add ability to check supported status

Signed-off-by: Vasiliy Tolstov <v.tolstov@selfip.ru>

encoding.go

@@ -83,6 +83,7 @@ type Encoding interface {
 	Type() EncodingType
 	Read(Conn, *Rectangle) error
 	Write(Conn, *Rectangle) error
+	Supported(Conn) bool
 }
 
 func setBit(n uint8, pos uint8) uint8 {

encoding_atenhermon.go

@@ -28,6 +28,10 @@ type AtenHermonSubrect struct {
 	Data []byte
 }
 
+func (*AtenHermon) Supported(Conn) bool {
+	return false
+}
+
 func (*AtenHermon) Type() EncodingType { return EncAtenHermon }
 
 func (enc *AtenHermon) Read(c Conn, rect *Rectangle) error {
@@ -113,6 +117,14 @@ func (enc *AtenHermon) Read(c Conn, rect *Rectangle) error {
 }
 
 func (enc *AtenHermon) Write(c Conn, rect *Rectangle) error {
+	if !enc.Supported(c) {
+		for _, ew := range enc.Encodings {
+			if err := ew.Write(c, rect); err != nil {
+				return err
+			}
+		}
+		return nil
+	}
 	var pad4 [4]byte
 
 	if err := binary.Write(c, binary.BigEndian, pad4); err != nil {
@@ -148,6 +160,10 @@ func (enc *AtenHermon) Write(c Conn, rect *Rectangle) error {
 	return nil
 }
 
+func (*AtenHermonSubrect) Supported(Conn) bool {
+	return false
+}
+
 func (enc *AtenHermonSubrect) Type() EncodingType {
 	return EncAtenHermonSubrect
 }
@@ -173,6 +189,9 @@ func (enc *AtenHermonSubrect) Read(c Conn, rect *Rectangle) error {
 }
 
 func (enc *AtenHermonSubrect) Write(c Conn, rect *Rectangle) error {
+	if !enc.Supported(c) {
+		return nil
+	}
 	if err := binary.Write(c, binary.BigEndian, enc.A); err != nil {
 		return err
 	}

encoding_copyrect.go

@@ -6,7 +6,11 @@ type CopyRectEncoding struct {
 	SX, SY uint16
 }
 
-func (CopyRectEncoding) Type() EncodingType { return EncCopyRect }
+func (*CopyRectEncoding) Supported(Conn) bool {
+	return true
+}
+
+func (*CopyRectEncoding) Type() EncodingType { return EncCopyRect }
 
 func (enc *CopyRectEncoding) Read(c Conn, rect *Rectangle) error {
 	if err := binary.Read(c, binary.BigEndian, &enc.SX); err != nil {

encoding_cursor.go

@@ -7,6 +7,10 @@ type CursorPseudoEncoding struct {
 	BitMask []byte
 }
 
+func (*CursorPseudoEncoding) Supported(Conn) bool {
+	return true
+}
+
 func (*CursorPseudoEncoding) Type() EncodingType { return EncCursorPseudo }
 
 func (enc *CursorPseudoEncoding) Read(c Conn, rect *Rectangle) error {

encoding_desktopname.go

@@ -7,6 +7,10 @@ type DesktopNamePseudoEncoding struct {
 	Name []byte
 }
 
+func (*DesktopNamePseudoEncoding) Supported(Conn) bool {
+	return true
+}
+
 func (*DesktopNamePseudoEncoding) Type() EncodingType { return EncDesktopNamePseudo }
 
 // Read implements the Encoding interface.

encoding_desktopsize.go

@@ -3,6 +3,10 @@ package vnc
 // DesktopSizePseudoEncoding represents a desktop size message from the server.
 type DesktopSizePseudoEncoding struct{}
 
+func (*DesktopSizePseudoEncoding) Supported(Conn) bool {
+	return true
+}
+
 func (*DesktopSizePseudoEncoding) Type() EncodingType { return EncDesktopSizePseudo }
 
 // Read implements the Encoding interface.

