From 9d7bc381a1922e3fcad2fbd68917372c99980a59 Mon Sep 17 00:00:00 2001
From: whywilson <m.tools@qq.com>
Date: Tue, 9 Dec 2025 11:01:16 +0800
Subject: [PATCH] Add nudge scroll on UpDownEncoder devices.

---
 src/graphics/Screen.cpp               | 20 +++++++++++++
 src/graphics/draw/MessageRenderer.cpp | 42 +++++++++++++++++++++++++++
 src/graphics/draw/MessageRenderer.h   |  4 +++
 3 files changed, 66 insertions(+)

diff --git a/src/graphics/Screen.cpp b/src/graphics/Screen.cpp
index 996d9b967..9a6b97c01 100644
--- a/src/graphics/Screen.cpp
+++ b/src/graphics/Screen.cpp
@@ -1656,6 +1656,26 @@ int Screen::handleInputEvent(const InputEvent *event)
 
         // If no modules are using the input, move between frames
         if (!inputIntercepted) {
+#if defined(INPUTDRIVER_ENCODER_TYPE) && INPUTDRIVER_ENCODER_TYPE == 2
+            bool handledEncoderScroll = false;
+            const bool isTextMessageFrame = (framesetInfo.positions.textMessage != 255 &&
+                                             this->ui->getUiState()->currentFrame == framesetInfo.positions.textMessage &&
+                                             !messageStore.getMessages().empty());
+            if (isTextMessageFrame) {
+                if (event->inputEvent == INPUT_BROKER_UP_LONG) {
+                    graphics::MessageRenderer::nudgeScroll(-1);
+                    handledEncoderScroll = true;
+                } else if (event->inputEvent == INPUT_BROKER_DOWN_LONG) {
+                    graphics::MessageRenderer::nudgeScroll(1);
+                    handledEncoderScroll = true;
+                }
+            }
+
+            if (handledEncoderScroll) {
+                setFastFramerate();
+                return 0;
+            }
+#endif
             if (event->inputEvent == INPUT_BROKER_LEFT || event->inputEvent == INPUT_BROKER_ALT_PRESS) {
                 showFrame(FrameDirection::PREVIOUS);
             } else if (event->inputEvent == INPUT_BROKER_RIGHT || event->inputEvent == INPUT_BROKER_USER_PRESS) {
diff --git a/src/graphics/draw/MessageRenderer.cpp b/src/graphics/draw/MessageRenderer.cpp
index 6046d42f3..ad0dfa144 100644
--- a/src/graphics/draw/MessageRenderer.cpp
+++ b/src/graphics/draw/MessageRenderer.cpp
@@ -238,6 +238,48 @@ void resetScrollState()
     didReset = false;
 }
 
+void nudgeScroll(int8_t direction)
+{
+    if (direction == 0)
+        return;
+
+    if (cachedHeights.empty()) {
+        scrollY = 0.0f;
+        return;
+    }
+
+    OLEDDisplay *display = (screen != nullptr) ? screen->getDisplayDevice() : nullptr;
+    const int displayHeight = display ? display->getHeight() : 64;
+    const int navHeight = FONT_HEIGHT_SMALL;
+    const int usableHeight = std::max(0, displayHeight - navHeight);
+
+    int totalHeight = 0;
+    for (int h : cachedHeights)
+        totalHeight += h;
+
+    if (totalHeight <= usableHeight) {
+        scrollY = 0.0f;
+        return;
+    }
+
+    const int scrollStop = std::max(0, totalHeight - usableHeight + cachedHeights.back());
+    const int step = std::max(FONT_HEIGHT_SMALL, usableHeight / 3);
+
+    float newScroll = scrollY + static_cast<float>(direction) * static_cast<float>(step);
+    if (newScroll < 0.0f)
+        newScroll = 0.0f;
+    if (newScroll > scrollStop)
+        newScroll = static_cast<float>(scrollStop);
+
+    if (newScroll != scrollY) {
+        scrollY = newScroll;
+        waitingToReset = false;
+        scrollStarted = false;
+        scrollStartDelay = millis();
+        lastTime = millis();
+    }
+}
+
 // Fully free cached message data from heap
 void clearMessageCache()
 {
diff --git a/src/graphics/draw/MessageRenderer.h b/src/graphics/draw/MessageRenderer.h
index 7f2e8b1e7..7dec6adec 100644
--- a/src/graphics/draw/MessageRenderer.h
+++ b/src/graphics/draw/MessageRenderer.h
@@ -5,6 +5,7 @@
 #include "OLEDDisplayUi.h"
 #include "graphics/emotes.h"
 #include "mesh/generated/meshtastic/mesh.pb.h" // for meshtastic_MeshPacket
+#include <cstdint>
 #include <string>
 #include <vector>
 
@@ -50,6 +51,9 @@ std::vector<int> calculateLineHeights(const std::vector<std::string> &lines, con
 // Reset scroll state when new messages arrive
 void resetScrollState();
 
+// Manual scroll control for encoder-style inputs
+void nudgeScroll(int8_t direction);
+
 // Helper to auto-select the correct thread mode from a message
 void setThreadFor(const StoredMessage &sm, const meshtastic_MeshPacket &packet);