Demo Treeview Object Properties

[(X)]

This is the tip of the iceberg, of a way I want to be able to work.

I want to be able to view and edit any object property 'on the fly'.

Attachments:

Demo Treeview Object Properties.G32 (5.25 KB)

[rogercabo]

Interesting!

F5 and i got this screen. Not sure if that's correct?

[(X)]

In that demo the treeview lines were not activated and subnodes not expanded. If you dbl click on the root treeview item it will/should show a list of node properties and the values.

This is just the start of what I would like to quickly and easily be able to accomplish 'on the fly' for any control or variable in a running or halted program.

[(X)]

I updated the demo to include lines and expanded all nodes in advance.

Go to the first post, to download the updated program.

[(X)]

The more I look at the OCX Overview built into the GFA-BASIC 32 for Windows Integrated Development Environment Menu; the more I think it is along these lines that I want to expand the programmers scope into runtime access of the OCX properties, adding, removing, moving, resizing etc...

[(X)]

I am making progress on listing and storing all the properties for all the declared controls and collections (such as App) in a program.
Once I have this worked out I want to be able to display and edit any property "on the fly" and make it persistent for the next time I open the program file.

I know this is a bit abstract, but, it fits well with my desire to be able to quickly setup a program with previously prepared libraries and solutions.

This is a function that returns the property value based on a given control and a property string: prop$.

Once I have the full demo worked out I will post it.

As you can see the number of properties are in the dozens and I am struggling to find a simple way to do all of this..

