wm/vend/xgbutil/xgbutil.go

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2023-06-11 14:21:08 +00:00
package xgbutil
import (
"log"
"os"
"sync"
"github.com/jezek/xgb"
"github.com/jezek/xgb/xinerama"
"github.com/jezek/xgb/xproto"
)
// Logger is used through xgbutil when messages need to be emitted to stderr.
var Logger = log.New(os.Stderr, "[xgbutil] ", log.Lshortfile)
// The current maximum request size. I think we can expand this with
// BigReq, but it probably isn't worth it at the moment.
const MaxReqSize = (1 << 16) * 4
// An XUtil represents the state of xgbutil. It keeps track of the current
// X connection, the root window, event callbacks, key/mouse bindings, etc.
// Regrettably, many of the members are exported, even though they should not
// be used directly by the user. They are exported for use in sub-packages.
// (Namely, xevent, keybind and mousebind.) In fact, there should *never*
// be a reason to access any members of an XUtil value directly. Any
// interaction with an XUtil value should be through its methods.
type XUtil struct {
// conn is the XGB connection object used to issue protocol requests.
conn *xgb.Conn
// Quit can be set to true, and the main event loop will finish processing
// the current event, and gracefully quit afterwards.
// This is exported for use in the xevent package. Please us xevent.Quit
// to set this value.
Quit bool // when true, the main event loop will stop gracefully
// setup contains all the setup information retrieved at connection time.
setup *xproto.SetupInfo
// screen is a simple alias to the default screen info.
screen *xproto.ScreenInfo
// root is an alias to the default root window.
root xproto.Window
// Atoms is a cache of atom names to resource identifiers. This minimizes
// round trips to the X server, since atom identifiers never change.
// It is exported for use in the xprop package. It should not be used.
Atoms map[string]xproto.Atom
AtomsLck *sync.RWMutex
// AtomNames is a cache just like 'atoms', but in the reverse direction.
// It is exported for use in the xprop package. It should not be used.
AtomNames map[xproto.Atom]string
AtomNamesLck *sync.RWMutex
// Evqueue is the queue that stores the results of xgb.WaitForEvent.
// Namely, each value is either an Event *or* an Error.
// It is exported for use in the xevent package. Do not use it.
// If you need to interact with the event queue, please use the functions
// available in the xevent package: Dequeue, DequeueAt, QueueEmpty
// and QueuePeek.
Evqueue []EventOrError
EvqueueLck *sync.RWMutex
// Callbacks is a map of event numbers to a map of window identifiers
// to callback functions.
// This is the data structure that stores all callback functions, where
// a callback function is always attached to a (event, window) tuple.
// It is exported for use in the xevent package. Do not use it.
Callbacks map[int]map[xproto.Window][]Callback
CallbacksLck *sync.RWMutex
// Hooks are called by the XEvent main loop before processing the event
// itself. These are meant for instances when it's not possible / easy
// to use the normal Hook system. You should not modify this yourself.
Hooks []CallbackHook
HooksLck *sync.RWMutex
// eventTime is the last time recorded by an event. It is automatically
// updated if xgbutil's main event loop is used.
eventTime xproto.Timestamp
// Keymap corresponds to xgbutil's current conception of the keyboard
// mapping. It is automatically kept up-to-date if xgbutil's event loop
// is used.
// It is exported for use in the keybind package. It should not be
// accessed directly. Instead, use keybind.KeyMapGet.
Keymap *KeyboardMapping
// Modmap corresponds to xgbutil's current conception of the modifier key
// mapping. It is automatically kept up-to-date if xgbutil's event loop
// is used.
// It is exported for use in the keybind package. It should not be
// accessed directly. Instead, use keybind.ModMapGet.
Modmap *ModifierMapping
// KeyRedirect corresponds to a window identifier that, when set,
// automatically receives *all* keyboard events. This is a sort-of
// synthetic grab and is helpful in avoiding race conditions.
// It is exported for use in the xevent and keybind packages. Do not use
// it directly. To redirect key events, please use xevent.RedirectKeyEvents.
KeyRedirect xproto.Window
// Keybinds is the data structure storing all callbacks for key bindings.
// This is extremely similar to the general notion of event callbacks,
// but adds extra support to make handling key bindings easier. (Like
// specifying human readable key sequences to bind to.)
// KeyBindKey is a struct representing the 4-tuple
// (event-type, window-id, modifiers, keycode).
