// When a cross is declared in its object literal form, it may not have the appropriate window.
// this function creates a new X11 window for the cross with the correct geometry depending
// on its Icon* parameters.
func (c *Cross) CreateWindow(X *xgbutil.XUtil, icons_per_direction int, bg_color uint32) (*xwindow.Window, error) {

	// calculate the dimensions of the spars of our cross +
	// width/height reflect the vertical-orientation rectangle
	width := c.IconMargin*2 + c.IconSize
	// padding between the icons, margin on the edges
	height := c.IconSize*icons_per_direction + c.IconPadding*(icons_per_direction-1) + c.IconMargin*2

	// intitialize a basic window for the cross
	win, err := xwindow.Generate(X)
	if err != nil {
		return nil, err
	}

	win.Create(X.RootWin(), 0, 0, height, height,
		xproto.CwBackPixel|xproto.CwOverrideRedirect, bg_color, 1)

	// the rects we will be adding together to form the shape of the cross
	vert := xrect.New(0, 0, width, height)
	horiz := xrect.New(0, 0, height, width)
	struts := []xrect.Rect{vert, horiz}

	geom, err := win.Geometry()
	if err != nil {
		return nil, err
	}

	// center struts over window
	x, y := util.CenterChild(vert, geom)
	vert.XSet(x)
	vert.YSet(y)
	x, y = util.CenterChild(horiz, geom)
	horiz.XSet(x)
	horiz.YSet(y)

	// build the cross shape from our friendly rectangles
	err = ComposeShape(X, win.Id, struts)
	if err != nil {
		return nil, err
	}

	// add the window to our cross struct
	c.Window = win

	// create icons from our images
	clr := RGB(bg_color)
	if c.imagesToBecomeIcons != nil {
		icons := make(map[string]*Icon, len(c.imagesToBecomeIcons))
		for name, img := range c.imagesToBecomeIcons {
			icon := NewIcon(X, img, win.Id)
			icon.Background = clr
			icons[name] = icon
		}
		c.Icons = icons
	} else {
		return nil, errors.New("Cross: you must create crosses using the NewCross function (this cross has now iconsToBecomeImage)")
	}

	return win, nil
}

func (c *Client) newClientState() clientState {
	s := clientState{
		geom:      xrect.New(xrect.Pieces(c.frame.Geom())),
		headGeom:  nil,
		frame:     c.frame,
		maximized: c.maximized,
	}
	if c.workspace.IsVisible() {
		s.headGeom = xrect.New(xrect.Pieces(c.workspace.HeadGeom()))
	}
	return s
}

func (c *Client) maybeInitPlace(presumedWorkspace workspace.Workspacer) {
	// This is a hack. Before a client gets sucked into some layout, we
	// always want to have some floating state to fall back on to. However,
	// by the time we're "allowed" to save the client's state, it will have
	// already been placed in the hands of some layout---which may or may
	// not be floating. So we inject our own state forcefully here.
	defer func() {
		wrk := presumedWorkspace
		if wrk.IsVisible() {
			c.states["last-floating"] = clientState{
				geom:      xrect.New(xrect.Pieces(c.frame.Geom())),
				headGeom:  xrect.New(xrect.Pieces(wrk.HeadGeom())),
				frame:     c.frame,
				maximized: c.maximized,
			}
		}
	}()

	// Any client that isn't normal doesn't get placed.
	// Let it do what it do, baby.
	if c.PrimaryType() != TypeNormal {
		return
	}

	// If it's sticky, let it do what it do.
	if _, ok := presumedWorkspace.(*workspace.Sticky); ok {
		return
	}

	// Transients never get placed.
	if c.transientFor != nil {
		return
	}

	// If a user/program position is specified, do not place.
	if c.nhints.Flags&icccm.SizeHintUSPosition > 0 ||
		c.nhints.Flags&icccm.SizeHintPPosition > 0 {

		return
	}

	// We're good, do a placement unless we're already mapped or on a
	// hidden workspace..
	if !presumedWorkspace.IsVisible() || !c.isAttrsUnmapped() {
		return
	}
	w := presumedWorkspace.(*workspace.Workspace)
	w.LayoutFloater().InitialPlacement(c)
}