Function F_Ctrl_Prop(c As Control, prop$) As Variant
Try
If Lower(prop$) == "" Return c.Name
If Lower(prop$) == "align" Return c.Align
If Lower(prop$) == "alignment" Return c.Alignment
If Lower(prop$) == "appearance" Return c.Appearance
If Lower(prop$) == "arguments" Return c.Arguments
If Lower(prop$) == "arrowkeys" Return c.ArrowKeys
If Lower(prop$) == "autoplay" Return c.Autoplay
If Lower(prop$) == "availpagefile" Return Hex(c.AvailPageFile)
If Lower(prop$) == "availphys" Return Hex(c.AvailPhys)
If Lower(prop$) == "availvirtual" Return Hex(c.AvailVirtual)
If Lower(prop$) == "backcolor" Return c.backcolor
If Lower(prop$) == "borderstyle" Return c.borderstyle
If Lower(prop$) == "buddycontrol" Return c.buddycontrol
If Lower(prop$) == "cancel" Return c.cancel
If Lower(prop$) == "caption" Return c.caption
If Lower(prop$) == "center" Return c.center
If Lower(prop$) == "comments" Return c.Comments
If Lower(prop$) == "companyname" Return c.CompanyName
If Lower(prop$) == "controlbox" Return c.controlbox
If Lower(prop$) == "default" Return c.default
If Lower(prop$) == "disablenoscroll" Return c.DisableNoScroll
If Lower(prop$) == "enabled" Return c.enabled
If Lower(prop$) == "filedescription" Return c.FileDescription
If Lower(prop$) == "filename" Return c.FileName
If Lower(prop$) == "fileversion" Return c.FileVersion
If Lower(prop$) == "font" Return c.Font
If Lower(prop$) == "forecolor" Return c.forecolor
If Lower(prop$) == "format" Return c.format
//If Lower(prop$) == "forms" Return c.Forms
If Lower(prop$) == "frompage" Return c.frompage
If Lower(prop$) == "internalname" Return c.InternalName
If Lower(prop$) == "integralheight" Return c.IntegralHeight
If Lower(prop$) == "height" Return c.height
If Lower(prop$) == "helpbutton" Return c.helpbutton
If Lower(prop$) == "helpcontextid" Return c.helpcontextid
If Lower(prop$) == "hinstance" Return c.hInstance
If Lower(prop$) == "horizontal" Return c.horizontal
If Lower(prop$) == "hottracking" Return c.hottracking
If Lower(prop$) == "hscmax" Return c.hscmax
If Lower(prop$) == "hscmin" Return c.hscmin
If Lower(prop$) == "hscpage" Return c.hscpage
If Lower(prop$) == "hscstep" Return c.hscstep
If Lower(prop$) == "increment" Return c.increment
If Lower(prop$) == "index" Return Iif(IsArray(c), c.index, "N/A")
If Lower(prop$) == "icon" Return c.icon
If Lower(prop$) == "left" Return c.left
If Lower(prop$) == "leftalign" Return c.leftalign
If Lower(prop$) == "max" Return c.max
If Lower(prop$) == "maxbutton" Return c.maxbutton
If Lower(prop$) == "mdichild" Return c.mdichild
If Lower(prop$) == "mdiparent" Return c.mdiparent
If Lower(prop$) == "min" Return c.min
If Lower(prop$) == "minbutton" Return c.minbutton
If Lower(prop$) == "mouseicon" Return c.mouseicon
If Lower(prop$) == "mousepointer" Return c.mousepointer
If Lower(prop$) == "moveable" Return c.moveable
If Lower(prop$) == "multiline" Return c.multiline
If Lower(prop$) == "multirow" Return c.multirow
If Lower(prop$) == "name" Return c.name
If Lower(prop$) == "owned" Return c.owned
If Lower(prop$) == "pgbottom" Return c.pgbottom
If Lower(prop$) == "pgleft" Return c.pgleft
If Lower(prop$) == "pgminbottom" Return c.pgminbottom
If Lower(prop$) == "pgminleft" Return c.pgminleft
If Lower(prop$) == "pgminright" Return c.pgminright
If Lower(prop$) == "pgmintop" Return c.pgmintop
If Lower(prop$) == "pgright" Return c.pgright
If Lower(prop$) == "pgscale" Return c.pgscale
If Lower(prop$) == "pgtop" Return c.pgtop
If Lower(prop$) == "picture" Return c.picture
If Lower(prop$) == "picturemode" Return c.picturemode
If Lower(prop$) == "placement" Return c.placement
If Lower(prop$) == "pushlike" Return c.pushlike
If Lower(prop$) == "scrollbars" Return c.scrollbars
If Lower(prop$) == "scrollopposite" Return c.scrollopposite
If Lower(prop$) == "separators" Return c.separators
If Lower(prop$) == "shownintaskbar" Return c.shownintaskbar
If Lower(prop$) == "simpletext" Return c.SimpleText
If Lower(prop$) == "sizeable" Return c.sizeable
If Lower(prop$) == "smallicon" Return c.smallicon
If Lower(prop$) == "sorted" Return c.Sorted
If Lower(prop$) == "startupmode" Return c.startupmode
If Lower(prop$) == "style" Return c.style
If Lower(prop$) == "tabfixedheight" Return c.tabfixedheight
If Lower(prop$) == "tabfixedwidth" Return c.tabfixedwidth
If Lower(prop$) == "tabminwidth" Return c.tabminwidth
If Lower(prop$) == "tabstop" Return c.TabStop
If Lower(prop$) == "tabwidthstyle" Return c.tabwidthstyle
If Lower(prop$) == "tag" Return c.tag
If Lower(prop$) == "threestate" Return c.threestate
If Lower(prop$) == "tooltiptext" Return c.tooltiptext
If Lower(prop$) == "top" Return c.top
If Lower(prop$) == "topage" Return c.topage
If Lower(prop$) == "transparent" Return c.transparent
If Lower(prop$) == "value" Return c.value
If Lower(prop$) == "visible" Return c.visible
If Lower(prop$) == "vscmax" Return c.vscmax
If Lower(prop$) == "vscmin" Return c.vscmin
If Lower(prop$) == "vscpage" Return c.vscpage
If Lower(prop$) == "vscstep" Return c.vscstep
If Lower(prop$) == "whatsthishelpid" Return c.whatsthishelpid
If Lower(prop$) == "width" Return c.width
If Lower(prop$) == "wrap" Return c.wrap
Debug "NO SUCH PROPERTY: " & #34 & c.NAME & "." & prop$ & #34
Return ""
Catch
'Debug "ERR$: ";Err$ & ": " & c.name & "." & prop$
Return ""
EndCatch
EndFunc

[dragonjim]

I wrote a program a few years ago which handled properties but in newly created Unicode Controls rather than GFA's OCX ones.

However, what may be useful to you from that project is the means of determining what properties each control type has and/or uses. Extrapolating from the code, you could have a hash table where the key is a property name and the value is a string containing codes showing which controls use that property.

For instance, for the Align property, the Hash entry would be property["align2"] = "*cbx*txt*lbx*cmd*" [and so on]

Then, to work with this, you could create a second Hash table with the control name as the key and the code as the value (so ctrl["combobox"] = "cbx").

