render: fix damage tracking of drag icons

river/DragIcon.zig

@@ -1,6 +1,6 @@
 // This file is part of river, a dynamic tiling wayland compositor.
 //
-// Copyright 2020 The River Developers
+// Copyright 2020-2021 The River Developers
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -15,7 +15,7 @@
 // You should have received a copy of the GNU General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
-const Self = @This();
+const DragIcon = @This();
 
 const std = @import("std");
 const wlr = @import("wlroots");
@@ -25,20 +25,72 @@ const server = &@import("main.zig").server;
 const util = @import("util.zig");
 
 const Seat = @import("Seat.zig");
+const Subsurface = @import("Subsurface.zig");
 
 seat: *Seat,
 wlr_drag_icon: *wlr.Drag.Icon,
 
+// Always active
 destroy: wl.Listener(*wlr.Drag.Icon) = wl.Listener(*wlr.Drag.Icon).init(handleDestroy),
+map: wl.Listener(*wlr.Drag.Icon) = wl.Listener(*wlr.Drag.Icon).init(handleMap),
+unmap: wl.Listener(*wlr.Drag.Icon) = wl.Listener(*wlr.Drag.Icon).init(handleUnmap),
+new_subsurface: wl.Listener(*wlr.Subsurface) = wl.Listener(*wlr.Subsurface).init(handleNewSubsurface),
 
-pub fn init(self: *Self, seat: *Seat, wlr_drag_icon: *wlr.Drag.Icon) void {
-    self.* = .{ .seat = seat, .wlr_drag_icon = wlr_drag_icon };
-    wlr_drag_icon.events.destroy.add(&self.destroy);
+// Only active while mapped
+commit: wl.Listener(*wlr.Surface) = wl.Listener(*wlr.Surface).init(handleCommit),
+
+pub fn init(drag_icon: *DragIcon, seat: *Seat, wlr_drag_icon: *wlr.Drag.Icon) void {
+    drag_icon.* = .{ .seat = seat, .wlr_drag_icon = wlr_drag_icon };
+
+    wlr_drag_icon.events.destroy.add(&drag_icon.destroy);
+    wlr_drag_icon.events.map.add(&drag_icon.map);
+    wlr_drag_icon.events.unmap.add(&drag_icon.unmap);
+    wlr_drag_icon.surface.events.new_subsurface.add(&drag_icon.new_subsurface);
+
+    // There may already be subsurfaces present on this surface that we
+    // aren't aware of and won't receive a new_subsurface event for.
+    var it = wlr_drag_icon.surface.subsurfaces.iterator(.forward);
+    while (it.next()) |s| Subsurface.create(s, .{ .drag_icon = drag_icon });
 }
 
 fn handleDestroy(listener: *wl.Listener(*wlr.Drag.Icon), wlr_drag_icon: *wlr.Drag.Icon) void {
-    const self = @fieldParentPtr(Self, "destroy", listener);
-    const node = @fieldParentPtr(std.SinglyLinkedList(Self).Node, "data", self);
+    const drag_icon = @fieldParentPtr(DragIcon, "destroy", listener);
+
+    const node = @fieldParentPtr(std.SinglyLinkedList(DragIcon).Node, "data", drag_icon);
     server.root.drag_icons.remove(node);
+
+    drag_icon.destroy.link.remove();
+    drag_icon.map.link.remove();
+    drag_icon.unmap.link.remove();
+    drag_icon.new_subsurface.link.remove();
+
     util.gpa.destroy(node);
 }
+
+fn handleMap(listener: *wl.Listener(*wlr.Drag.Icon), wlr_drag_icon: *wlr.Drag.Icon) void {
+    const drag_icon = @fieldParentPtr(DragIcon, "map", listener);
+
+    wlr_drag_icon.surface.events.commit.add(&drag_icon.commit);
+    var it = server.root.outputs.first;
+    while (it) |node| : (it = node.next) node.data.damage.addWhole();
+}
+
+fn handleUnmap(listener: *wl.Listener(*wlr.Drag.Icon), wlr_drag_icon: *wlr.Drag.Icon) void {
+    const drag_icon = @fieldParentPtr(DragIcon, "unmap", listener);
+
+    drag_icon.commit.link.remove();
+    var it = server.root.outputs.first;
+    while (it) |node| : (it = node.next) node.data.damage.addWhole();
+}
+fn handleCommit(listener: *wl.Listener(*wlr.Surface), surface: *wlr.Surface) void {
+    const drag_icon = @fieldParentPtr(DragIcon, "commit", listener);
+
+    var it = server.root.outputs.first;
+    while (it) |node| : (it = node.next) node.data.damage.addWhole();
+}
+
+fn handleNewSubsurface(listener: *wl.Listener(*wlr.Subsurface), wlr_subsurface: *wlr.Subsurface) void {
+    const drag_icon = @fieldParentPtr(DragIcon, "new_subsurface", listener);
+
+    Subsurface.create(wlr_subsurface, .{ .drag_icon = drag_icon });
+}

river/Subsurface.zig

@@ -21,19 +21,26 @@ const std = @import("std");
 const wlr = @import("wlroots");
 const wl = @import("wayland").server.wl;
 
+const server = &@import("main.zig").server;
 const util = @import("util.zig");
 
+const DragIcon = @import("DragIcon.zig");
 const LayerSurface = @import("LayerSurface.zig");
 const View = @import("View.zig");
 
 pub const Parent = union(enum) {
     view: *View,
     layer_surface: *LayerSurface,
+    drag_icon: *DragIcon,
 
     pub fn damageWholeOutput(parent: Parent) void {
         switch (parent) {
             .view => |view| view.output.damage.addWhole(),
             .layer_surface => |layer_surface| layer_surface.output.damage.addWhole(),
+            .drag_icon => |drag_icon| {
+                var it = server.root.outputs.first;
+                while (it) |node| : (it = node.next) node.data.damage.addWhole();
+            },
         }
     }
 };

river/XdgPopup.zig

@@ -54,10 +54,12 @@ pub fn create(wlr_xdg_popup: *wlr.XdgPopup, parent: Parent) void {
     const parent_box = switch (parent) {
         .view => |view| &view.pending.box,
         .layer_surface => |layer_surface| &layer_surface.box,
+        .drag_icon => unreachable,
     };
     const output_dimensions = switch (parent) {
         .view => |view| view.output.getEffectiveResolution(),
         .layer_surface => |layer_surface| layer_surface.output.getEffectiveResolution(),
+        .drag_icon => unreachable,
     };
 
     // The output box relative to the parent of the popup