// PhyiscalHeads returns the list of heads in a physical ordering.
// Namely, left to right then top to bottom. (Defined by (X, Y).)
// Xinerama must have been initialized, otherwise the xinerama.QueryScreens
// request will panic.
// PhysicalHeads also checks to make sure each rectangle has a unique (x, y)
// tuple, so as not to return the geometry of cloned displays.
// (At present moment, xgbutil initializes Xinerama automatically during
// initial connection.)
func PhysicalHeads(xu *xgbutil.XUtil) (Heads, error) {
	xinfo, err := xinerama.QueryScreens(xu.Conn()).Reply()
	if err != nil {
		return nil, err
	}

	hds := make(Heads, 0)
	for _, info := range xinfo.ScreenInfo {
		head := xrect.New(int(info.XOrg), int(info.YOrg),
			int(info.Width), int(info.Height))

		// Maybe Xinerama is enabled, but we have cloned displays...
		unique := true
		for _, h := range hds {
			if h.X() == head.X() && h.Y() == head.Y() {
				unique = false
				break
			}
		}

		if unique {
			hds = append(hds, head)
		}
	}

	sort.Sort(hds)
	return hds, nil
}

func query(X *xgbutil.XUtil) xinerama.Heads {
	if X.ExtInitialized("XINERAMA") {
		heads, err := xinerama.PhysicalHeads(X)
		if err != nil || len(heads) == 0 {
			if err == nil {
				logger.Warning.Printf("Could not find any physical heads " +
					"with the Xinerama extension.")
			} else {
				logger.Warning.Printf("Could not load physical heads via "+
					"Xinerama: %s", err)
			}
			logger.Warning.Printf("Assuming one head with size equivalent " +
				"to the root window.")
		} else {
			return heads
		}
	}

	// If we're here, then something went wrong or the Xinerama extension
	// isn't available. So query the root window for its geometry and use that.
	rgeom := xwindow.RootGeometry(X)
	return xinerama.Heads{
		xrect.New(rgeom.X(), rgeom.Y(), rgeom.Width(), rgeom.Height()),
	}
}

func (hds *Heads) ApplyStruts(clients Clients) {
	hds.workarea = make(xinerama.Heads, len(hds.geom))
	for i, hd := range hds.geom {
		hds.workarea[i] = xrect.New(hd.X(), hd.Y(), hd.Width(), hd.Height())
	}

	rgeom := xwindow.RootGeometry(hds.X)
	for i := 0; i < clients.Len(); i++ {
		c := clients.Get(i)

		strut, _ := ewmh.WmStrutPartialGet(hds.X, c.Id())
		if strut == nil {
			continue
		}
		xrect.ApplyStrut(hds.workarea, rgeom.Width(), rgeom.Height(),
			strut.Left, strut.Right, strut.Top, strut.Bottom,
			strut.LeftStartY, strut.LeftEndY,
			strut.RightStartY, strut.RightEndY,
			strut.TopStartX, strut.TopEndX,
			strut.BottomStartX, strut.BottomEndX)
	}
	for _, wrk := range hds.workspaces.Wrks {
		wrk.Place()
	}
}

func (cmd Focus) Run() gribble.Value {
	return syncRun(func() gribble.Value {
		return withClient(cmd.Client, func(c *xclient.Client) {
			if c == nil {
				focus.Root()

				// Use the mouse coordinates to find which workspace it was
				// clicked in. If a workspace can be found (i.e., no clicks in
				// dead areas), then activate it.
				xc, rw := wm.X.Conn(), wm.X.RootWin()
				qp, err := xproto.QueryPointer(xc, rw).Reply()
				if err != nil {
					logger.Warning.Printf("Could not query pointer: %s", err)
					return
				}

				geom := xrect.New(int(qp.RootX), int(qp.RootY), 1, 1)
				if wrk := wm.Heads.FindMostOverlap(geom); wrk != nil {
					wm.SetWorkspace(wrk, false)
				}
			} else {
				c.Focus()
				xevent.ReplayPointer(wm.X)
			}
		})
	})
}

