From c94804588e33d72ff5ab2798241e26a2b99492be Mon Sep 17 00:00:00 2001
From: Charlotte Meyer <dev@buffet.sh>
Date: Sat, 14 Aug 2021 18:39:04 +0000
Subject: [PATCH] Add scoll event

---
 include/input/cursor.h    |  8 ++++++
 kiwmi/input/cursor.c      | 26 +++++++++++++-----
 kiwmi/luak/kiwmi_cursor.c | 56 +++++++++++++++++++++++++++++++++++++++
 lua_docs.md               |  8 ++++++
 4 files changed, 91 insertions(+), 7 deletions(-)

diff --git a/include/input/cursor.h b/include/input/cursor.h
index 1271e6f..540cc3d 100644
--- a/include/input/cursor.h
+++ b/include/input/cursor.h
@@ -44,6 +44,7 @@ struct kiwmi_cursor {
         struct wl_signal button_down;
         struct wl_signal button_up;
         struct wl_signal motion;
+        struct wl_signal scroll;
     } events;
 };
 
@@ -59,6 +60,13 @@ struct kiwmi_cursor_motion_event {
     double newy;
 };
 
+struct kiwmi_cursor_scroll_event {
+    const char *device_name;
+    bool is_vertical;
+    double length;
+    bool handled;
+};
+
 struct kiwmi_cursor *cursor_create(
     struct kiwmi_server *server,
     struct wlr_output_layout *output_layout);
diff --git a/kiwmi/input/cursor.c b/kiwmi/input/cursor.c
index c591013..dd801b1 100644
--- a/kiwmi/input/cursor.c
+++ b/kiwmi/input/cursor.c
@@ -210,13 +210,24 @@ cursor_axis_notify(struct wl_listener *listener, void *data)
     struct kiwmi_input *input            = &server->input;
     struct wlr_event_pointer_axis *event = data;
 
-    wlr_seat_pointer_notify_axis(
-        input->seat->seat,
-        event->time_msec,
-        event->orientation,
-        event->delta,
-        event->delta_discrete,
-        event->source);
+    struct kiwmi_cursor_scroll_event new_event = {
+        .device_name = event->device->name,
+        .is_vertical = event->orientation == WLR_AXIS_ORIENTATION_VERTICAL,
+        .length      = event->delta,
+        .handled     = false,
+    };
+
+    wl_signal_emit(&cursor->events.scroll, &new_event);
+
+    if (!new_event.handled) {
+        wlr_seat_pointer_notify_axis(
+            input->seat->seat,
+            event->time_msec,
+            event->orientation,
+            event->delta,
+            event->delta_discrete,
+            event->source);
+    }
 }
 
 static void
@@ -277,6 +288,7 @@ cursor_create(
     wl_signal_init(&cursor->events.button_down);
     wl_signal_init(&cursor->events.button_up);
     wl_signal_init(&cursor->events.motion);
+    wl_signal_init(&cursor->events.scroll);
 
     return cursor;
 }
diff --git a/kiwmi/luak/kiwmi_cursor.c b/kiwmi/luak/kiwmi_cursor.c
index 2a1e0c7..97eb159 100644
--- a/kiwmi/luak/kiwmi_cursor.c
+++ b/kiwmi/luak/kiwmi_cursor.c
@@ -162,6 +162,36 @@ kiwmi_cursor_on_motion_notify(struct wl_listener *listener, void *data)
     }
 }
 
+static void
+kiwmi_cursor_on_scroll_notify(struct wl_listener *listener, void *data)
+{
+    struct kiwmi_lua_callback *lc = wl_container_of(listener, lc, listener);
+    struct kiwmi_server *server   = lc->server;
+    lua_State *L                  = server->lua->L;
+    struct kiwmi_cursor_scroll_event *event = data;
+
+    lua_rawgeti(L, LUA_REGISTRYINDEX, lc->callback_ref);
+
+    lua_newtable(L);
+
+    lua_pushstring(L, event->device_name);
+    lua_setfield(L, -2, "device");
+
+    lua_pushnumber(L, event->is_vertical);
+    lua_setfield(L, -2, "vertical");
+
+    lua_pushnumber(L, event->length);
+    lua_setfield(L, -2, "length");
+
+    if (lua_pcall(L, 1, 1, 0)) {
+        wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
+        lua_pop(L, 1);
+    }
+
+    event->handled |= lua_toboolean(L, -1);
+    lua_pop(L, 1);
+}
+
 static int
 l_kiwmi_cursor_on_button_down(lua_State *L)
 {
@@ -237,10 +267,36 @@ l_kiwmi_cursor_on_motion(lua_State *L)
     return 0;
 }
 
+static int
+l_kiwmi_cursor_on_scroll(lua_State *L)
+{
+    struct kiwmi_object *obj =
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_cursor");
+    luaL_checktype(L, 2, LUA_TFUNCTION);
+
+    struct kiwmi_cursor *cursor = obj->object;
+    struct kiwmi_server *server = cursor->server;
+
+    lua_pushcfunction(L, luaK_kiwmi_lua_callback_new);
+    lua_pushlightuserdata(L, server);
+    lua_pushvalue(L, 2);
+    lua_pushlightuserdata(L, kiwmi_cursor_on_scroll_notify);
+    lua_pushlightuserdata(L, &cursor->events.scroll);
+    lua_pushlightuserdata(L, obj);
+
+    if (lua_pcall(L, 5, 0, 0)) {
+        wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
+        return 0;
+    }
+
+    return 0;
+}
+
 static const luaL_Reg kiwmi_cursor_events[] = {
     {"button_down", l_kiwmi_cursor_on_button_down},
     {"button_up", l_kiwmi_cursor_on_button_up},
     {"motion", l_kiwmi_cursor_on_motion},
+    {"scroll", l_kiwmi_cursor_on_scroll},
     {NULL, NULL},
 };
 
diff --git a/lua_docs.md b/lua_docs.md
index 1de2b7e..098000c 100644
--- a/lua_docs.md
+++ b/lua_docs.md
@@ -149,6 +149,14 @@ The compositor will not forward it to the view under the cursor.
 The cursor got moved.
 Callback receives a table containing `oldx`, `oldy`, `newx`, and `newy`.
 
+#### scroll
+
+Something was scrolled.
+The callback receives a table containing `device` with the device name, `vertical` indicating whether it was a vertical or horizontal scroll, and `length` with the length of the vector (negative for left of up scrolls).
+
+The callback is supposed to return `true` if the event was handled.
+The compositor will not forward it to the view under the cursor.
+
 ## kiwmi_keyboard
 
 A handle to a keyboard.