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

build.zig

@@ -153,6 +153,7 @@ const ScanProtocolsStep = struct {
         const protocol_dir_paths = [_][]const []const u8{
             &[_][]const u8{ protocol_dir, "stable/xdg-shell/xdg-shell.xml" },
             &[_][]const u8{ "protocol", "wlr-layer-shell-unstable-v1.xml" },
+            &[_][]const u8{ "protocol", "wlr-output-power-management-unstable-v1.xml" },
             &[_][]const u8{ "protocol", "river-control-unstable-v1.xml" },
             &[_][]const u8{ "protocol", "river-status-unstable-v1.xml" },
         };
@@ -160,6 +161,7 @@ const ScanProtocolsStep = struct {
         const server_protocols = [_][]const u8{
             "xdg-shell",
             "wlr-layer-shell-unstable-v1",
+            "wlr-output-power-management-unstable-v1",
             "river-control-unstable-v1",
             "river-status-unstable-v1",
         };

protocol/wlr-output-power-management-unstable-v1.xml

@@ -0,0 +1,128 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<protocol name="wlr_output_power_management_unstable_v1">
+  <copyright>
+    Copyright © 2019 Purism SPC
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice (including the next
+    paragraph) shall be included in all copies or substantial portions of the
+    Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+  </copyright>
+
+  <description summary="Control power management modes of outputs">
+    This protocol allows clients to control power management modes
+    of outputs that are currently part of the compositor space. The
+    intent is to allow special clients like desktop shells to power
+    down outputs when the system is idle.
+
+    To modify outputs not currently part of the compositor space see
+    wlr-output-management.
+
+    Warning! The protocol described in this file is experimental and
+    backward incompatible changes may be made. Backward compatible changes
+    may be added together with the corresponding interface version bump.
+    Backward incompatible changes are done by bumping the version number in
+    the protocol and interface names and resetting the interface version.
+    Once the protocol is to be declared stable, the 'z' prefix and the
+    version number in the protocol and interface names are removed and the
+    interface version number is reset.
+  </description>
+
+  <interface name="zwlr_output_power_manager_v1" version="1">
+    <description summary="manager to create per-output power management">
+      This interface is a manager that allows creating per-output power
+      management mode controls.
+    </description>
+
+    <request name="get_output_power">
+      <description summary="get a power management for an output">
+        Create an output power management mode control that can be used to
+        adjust the power management mode for a given output.
+      </description>
+      <arg name="id" type="new_id" interface="zwlr_output_power_v1"/>
+      <arg name="output" type="object" interface="wl_output"/>
+    </request>
+
+    <request name="destroy" type="destructor">
+      <description summary="destroy the manager">
+        All objects created by the manager will still remain valid, until their
+        appropriate destroy request has been called.
+      </description>
+    </request>
+  </interface>
+
+  <interface name="zwlr_output_power_v1" version="1">
+    <description summary="adjust power management mode for an output">
+      This object offers requests to set the power management mode of
+      an output.
+    </description>
+
+    <enum name="mode">
+      <entry name="off" value="0"
+             summary="Output is turned off."/>
+      <entry name="on" value="1"
+             summary="Output is turned on, no power saving"/>
+    </enum>
+
+    <enum name="error">
+      <entry name="invalid_mode" value="1" summary="nonexistent power save mode"/>
+    </enum>
+
+    <request name="set_mode">
+      <description summary="Set an outputs power save mode">
+        Set an output's power save mode to the given mode. The mode change
+        is effective immediately. If the output does not support the given
+        mode a failed event is sent.
+      </description>
+      <arg name="mode" type="uint" enum="mode" summary="the power save mode to set"/>
+    </request>
+
+    <event name="mode">
+      <description summary="Report a power management mode change">
+        Report the power management mode change of an output.
+
+        The mode event is sent after an output changed its power
+        management mode. The reason can be a client using set_mode or the
+        compositor deciding to change an output's mode.
+        This event is also sent immediately when the object is created
+        so the client is informed about the current power management mode.
+      </description>
+      <arg name="mode" type="uint" enum="mode"
+           summary="the output's new power management mode"/>
+    </event>
+
+    <event name="failed">
+      <description summary="object no longer valid">
+        This event indicates that the output power management mode control
+        is no longer valid. This can happen for a number of reasons,
+        including:
+        - The output doesn't support power management
+        - Another client already has exclusive power management mode control
+          for this output
+        - The output disappeared
+
+        Upon receiving this event, the client should destroy this object.
+      </description>
+    </event>
+
+    <request name="destroy" type="destructor">
+      <description summary="destroy this power management">
+        Destroys the output power management mode control object.
+      </description>
+    </request>
+  </interface>
+</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");