// New creates a new window value from a window id and an XUtil type.
// Geom is initialized to zero values. Use Window.Geometry to load it.
// Note that the geometry is the size of this particular window and nothing
// else. If you want the geometry of a client window including decorations,
// please use Window.DecorGeometry.
func New(xu *xgbutil.XUtil, win xproto.Window) *Window {
	return &Window{
		X:         xu,
		Id:        win,
		Geom:      xrect.New(0, 0, 1, 1),
		Destroyed: false,
	}
}

// RawGeometry isn't smart. It just queries the window given for geometry.
func RawGeometry(xu *xgbutil.XUtil, win xproto.Drawable) (xrect.Rect, error) {
	xgeom, err := xproto.GetGeometry(xu.Conn(), win).Reply()
	if err != nil {
		return nil, err
	}
	return xrect.New(int(xgeom.X), int(xgeom.Y),
		int(xgeom.Width), int(xgeom.Height)), nil
}

func main() {
	X, _ := xgbutil.NewConn()

	heads, err := xinerama.PhysicalHeads(X)
	if err != nil {
		fmt.Printf("ERROR: %v\n", err)
	}

	// Test intersection
	r1 := xrect.New(0, 0, 100, 100)
	r2 := xrect.New(100, 100, 100, 100)
	fmt.Println(xrect.IntersectArea(r1, r2))

	// Test largest overlap
	window := xrect.New(1800, 0, 300, 200)
	fmt.Println(xrect.LargestOverlap(window, heads))

	// Test ApplyStrut
	rgeom, _ := xwindow.RawGeometry(X, xproto.Drawable(X.RootWin()))
	fmt.Println("---------------------------")
	for i, head := range heads {
		fmt.Printf("%d - %v\n", i, head)
	}

	// Let's actually apply struts to the current environment
	clients, _ := ewmh.ClientListGet(X)
	for _, client := range clients {
		strut, err := ewmh.WmStrutPartialGet(X, client)
		if err == nil {
			xrect.ApplyStrut(heads, rgeom.Width(), rgeom.Height(),
				strut.Left, strut.Right, strut.Top, strut.Bottom,
				strut.LeftStartY, strut.LeftEndY,
				strut.RightStartY, strut.RightEndY,
				strut.TopStartX, strut.TopEndX,
				strut.BottomStartX, strut.BottomEndX)
		}
	}

	fmt.Println("---------------------------")
	fmt.Println("After applying struts...")
	for i, head := range heads {
		fmt.Printf("%d - %v\n", i, head)
	}
}

// given a slice of rects, return a rect that covers all of them!
func Bound(rects []xrect.Rect) xrect.Rect {
	min_x, min_y, max_x, max_y := coords(rects[0])
	for _, rect := range rects[1:] {
		x1, y1, x2, y2 := coords(rect)
		min_x = min(x1, min_x)
		min_y = min(y1, min_y)
		max_x = max(x2, max_x)
		max_y = max(y2, max_y)
	}
	return xrect.New(min_x, min_y, max_x-min_x, max_y-min_y)
}

func (c *Client) DragMoveBegin(rx, ry, ex, ey int) {
	f := c.frame
	moving := f.MovingState()
	moving.Moving = true
	moving.RootX, moving.RootY = rx, ry

	// call for side-effect; makes sure parent window has a valid geometry
	f.Parent().Geometry()

	// unmax!
	c.EnsureUnmax()

	c.dragGeom = xrect.New(xrect.Pieces(f.Geom()))
}

// Convert takes a source and a destination rect, along with a rect
// in the source's rectangle, and returns a new rect translated into the
// destination rect.
func Convert(rect, src, dest xrect.Rect) xrect.Rect {
	nx, ny, nw, nh := xrect.Pieces(rect)

	rectRatio := func(r xrect.Rect) float64 {
		return float64(r.Width()) / float64(r.Height())
	}
	ratio := rectRatio(dest) / rectRatio(src)

	nx = int(ratio*float64(nx-src.X())) + dest.X()
	ny = int(ratio*float64(ny-src.Y())) + dest.Y()

	// XXX: Allow window scaling as a config option.

