From 8c729698a8a4332dfd1e8663c1d6e3099ea04663 Mon Sep 17 00:00:00 2001
From: David Anderson <dave@natulte.net>
Date: Mon, 16 Sep 2024 16:10:17 -0700
Subject: [PATCH] debugger: implement scrolling in the hex view

---
 debugger/hexview.go | 11 +++++++++++
 debugger/main.go    |  2 +-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/debugger/hexview.go b/debugger/hexview.go
index 6fb12c4..5c264a7 100644
--- a/debugger/hexview.go
+++ b/debugger/hexview.go
@@ -56,6 +56,17 @@ func (m *HexView) moveSelection(delta int) bool {
 	newAddr := m.selectedAddr + delta
 	if newAddr >= 0 && newAddr < m.mem.Len() {
 		m.selectedAddr = newAddr
+		start, end := m.VisibleBytes()
+		newFirstLine := newAddr / 16
+		if newAddr < start {
+			newFirstLine = newFirstLine - (m.height * 4 / 5)
+			newFirstLine = max(newFirstLine, 0)
+			m.firstAddr = newFirstLine * 16
+		} else if newAddr >= end {
+			newFirstLine = newFirstLine - (m.height * 1 / 5)
+			newFirstLine = min(newFirstLine, (m.mem.Len()/16)-m.height)
+			m.firstAddr = newFirstLine * 16
+		}
 		return true
 	}
 	return false
diff --git a/debugger/main.go b/debugger/main.go
index dcd1096..891593e 100644
--- a/debugger/main.go
+++ b/debugger/main.go
@@ -14,7 +14,7 @@ func main() {
 	}
 	defer dbg.Close()
 
-	mem := memory.New(dbg, 768)
+	mem := memory.New(dbg, 4*1024)
 
 	if err := UI(mem); err != nil {
 		log.Fatal(err)