Merge branch 'downarowiczd-master'

example1/example1.go

@@ -33,6 +33,9 @@ var screen1 = go3270.Screen{
 	{Row: 6, Col: 0, Content: "Password  . . . ."},
 	{Row: 6, Col: 19, Name: "password", Write: true, Hidden: true},
 	{Row: 6, Col: 40}, // field "stop" character
+	{Row: 7, Col: 0, Content: "Employee ID . . ."},
+	{Row: 7, Col: 19, Name: "employeeID", Write: true, Highlighting: go3270.Underscore, NumericOnly: true},
+	{Row: 7, Col: 40}, // field "stop" character
 	{Row: 8, Col: 0, Content: "Press"},
 	{Row: 8, Col: 6, Intense: true, Content: "enter"},
 	{Row: 8, Col: 12, Content: "to submit your name."},
@@ -47,14 +50,16 @@ var screen2 = go3270.Screen{
 	{Row: 4, Col: 19, Name: "fname"}, // We're giving this field a name to replace its value at runtime
 	{Row: 5, Col: 0, Content: "And your last name is"},
 	{Row: 5, Col: 22, Name: "lname"}, // We're giving this field a name to replace its value at runtime
-	{Row: 6, Col: 0, Name: "passwordOutput"},
-	{Row: 8, Col: 0, Content: "Press"},
-	{Row: 8, Col: 6, Intense: true, Content: "enter"},
-	{Row: 8, Col: 12, Content: "to enter your name again, or"},
-	{Row: 8, Col: 41, Intense: true, Content: "PF3"},
-	{Row: 8, Col: 45, Content: "to quit and disconnect."},
-	{Row: 11, Col: 0, Color: go3270.Turquoise, Highlighting: go3270.ReverseVideo, Content: "Here is a field with extended attributes."},
-	{Row: 11, Col: 42}, // remember to "stop" fields with a regular field, to clear the reverse video for example
+	{Row: 6, Col: 0, Content: "And your employeed ID is"},
+	{Row: 6, Col: 22, Name: "employeeID"}, // We're giving this field a name to replace its value at runtime
+	{Row: 7, Col: 0, Name: "passwordOutput"},
+	{Row: 9, Col: 0, Content: "Press"},
+	{Row: 9, Col: 6, Intense: true, Content: "enter"},
+	{Row: 9, Col: 12, Content: "to enter your name again, or"},
+	{Row: 9, Col: 41, Intense: true, Content: "PF3"},
+	{Row: 9, Col: 45, Content: "to quit and disconnect."},
+	{Row: 12, Col: 0, Color: go3270.Turquoise, Highlighting: go3270.ReverseVideo, Content: "Here is a field with extended attributes."},
+	{Row: 12, Col: 42}, // remember to "stop" fields with a regular field, to clear the reverse video for example
 	{Row: 22, Col: 0, Content: "PF3 Exit"},
 }
 

screen.go

@@ -40,6 +40,11 @@ type Field struct {
 	// password input field).
 	Hidden bool
 
+	// NumericOnly indicates that only numbers may be entered into the field.
+	// Very fiew 3270 clients support this, so you must always still validate
+	// the input on the server side.
+	NumericOnly bool
+
 	// Color is the field color. The default value is the default color.
 	Color Color
 
@@ -193,7 +198,8 @@ func buildField(f Field) []byte {
 	if f.Color == DefaultColor && f.Highlighting == DefaultHighlight {
 		// this is a traditional field, issue a normal sf command
 		buf.WriteByte(0x1d) // sf - "start field"
-		buf.WriteByte(sfAttribute(f.Write, f.Intense, f.Hidden, f.Autoskip))
+		buf.WriteByte(sfAttribute(f.Write, f.Intense, f.Hidden, f.Autoskip,
+			f.NumericOnly))
 		return buf.Bytes()
 	}
 
@@ -210,7 +216,8 @@ func buildField(f Field) []byte {
 
 	// Write the basic field attribute
 	buf.WriteByte(0xc0)
-	buf.WriteByte(sfAttribute(f.Write, f.Intense, f.Hidden, f.Autoskip))
+	buf.WriteByte(sfAttribute(f.Write, f.Intense, f.Hidden, f.Autoskip,
+		f.NumericOnly))
 
 	// Write the highlighting attribute
 	if f.Highlighting != DefaultHighlight {
@@ -228,7 +235,7 @@ func buildField(f Field) []byte {
 }
 
 // sfAttribute builds the attribute byte for the "start field" 3270 command
-func sfAttribute(write, intense, hidden, skip bool) byte {
+func sfAttribute(write, intense, hidden, skip, numeric bool) byte {
 	var attribute byte
 	if !write {
 		attribute |= 1 << 5 // set "bit 2"
@@ -239,7 +246,9 @@ func sfAttribute(write, intense, hidden, skip bool) byte {
 		// The MDT bit -- we always want writable field values returned,
 		// even if unchanged
 		attribute |= 1 // set "bit 7"
-
+		if numeric {
+			attribute |= 1 << 4 // set "bit 3"
+		}
 	}
 	if intense {
 		attribute |= 1 << 3 // set "bit 4"