That way, you can use Typename to interrogate any control to return the control type like this:

Ocx ComboBox cbx = "", 10, 10, 100, 15
Debug TypeName(cbx) // Returns ComboBox

... and thus create a list of properties by cross referencing with your hash tables.

Thinking about it, you can even miss out the second hash table and just put the control names in full in the value part of the property hash table...

I hope this is helpful.

[(X)]

Thanks dj.

This project is slowly building steam. I've had it in the back of my mind for years it seems.

I am throttled by by the question: "Why are you doing this? It seems like you are re-inventing the wheel! Isn't this overly complicated?"
I am encouraged by the answer: "I have a gut feeling that if I can get this to work, then, at the very least I will understand programming a little better, and if things go well, this will be a whole new way for me to build applications from the ground up."

The nuts and bolts...
I was thinking of sequentially trying to log all the property values for any control I provide, if the property doesn't exist it will simply be ignored.
If the property does exist, I will log the control name, property name and it's value likely as a variant. This way I could build a [control + property + value] roster for any control existing in the code.

I woke up yesterday with the feeling: "This could be the day!" I will be making trials to iterate over all possible properties for each control and see what comes of it.

I welcome any feedback.

[dragonjim]

I can see one practical use for this (I am sure there are many more) if it is called as part of debugging to find out what may or may not be going wrong with controls on a Form.

As I'm sure you're aware, you can process all the controls belonging to any Form using the Controls property, which would be useful for creating such a report that could then be sent to a different, dedicated Form containing your Treeview object.

To facilitate this and any other uses you may think of, you can use the Ocx Timer or any other Timer object to call a second thread to process all the information on a form in real time without having to interrupt the main program flow. You could create two small sub routines to allow this debugging to be switched on and off within the main program and also control the time interval and thus how often it is called (calling this routine too often could cause performance lags and possible crashes - it would also be useful to have a dedicated global variable which alerts these sub routines that the second thread is already in operation so that it does not try to overwrite information already being processed which can cause a crash).

[(X)]

Just in case I missed it.

To your knowledge, is there a method 'built-in' to GFA-BASIC 32 to iterate through the properties of a control?

[dragonjim]

No, you will need to do this manually, something like:

$Library "gfawinx"
$Library "C:\Program Files (x86)\GFABASIC32\Include\UpdateRT.lg32"
$Library "C:\Program Files (x86)\GFABASIC32\Include\Variants.lg32"
UpdateRuntime      ' Patches GfaWin23.Ocx

Dim varr As Variant : varr = Array(0, 0, 0, 0)
Dim vsubarr As Variant // 0 - Name, 1 - Type, 2 - Properties
Dim vproparr As Variant
Dim ct As Int32

OpenW 1
Ocx Command cmd = "Hello", 20, 20, 100, 20
Ocx Command bye = "Goodbye", 20, 45, 100, 20
Ocx Option opt = "Check me...", 20, 70, 100, 15 : opt.Value = 1
Ocx Option op2 = "...no me", 20, 90, 100, 15
Local c As Control
For Each c In Win_1.Controls
 vsubarr = Array("", "", 0)
 vsubarr(0) = c.name : Trace c.name
 vsubarr(1) = TypeName(c) : Trace TypeName(c)
 vproparr = Array("", 0)
 vproparr(0) = "Align"
 vproparr(1) = c.align : Trace c.align
 VarArraySet vsubarr, 2, vproparr
 VarArraySet varr, ct, vsubarr
 Inc ct
Next
Debug.Show
Trace VarPrint (varr, VARPRINT_ARRAYINFULL)
Do : Sleep : Until Win_1 Is Nothing

Sadly, it does not look like to can assign the controls to a collection through direct transfer either.

[dragonjim]

Looking again at my code, you can shorten the creation of vsubarr to:

vsubarr = Array(c.name, TypeName(c), Array("Align", c.align))

and do away with vproparr all together in this example; however, I am guessing that you will want to use a variable length variant array for properties so this would not be practical for your planned program.

