Implement wlr-output-power-management-unstable-v1 protocol

river/Output.zig

@@ -2,6 +2,7 @@
 //
 // Copyright 2020 Isaac Freund
 // Copyright 2020 Leon Henrik Plickat
+// Copyright 2020 Marten Ringwelski
 //
 // 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
@@ -600,6 +601,11 @@ fn handleFrame(listener: ?*c.wl_listener, data: ?*c_void) callconv(.C) void {
     // This function is called every time an output is ready to display a frame,
     // generally at the output's refresh rate (e.g. 60Hz).
     const self = @fieldParentPtr(Self, "listen_frame", listener.?);
+
+    // TODO(wlroots) Remove this check when we update wlroots 0.11 to 0.12
+    // wlroots fix: https://github.com/swaywm/wlroots/commit/85757665e6e1393773b36282aa244feb10b7a5fe
+    if (!self.wlr_output.enabled) return;
+
     render.renderOutput(self);
 }
 

river/Server.zig

@@ -51,6 +51,9 @@ listen_new_xdg_surface: c.wl_listener,
 wlr_layer_shell: *c.wlr_layer_shell_v1,
 listen_new_layer_surface: c.wl_listener,
 
+wlr_output_power_manager: *c.wlr_output_power_manager_v1,
+listen_output_power_manager_set_mode: c.wl_listener,
+
 wlr_xwayland: if (build_options.xwayland) *c.wlr_xwayland else void,
 listen_new_xwayland_surface: if (build_options.xwayland) c.wl_listener else void,
 
@@ -100,6 +103,11 @@ pub fn init(self: *Self) !void {
     const wlr_compositor = c.wlr_compositor_create(self.wl_display, wlr_renderer) orelse
         return error.OutOfMemory;
 
+    // Set up output power manager
+    self.wlr_output_power_manager = c.wlr_output_power_manager_v1_create(self.wl_display);
+    self.listen_output_power_manager_set_mode.notify = handleOutputPowerManagementSetMode;
+    c.wl_signal_add(&self.wlr_output_power_manager.events.set_mode, &self.listen_output_power_manager_set_mode);
+
     // Set up xdg shell
     self.wlr_xdg_shell = c.wlr_xdg_shell_create(self.wl_display) orelse return error.OutOfMemory;
     self.listen_new_xdg_surface.notify = handleNewXdgSurface;
@@ -284,3 +292,28 @@ fn handleNewXwaylandSurface(listener: ?*c.wl_listener, data: ?*c_void) callconv(
     const node = util.gpa.create(ViewStack(View).Node) catch return;
     node.view.init(output, output.current.tags, wlr_xwayland_surface);
 }
+
+fn handleOutputPowerManagementSetMode(listener: ?*c.wl_listener, data: ?*c_void) callconv(.C) void {
+    const self = @fieldParentPtr(Self, "listen_output_power_manager_set_mode", listener.?);
+    const mode_event = util.voidCast(c.wlr_output_power_v1_set_mode_event, data.?);
+    const wlr_output: *c.wlr_output = mode_event.output;
+
+    const enable = mode_event.mode == .ZWLR_OUTPUT_POWER_V1_MODE_ON;
+
+    const log_text = if (enable) "Enabling" else "Disabling";
+    log.debug(
+        .server,
+        "{} dpms for output {}",
+        .{log_text, wlr_output.name},
+    );
+
+    c.wlr_output_enable(wlr_output, enable);
+    if (!c.wlr_output_commit(wlr_output)) {
+        log.err(
+            .server,
+            "wlr_output_commit failed for {}",
+            .{wlr_output.name},
+        );
+    }
+
+}

river/c.zig

@@ -47,6 +47,7 @@ pub usingnamespace @cImport({
     @cInclude("wlr/types/wlr_matrix.h");
     @cInclude("wlr/types/wlr_output.h");
     @cInclude("wlr/types/wlr_output_layout.h");
+    @cInclude("wlr/types/wlr_output_power_management_v1.h");
     @cInclude("wlr/types/wlr_pointer.h");
     @cInclude("wlr/types/wlr_primary_selection.h");
     @cInclude("wlr/types/wlr_primary_selection_v1.h");