initOnce()

plugin.go

@@ -9,6 +9,8 @@ package tree
 */
 
 import (
+	"time"
+
 	"go.wit.com/widget"
 )
 
@@ -36,6 +38,21 @@ func (n *Node) FindWidgetId(id int) *Node {
 	return nil
 }
 
+func (me *TreeInfo) InitOK() {
+	me.ok = true
+}
+
+// this hack is to wait for the application to send something
+// before trying to do anything. todo: rethink this someday
+func (me *TreeInfo) waitOK() {
+	for {
+		if me.ok {
+			return
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+}
+
 // Other goroutines must use this to access the GUI
 //
 // You can not acess / process the GUI thread directly from
@@ -47,6 +64,8 @@ func (me *TreeInfo) Callback(guiCallback chan widget.Action) {
 	me.callback = guiCallback
 }
 
+// this is the function that receives things from the application
 func (me *TreeInfo) PluginChannel() chan widget.Action {
+	me.waitOK()
 	return me.pluginChan
 }

structs.go

@@ -17,6 +17,7 @@ import (
 var treeRoot *Node
 
 type TreeInfo struct {
+	ok           bool                           // indicates the plugin actually initialized
 	PluginName   string                         // used to identify the plugin
 	config       *ToolkitConfigs                // protobuf of plugin settings
 	callback     chan widget.Action             // mouse clicks or keyboard events back to the program