75 lines
1.5 KiB
Go
75 lines
1.5 KiB
Go
package display
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// #cgo CFLAGS: --std=gnu99 -pedantic -Wall
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// #cgo LDFLAGS: -lX11 -lXext
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// #include "dpms.h"
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// #include <stdlib.h>
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// #include <stdbool.h>
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import "C"
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import (
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"unsafe"
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"errors"
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"os"
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)
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// Xset monitors/controls the display using the DPMS X extension
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type Xset struct {}
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// Suspend the display
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func (Xset) Suspend() error {
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xDisplayName := C.CString(tryGetXDisplay())
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defer C.free(unsafe.Pointer(xDisplayName))
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err := C.turn_display_off(xDisplayName)
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if err != C.int(0) {
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return convertErrorIntToGoError(err)
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}
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return nil
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}
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func tryGetXDisplay() string {
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display := os.Getenv("DISPLAY")
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if display == "" {
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panic(errors.New("DISPLAY envvar not set"))
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}
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return display
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}
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func convertErrorIntToGoError(err C.int) error {
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errorMsg := ""
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switch err {
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case C.BADDISPLAY:
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errorMsg = "Failed to open X display"
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case C.NODPMSEXTENSION:
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errorMsg = "DPMS extension is not available"
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case C.NOTDPMSCAPABLE:
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errorMsg = "Display is not DPMS capable"
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case C.UNKNOWNDPMSMODE:
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errorMsg = "Reported DPMS state unknown"
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case C.DPMSDISABLED:
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errorMsg = "DPMS is disabled"
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default:
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errorMsg = "Unknown error from dpms.h"
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}
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return errors.New(errorMsg)
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}
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// IsOn determines if the display is on
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func (Xset) IsOn() (bool, error) {
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xDisplayName := C.CString(tryGetXDisplay())
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defer C.free(unsafe.Pointer(xDisplayName))
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var isDisplayOn C.bool
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err := C.is_display_on(xDisplayName, &isDisplayOn)
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if err != C.int(0) {
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return false, convertErrorIntToGoError(err)
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}
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if isDisplayOn {
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return true, nil
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}
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return false, nil
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}
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