encoding_raw.go

@@ -4,6 +4,10 @@ type RawEncoding struct {
 	Colors []Color
 }
 
+func (*RawEncoding) Supported(Conn) bool {
+	return true
+}
+
 func (enc *RawEncoding) Write(c Conn, rect *Rectangle) error {
 	var err error
 

encoding_tight.go

@@ -28,6 +28,10 @@ const (
 
 type TightEncoding struct{}
 
+func (*TightEncoding) Supported(Conn) bool {
+	return true
+}
+
 func (*TightEncoding) Type() EncodingType { return EncTight }
 
 func (enc *TightEncoding) Write(c Conn, rect *Rectangle) error {

encoding_tightpng.go

@@ -11,6 +11,10 @@ import (
 	"io"
 )
 
+func (*TightPngEncoding) Supported(Conn) bool {
+	return true
+}
+
 func (enc *TightPngEncoding) Write(c Conn, rect *Rectangle) error {
 	if err := writeTightCC(c, enc.TightCC); err != nil {
 		return err

encoding_xcursor.go

@@ -16,6 +16,10 @@ type XCursorPseudoEncoding struct {
 	Bitmask    []byte
 }
 
+func (*XCursorPseudoEncoding) Supported(Conn) bool {
+	return true
+}
+
 func (*XCursorPseudoEncoding) Type() EncodingType { return EncXCursorPseudo }
 
 // Read implements the Encoding interface.

image.go

@@ -50,15 +50,16 @@ func NewRectangle() *Rectangle {
 // Write marshal color to conn
 func (clr *Color) Write(c Conn) error {
 	var err error
-	order := clr.pf.order()
+	pf := c.PixelFormat()
+	order := pf.order()
 	pixel := clr.cmIndex
 	if clr.pf.TrueColor != 0 {
-		pixel = uint32(clr.R) << clr.pf.RedShift
-		pixel |= uint32(clr.G) << clr.pf.GreenShift
-		pixel |= uint32(clr.B) << clr.pf.BlueShift
+		pixel = uint32(clr.R) << pf.RedShift
+		pixel |= uint32(clr.G) << pf.GreenShift
+		pixel |= uint32(clr.B) << pf.BlueShift
 	}
 
-	switch clr.pf.BPP {
+	switch pf.BPP {
 	case 8:
 		err = binary.Write(c, order, byte(pixel))
 	case 16:

messages.go

@@ -70,6 +70,7 @@ type ClientMessage interface {
 	Type() ClientMessageType
 	Read(Conn) (ClientMessage, error)
 	Write(Conn) error
+	Supported(Conn) bool
 }
 
 type ServerMessage interface {
@@ -77,6 +78,7 @@ type ServerMessage interface {
 	Type() ServerMessageType
 	Read(Conn) (ServerMessage, error)
 	Write(Conn) error
+	Supported(Conn) bool
 }
 
 // FramebufferUpdate holds a FramebufferUpdate wire format message.
@@ -91,6 +93,10 @@ func (msg *FramebufferUpdate) String() string {
 	return fmt.Sprintf("rects %d rectangle[]: { %v }", msg.NumRect, msg.Rects)
 }
 
+func (msg *FramebufferUpdate) Supported(c Conn) bool {
+	return true
+}
+
 // Type return MessageType
 func (*FramebufferUpdate) Type() ServerMessageType {
 	return FramebufferUpdateMsgType
@@ -144,6 +150,10 @@ type ServerCutText struct {
 	Text   []byte
 }
 
+func (msg *ServerCutText) Supported(c Conn) bool {
+	return true
+}
+
 // String returns string
 func (msg *ServerCutText) String() string {
 	return fmt.Sprintf("lenght: %d text: %s", msg.Length, msg.Text)
@@ -200,6 +210,10 @@ func (msg *ServerCutText) Write(c Conn) error {
 // Bell server message
 type Bell struct{}
 
+func (*Bell) Supported(c Conn) bool {
+	return true
+}
+
 // String return string
 func (*Bell) String() string {
 	return fmt.Sprintf("bell")
@@ -231,6 +245,10 @@ type SetColorMapEntries struct {
 	Colors     []Color
 }
 
+func (msg *SetColorMapEntries) Supported(c Conn) bool {
+	return true
+}
+
 // String returns string
 func (msg *SetColorMapEntries) String() string {
 	return fmt.Sprintf("first color: %d, numcolors: %d, colors[]: { %v }", msg.FirstColor, msg.ColorsNum, msg.Colors)
@@ -308,6 +326,10 @@ type SetPixelFormat struct {
 	PF PixelFormat // pixel-format
 }
 
