scroll notes

include/config.h

@@ -46,10 +46,15 @@
 #define KB_KEY_BACKSPACE 0x08
 #define KB_KEY_TAB       0x09
 #define KB_KEY_ESC       0x1B
+#define KB_KEY_LEFT      0xB4
+#define KB_KEY_UP        0xB5
+#define KB_KEY_DOWN      0xB6
+#define KB_KEY_RIGHT     0xB7
 
 // Notes mode / BT dump
 #define BT_DUMP_COUNTDOWN_S    3
 #define NOTES_FILE "/notes.txt"
+#define NOTES_HISTORY_LINES    100 // scrollback kept in RAM for notes mode
 
 
 // ESP-NOW Chat

src/meshberry/chat.cpp

@@ -4,7 +4,7 @@
 // Original author : 7h30th3r0n3, https://github.com/7h30th3r0n3/Evil-M5Project
 //
 // I've tried to keep the original code as much as possible as it was
-// but some ui/logic snuck in when adding the BT functonality. 
+// but –some- a lot ui/logic snuck in when adding the BT functonality. 
 
 #include "chat.h"
 #include "config.h"
@@ -108,13 +108,24 @@ static void chat_show_recent() {
     }
 }
 
-// get the last few lines of the notes file.
+static char notesBuf[NOTES_HISTORY_LINES][MAX_MSG_LEN];
-static void notes_show_recent() {
+static int currNote = 0;// next pos
+static int notesCount = 0;
+static int notesScrollPos = 0;
+
+static void notes_to_buffer(const char* line) {
+    strncpy(notesBuf[currNote], line, MAX_MSG_LEN - 1);
+    notesBuf[currNote][MAX_MSG_LEN - 1] = '\0';
+    currNote = (currNote + 1) % NOTES_HISTORY_LINES;
+    if (notesCount < NOTES_HISTORY_LINES) notesCount++;
+}
+
+static void notes_load() {
+    notesCount = 0; currNote = 0; notesScrollPos = 0;
+
     File f = LittleFS.open(NOTES_FILE, "r");
     if (!f) return;
 
-    static char buf[MODE_HISTORY_LINES][MAX_MSG_LEN];
-    int count = 0, head = 0;
     char line[MAX_MSG_LEN];
     while (f.available()) {
         int n = f.readBytesUntil('\n', line, sizeof(line) - 1);
@@ -122,20 +133,30 @@ static void notes_show_recent() {
             n--; // remove trailing /r from .println
         line[n] = '\0';
         if (n == 0) continue;
-        strncpy(buf[head], line, MAX_MSG_LEN - 1);
+        notes_to_buffer(line);
-        buf[head][MAX_MSG_LEN - 1] = '\0';
-        head = (head + 1) % MODE_HISTORY_LINES;
-        if (count < MODE_HISTORY_LINES) count++;
     }
-    
     f.close();
-    int start = (count < MODE_HISTORY_LINES) ? 0 : head;
+}
-    for (int i = 0; i < count; i++)
+
-        ui_push_message("", buf[(start + i) % MODE_HISTORY_LINES], true, false);
+static void notes_render() {
+    int visible   = UI_VISIBLE_LINES;
+    int maxScroll = (notesCount > visible) ? (notesCount - visible) : 0;
+    if (notesScrollPos > maxScroll) notesScrollPos = maxScroll;
+    if (notesScrollPos < 0) notesScrollPos = 0;
+
+    int windowEnd = notesCount - notesScrollPos;
+    int windowStart = windowEnd - visible;
+    if (windowStart < 0) windowStart = 0;
+
+    int start = (notesCount < NOTES_HISTORY_LINES) ? 0 : currNote;
+
+    ui_clear_messages();
+    for (int i = windowStart; i < windowEnd; i++)
+        ui_push_message("", notesBuf[(start + i) % NOTES_HISTORY_LINES], true, false);
 }
 
 /*
-Switch between chat mode (default) adn notes mode. 
+Switch between chat mode (default) adn notes mode.
 also redraw the UI somewhat
 */
 static void switch_mode(AppMode m) {
@@ -143,7 +164,8 @@ static void switch_mode(AppMode m) {
     ui_clear_messages();
     if (m == AppMode::NOTES) {
         ui_set_header_mode("NOTE MODE");
-        notes_show_recent();
+        notes_load();
+        notes_render();
     } else {
         ui_set_header(nodesCount, currentNick);
         chat_show_recent();
@@ -767,6 +789,14 @@ void chat_tick(char key) {
         return;
     }
 
+    /* Scroll through notes */
+    if (appMode == AppMode::NOTES &&
+        ((uint8_t)key == KB_KEY_UP || (uint8_t)key == KB_KEY_DOWN)) {
+        notesScrollPos += ((uint8_t)key == KB_KEY_UP) ? 1 : -1;
+        notes_render();
+        return;
+    }
+
     if (appMode == AppMode::BT) {
         if((uint8_t)key == 0x80) { // FN + ESC
             bt_dump_start();
@@ -798,7 +828,9 @@ void chat_tick(char key) {
                     handleCommand(inputBuffer);
                 else if (appMode == AppMode::NOTES) {
                     notes_append(inputBuffer);
-                    ui_push_message("", inputBuffer, true, false);
+                    notes_to_buffer(inputBuffer);
+                    notesScrollPos = 0;           // snap back to the latest note
+                    notes_render();
                 } else if (appMode == AppMode::CHAT) {
                     broadcastChatMessage(currentNick, inputBuffer);
                 }