[(X)]

I am getting hung up on this line:

Dim dw% = StdCall(proc_addr%)( L: hCtrl, Var: prop_val)


// Would it be possible to do something like this?
// Where: proc_addr% would be set in advance in the hash table
// pa% = ProcAddr(P_Get_Align)

Function F_Return_prop_val(ctrl As Control, prop$) As Variant
Dim H_Proc_Addr_by_Prop_Str As Hash Long
Dim pa% = ProcAddr(P_Get_Alignment)
Trace Hex(pa%)
H_Proc_Addr_by_Prop_Str["Alignment"] = pa%
Trace Hex(H_Proc_Addr_by_Prop_Str["alignment"])
Dim proc_addr% = H_Proc_Addr_by_Prop_Str[prop$]
Trace Hex(proc_addr)
Dim prop_val As Variant
Dim hCtrl% = ctrl.hWnd
Dim dw% = StdCall(proc_addr%)( L: hCtrl, Var: prop_val)
Trace dw
Trace prop_val
Return prop_val
EndFunc

// Where:
Proc P_Get_Alignment(hCtrl%, ByRef v As Variant)
Dim ctrl As Control
Set ctrl = OCX(hCtrl)
Trace ctrl.name
Trace ctrl.alignment
v = ctrl.Alignment
EndProc

[(X)]

Using:

 
 ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
 ' Init
 '
 Global v As Variant
 Global H_Proc_Addr_by_Prop_Str As Hash Long
 H_Proc_Addr_by_Prop_Str["Alignment"] = ProcAddr(P_Get_Alignment)
 H_Proc_Addr_by_Prop_Str["Caption"] = ProcAddr(P_Get_Caption)

Proc P_Get_Alignment(hCtrl%)
 Dim ctrl As Control
 Set ctrl = OCX(hCtrl)
 v = ctrl.Alignment
EndProc

Proc P_Get_Caption(hCtrl%)
 Dim ctrl As Control
 Set ctrl = OCX(hCtrl)
 v = ctrl.Caption
EndProc

Function F_Prop_Val(ctrl As Control, prop$) As Variant
 Dim dw% = StdCall(H_Proc_Addr_by_Prop_Str[prop$])( L:ctrl.hWnd)
 Return v
EndFunc


This works:

 Trace F_Prop_Val(lbl(0), "alignment")
 Trace F_Prop_Val(lbl(0), "caption")

Obviously the procedures would be stored in a library ahead of time and Try..Catch.. will probably be necessary for inapporpriate requests.

[dragonjim]

I am getting hung up on this line:

Dim dw% = StdCall(proc_addr%)( L: hCtrl, Var: prop_val)

There used to be a problem passing the second and later parameters if they were not 32-bit integers, but this has been fixed and, anyway, your code works if v is passed as a Large value.

From what I can see, it seems that StdCall has a problem with passing Variants.

One workaround would be to alter your code, where you are looking to return the align(ment) value in a Variant, as follows:

OpenW 1
Ocx Command cmd = "Hello", 10, 10, 100, 20 : cmd.Align = 1
Trace F_Return_prop_val(cmd, "Align")
Do : Sleep : Until Win_1 Is Nothing

// Would it be possible to do something like this?
// Where: proc_addr% would be set in advance in the hash table
// pa% = ProcAddr(P_Get_Align)

Function F_Return_prop_val(ctrl As Control, prop$) As Variant
 Dim H_Proc_Addr_by_Prop_Str As Hash Long
 Dim pa% = ProcAddr(P_Get_Align)
 Trace Hex(pa%)
 H_Proc_Addr_by_Prop_Str["Align"] = pa%
 Trace Hex(H_Proc_Addr_by_Prop_Str["align"])
 Dim proc_addr% = H_Proc_Addr_by_Prop_Str[prop$]
 Trace Hex(proc_addr)
 Dim prop_val As Variant
 Dim hCtrl% = ctrl.hWnd
 Dim dw% = StdCall(proc_addr%)( L: hCtrl, V:prop_val) // <--- Pass the address of the Variant
 Trace dw
 Trace prop_val
 Return prop_val
EndFunc

// Where:
Proc P_Get_Align(hCtrl%, vv%)
 Dim ctrl As Control, v As Variant
 Set ctrl = OCX(hCtrl)
 Trace ctrl.name
 Trace ctrl.align
 v = ctrl.Align
 BMove V:v, vv%, 16  // <--- Move the value of the local Variant to the address passed for prop_val
EndProc


[(X)]

Oooooooooooooooooooooooooo!!!!!!!!

I stumbled upon this!  It seems to work for getting a property by passing a control name and a property name as a string parameter.


