ge.go

Documentation: github.com/jezek/xgb/ge

     1  // Package ge is the X client API for the Generic Event Extension extension.
     2  package ge
     3  
     4  // This file is automatically generated from ge.xml. Edit at your peril!
     5  
     6  import (
     7  	"github.com/jezek/xgb"
     8  
     9  	"github.com/jezek/xgb/xproto"
    10  )
    11  
    12  // Init must be called before using the Generic Event Extension extension.
    13  func Init(c *xgb.Conn) error {
    14  	reply, err := xproto.QueryExtension(c, 23, "Generic Event Extension").Reply()
    15  	switch {
    16  	case err != nil:
    17  		return err
    18  	case !reply.Present:
    19  		return xgb.Errorf("No extension named Generic Event Extension could be found on on the server.")
    20  	}
    21  
    22  	c.ExtLock.Lock()
    23  	c.Extensions["Generic Event Extension"] = reply.MajorOpcode
    24  	c.ExtLock.Unlock()
    25  	for evNum, fun := range xgb.NewExtEventFuncs["Generic Event Extension"] {
    26  		xgb.NewEventFuncs[int(reply.FirstEvent)+evNum] = fun
    27  	}
    28  	for errNum, fun := range xgb.NewExtErrorFuncs["Generic Event Extension"] {
    29  		xgb.NewErrorFuncs[int(reply.FirstError)+errNum] = fun
    30  	}
    31  	return nil
    32  }
    33  
    34  func init() {
    35  	xgb.NewExtEventFuncs["Generic Event Extension"] = make(map[int]xgb.NewEventFun)
    36  	xgb.NewExtErrorFuncs["Generic Event Extension"] = make(map[int]xgb.NewErrorFun)
    37  }
    38  
    39  // Skipping definition for base type 'Bool'
    40  
    41  // Skipping definition for base type 'Byte'
    42  
    43  // Skipping definition for base type 'Card8'
    44  
    45  // Skipping definition for base type 'Char'
    46  
    47  // Skipping definition for base type 'Void'
    48  
    49  // Skipping definition for base type 'Double'
    50  
    51  // Skipping definition for base type 'Float'
    52  
    53  // Skipping definition for base type 'Int16'
    54  
    55  // Skipping definition for base type 'Int32'
    56  
    57  // Skipping definition for base type 'Int8'
    58  
    59  // Skipping definition for base type 'Card16'
    60  
    61  // Skipping definition for base type 'Card32'
    62  
    63  // QueryVersionCookie is a cookie used only for QueryVersion requests.
    64  type QueryVersionCookie struct {
    65  	*xgb.Cookie
    66  }
    67  
    68  // QueryVersion sends a checked request.
    69  // If an error occurs, it will be returned with the reply by calling QueryVersionCookie.Reply()
    70  func QueryVersion(c *xgb.Conn, ClientMajorVersion uint16, ClientMinorVersion uint16) QueryVersionCookie {
    71  	c.ExtLock.RLock()
    72  	defer c.ExtLock.RUnlock()
    73  	if _, ok := c.Extensions["Generic Event Extension"]; !ok {
    74  		panic("Cannot issue request 'QueryVersion' using the uninitialized extension 'Generic Event Extension'. ge.Init(connObj) must be called first.")
    75  	}
    76  	cookie := c.NewCookie(true, true)
    77  	c.NewRequest(queryVersionRequest(c, ClientMajorVersion, ClientMinorVersion), cookie)
    78  	return QueryVersionCookie{cookie}
    79  }
    80  
    81  // QueryVersionUnchecked sends an unchecked request.
    82  // If an error occurs, it can only be retrieved using xgb.WaitForEvent or xgb.PollForEvent.
    83  func QueryVersionUnchecked(c *xgb.Conn, ClientMajorVersion uint16, ClientMinorVersion uint16) QueryVersionCookie {
    84  	c.ExtLock.RLock()
    85  	defer c.ExtLock.RUnlock()
    86  	if _, ok := c.Extensions["Generic Event Extension"]; !ok {
    87  		panic("Cannot issue request 'QueryVersion' using the uninitialized extension 'Generic Event Extension'. ge.Init(connObj) must be called first.")
    88  	}
    89  	cookie := c.NewCookie(false, true)
    90  	c.NewRequest(queryVersionRequest(c, ClientMajorVersion, ClientMinorVersion), cookie)
    91  	return QueryVersionCookie{cookie}
    92  }
    93  
    94  // QueryVersionReply represents the data returned from a QueryVersion request.
    95  type QueryVersionReply struct {
    96  	Sequence uint16 // sequence number of the request for this reply
    97  	Length   uint32 // number of bytes in this reply
    98  	// padding: 1 bytes
    99  	MajorVersion uint16
   100  	MinorVersion uint16
   101  	// padding: 20 bytes
   102  }
   103  
   104  // Reply blocks and returns the reply data for a QueryVersion request.
   105  func (cook QueryVersionCookie) Reply() (*QueryVersionReply, error) {
   106  	buf, err := cook.Cookie.Reply()
   107  	if err != nil {
   108  		return nil, err
   109  	}
   110  	if buf == nil {
   111  		return nil, nil
   112  	}
   113  	return queryVersionReply(buf), nil
   114  }
   115  
   116  // queryVersionReply reads a byte slice into a QueryVersionReply value.
   117  func queryVersionReply(buf []byte) *QueryVersionReply {
   118  	v := new(QueryVersionReply)
   119  	b := 1 // skip reply determinant
   120  
   121  	b += 1 // padding
   122  
   123  	v.Sequence = xgb.Get16(buf[b:])
   124  	b += 2
   125  
   126  	v.Length = xgb.Get32(buf[b:]) // 4-byte units
   127  	b += 4
   128  
   129  	v.MajorVersion = xgb.Get16(buf[b:])
   130  	b += 2
   131  
   132  	v.MinorVersion = xgb.Get16(buf[b:])
   133  	b += 2
   134  
   135  	b += 20 // padding
   136  
   137  	return v
   138  }
   139  
   140  // Write request to wire for QueryVersion
   141  // queryVersionRequest writes a QueryVersion request to a byte slice.
   142  func queryVersionRequest(c *xgb.Conn, ClientMajorVersion uint16, ClientMinorVersion uint16) []byte {
   143  	size := 8
   144  	b := 0
   145  	buf := make([]byte, size)
   146  
   147  	c.ExtLock.RLock()
   148  	buf[b] = c.Extensions["Generic Event Extension"]
   149  	c.ExtLock.RUnlock()
   150  	b += 1
   151  
   152  	buf[b] = 0 // request opcode
   153  	b += 1
   154  
   155  	xgb.Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
   156  	b += 2
   157  
   158  	xgb.Put16(buf[b:], ClientMajorVersion)
   159  	b += 2
   160  
   161  	xgb.Put16(buf[b:], ClientMinorVersion)
   162  	b += 2
   163  
   164  	return buf
   165  }
   166
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