+func (msg *SetPixelFormat) Supported(c Conn) bool {
+	return true
+}
+
 // String returns string
 func (msg *SetPixelFormat) String() string {
 	return fmt.Sprintf("%s", msg.PF)
@@ -353,6 +375,10 @@ type SetEncodings struct {
 	Encodings []EncodingType
 }
 
+func (msg *SetEncodings) Supported(c Conn) bool {
+	return true
+}
+
 // String return string
 func (msg *SetEncodings) String() string {
 	return fmt.Sprintf("encnum: %d, encodings[]: { %v }", msg.EncNum, msg.Encodings)
@@ -417,6 +443,10 @@ type FramebufferUpdateRequest struct {
 	Width, Height uint16 // width, height
 }
 
+func (msg *FramebufferUpdateRequest) Supported(c Conn) bool {
+	return true
+}
+
 // String returns string
 func (msg *FramebufferUpdateRequest) String() string {
 	return fmt.Sprintf("incremental: %d, x: %d, y: %d, width: %d, height: %d", msg.Inc, msg.X, msg.Y, msg.Width, msg.Height)
@@ -454,6 +484,10 @@ type KeyEvent struct {
 	Key  Key     // key
 }
 
+func (msg *KeyEvent) Supported(c Conn) bool {
+	return true
+}
+
 // String returns string
 func (msg *KeyEvent) String() string {
 	return fmt.Sprintf("down: %d, key: %v", msg.Down, msg.Key)
@@ -490,6 +524,10 @@ type PointerEvent struct {
 	X, Y uint16 // x-, y-position
 }
 
+func (msg *PointerEvent) Supported(c Conn) bool {
+	return true
+}
+
 // String returns string
 func (msg *PointerEvent) String() string {
 	return fmt.Sprintf("mask %d, x: %d, y: %d", msg.Mask, msg.X, msg.Y)
@@ -527,6 +565,10 @@ type ClientCutText struct {
 	Text   []byte
 }
 
+func (msg *ClientCutText) Supported(c Conn) bool {
+	return true
+}
+
 // String returns string
 func (msg *ClientCutText) String() string {
 	return fmt.Sprintf("length: %d, text: %s", msg.Length, msg.Text)

messages_aten.go

@@ -39,6 +39,10 @@ type AteniKVMPointerEvent struct {
 	_    [11]byte // padding
 }
 
+func (msg *AteniKVMPointerEvent) Supported(c Conn) bool {
+	return false
+}
+
 func (msg *AteniKVMPointerEvent) String() string {
 	return fmt.Sprintf("mask: %d, x:%d, y:%d", msg.Mask, msg.X, msg.Y)
 }
@@ -56,6 +60,9 @@ func (*AteniKVMPointerEvent) Read(c Conn) (ClientMessage, error) {
 }
 
 func (msg *AteniKVMPointerEvent) Write(c Conn) error {
+	if !msg.Supported(c) {
+		return nil
+	}
 	if err := binary.Write(c, binary.BigEndian, msg.Type()); err != nil {
 		return err
 	}
@@ -65,6 +72,10 @@ func (msg *AteniKVMPointerEvent) Write(c Conn) error {
 	return c.Flush()
 }
 
+func (msg *AteniKVMKeyEvent) Supported(c Conn) bool {
+	return false
+}
+
 func (msg *AteniKVMKeyEvent) String() string {
 	return fmt.Sprintf("down:%d, key:%s", msg.Down, msg.Key)
 }
@@ -82,6 +93,9 @@ func (*AteniKVMKeyEvent) Read(c Conn) (ClientMessage, error) {
 }
 
 func (msg *AteniKVMKeyEvent) Write(c Conn) error {
+	if !msg.Supported(c) {
+		return nil
+	}
 	if err := binary.Write(c, binary.BigEndian, msg.Type()); err != nil {
 		return err
 	}
@@ -96,6 +110,10 @@ type AteniKVMFrontGroundEvent struct {
 	_ [20]byte
 }
 
+func (msg *AteniKVMFrontGroundEvent) Supported(c Conn) bool {
+	return false
+}
+
 // String return string representation
 func (msg *AteniKVMFrontGroundEvent) String() string {
 	return fmt.Sprintf("%s", msg.Type())
@@ -118,6 +136,9 @@ func (*AteniKVMFrontGroundEvent) Read(c Conn) (ServerMessage, error) {
 