	return xrect.New(nx, ny, nw, nh)
}

func handleMotionNotify(X *xgbutil.XUtil, ev xevent.MotionNotifyEvent) {
	qp, err := xproto.QueryPointer(X.Conn(), X.RootWin()).Reply()
	if err != nil {
		logger.Warning.Printf("Could not query pointer: %s", err)
		return
	}

	geom := xrect.New(int(qp.RootX), int(qp.RootY), 1, 1)
	if wrk := wm.Heads.FindMostOverlap(geom); wrk != nil {
		if wrk != wm.Workspace() {
			wm.SetWorkspace(wrk, false)
			wm.FocusFallback()
		}
	}
}

func (c *Client) DragMoveBegin(rx, ry, ex, ey int) bool {
	if c.IsMaximized() {
		return false
	}

	f := c.frame
	moving := f.MovingState()
	moving.Moving = true
	moving.RootX, moving.RootY = rx, ry

	// call for side-effect; makes sure parent window has a valid geometry
	f.Parent().Geometry()

	c.dragGeom = xrect.New(xrect.Pieces(f.Geom()))
	return true
}

//.........这里部分代码省略.........
	// (ex, ey) is the position of the mouse.
	// We basically split the window into something like a tic-tac-toe board:
	// -------------------------
	// |       |       |       |
	// |   A   |       |   F   |
	// |       |   D   |       |
	// ---------       |--------
	// |       |       |       |
	// |   B   |-------|   G   |
	// |       |       |       |
	// ---------       |--------
	// |       |   E   |       |
	// |   C   |       |   H   |
	// |       |       |       |
	// -------------------------
	// Where A, B, C correspond to 'ex < w / 3'
	// and F, G, H correspond to 'ex > w * 2 / 3'
	// and D and E correspond to 'ex >= w / 3 && ex <= w * 2 / 3'
	// The direction is not only important for assigning which cursor to display
	// (where each of the above blocks gets its own cursor), but it is also
	// important for choosing which parts of the geometry to change.
	// For example, if the mouse is in 'H', then the width and height could
	// be changed, but x and y cannot. Conversely, if the mouse is in 'A',
	// all parts of the geometry can change: x, y, width and height.
	// As one last example, if the mouse is in 'D', only y and height of the
	// window can change.
	if dir == ewmh.Infer {
		if ex < w/3 {
			switch {
			case ey < h/3:
				dir = ewmh.SizeTopLeft
			case ey > h*2/3:
				dir = ewmh.SizeBottomLeft
			default: // ey >= h / 3 && ey <= h * 2 / 3
				dir = ewmh.SizeLeft
			}
		} else if ex > w*2/3 {
			switch {
			case ey < h/3:
				dir = ewmh.SizeTopRight
			case ey > h*2/3:
				dir = ewmh.SizeBottomRight
			default: // ey >= h / 3 && ey <= h * 2 / 3
				dir = ewmh.SizeRight
			}
		} else { // ex >= w / 3 && ex <= w * 2 / 3
			switch {
			case ey < h/2:
				dir = ewmh.SizeTop
			default: // ey >= h / 2
				dir = ewmh.SizeBottom
			}
		}
	}

	// Find the right cursor
	var cursor xproto.Cursor = 0
	switch dir {
	case ewmh.SizeTop:
		cursor = cursors.TopSide
	case ewmh.SizeTopRight:
		cursor = cursors.TopRightCorner
	case ewmh.SizeRight:
		cursor = cursors.RightSide
	case ewmh.SizeBottomRight:
		cursor = cursors.BottomRightCorner
	case ewmh.SizeBottom:
		cursor = cursors.BottomSide
	case ewmh.SizeBottomLeft:
		cursor = cursors.BottomLeftCorner
	case ewmh.SizeLeft:
		cursor = cursors.LeftSide
	case ewmh.SizeTopLeft:
		cursor = cursors.TopLeftCorner
	}

	// Save some state that we'll need when computing a window's new geometry
	resizing.Resizing = true
	resizing.RootX, resizing.RootY = rx, ry
	resizing.X, resizing.Y = f.Geom().X(), f.Geom().Y()
	resizing.Width, resizing.Height = f.Geom().Width(), f.Geom().Height()

