Kerosoft : Modus Operandi

どのイベントを拾うか

DPMS

Display *disp = XOpenDisplay(NULL);
CARD16 power_level;
BOOL state;
DPMSInfo(disp, &power_level, &state);
XCloseDisplay(disp);

$ xset q
Keyboard Control:
  auto repeat:  on    key click percent:  0    LED mask:  00000000
  XKB indicators:
    00: Caps Lock:   off    01: Num Lock:    off    02: Scroll Lock: off
    03: Compose:     off    04: Kana:        off    05: Sleep:       off
    06: Suspend:     off    07: Mute:        off    08: Misc:        off
    09: Mail:        off    10: Charging:    off    11: Shift Lock:  off
    12: Group 2:     off    13: Mouse Keys:  off
  auto repeat delay:  500    repeat rate:  33
  auto repeating keys:  00ffffffdffffbbf
                        fadfffefffedffff
                        9fffffffffffffff
                        fff7ffffffffffff
  bell percent:  50    bell pitch:  400    bell duration:  100
Pointer Control:
  acceleration:  2/1    threshold:  4
Screen Saver:
  prefer blanking:  yes    allow exposures:  yes
  timeout:  0    cycle:  0
Colors:
  default colormap:  0x3f    BlackPixel:  0x0    WhitePixel:  0xffffff
Font Path:
  catalogue:/etc/X11/fontpath.d,built-ins
DPMS (Display Power Management Signaling):
  Server does not have the DPMS Extension

$ xset q
Keyboard Control:
  auto repeat:  on    key click percent:  0    LED mask:  00000000
  XKB indicators:
    00: Caps Lock:   off    01: Num Lock:    off    02: Scroll Lock: off
    03: Compose:     off    04: Kana:        off    05: Sleep:       off
    06: Suspend:     off    07: Mute:        off    08: Misc:        off
    09: Mail:        off    10: Charging:    off    11: Shift Lock:  off
    12: Group 2:     off    13: Mouse Keys:  off
  auto repeat delay:  500    repeat rate:  33
  auto repeating keys:  00ffffffdffffbbf
                        fadfffefffedffff
                        9fffffffffffffff
                        fff7ffffffffffff
  bell percent:  50    bell pitch:  400    bell duration:  100
Pointer Control:
  acceleration:  2/1    threshold:  4
Screen Saver:
  prefer blanking:  yes    allow exposures:  yes
  timeout:  0    cycle:  0
Colors:
  default colormap:  0x20    BlackPixel:  0x0    WhitePixel:  0xffffff
Font Path:
  catalogue:/etc/X11/fontpath.d,built-ins
DPMS (Display Power Management Signaling):
  Standby: 0    Suspend: 0    Off: 0
  DPMS is Enabled
  Monitor is On

xrandr

$ DISPLAY=:1 xrandr
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
eDP-1 connected (normal left inverted right x axis y axis)
   1920x1080     60.04 +  60.01    59.97    59.96    59.93
   1680x1050     59.95    59.88
   1400x1050     59.98
   1600x900      59.99    59.94    59.95    59.82
   1280x1024     60.02
   1400x900      59.96    59.88
   1280x960      60.00
   1440x810      60.00    59.97
   1368x768      59.88    59.85
   1280x800      59.99    59.97    59.81    59.91
   1280x720      60.00    59.99    59.86    59.74
   1024x768      60.04    60.00
   960x720       60.00
   928x696       60.05
   896x672       60.01
   1024x576      59.95    59.96    59.90    59.82
   960x600       59.93    60.00
   960x540       59.96    59.99    59.63    59.82
   800x600       60.00    60.32    56.25
   840x525       60.01    59.88
   864x486       59.92    59.57
   700x525       59.98
   800x450       59.95    59.82
   640x512       60.02
   700x450       59.96    59.88
   640x480       60.00    59.94
   720x405       59.51    58.99
   684x384       59.88    59.85
   640x400       59.88    59.98
   640x360       59.86    59.83    59.84    59.32
   512x384       60.00
   512x288       60.00    59.92
   480x270       59.63    59.82
   400x300       60.32    56.34
   432x243       59.92    59.57
   320x240       60.05
   360x202       59.51    59.13
   320x180       59.84    59.32
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
DP-2 disconnected (normal left inverted right x axis y axis)
HDMI-2 disconnected (normal left inverted right x axis y axis)
  1920x1080 (0x9a) 148.500MHz +HSync +VSync
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  67.50KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  60.00Hz

(略)
HDMI-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 819mm x 461mm
   1920x1080     60.00*+  59.94    24.00    23.98    23.97
   1920x1080i    60.00    59.94
   1280x720      60.00    59.94
   1440x480i     59.94
   720x480       60.00    59.94
   720x480i      60.00    59.94
   640x480       60.00    59.94

libXrandr

Display *disp = XOpenDisplay(NULL);
Window root = DefaultRootWindow(disp);
XRRScreenResources *res = XRRGetScreenResources(disp, root);
for(int i=0; i<res->noutput; i++) {
    XRROutputInfo *info = XRRGetOutputInfo(disp, res, res->output[i]);
    if(!strcmp("HDMI-1", info->name) {
        printf("connection: %d\n", (info->connection & 0x1));
    }
    XRRFreeOutputInfo(info);
}
XRRFreeScreenResources(res);
XCloseDisplay(disp);

しばしテスト

XRRGetScreenResourcesを呼ぶと、ドロップフレームする

単発でinfo->connectionが変化するときがある

結局は…

Windowsでは？

• デバイスマネージャ上は、接続したときにデバイスが見え、その後はディスプレイ側の電源状態に関係無く接続済として見える
• SystemEvents.DisplaySettingsChangedにイベントハンドラーを登録しても、物理的な挿抜を伴わない状況では意味ない模様。
• GetDevicePowerStateでは、ディスプレイの電源状態は取れないとわざわざ書いてある。*4
• EnumDisplayMonitorsやQueryDisplayConfigを叩いてみた結果も同様。ディスプレイは消灯していても、デバイスとしては接続されているので、使用可というスタンスのようだ。
• WM_POWERBROADCAST - PBT_POWERSETTINGCHANGEのウィンドウメッセージハンドラをフックして云々については、Windows側の電源変化イベントをフックするのが目的であって、ディスプレイ側のイベント変化は取れない。