From dc71d5d162a7e2e4e9e7b3e253648afd629d53ab Mon Sep 17 00:00:00 2001
From: Andreas Scherer <andreas_github@freenet.de>
Date: Sun, 27 Aug 2023 12:27:23 +0200
Subject: [PATCH] Add callback function for mouse scroll events.

See https://www.glfw.org/docs/3.3/input_guide.html#scrolling
for details. This should work with a mouse scrollwheel and with
touchpad gestures.
---
 hintview/Linux/main.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/hintview/Linux/main.c b/hintview/Linux/main.c
index 63ce023..3be9e21 100644
--- a/hintview/Linux/main.c
+++ b/hintview/Linux/main.c
@@ -528,6 +528,21 @@ void mouse_button_callback(GLFWwindow* window, int button, int action, int mods)
   }      
 }
 
+void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
+{
+  if (yoffset > 0.0)
+  {
+    pos=hint_page_prev();
+    hint_page();
+    clear_cursor();
+  } else if (yoffset < 0.0)
+  {
+    pos=hint_page_next();
+    hint_page();
+    clear_cursor();
+  }
+}
+
 void cursor_enter_callback(GLFWwindow* window, int entered)
 { if (entered && autoreload && new_file_time())
     reload_file();
@@ -573,6 +588,7 @@ int create_window(void)
   glfwSetKeyCallback(window, key_callback);
   glfwSetCursorEnterCallback(window,cursor_enter_callback);
   glfwSetMouseButtonCallback(window, mouse_button_callback);
+  glfwSetScrollCallback(window, scroll_callback);
   glfwSetCursorPosCallback(window, cursor_position_callback);
 
   glfwSetCursorPos(window, px_h/2, px_v/2);