From 79dd97fb92f27422ab086eb599dc353ebc6fb8eb Mon Sep 17 00:00:00 2001
From: Pseurae <adhith.chand@gmail.com>
Date: Sat, 5 Oct 2024 10:49:45 +0000
Subject: [PATCH] Add scroll indicators to list menu

---
 include/menu.h    | 22 +++++++++++++++++++++-
 linker/text.ld    |  5 +++++
 src/script_menu.c | 22 ++++++++++++++++++++++
 3 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/include/menu.h b/include/menu.h
index 10fdad1..f857b4a 100644
--- a/include/menu.h
+++ b/include/menu.h
@@ -22,4 +22,24 @@ u8 LONG_CALL PrintStringWithNewlines(
 void LONG_CALL Menu_PrintItems(u8, u8, u8, const void *);
 void LONG_CALL Menu_DestroyCursor(void);
 u8 LONG_CALL InitMenu(u8, u8, u8, u8, u8, u8);
-u8 LONG_CALL Menu_MoveCursor(s8);
\ No newline at end of file
+u8 LONG_CALL Menu_MoveCursor(s8);
+
+enum
+{
+    TOP_ARROW,
+    BOTTOM_ARROW,
+    LEFT_ARROW, // Bag arrows
+    RIGHT_ARROW
+};
+
+enum
+{
+    VISIBLE,
+    INVISIBLE
+};
+
+void LONG_CALL CreateVerticalScrollIndicators(u8, u16, u16);
+void LONG_CALL SetVerticalScrollIndicators(u8, bool8);
+void LONG_CALL DestroyVerticalScrollIndicator(u8);
+void LONG_CALL LoadScrollIndicatorPalette(void);
+void LONG_CALL ClearVerticalScrollIndicatorPalettes(void);
\ No newline at end of file
diff --git a/linker/text.ld b/linker/text.ld
index f508279..a14d636 100644
--- a/linker/text.ld
+++ b/linker/text.ld
@@ -231,3 +231,8 @@ CalculateBoxMonChecksum = 0x803b124 | 1;
 EncryptBoxMon = 0x803c5f0 | 1;
 DecryptBoxMon = 0x803c614 | 1;
 CalculateMonStats = 0x803b1b8 | 1;
+CreateVerticalScrollIndicators = 0x80f953c | 1;
+SetVerticalScrollIndicators = 0x80f979c | 1;
+DestroyVerticalScrollIndicator = 0x80f97e0 | 1;
+LoadScrollIndicatorPalette = 0x80f9818 | 1;
+ClearVerticalScrollIndicatorPalettes = 0x80f944c | 1;
\ No newline at end of file
diff --git a/src/script_menu.c b/src/script_menu.c
index 45ae462..06889f0 100644
--- a/src/script_menu.c
+++ b/src/script_menu.c
@@ -220,6 +220,14 @@ static void StartListMenuTask(const struct MenuAction *list, u8 left, u8 top, u8
         gTasks[taskId].tDoWrap = TRUE;
     else
         gTasks[taskId].tDoWrap = FALSE;
+
+    if (totalCount > displayCount)
+    {
+        ClearVerticalScrollIndicatorPalettes();
+        CreateVerticalScrollIndicators(TOP_ARROW, (left + right + 1) << 2, top << 3);
+        CreateVerticalScrollIndicators(BOTTOM_ARROW, (left + right + 1) << 2, bottom << 3);
+        SetVerticalScrollIndicators(TOP_ARROW, INVISIBLE);
+    }
 }
 
 static void Task_HandleListMenuInput(u8 taskId)
@@ -234,6 +242,8 @@ static void Task_HandleListMenuInput(u8 taskId)
         Menu_EraseWindowRect(gTasks[taskId].tLeft, gTasks[taskId].tTop, gTasks[taskId].tRight, gTasks[taskId].tBottom);
         DestroyTask(taskId);
         EnableBothScriptContexts();
+        DestroyVerticalScrollIndicator(TOP_ARROW);
+        DestroyVerticalScrollIndicator(BOTTOM_ARROW);
     } else if (gMain.newKeys & B_BUTTON) {
         if (tIgnoreBPress) return;
 
@@ -242,6 +252,8 @@ static void Task_HandleListMenuInput(u8 taskId)
         Menu_EraseWindowRect(gTasks[taskId].tLeft, gTasks[taskId].tTop, gTasks[taskId].tRight, gTasks[taskId].tBottom);
         DestroyTask(taskId);
         EnableBothScriptContexts();
+        DestroyVerticalScrollIndicator(TOP_ARROW);
+        DestroyVerticalScrollIndicator(BOTTOM_ARROW);
     } else if ((gMain.newAndRepeatedKeys & DPAD_ANY) == DPAD_DOWN) {
         if (tCursor == tDisplayCount - 1) {
             if (tCursor + tScrollOffset == tTotalCount - 1) return;
@@ -265,4 +277,14 @@ static void Task_HandleListMenuInput(u8 taskId)
             tCursor = Menu_MoveCursor(-1);
         }
     }
+
+    if (tScrollOffset == 0)
+        SetVerticalScrollIndicators(TOP_ARROW, INVISIBLE);
+    else
+        SetVerticalScrollIndicators(TOP_ARROW, VISIBLE);
+
+    if (tScrollOffset + tDisplayCount == tTotalCount)
+        SetVerticalScrollIndicators(BOTTOM_ARROW, INVISIBLE);
+    else
+        SetVerticalScrollIndicators(BOTTOM_ARROW, VISIBLE);
 }
\ No newline at end of file