Local idisp As Int32 = _DispID(lbl(0), "Caption")
Trace lbl(0).{idisp}

// Which can be shortened to:
Trace <some control>.{<some control>,<"some property string">}


Debug output:
TRACE:frm1_Close(8):lbl(0).{idisp} = IMG
From the Help document:

_DispID and .{}
GFABasic has two functions which can be used when determining and returning values of Automation object properties: _DispID and .{}. These are discussed in detail on Sjouke Hamstra's blog but a quick precis of the details are as follows.

Generally, most properties related to a COM object can be accessed using the property's name: hence, to check that Internet Explorer is visible, ie.Visible is queried and returns either a True or False value accordingly.

Sometimes, a COM property may not be available to a program as a named property (usually because it is new): this is where _DispID(Object, PropertyName) and Object.{IDispatchID} come in useful. _DispID queries the Object for the PropertyName which returns the IDispatchID (if the property exists) which can then be used by .{} to retrieve the relevant value. Hence, for the Internet Explorer Visible property, the following procedure could be followed:

Debug.Show

Dim ie As Object

Set ie = CreateObject("InternetExplorer.Application")

Trace ie.visible

Local idisp As Int32 = _DispID(ie, "Visible")

Trace idisp

Trace ie.{idisp}

~ie.quit

Set ie = Nothing


Unfortunately, at the time of writing, the .{} function can not be used to set the property due to a compiler error; when it is used in the logical fashion ie.{402} = True, an 'Internal: Set Prop value' error message is displayed.

[(X)]

This may offer a "mine-able" source of property names and types of all the OCX or TypeLib information I am looking for...

gfabasic32.blogspot.com/2013/11/using-olecom-object-viewer.html

[(X)]

There is a way to get the control property value using the control as a variable and property as a string.*

<ctl_val> = <control>.{_DispID(<control>, <property_string>)}

*

Q: Why not use the explicit form of: "<val> = <ctrl>.<property>" e.g.: "w = lbl.width"? 

A: By all means do so if you can.  I am trying to work with a specific case 'where that won't do'.  I am trying to use code to perform the task of getting the control property value.  In this case, using a 'property string' parameter works to our advantage.

If you think there is a better way to do things, someone may well have thought so too, and with a little looking around you might find it.  In this case, I think you'll agree: the command names give very little indication of their use. 

The following code stands out as an example of starting out with a long way and only later, by pure chance, finding a shorter way:

CODE EXAMPLE:

Function F_Ctl_Prp_Val(c As Control, prop$) As Variant
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' There is a way to get the control property value using the control and
' property name passed as a string. I know, I didn't believe it myself!
'
'    <control>.{_DispID(<control>, <property_string>)}
'
Try
   Return c.{_DispID(c, prop$)}
Catch
   Debug "ERR$: ";Err$ & ": " & c.name & "." & prop$
Return ""
EndCatch
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' This does away with all that follows. I will leave this here as a reminder
' that if you think there is a better way to do things, someone may well have
' thought so too, and with a little looking around you might find it.
'
°Try
°If Lower(prop$) == "" Return c.Name
°If Lower(prop$) == "align" Return c.Align
°If Lower(prop$) == "alignment" Return c.Alignment
°If Lower(prop$) == "appearance" Return c.Appearance
°If Lower(prop$) == "arguments" Return c.Arguments
°If Lower(prop$) == "arrowkeys" Return c.ArrowKeys
°If Lower(prop$) == "autoplay" Return c.Autoplay
°If Lower(prop$) == "availpagefile" Return Hex(c.AvailPageFile)
°If Lower(prop$) == "availphys" Return Hex(c.AvailPhys)
°If Lower(prop$) == "availvirtual" Return Hex(c.AvailVirtual)
°If Lower(prop$) == "backcolor" Return c.backcolor
°If Lower(prop$) == "borderstyle" Return c.borderstyle
°If Lower(prop$) == "buddycontrol" Return c.buddycontrol
°If Lower(prop$) == "cancel" Return c.cancel
°If Lower(prop$) == "caption" Return c.caption
°If Lower(prop$) == "center" Return c.center
°If Lower(prop$) == "comments" Return c.Comments
°If Lower(prop$) == "companyname" Return c.CompanyName
°If Lower(prop$) == "controlbox" Return c.controlbox
°If Lower(prop$) == "default" Return c.default
°If Lower(prop$) == "disablenoscroll" Return c.DisableNoScroll
°If Lower(prop$) == "enabled" Return c.enabled
°If Lower(prop$) == "filedescription" Return c.FileDescription
°If Lower(prop$) == "filename" Return c.FileName
°If Lower(prop$) == "fileversion" Return c.FileVersion
°If Lower(prop$) == "font" Return c.Font
°If Lower(prop$) == "forecolor" Return c.forecolor
°If Lower(prop$) == "format" Return c.format
°//If Lower(prop$) == "forms" Return c.Forms
°If Lower(prop$) == "frompage" Return c.frompage
°If Lower(prop$) == "height" Return c.height
°If Lower(prop$) == "helpbutton" Return c.helpbutton
°If Lower(prop$) == "helpcontextid" Return c.helpcontextid
°If Lower(prop$) == "hinstance" Return c.hInstance
°If Lower(prop$) == "horizontal" Return c.horizontal
°If Lower(prop$) == "hottracking" Return c.hottracking
°If Lower(prop$) == "hscmax" Return c.hscmax
°If Lower(prop$) == "hscmin" Return c.hscmin
°If Lower(prop$) == "hscpage" Return c.hscpage
°If Lower(prop$) == "hscstep" Return c.hscstep
°If Lower(prop$) == "icon" Return c.icon
°If Lower(prop$) == "increment" Return c.increment
°If Lower(prop$) == "index" Return Iif(IsArray(c), c.index, "N/A")
°If Lower(prop$) == "integralheight" Return c.IntegralHeight
°If Lower(prop$) == "internalname" Return c.InternalName
°If Lower(prop$) == "left" Return c.left
°If Lower(prop$) == "leftalign" Return c.leftalign
°If Lower(prop$) == "legalcopyright" Return c.LegalCopyright
°If Lower(prop$) == "legaltrademarks" Return c.LegalTrademarks
°If Lower(prop$) == "max" Return c.max
°If Lower(prop$) == "maxbutton" Return c.maxbutton
°If Lower(prop$) == "mdichild" Return c.mdichild
°If Lower(prop$) == "mdiparent" Return c.mdiparent
°If Lower(prop$) == "min" Return c.min
°If Lower(prop$) == "minbutton" Return c.minbutton
°If Lower(prop$) == "mouseicon" Return c.mouseicon
°If Lower(prop$) == "mousepointer" Return c.mousepointer
°If Lower(prop$) == "moveable" Return c.moveable
°If Lower(prop$) == "multiline" Return c.multiline
°If Lower(prop$) == "multirow" Return c.multirow
°If Lower(prop$) == "name" Return c.name
°If Lower(prop$) == "owned" Return c.owned
°If Lower(prop$) == "pgbottom" Return c.pgbottom
°If Lower(prop$) == "pgleft" Return c.pgleft
°If Lower(prop$) == "pgminbottom" Return c.pgminbottom
°If Lower(prop$) == "pgminleft" Return c.pgminleft
°If Lower(prop$) == "pgminright" Return c.pgminright
°If Lower(prop$) == "pgmintop" Return c.pgmintop
°If Lower(prop$) == "pgright" Return c.pgright
°If Lower(prop$) == "pgscale" Return c.pgscale
°If Lower(prop$) == "pgtop" Return c.pgtop
°If Lower(prop$) == "picture" Return c.picture
°If Lower(prop$) == "picturemode" Return c.picturemode
°If Lower(prop$) == "placement" Return c.placement
°If Lower(prop$) == "pushlike" Return c.pushlike
°If Lower(prop$) == "scrollbars" Return c.scrollbars
°If Lower(prop$) == "scrollopposite" Return c.scrollopposite
°If Lower(prop$) == "separators" Return c.separators
°If Lower(prop$) == "shownintaskbar" Return c.shownintaskbar
°If Lower(prop$) == "simpletext" Return c.SimpleText
°If Lower(prop$) == "sizeable" Return c.sizeable
°If Lower(prop$) == "smallicon" Return c.smallicon
°If Lower(prop$) == "sorted" Return c.Sorted
°If Lower(prop$) == "startupmode" Return c.startupmode
°If Lower(prop$) == "style" Return c.style
°If Lower(prop$) == "tabfixedheight" Return c.tabfixedheight
°If Lower(prop$) == "tabfixedwidth" Return c.tabfixedwidth
°If Lower(prop$) == "tabminwidth" Return c.tabminwidth
°If Lower(prop$) == "tabstop" Return c.TabStop
°If Lower(prop$) == "tabwidthstyle" Return c.tabwidthstyle
°If Lower(prop$) == "tag" Return c.tag
°If Lower(prop$) == "threestate" Return c.threestate
°If Lower(prop$) == "tooltiptext" Return c.tooltiptext
°If Lower(prop$) == "top" Return c.top
°If Lower(prop$) == "topage" Return c.topage
°If Lower(prop$) == "transparent" Return c.transparent
°If Lower(prop$) == "value" Return c.value
°If Lower(prop$) == "visible" Return c.visible
°If Lower(prop$) == "vscmax" Return c.vscmax
°If Lower(prop$) == "vscmin" Return c.vscmin
°If Lower(prop$) == "vscpage" Return c.vscpage
°If Lower(prop$) == "vscstep" Return c.vscstep
°If Lower(prop$) == "whatsthishelpid" Return c.whatsthishelpid
°If Lower(prop$) == "width" Return c.width
°If Lower(prop$) == "wrap" Return c.wrap
°Debug "NO SUCH PROPERTY: " & #34 & c.NAME & "." & prop$ & #34
°Return ""
°Catch
°'Debug "ERR$: ";Err$ & ": " & c.name & "." & prop$
°Return ""
°EndCatch
EndFunc