// It is exported for use in the keybind package. Do not access it directly.
Keybinds map[KeyKey][]CallbackKey
KeybindsLck *sync.RWMutex
// Keygrabs is a frequency count of the number of callbacks associated
// with a particular KeyBindKey. This is necessary because we can only
// grab a particular key *once*, but we may want to attach several callbacks
// to a single keypress.
// It is exported for use in the keybind package. Do not access it directly.
Keygrabs map[KeyKey]int
// Keystrings is a list of all key strings used to connect keybindings.
// They are used to rebuild key grabs when the keyboard mapping is updated.
// It is exported for use in the keybind package. Do not access it directly.
Keystrings []KeyString
// Mousebinds is the data structure storing all callbacks for mouse
// bindings.This is extremely similar to the general notion of event
// callbacks,but adds extra support to make handling mouse bindings easier.
// (Like specifying human readable mouse sequences to bind to.)
// MouseBindKey is a struct representing the 4-tuple
// (event-type, window-id, modifiers, button).
// It is exported for use in the mousebind package. Do not use it.
Mousebinds map[MouseKey][]CallbackMouse
MousebindsLck *sync.RWMutex
// Mousegrabs is a frequency count of the number of callbacks associated
// with a particular MouseBindKey. This is necessary because we can only
// grab a particular mouse button *once*, but we may want to attach
// several callbacks to a single button press.
// It is exported for use in the mousebind package. Do not use it.
Mousegrabs map[MouseKey]int
// InMouseDrag is true if a drag is currently in progress.
// It is exported for use in the mousebind package. Do not use it.
InMouseDrag bool
// MouseDragStep is the function executed for each step (i.e., pointer
// movement) in the current mouse drag. Note that this is nil when a drag
// is not in progress.
// It is exported for use in the mousebind package. Do not use it.
MouseDragStepFun MouseDragFun
// MouseDragEnd is the function executed at the end of the current
// mouse drag. This is nil when a drag is not in progress.
// It is exported for use in the mousebind package. Do not use it.
MouseDragEndFun MouseDragFun
// gc is a general purpose graphics context; used to paint images.
// Since we don't do any real X drawing, we don't really care about the
// particulars of our graphics context.
gc xproto.Gcontext
// dummy is a dummy window used for mouse/key GRABs.
// Basically, whenever a grab is instituted, mouse and key events are
// redirected to the dummy the window.
dummy xproto.Window
// ErrorHandler is the function that handles errors *in the event loop*.
// By default, it simply emits them to stderr.
// It is exported for use in the xevent package. To set the default error
// handler, please use xevent.ErrorHandlerSet.
ErrorHandler ErrorHandlerFun
}
// NewConn connects to the X server using the DISPLAY environment variable
// and creates a new XUtil. Most environments have the DISPLAY environment
// variable set, so this is probably what you want to use to connect to X.
func NewConn() (*XUtil, error) {
return NewConnDisplay("")
}
// NewConnDisplay connects to the X server and creates a new XUtil.
// If 'display' is empty, the DISPLAY environment variable is used. Otherwise
// there are several different display formats supported:
//
// NewConn(":1") -> net.Dial("unix", "", "/tmp/.X11-unix/X1")
// NewConn("/tmp/launch-12/:0") -> net.Dial("unix", "", "/tmp/launch-12/:0")
// NewConn("hostname:2.1") -> net.Dial("tcp", "", "hostname:6002")
// NewConn("tcp/hostname:1.0") -> net.Dial("tcp", "", "hostname:6001")
func NewConnDisplay(display string) (*XUtil, error) {
c, err := xgb.NewConnDisplay(display)
if err != nil {
return nil, err
}
return NewConnXgb(c)
}
// NewConnXgb use the specific xgb.Conn to create a new XUtil.
