Group lockscreen and display suspension related code

xdg/display/display.go

@@ -0,0 +1,48 @@
+package display
+
+import (
+	"os/exec"
+	"regexp"
+	"strings"
+)
+
+
+// Xset monitors/controls the display using xset
+type Xset struct {}
+
+// Suspend the display
+func (Xset) Suspend() error {
+	cmd := exec.Command("xset",
+		"dpms",
+		"force",
+		"suspend",
+	)
+	return cmd.Run()
+}
+
+// IsOn determines if the display is on
+func (Xset) IsOn() (bool, error) {
+	cmd := exec.Command("xset", "q")
+	outputBytes, err := cmd.CombinedOutput()
+	if err != nil {
+		return false, err
+	}
+	return determineIfDisplayIsOn(string(outputBytes)), nil
+}
+
+func determineIfDisplayIsOn(xsetOutput string) bool {
+	if ! strings.Contains(xsetOutput, "Monitor") {
+		// after booting xset q is missing this line
+		// lacking better ideas assume display is on
+		return true
+	}
+
+	re := regexp.MustCompile(`Monitor is (\w+)`)
+	matches := re.FindStringSubmatch(xsetOutput)
+	if len(matches) >= 2 {
+		if matches[1] == "On" {
+			return true
+		}
+	}
+	return false
+}

xdg/keypressdetector/evdev.c

@@ -0,0 +1,33 @@
+#include "evdev.h"
+
+
+int block_until_keypress(const char* keyboardPath) {
+    int keyboardFd = open(keyboardPath, O_RDONLY);
+    if (keyboardFd < 0) {
+        return keyboardFd;
+    }
+
+    int eventSize = sizeof(struct input_event);
+    int bytesRead = 0;
+    struct input_event events[NUM_EVENTS];
+
+    int readEvents = 1;
+    while(readEvents) {
+        bytesRead = read(keyboardFd, events, eventSize * NUM_EVENTS);
+        if (bytesRead < 0) {
+            return bytesRead;
+        }
+
+        for(int i = 0; i < (bytesRead / eventSize); ++i) {
+            struct input_event event = events[i];
+            if(event.type == EV_KEY) {
+                if(event.value == 1) {
+                    readEvents = 0;
+                }
+            }
+        }
+    }
+
+    close(keyboardFd);
+    return 0;
+}

xdg/keypressdetector/evdev.go

@@ -0,0 +1,28 @@
+package keypressdetector
+
+// #cgo CFLAGS: -g -Wall
+// #include "evdev.h"
+// #include <stdlib.h>
+import "C"
+
+import (
+	"unsafe"
+	"syscall"
+)
+
+
+// Evdev can detect keypresses on /dev/input devices
+type Evdev struct {}
+
+// BlockUntilKeypress waits until a key is pressed on the specified device
+func (Evdev) BlockUntilKeypress(devicePath string) error {
+	path := C.CString(devicePath)
+	defer C.free(unsafe.Pointer(path))
+
+	ret := C.block_until_keypress(path)
+	if ret < 0 {
+		return syscall.Errno(ret)
+	}
+
+	return nil
+}

xdg/keypressdetector/evdev.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include <linux/input.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+
+#define NUM_EVENTS 128
+
+int block_until_keypress(const char* keyboardPath);

xdg/lockscreen/lockscreen.go

@@ -0,0 +1,29 @@
+package lockscreen
+
+import (
+	"os/exec"
+	"strings"
+)
+
+
+// XDG uses qdbus to monitor the freedesktop screensaver status
+type XDG struct {}
+
+// IsActive checks whether the screen is locked (checks if the screensaver is active)
+func (XDG) IsActive() (bool, error) {
+	cmd := exec.Command("qdbus",
+		"org.kde.screensaver",
+		"/ScreenSaver",
+		"org.freedesktop.ScreenSaver.GetActive",
+	)
+	outputBytes, err := cmd.CombinedOutput()
+	if err != nil {
+		return false, err
+	}
+	output := string(outputBytes)
+
+	if strings.HasPrefix(output, "true") {
+		return true, nil
+	}
+	return false, nil
+}