added and use MDIArea.findSubWindow

mainwin.py

@@ -44,30 +44,25 @@ class MainWindow(QMainWindow):
     def new_plot(self, name, cfg):
         desc = PlotDescription(**cfg)
         self.lst.add(name, desc)
-        for sub in self.mdi.subWindowList():
-            if sub.windowTitle() == name:
-                return
-        self.sig_make_new_plot.emit(name, desc)
+        if not self.mdi.findSubWindow(name):
+            self.sig_make_new_plot.emit(name, desc)
 
 
     def append_data(self, name, point):
-        lst = self.lst
-        lst.append(name, point)
-        for sub in self.mdi.subWindowList():
-            if sub.windowTitle() == name:
-                desc = lst.data[name]
-                sub.plot.setData(*desc.data)
+        self.lst.append(name, point)
+        sub = self.mdi.findSubWindow(name)
+        if sub:
+            desc = self.lst.data[name]
+            sub.plot.setData(*desc.data)
 
 
     def on_select_list_item(self, index):
         name, desc = self.lst.get(index)
-
-        for sub in self.mdi.subWindowList():
-            if sub.windowTitle() == name:
-                self.mdi.setActiveSubWindow(sub)
-                return
-
-        self.on_make_new_plot(name, desc)
+        sub = self.mdi.findSubWindow(name)
+        if sub:
+            self.mdi.setActiveSubWindow(sub)
+        else:
+            self.on_make_new_plot(name, desc)
 
 
     def on_make_new_plot(self, *args, **kwargs):

mdi.py

@@ -62,6 +62,12 @@ class MDIArea(QMdiArea):
         painter.end()
 
 
+    def findSubWindow(self, name):
+        for sub in self.subWindowList():
+            if sub.windowTitle() == name:
+                return sub
+
+
 
 class MDISubPlot(QMdiSubWindow):