vb6 Addin Part 2

Author: Dave
Date: 06.22.15 - 6:46pm

So one other bug I want to quash in my addin, is a kind of unexpected one.

If you use debug.print statements, you will be aware that the output window is never cleared and the results build up. If you reset the cursor in the output window using it to query data and variables (immediate window output) now its adding data in the middle of the pane. Annoying. (and I love to use the immediate window to query data at runtime its one of vb6 strong suits!)

So, i wanted an addin feature that would clear the immediate window for me automatically everytime i entered a new debug session.

First is clearing the immediate window possible? Well no directly but it is with some sendkeys magic..

Sub ClearImmediateWindow()
    On Error Resume Next
    Dim oWindow As VBIDE.Window
    Set oWindow = VBInstance.ActiveWindow
    VBInstance.Windows("Immediate").SetFocus
    SendKeys "^{Home}", True
    SendKeys "^+{End}", True
    SendKeys "{Del}", True
    oWindow.SetFocus
End Sub

Ok, now how do we trigger this code when a debug session is launched. Turns out all of the menu items are accessible to addins (even vb native ones) and you can sink thier events to receive notification when they are called.

Set mcbRealStartButton = FindRunButton()
If Not mcbRealStartButton Is Nothing Then
    Set mnuRealRun = VBInstance.Events.CommandBarEvents(mcbRealStartButton)
End If

Private Function FindRunButton() As Office.CommandBarControl
    
    Dim cbToolbar As Office.CommandBar
    Dim cbSubMenu As Office.CommandBarControl
    
    For Each cbToolbar In VBInstance.CommandBars
        'Debug.Print "Toolbar: " & cbToolbar.Index
        'If cbToolbar.Index = 17 Then Stop
        For Each cbSubMenu In cbToolbar.Controls
            'Debug.Print vbTab & cbSubMenu.caption
            If cbSubMenu.caption = "&Start" Then
                Set FindRunButton = cbSubMenu
                Exit Function
            End If
        Next
    Next
    
End Function

Ok this is awesome mission accomplished! True..but see there is one fly in teh soup. When a debug session is launched, addin buttons, menus bars etc are all disabled so as not to interfere with the operation of the IDE. Makes sense. BUT..even if you sink events for a VB native menu items..well thats enough to make the IDE disable it as well. Also, even though we hooked the Start menu item..the blue run button gets disabled as well.

So teh bug is, once we enter a debug session with this event hooked, now we can ONLY use F5 key to resume full execution again. I have been dealing with it because i like the clean immediate window...but its just too annoying to deal with anymore. I have a 20yr habit of clicking that stupid run arrow.

Ok..so now what? Well I poked around the internals of the IDE some this weekend, and found that the VBA6.EbSetCommandLine export is always called when a debug session starts. I could use a detours style hook from my addin to call the clear window code..but this is a little heavy handed. I am sure it would work just fine though. Maybe i will go this route. The other alternative is even simplier..

I can just add another addin button, my own blue arrow..that will clear the window and then do a sendkeys f5 to the IDE to start the debug session. This is probably what I will do, since then I can explicitly control when the debug window is cleared. Even though its almost always my desired outcome..not always (like when I have entered manual query commands down there that I will be using again for next debug session)

So after a whole lot of work, a half days worth of poking around in the debugger, and a long ass blog post..I am going to revert back to a freshman level solution and its going to be perfectly suited to the task.

Sometimes having to much knowledge blinds you to the simple solutions.