1 files changed, 168 insertions, 0 deletions
diff --git a/nexgb/xgbgen/context.go b/nexgb/xgbgen/context.go
new file mode 100644
index 0000000..0728b64
--- /dev/null
+++ b/nexgb/xgbgen/context.go
@@ -0,0 +1,168 @@
+package main
+
+import (
+	"bytes"
+	"encoding/xml"
+	"fmt"
+	"log"
+	"sort"
+)
+
+// Context represents the protocol we're converting to Go, and a writer
+// buffer to write the Go source to.
+type Context struct {
+	protocol *Protocol
+	out      *bytes.Buffer
+}
+
+func newContext() *Context {
+	return &Context{
+		out: bytes.NewBuffer([]byte{}),
+	}
+}
+
+// Putln calls put and adds a new line to the end of 'format'.
+func (c *Context) Putln(format string, v ...interface{}) {
+	c.Put(format+"\n", v...)
+}
+
+// Put is a short alias to write to 'out'.
+func (c *Context) Put(format string, v ...interface{}) {
+	_, err := c.out.WriteString(fmt.Sprintf(format, v...))
+	if err != nil {
+		log.Fatalf("There was an error writing to context buffer: %s", err)
+	}
+}
+
+// Morph is the big daddy of them all. It takes in an XML byte slice,
+// parse it, transforms the XML types into more usable types,
+// and writes Go code to the 'out' buffer.
+func (c *Context) Morph(xmlBytes []byte) {
+	parsedXml := &XML{}
+	err := xml.Unmarshal(xmlBytes, parsedXml)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Parse all imports
+	parsedXml.Imports.Eval()
+
+	// Translate XML types to nice types
+	c.protocol = parsedXml.Translate(nil)
+	
+	// For backwards compatibility we patch the type of the send_event field of
+	// PutImage to be byte
+	if c.protocol.Name == "shm" {
+		for _, req := range c.protocol.Requests {
+			if req.xmlName != "PutImage" {
+				continue
+			}
+			for _, ifield := range req.Fields {
+				field, ok := ifield.(*SingleField)
+				if !ok || field.xmlName != "send_event" {
+					continue
+				}
+				field.Type = &Base{ srcName: "byte", xmlName: "CARD8", size: newFixedSize(1, true) }
+			}
+		}
+	}
+
+	// Start with Go header.
+	c.Putln("// Package %s is the X client API for the %s extension.",
+		c.protocol.PkgName(), c.protocol.ExtXName)
+	c.Putln("package %s", c.protocol.PkgName())
+	c.Putln("")
+	c.Putln("// This file is automatically generated from %s.xml. "+
+		"Edit at your peril!", c.protocol.Name)
+	c.Putln("")
+
+	// Write imports. We always need to import at least xgb.
+	// We also need to import xproto if it's an extension.
+	c.Putln("import (")
+	c.Putln("\"github.com/BurntSushi/xgb\"")
+	c.Putln("")
+	if c.protocol.isExt() {
+		c.Putln("\"github.com/BurntSushi/xgb/xproto\"")
+	}
+
+	sort.Sort(Protocols(c.protocol.Imports))
+	for _, imp := range c.protocol.Imports {
+		// We always import xproto, so skip it if it's explicitly imported
+		if imp.Name == "xproto" {
+			continue
+		}
+		c.Putln("\"github.com/BurntSushi/xgb/%s\"", imp.Name)
+	}
+	c.Putln(")")
+	c.Putln("")
+
+	// If this is an extension, create a function to initialize the extension
+	// before it can be used.
+	if c.protocol.isExt() {
+		xname := c.protocol.ExtXName
+
+		c.Putln("// Init must be called before using the %s extension.",
+			xname)
+		c.Putln("func Init(c *xgb.Conn) error {")
+		c.Putln("reply, err := xproto.QueryExtension(c, %d, \"%s\").Reply()",
+			len(xname), xname)
+		c.Putln("switch {")
+		c.Putln("case err != nil:")
+		c.Putln("return err")
+		c.Putln("case !reply.Present:")
+		c.Putln("return xgb.Errorf(\"No extension named %s could be found on "+
+			"on the server.\")", xname)
+		c.Putln("}")
+		c.Putln("")
+		c.Putln("c.ExtLock.Lock()")
+		c.Putln("c.Extensions[\"%s\"] = reply.MajorOpcode", xname)
+		c.Putln("c.ExtLock.Unlock()")
+		c.Putln("for evNum, fun := range xgb.NewExtEventFuncs[\"%s\"] {",
+			xname)
+		c.Putln("xgb.NewEventFuncs[int(reply.FirstEvent) + evNum] = fun")
+		c.Putln("}")
+		c.Putln("for errNum, fun := range xgb.NewExtErrorFuncs[\"%s\"] {",
+			xname)
+		c.Putln("xgb.NewErrorFuncs[int(reply.FirstError) + errNum] = fun")
+		c.Putln("}")
+		c.Putln("return nil")
+		c.Putln("}")
+		c.Putln("")
+
+		// Make sure newExtEventFuncs["EXT_NAME"] map is initialized.
+		// Same deal for newExtErrorFuncs["EXT_NAME"]
+		c.Putln("func init() {")
+		c.Putln("xgb.NewExtEventFuncs[\"%s\"] = make(map[int]xgb.NewEventFun)",
+			xname)
+		c.Putln("xgb.NewExtErrorFuncs[\"%s\"] = make(map[int]xgb.NewErrorFun)",
+			xname)
+		c.Putln("}")
+		c.Putln("")
+	} else {
+		// In the xproto package, we must provide a Setup function that uses
+		// SetupBytes in xgb.Conn to return a SetupInfo structure.
+		c.Putln("// Setup parses the setup bytes retrieved when")
+		c.Putln("// connecting into a SetupInfo struct.")
+		c.Putln("func Setup(c *xgb.Conn) *SetupInfo {")
+		c.Putln("setup := new(SetupInfo)")
+		c.Putln("SetupInfoRead(c.SetupBytes, setup)")
+		c.Putln("return setup")
+		c.Putln("}")
+		c.Putln("")
+		c.Putln("// DefaultScreen gets the default screen info from SetupInfo.")
+		c.Putln("func (s *SetupInfo) DefaultScreen(c *xgb.Conn) *ScreenInfo {")
+		c.Putln("return &s.Roots[c.DefaultScreen]")
+		c.Putln("}")
+		c.Putln("")
+	}
+
+	// Now write Go source code
+	sort.Sort(Types(c.protocol.Types))
+	sort.Sort(Requests(c.protocol.Requests))
+	for _, typ := range c.protocol.Types {
+		typ.Define(c)
+	}
+	for _, req := range c.protocol.Requests {
+		req.Define(c)
+	}
+}