, or should instead trigger a default behavior
 
+#### Factory Reset
+
+The Events class handles the admin messages(s) which trigger factory reset. We set `Events::doFactoryReset = true`, which causes `Events::onReboot` to erase the contents of InkHUD's data directory. We do this because some applets (e.g. ThreadedMessageApplet) save their own data to flash, so if we erased earlier, that data would get re-written during reboot.
+
 ---
 
 ### `InkHUD::Applet`

src/modules/AdminModule.cpp

@@ -284,7 +284,6 @@ bool AdminModule::handleReceivedProtobuf(const meshtastic_MeshPacket &mp, meshta
     case meshtastic_AdminMessage_remove_by_nodenum_tag: {
         LOG_INFO("Client received remove_nodenum command");
         nodeDB->removeNodeByNum(r->remove_by_nodenum);
-        this->notifyObservers(r); // Observed by screen
         break;
     }
     case meshtastic_AdminMessage_set_favorite_node_tag: {
@@ -444,6 +443,9 @@ bool AdminModule::handleReceivedProtobuf(const meshtastic_MeshPacket &mp, meshta
         myReply = allocErrorResponse(meshtastic_Routing_Error_NONE, &mp);
     }
 
+    // Allow any observers (e.g. the UI) to respond to this event
+    notifyObservers(r);
+
     return handled;
 }