Dim MacBook keyboard backlight during video playback on OSX

This patch adds the option to smoothly turn off the keyboard backlight when
a video is playing in fullscreen, to the OSX user interface.
The option is off by default and it works better if the automatic
keyboard backlight adjustment is disabled in System Preferences.
Signed-off-by: David Fuhrmann <dfuhrmann@videolan.org>

modules/gui/macosx/KeyboardBacklight.h

+/*****************************************************************************
+ * KeyboardBacklight.h: MacBook keyboard backlight control for VLC
+ *****************************************************************************
+ * Copyright (C) 2015 VLC authors and VideoLAN
+ *
+ *
+ * Authors: Maxime Mouchet <max@maxmouchet.com>
+ *
+ * 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
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#import <Foundation/Foundation.h>
+#import <IOKit/IOKitLib.h>
+
+enum {
+    kGetSensorReadingID = 0, // getSensorReading(int *, int *)
+    kGetLEDBrightnessID = 1, // getLEDBrightness(int, int *)
+    kSetLEDBrightnessID = 2, // setLEDBrightness(int, int, int *)
+    kSetLEDFadeID = 3        // setLEDFade(int, int, int, int *)
+};
+
+@interface KeyboardBacklight : NSObject
+
+/*!
+ *  Initialize an instance of KeyboardBacklight.
+ *
+ *  Note: this will return nil if the connection to
+ *  the controller could not be opened.
+ */
+- (id)init;
+
+/*!
+ *  Smoothly turn on backlight on MacBook keyboard.
+ *
+ *  Try to restore the previous brightness level. If the user has put
+ *  the backlight on manually (using hardware keys), nothing will be done.
+ */
+- (void)lightsUp;
+
+/*!
+ *  Smoothly turn off backlight on MacBook keyboard.
+ */
+- (void)lightsDown;
+
+/*!
+ *  Smoothly switch on or off backlight on MacBook keyboard.
+ *  This will return immediately.
+ */
+- (void)switchLightsAsync:(BOOL)on;
+
+/*!
+ *  Instantly switch on or off backlight on MacBook keyboard.
+ */
+- (void)switchLightsInstantly:(BOOL)on;
+
+@end

modules/gui/macosx/KeyboardBacklight.m

+/*****************************************************************************
+ * KeyboardBacklight.m: MacBook keyboard backlight control for VLC
+ *****************************************************************************
+ * Copyright (C) 2015 VLC authors and VideoLAN
+ *
+ *
+ * Authors: Maxime Mouchet <max@maxmouchet.com>
+ *
+ * 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
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#import "KeyboardBacklight.h"
+
+@implementation KeyboardBacklight {
+    io_connect_t dataPort;
+}
+
+static float lastBrightnessLevel;
+
+- (id)init {
+    dataPort = [self getDataPort];
+    lastBrightnessLevel = [self getBrightness];
+    return self;
+}
+
+- (void)dealloc {
+    if (dataPort) { IOServiceClose(dataPort); }
+    [super dealloc];
+}
+
+- (io_connect_t)getDataPort {
+    if (dataPort) return dataPort;
+
+    io_service_t serviceObject = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("AppleLMUController"));
+
+    if (!serviceObject) return 0;
+
+    kern_return_t kr = IOServiceOpen(serviceObject, mach_task_self(), 0, &dataPort);
+    IOObjectRelease(serviceObject);
+
+    if (kr != KERN_SUCCESS) return 0;
+
+    return dataPort;
+}
+
+- (void)setBrightness:(float)brightness {
+    if (!dataPort) return;
+
+    UInt32 inputCount = 2;
+    UInt64 inputValues[2] = { 0, brightness * 0xfff };
+
+    UInt32 outputCount = 1;
+    UInt64 outputValues[1];
+
+    kern_return_t kr = IOConnectCallScalarMethod(dataPort,
+                                                 kSetLEDBrightnessID,
+                                                 inputValues,
+                                                 inputCount,
+                                                 outputValues,
+                                                 &outputCount);
+
+    if (kr != KERN_SUCCESS) return;
+}
+
+- (float)getBrightness {
+    if (!dataPort) return 0.0;
+
+    uint32_t inputCount = 1;
+    uint64_t inputValues[1] = { 0 };
+
+    uint32_t outputCount = 1;
+    uint64_t outputValues[1];
+
+    kern_return_t kr = IOConnectCallScalarMethod(dataPort,
+                                                 kGetLEDBrightnessID,
+                                                 inputValues,
+                                                 inputCount,
+                                                 outputValues,
+                                                 &outputCount);
+
+    float brightness = -1.0;
+    if (kr == KERN_SUCCESS) {
+        brightness = (float)outputValues[0] / 0xfff;
+    }
+
+    return brightness;
+}
+
+- (void)lightsUp {
+    if (!dataPort) return;
+
+    @synchronized(self) {
+        float start = [self getBrightness];
+        float target = lastBrightnessLevel;
+
+        // Don't do anything if the user has put
+        // backlight on again during playback.
+        if (start != 0) return;
+
+        for (float i = start; i <= target; i += 0.08) {
+            [self setBrightness:i];
+            [NSThread sleepForTimeInterval:0.05];
+        }
+
+        [self setBrightness:target];
+    }
+}
+
+- (void)lightsDown {
+    if (!dataPort) return;
+
+    @synchronized(self) {
+        float start = [self getBrightness];
+        float target = 0;
+
+        lastBrightnessLevel = start;
+
+        for (float i = start; i >= target; i -= 0.08) {
+            [self setBrightness:i];
+            [NSThread sleepForTimeInterval:0.05];
+        }
+
+        [self setBrightness:target];
+    }
+}
+
+- (void)switchLightsAsync:(BOOL)on {
+    if (on) {
+        [NSThread detachNewThreadSelector:@selector(lightsUp) toTarget:self withObject:nil];
+    } else {
+        [NSThread detachNewThreadSelector:@selector(lightsDown) toTarget:self withObject:nil];
+    }
+}
+
+- (void)switchLightsInstantly:(BOOL)on {
+    if (on) {
+        // Don't do anything if the user has put backlight on again during playback.
+        if ([self getBrightness] == 0) {
+            [self setBrightness:lastBrightnessLevel];
+        }
+    } else {
+        [self setBrightness:0];
+    }
+}
+
+@end