 // Write marshal message to conn
 func (msg *AteniKVMFrontGroundEvent) Write(c Conn) error {
+	if !msg.Supported(c) {
+		return nil
+	}
 	var pad [20]byte
 	if err := binary.Write(c, binary.BigEndian, msg.Type()); err != nil {
 		return err
@@ -133,6 +154,10 @@ type AteniKVMKeepAliveEvent struct {
 	_ [1]byte
 }
 
+func (msg *AteniKVMKeepAliveEvent) Supported(c Conn) bool {
+	return false
+}
+
 // String return string representation
 func (msg *AteniKVMKeepAliveEvent) String() string {
 	return fmt.Sprintf("%s", msg.Type())
@@ -155,6 +180,9 @@ func (*AteniKVMKeepAliveEvent) Read(c Conn) (ServerMessage, error) {
 
 // Write marshal message to conn
 func (msg *AteniKVMKeepAliveEvent) Write(c Conn) error {
+	if !msg.Supported(c) {
+		return nil
+	}
 	var pad [1]byte
 	if err := binary.Write(c, binary.BigEndian, msg.Type()); err != nil {
 		return err
@@ -170,6 +198,10 @@ type AteniKVMVideoGetInfo struct {
 	_ [20]byte
 }
 
+func (msg *AteniKVMVideoGetInfo) Supported(c Conn) bool {
+	return false
+}
+
 // String return string representation
 func (msg *AteniKVMVideoGetInfo) String() string {
 	return fmt.Sprintf("%s", msg.Type())
@@ -192,6 +224,9 @@ func (*AteniKVMVideoGetInfo) Read(c Conn) (ServerMessage, error) {
 
 // Write marshal message to conn
 func (msg *AteniKVMVideoGetInfo) Write(c Conn) error {
+	if !msg.Supported(c) {
+		return nil
+	}
 	var pad [4]byte
 	if err := binary.Write(c, binary.BigEndian, msg.Type()); err != nil {
 		return err
@@ -207,6 +242,10 @@ type AteniKVMMouseGetInfo struct {
 	_ [2]byte
 }
 
+func (msg *AteniKVMMouseGetInfo) Supported(c Conn) bool {
+	return false
+}
+
 // String return string representation
 func (msg *AteniKVMMouseGetInfo) String() string {
 	return fmt.Sprintf("%s", msg.Type())
@@ -229,6 +268,9 @@ func (*AteniKVMMouseGetInfo) Read(c Conn) (ServerMessage, error) {
 
 // Write marshal message to conn
 func (msg *AteniKVMMouseGetInfo) Write(c Conn) error {
+	if !msg.Supported(c) {
+		return nil
+	}
 	var pad [2]byte
 	if err := binary.Write(c, binary.BigEndian, msg.Type()); err != nil {
 		return err
@@ -244,6 +286,10 @@ type AteniKVMSessionMessage struct {
 	_ [264]byte
 }
 
+func (msg *AteniKVMSessionMessage) Supported(c Conn) bool {
+	return false
+}
+
 // String return string representation
 func (msg *AteniKVMSessionMessage) String() string {
 	return fmt.Sprintf("%s", msg.Type())
@@ -266,6 +312,9 @@ func (*AteniKVMSessionMessage) Read(c Conn) (ServerMessage, error) {
 
 // Write marshal message to conn
 func (msg *AteniKVMSessionMessage) Write(c Conn) error {
+	if !msg.Supported(c) {
+		return nil
+	}
 	var pad [264]byte
 	if err := binary.Write(c, binary.BigEndian, msg.Type()); err != nil {
 		return err
@@ -281,6 +330,10 @@ type AteniKVMGetViewerLang struct {
 	_ [8]byte
 }
 
+func (msg *AteniKVMGetViewerLang) Supported(c Conn) bool {
+	return false
+}
+
 // String return string representation
 func (msg *AteniKVMGetViewerLang) String() string {
 	return fmt.Sprintf("%s", msg.Type())
@@ -303,6 +356,9 @@ func (*AteniKVMGetViewerLang) Read(c Conn) (ServerMessage, error) {
 
 // Write marshal message to conn
 func (msg *AteniKVMGetViewerLang) Write(c Conn) error {
+	if !msg.Supported(c) {
+		return nil
+	}
 	var pad [8]byte
 	if err := binary.Write(c, binary.BigEndian, msg.Type()); err != nil {
 		return err