wm/vend/xgbutil/_examples/simple-mousebinding/main.go

86 lines
3.1 KiB
Go

// Example simple-mousebinding shows how to grab buttons on the root window and
// respond to them via callback functions. It also shows how to remove such
// callbacks so that they no longer respond to the button events.
// Note that more documentation can be found in the mousebind package.
package main
import (
"log"
"github.com/jezek/xgbutil"
"github.com/jezek/xgbutil/mousebind"
"github.com/jezek/xgbutil/xevent"
)
func main() {
// Connect to the X server using the DISPLAY environment variable.
X, err := xgbutil.NewConn()
if err != nil {
log.Fatal(err)
}
// Anytime the mousebind (keybind) package is used, mousebind.Initialize
// *should* be called once. In the case of the mousebind package, this
// isn't strictly necessary, but the 'Drag' features of the mousebind
// package won't work without it.
mousebind.Initialize(X)
// Before attaching callbacks, wrap them in a callback function type.
// The mouse package exposes two such callback types:
// mousebind.ButtonPressFun and mousebind.ButtonReleaseFun.
cb1 := mousebind.ButtonPressFun(
func(X *xgbutil.XUtil, e xevent.ButtonPressEvent) {
log.Println("Button press!")
})
// We can now attach the callback to a particular window and button
// combination. This particular example grabs a button on the root window,
// which makes it a global mouse binding.
// Also, "Mod4-1" typically corresponds to pressing down the "Super" or
// "Windows" key on your keyboard, and then pressing the left mouse button.
// The last two parameters are whether to make a synchronous grab and
// whether to actually issue a grab, respectively.
// (The parameters used here are the common case.)
// See the documentation for the Connect method for more details.
err = cb1.Connect(X, X.RootWin(), "Mod4-1", false, true)
// A mouse binding can fail if the mouse string could not be parsed, or if
// you're trying to bind a button that has already been grabbed by another
// client.
if err != nil {
log.Fatal(err)
}
// We can even attach multiple callbacks to the same button.
err = mousebind.ButtonPressFun(
func(X *xgbutil.XUtil, e xevent.ButtonPressEvent) {
log.Println("A second handler always happens after the first.")
}).Connect(X, X.RootWin(), "Mod4-1", false, true)
if err != nil {
log.Fatal(err)
}
// Finally, if we want this client to stop responding to mouse events, we
// can attach another handler that, when run, detaches all previous
// handlers.
// This time, we'll show an example of a ButtonRelease binding.
err = mousebind.ButtonReleaseFun(
func(X *xgbutil.XUtil, e xevent.ButtonReleaseEvent) {
// Use mousebind.Detach to detach the root window
// from all ButtonPress *and* ButtonRelease handlers.
mousebind.Detach(X, X.RootWin())
mousebind.Detach(X, X.RootWin())
log.Printf("Detached all Button{Press,Release}Events from the "+
"root window (%d).", X.RootWin())
}).Connect(X, X.RootWin(), "Mod4-Shift-1", false, true)
if err != nil {
log.Fatal(err)
}
// Finally, start the main event loop. This will route any appropriate
// ButtonPressEvents to your callback function.
log.Println("Program initialized. Start pressing mouse buttons!")
xevent.Main(X)
}