Speed tip with popupmenus

9 Replies to “Speed tip with popupmenus”

1. Can you test:
   PopupMenu1.ListIndex = -1
   For i As Integer = 0 To 1000
   PopupMenu1.AddRow Str(i)
   PopupMenu1.ListIndex = 0
   Next
   PopupMenu1.ListIndex = -1

   and comment about the results? Thanks

   1. You could but I suspect setting listindex on every iteration of the loop would simply make things slower than they need to be

      1. On my mac with 10.12.6 debug:
         Total 1 = 0.01742
         Total 2 = 0.00547
         Total 3 = 0.00776
         I suspected slower speed than listindex -1 (Total 1) but is just a little slower than the addrow/removerow workaround (Total 2).

         Remote debug to Mojave VM:
         Total 1 = 0.97851
         Total 2 = 0.01481
         Total 3 = 0.01587

2. Hi Norman! Nice tip, but why not:

   PopupMenu2.AddRow Str(0)
   PopupMenu2.ListIndex = 0
   For i As Integer = 1 To 1000
   PopupMenu2.AddRow Str(i)
   Next

   1. This would work assuming you wanted to retain the 0th element
      Basically avoiding the listindex = -1 setting until after the list was loaded has the best impact on speed

      1. Well, if you want to fill the PopupMenu then you might as well use the data you want to fill it with. So there is no need to remove the 0th element.

         As an extension method I would write it something like this:

         Public Sub SetToArray(Extends pop As PopupMenu, arr() As String)

         Dim NumberOfArrayElements As Integer = arr.Ubound

         Select Case True

         Case NumberOfArrayElements > 1

         pop.AddRow arr(0)
         pop.ListIndex = 0

         For i As Integer = 1 To NumberOfArrayElements
         pop.AddRow arr(i)
         Next

         Case NumberOfArrayElements = 1

         pop.AddRow arr(0)
         pop.ListIndex = 0

         Case NumberOfArrayElements = 0

         MsgBox “Oops!”

         End Select

         End Sub

3. I made two more additions to the test:

   Method 3 with my modification as mentioned above
   Method 4 with the code in its own extension method

   Public Sub SetToArray(Extends pop As PopupMenu)
   pop.AddRow Str(0)
   pop.ListIndex = 0
   For i As Integer = 1 To 1000
   pop.AddRow Str(i)
   Next
   End Sub

   The results (average of 10 runs) are from the build app and are pretty consistent:

   On High Sierra:

   Method 1: 0.05144
   Method 2: 0.01422
   Method 3: 0.01440
   Method 4: 0.01186

   Mojave (different computer, single-core performance is about twice as fast):
   Method 1: 1.28073
   Method 2: 0.01274
   Method 3: 0.01104
   Method 4: 0.00999

   Interestingly putting the code in its own method speeds it up by 10-20%. I would have thought the overhead of the method call would slow it down slightly, but it might be worth it for the convenience, but the speedup was unexpected. Maybe due to better optimization?

   Complete code is:

   Sub Action() Handles Action
   #Pragma BackgroundTasks False
   #Pragma BoundsChecking False
   #Pragma NilObjectChecking False
   #Pragma StackOverflowChecking False

   Dim total1 As Double
   Dim total2 As Double
   Dim total3 As Double
   Dim total4 As Double

   Dim NumberOfRuns As Integer = 10
   Dim Counter As Integer

   For Counter = 1 To NumberOfRuns

   PopupMenu1.DeleteAllRows
   PopupMenu2.DeleteAllRows
   PopupMenu3.DeleteAllRows
   PopupMenu4.DeleteAllRows

   Dim startTime1 As Double
   Dim endTime1 As Double

   Dim startTime2 As Double
   Dim endTime2 As Double

   Dim startTime3 As Double
   Dim endTime3 As Double

   Dim startTime4 As Double
   Dim endTime4 As Double

   startTime1 = Microseconds
   PopupMenu1.ListIndex = -1
   For i As Integer = 0 To 1000
   PopupMenu1.AddRow Str(i)
   Next
   PopupMenu1.ListIndex = 0
   endTime1 = Microseconds

   startTime2 = Microseconds
   PopupMenu2.AddRow “”
   PopupMenu2.ListIndex = 0
   For i As Integer = 0 To 1000
   PopupMenu2.AddRow Str(i)
   Next
   PopupMenu2.RemoveRow 0
   endTime2 = Microseconds

   startTime3 = Microseconds
   PopupMenu3.AddRow Str(0)
   PopupMenu3.ListIndex = 0
   For i As Integer = 1 To 1000
   PopupMenu3.AddRow Str(i)
   Next
   endTime3 = Microseconds

   startTime4 = Microseconds
   PopupMenu4.SetToArray
   endTime4 = Microseconds

   total1 = total1 + (endtime1 – startTime1)
   total2 = total2 + (endtime2 – startTime2)
   total3 = total3 + (endtime3 – startTime3)
   total4 = total4 + (endtime4 – startTime4)

   Next

   total1 = total1 / (1000000 * NumberOfRuns)
   total2 = total2 / (1000000 * NumberOfRuns)
   total3 = total3 / (1000000 * NumberOfRuns)
   total4 = total4 / (1000000 * NumberOfRuns)

   label1.Text = Str(total1, “###.00000”)
   label2.Text = Str(total2, “###.00000”)
   label3.Text = Str(total3, “###.00000”)
   label4.Text = Str(total4, “###.00000”)

   Result = “Method 1: ” + Str(total1, “###.00000”) + EndOfLine + _
   “Method 2: ” + Str(total2, “###.00000”) + EndOfLine + _
   “Method 3: ” + Str(total3, “###.00000”) + EndOfLine + _
   “Method 4: ” + Str(total4, “###.00000”)

   End Sub

   Public Sub SetToArray(Extends pop As PopupMenu)

   pop.AddRow Str(0)
   pop.ListIndex = 0
   For i As Integer = 1 To 1000
   pop.AddRow Str(i)
   Next
   End Sub

4. It wasn’t so much to find the optimal way to do this just to publicise a rather curious effect that doing that might seem normal, setting listindex = -1, suddenly had a noticeable and measurable side effect on Mojave.
   Ideally the framework would be fixed to NOT do whatever is causing this.

5. A good question was posed to me elsewhere
   >norman , does the speed tip for popup menu work for dropdown/combobox?
   It appears to NOT have the same huge slowdown as the popup menu when doing the same addition of rows to a combobox

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