/*
Package motif has a few functions to allow easy access to Motif related
properties.

The main purpose here is that some applications communicate "no window
decorations" to the window manager using _MOTIF_WM_HINTS. (Like Google
Chrome.) I haven't seen Motif stuff used for other purposes in the wild for
a long time.

As a result, only the useful bits are implemented here. More may be added
on an on-demand basis, but don't count on it.

Try not to bash your head against your desk too hard:
http://www.opengroup.org/openmotif/hardcopydocs.html

Example

To test if a window wants decorations or not:

	mh, err := motif.WmHintsGet(XUtilValue, window-id)
	if err != nil {
		log.Fatal(err)
	} else {
		log.Println("Decorations? ", motif.Decor(mh))
	}

*/
package motif

import (
	"fmt"

	"github.com/jezek/xgb/xproto"

	"github.com/jezek/xgbutil"
	"github.com/jezek/xgbutil/xprop"
)

const (
	HintFunctions = (1 << iota)
	HintDecorations
	HintInputMode
	HintStatus
)

const (
	FunctionAll = (1 << iota)
	FunctionResize
	FunctionMove
	FunctionMinimize
	FunctionMaximize
	FunctionClose
	FunctionNone = 0
)

const (
	DecorationAll = (1 << iota)
	DecorationBorder
	DecorationResizeH
	DecorationTitle
	DecorationMenu
	DecorationMinimize
	DecorationMaximize
	DecorationNone = 0
)

const (
	InputPrimaryApplicationModal = (1 << iota)
	InputSystemModal
	InputFullApplicationModal
	InputModeless = 0
)

const StatusTearoffWindow = 1

// Decor checks a Hints value for whether or not the client has requested
// that the window manager paint decorations.
// That is, Decor returns false when the hints provided indicate no
// decorations and true otherwise.
func Decor(mh *Hints) bool {
	if mh.Flags&HintDecorations > 0 {
		noDecor := mh.Decoration == DecorationNone ||
			(mh.Decoration&DecorationAll == 0 &&
				mh.Decoration&DecorationTitle == 0 &&
				mh.Decoration&DecorationResizeH == 0)
		return !noDecor
	}
	return true
}

// Hints is a struct that organizes the information related to the
// WM_NORMAL_HINTS property.
type Hints struct {
	Flags                               uint
	Function, Decoration, Input, Status uint
}

// _MOTIF_WM_HINTS get
func WmHintsGet(xu *xgbutil.XUtil, win xproto.Window) (mh *Hints, err error) {
	lenExpect := 5
	hints, err := xprop.PropValNums(xprop.GetProperty(xu, win,
		"_MOTIF_WM_HINTS"))
	if err != nil {
		return nil, err
	}
	if len(hints) != lenExpect {
		return nil,
			fmt.Errorf("motif.WmHintsGet: There are %d fields in "+
				"_MOTIF_WM_HINTS, but xgbutil expects %d.",
				len(hints), lenExpect)
	}

	mh = &Hints{}
	mh.Flags = hints[0]
	mh.Function = hints[1]
	mh.Decoration = hints[2]
	mh.Input = hints[3]
	mh.Status = hints[4]

	return
}

// _MOTIF_WM_HINTS set
func WmHintsSet(xu *xgbutil.XUtil, win xproto.Window, mh *Hints) error {
	raw := []uint{mh.Flags, mh.Function, mh.Decoration, mh.Input, mh.Status}
	return xprop.ChangeProp32(xu, win, "_MOTIF_WM_HINTS", "_MOTIF_WM_HINTS",
		raw...)
}