	// Our geometry calculations depend upon which direction we're resizing.
	// Namely, the direction determines which parts of the geometry need to
	// be modified. Pre-compute those parts (i.e., x, y, width and/or height)
	resizing.Xs = dir == ewmh.SizeLeft || dir == ewmh.SizeTopLeft ||
		dir == ewmh.SizeBottomLeft
	resizing.Ys = dir == ewmh.SizeTop || dir == ewmh.SizeTopLeft ||
		dir == ewmh.SizeTopRight
	resizing.Ws = dir == ewmh.SizeTopLeft || dir == ewmh.SizeTopRight ||
		dir == ewmh.SizeRight || dir == ewmh.SizeBottomRight ||
		dir == ewmh.SizeBottomLeft || dir == ewmh.SizeLeft
	resizing.Hs = dir == ewmh.SizeTopLeft || dir == ewmh.SizeTop ||
		dir == ewmh.SizeTopRight || dir == ewmh.SizeBottomRight ||
		dir == ewmh.SizeBottom || dir == ewmh.SizeBottomLeft

	c.dragGeom = xrect.New(xrect.Pieces(f.Geom()))

	return true, cursor
}

func (c *Client) maybeInitPlace(presumedWorkspace workspace.Workspacer) {
	// This is a hack. Before a client gets sucked into some layout, we
	// always want to have some floating state to fall back on to. However,
	// by the time we're "allowed" to save the client's state, it will have
	// already been placed in the hands of some layout---which may or may
	// not be floating. So we inject our own state forcefully here.
	defer func() {
		wrk := presumedWorkspace
		if wrk.IsVisible() {
			c.states["last-floating"] = clientState{
				geom:      xrect.New(xrect.Pieces(c.frame.Geom())),
				headGeom:  xrect.New(xrect.Pieces(wrk.HeadGeom())),
				frame:     c.frame,
				maximized: c.maximized,
			}
		} else if wm.Startup {
			// This is a bit tricky. If the window manager is starting up and
			// has to manage existing clients, then we need to find which
			// head the client is on and save its state. This is so future
			// workspace switches will be able to place the client
			// appropriately.
			// (This is most common on a Wingo restart.)
			// We refer to detected workspace as "fake" because the client
			// isn't on a visible workspace (see above), and therefore the
			// visible workspace returned by FindMostOverlap *cannot* contain
			// this client. Therefore, we're only using the fake workspace
			// to get the geometry.
			// (This would make more sense if FindMostOverlap returned a head
			// geometry, but it turns out that a workspace geometry is more
			// useful.)
			cgeom := c.frame.Geom()
			if fakeWrk := wm.Heads.FindMostOverlap(cgeom); fakeWrk != nil {
				c.states["last-floating"] = clientState{
					geom:      xrect.New(xrect.Pieces(c.frame.Geom())),
					headGeom:  xrect.New(xrect.Pieces(fakeWrk.HeadGeom())),
					frame:     c.frame,
					maximized: c.maximized,
				}
			}
		}
	}()

	// Any client that isn't normal doesn't get placed.
	// Let it do what it do, baby.
	if c.PrimaryType() != TypeNormal {
		return
	}

	// If it's sticky, let it do what it do.
	if _, ok := presumedWorkspace.(*workspace.Sticky); ok {
		return
	}

	// Transients never get placed.
	if c.transientFor != nil {
		return
	}

	// If a user/program position is specified, do not place.
	if c.nhints.Flags&icccm.SizeHintUSPosition > 0 ||
		c.nhints.Flags&icccm.SizeHintPPosition > 0 {

		return
	}

	// We're good, do a placement unless we're already mapped or on a
	// hidden workspace..
	if !presumedWorkspace.IsVisible() || !c.isAttrsUnmapped() {
		return
	}
	w := presumedWorkspace.(*workspace.Workspace)
	w.LayoutFloater().InitialPlacement(c)
}

func Maximize(f Frame) {
	hg := xrect.New(xrect.Pieces(f.Client().HeadGeom()))
	f.MoveResize(false, hg.X(), hg.Y(), hg.Width(), hg.Height())
}