modules/gui/macosx/Modules.am

 AM_LIBTOOLFLAGS=--tag=CC
+AM_LDFLAGS=-framework IOKit
 
 SOURCES_macosx = \
 	CompatibilityFixes.h \
@@ -99,4 +100,6 @@ SOURCES_macosx = \
 	PLItem.m \
 	PLModel.h \
 	PLModel.m \
+	KeyboardBacklight.h \
+	KeyboardBacklight.m
 	$(NULL)

modules/gui/macosx/VLCVoutWindowController.h

@@ -25,6 +25,7 @@
 #import <Cocoa/Cocoa.h>
 
 #import <vlc_vout_window.h>
+#import "KeyboardBacklight.h"
 
 @class VLCVideoWindowCommon;
 @class VLCVoutView;
@@ -32,6 +33,7 @@
 @interface VLCVoutWindowController : NSObject
 {
     NSMutableDictionary *o_vout_dict;
+    KeyboardBacklight *o_keyboard_backlight;
 
     NSPoint top_left_point;
 

modules/gui/macosx/VLCVoutWindowController.m

@@ -40,6 +40,7 @@
 {
     self = [super init];
     o_vout_dict = [[NSMutableDictionary alloc] init];
+    o_keyboard_backlight = [[KeyboardBacklight alloc] init];
     i_currentWindowLevel = NSNormalWindowLevel;
     i_currentFloatingWindowLevel = NSFloatingWindowLevel;
     return self;
@@ -51,6 +52,11 @@
     for (NSValue *key in keys)
         [self removeVoutforDisplay:key];
 
+    if (var_InheritBool(VLCIntf, "macosx-dim-keyboard")) {
+        [o_keyboard_backlight switchLightsInstantly:YES];
+    }
+
+    [o_keyboard_backlight release];
     [o_vout_dict release];
     [super dealloc];
 }
@@ -339,6 +345,10 @@
     if(p_wnd)
         o_current_window = [o_vout_dict objectForKey:[NSValue valueWithPointer:p_wnd]];
 
+    if (var_InheritBool(p_intf, "macosx-dim-keyboard")) {
+        [o_keyboard_backlight switchLightsAsync:!b_fullscreen];
+    }
+
     if (b_nativeFullscreenMode) {
         if(!o_current_window)
             o_current_window = [VLCMainWindow sharedInstance];

modules/gui/macosx/macosx.m

@@ -107,6 +107,9 @@ void WindowClose  (vout_window_t *);
 
 #define LOCK_ASPECT_RATIO_TEXT N_("Lock Aspect Ratio")
 
+#define DIM_KEYBOARD_PLAYBACK_TEXT N_("Dim keyboard backlight during fullscreen playback")
+#define DIM_KEYBOARD_PLAYBACK_LONGTEXT N_("Turn off the MacBook keyboard backlight while a video is playing in fullscreen. Automatic brightness adjustment should be disabled in System Preferences.")
+
 #define JUMPBUTTONS_TEXT N_("Show Previous & Next Buttons")
 #define JUMPBUTTONS_LONGTEXT N_("Shows the previous and next buttons in the main window.")
 
@@ -168,6 +171,7 @@ vlc_module_begin()
         add_bool("macosx-video-autoresize", true, KEEPSIZE_TEXT, KEEPSIZE_LONGTEXT, false)
         add_bool("macosx-pause-minimized", false, PAUSE_MINIMIZED_TEXT, PAUSE_MINIMIZED_LONGTEXT, false)
         add_bool("macosx-lock-aspect-ratio", true, LOCK_ASPECT_RATIO_TEXT, LOCK_ASPECT_RATIO_TEXT, true)
+        add_bool("macosx-dim-keyboard", false, DIM_KEYBOARD_PLAYBACK_TEXT, DIM_KEYBOARD_PLAYBACK_LONGTEXT, false)
         add_integer("macosx-control-itunes", 1, ITUNES_TEXT, ITUNES_LONGTEXT, false)
         change_integer_list(itunes_list, itunes_list_text)
         add_integer("macosx-continue-playback", 0, CONTINUE_PLAYBACK_TEXT, CONTINUE_PLAYBACK_LONGTEXT, false)