//
// NewConn, NewConnDisplay are wrapper of this function.
func NewConnXgb(c *xgb.Conn) (*XUtil, error) {
setup := xproto.Setup(c)
screen := setup.DefaultScreen(c)
// Initialize our central struct that stores everything.
xu := &XUtil{
conn: c,
Quit: false,
Evqueue: make([]EventOrError, 0, 1000),
EvqueueLck: &sync.RWMutex{},
setup: setup,
screen: screen,
root: screen.Root,
eventTime: xproto.Timestamp(0), // last event time
Atoms: make(map[string]xproto.Atom, 50),
AtomsLck: &sync.RWMutex{},
AtomNames: make(map[xproto.Atom]string, 50),
AtomNamesLck: &sync.RWMutex{},
Callbacks: make(map[int]map[xproto.Window][]Callback, 33),
CallbacksLck: &sync.RWMutex{},
Hooks: make([]CallbackHook, 0),
HooksLck: &sync.RWMutex{},
Keymap: nil, // we don't have anything yet
Modmap: nil,
KeyRedirect: 0,
Keybinds: make(map[KeyKey][]CallbackKey, 10),
KeybindsLck: &sync.RWMutex{},
Keygrabs: make(map[KeyKey]int, 10),
Keystrings: make([]KeyString, 0, 10),
Mousebinds: make(map[MouseKey][]CallbackMouse, 10),
MousebindsLck: &sync.RWMutex{},
Mousegrabs: make(map[MouseKey]int, 10),
InMouseDrag: false,
MouseDragStepFun: nil,
MouseDragEndFun: nil,
ErrorHandler: func(err xgb.Error) { Logger.Println(err) },
}
var err error = nil
// Create a general purpose graphics context
xu.gc, err = xproto.NewGcontextId(xu.conn)
if err != nil {
return nil, err
}
xproto.CreateGC(xu.conn, xu.gc, xproto.Drawable(xu.root),
xproto.GcForeground, []uint32{xu.screen.WhitePixel})
// Create a dummy window
xu.dummy, err = xproto.NewWindowId(xu.conn)
if err != nil {
return nil, err
}
xproto.CreateWindow(xu.conn, xu.Screen().RootDepth, xu.dummy, xu.RootWin(),
-1000, -1000, 1, 1, 0,
xproto.WindowClassInputOutput, xu.Screen().RootVisual,
xproto.CwEventMask|xproto.CwOverrideRedirect,
[]uint32{1, xproto.EventMaskPropertyChange})
xproto.MapWindow(xu.conn, xu.dummy)
// Register the Xinerama extension... because it doesn't cost much.
err = xinerama.Init(xu.conn)
// If we can't register Xinerama, that's okay. Output something
// and move on.
if err != nil {
Logger.Printf("WARNING: %s\n", err)
Logger.Printf("MESSAGE: The 'xinerama' package cannot be used " +
"because the XINERAMA extension could not be loaded.")
}
return xu, nil
}
// Conn returns the xgb connection object.
func (xu *XUtil) Conn() *xgb.Conn {
return xu.conn
}
// ExtInitialized returns true if an extension has been initialized.
// This is useful for determining whether an extension is available or not.
func (xu *XUtil) ExtInitialized(extName string) bool {
_, ok := xu.Conn().Extensions[extName]
return ok
}
// Sync forces XGB to catch up with all events/requests and synchronize.
// This is done by issuing a benign round trip request to X.
func (xu *XUtil) Sync() {
xproto.GetInputFocus(xu.Conn()).Reply()
}
// Setup returns the setup information retrieved during connection time.
func (xu *XUtil) Setup() *xproto.SetupInfo {
return xu.setup
}
// Screen returns the default screen
func (xu *XUtil) Screen() *xproto.ScreenInfo {
return xu.screen
}
// RootWin returns the current root window.
func (xu *XUtil) RootWin() xproto.Window {
return xu.root
}
// RootWinSet will change the current root window to the one provided.
// N.B. This probably shouldn't be used unless you're desperately trying
// to support multiple X screens. (This is *not* the same as Xinerama/RandR or
// TwinView. All of those have a single root window.)
func (xu *XUtil) RootWinSet(root xproto.Window) {
xu.root = root
}
// TimeGet gets the most recent time seen by an event.
func (xu *XUtil) TimeGet() xproto.Timestamp {
return xu.eventTime
}
// TimeSet sets the most recent time seen by an event.
func (xu *XUtil) TimeSet(t xproto.Timestamp) {
xu.eventTime = t
}
// GC gets a general purpose graphics context that is typically used to simply
// paint images.
func (xu *XUtil) GC() xproto.Gcontext {
return xu.gc
}
// Dummy gets the id of the dummy window.
func (xu *XUtil) Dummy() xproto.Window {
return xu.dummy
}
// Grabs the server. Everything becomes synchronous.
func (xu *XUtil) Grab() {
xproto.GrabServer(xu.Conn())
}
// Ungrabs the server.
func (xu *XUtil) Ungrab() {
xproto.UngrabServer(xu.Conn())
}