[(X)]

It is a great exercise to be able to layout all the App, Forms, Controls, Printers and all their properties. I am struggling to write a recursive algorithm that doesn't tie itself into knots.

This is such a fundamental task that I thought it was going to be easy. Understanding why one gets an Allocation error has stumped me on many occaisions in this project but I am making progress and I think the result will be worth it.

A programmer's job is to know how to get results, yes, but, sometimes it seems 99% of the work is learning to avoid and handle every little error and exception that may come along, then find out why, then avoid or handle them completely. :)

[(X)]

I finally got over a hump that was a "tough nut to crack" and was stopping me from moving on.

It has to do with the use of the TypeName() function applied to a 'Control.Property' pair when the property is '.Picture'.

In a nutshell: "Can you use TypeName() for any variable? Short answer: Nope."

These are demonstrations of some cases where TypeName() fails, in my opinion, for no good reason.  But then, I admit: "I don't know everything."

$Library "gfawinx"
$Library "UpdateRT"
UpdateRuntime      ' Patches GfaWin23.Ocx
//
// CAN YOU USE TypeName() willy nilly?  Short answer NO.
// It seems using a picture variable of type New StdPicture fairs
// better than New Picture or Picture type.
//
Try
 
 LoadForm frm1
 
 // OK, return: frm1.Picture = Object(:0xb1e0128)
 Trace frm1.Picture
 
 Trace TypeName(frm1.Caption)
 // Even if there is a Picture assigned to the form...
 'Trace TypeName(frm1.Picture) // Access-Violation
 
 Dim pic As New StdPicture
 'Dim pic As New Picture
 'Set pic = Nothing  // Not necessary
 Set pic = frm1.Picture
 // If Picture     : Access-Violation
 // If StdPicture  : OK
 Trace TypeName(pic)
 
 Dim var As Variant
 Set var = frm1.Picture
 // Access-Violation
 'Trace TypeName(var)
 
 Dim o As Object
 Set o = frm1.Picture
 // If Picture     : Must set to nothing or Access-Violation
 // If StdPicture  : No need to set to nothing.  Makes no difference.
 'Set pic = Nothing
 Set pic = o
 // For StdPicture or Picture type...
 // If form picture assigned: Picture, else, Nothing.
 Trace TypeName(pic)           // OK
 
 Dim c As Control
 Set c = frm1.Picture
 // If Picture     : Must set to nothing or Access-Violation
 // If StdPicture  : No need to set to nothing.  Makes no difference.
 'Set pic = Nothing
 Set pic = c
 // For StdPicture or Picture type...
 // If form picture assigned: Picture, else, Nothing.
 Trace TypeName(pic)           // OK
 
 Dim v As Variant
 Set v = frm1.Picture
 'Set pic = Nothing
 Set pic = v
 // If form picture assigned: Picture, else, Access-Violation.
 Trace TypeName(pic)
 
Catch
 Trace Err$
EndCatch


Attachments:

Demo Test TypeNameform.picture.G32 (5.78 KB)

[dragonjim]

Not sure if this is the best explanation for why these differences in behaviour occur, but I'll have a go.

A Picture object is a COM Interface, while a StdPicture object is a COM class (or coclass).

To quote from the Microsoft site: "A COM interface is a predefined group of related functions that a COM class implements".

Therefore, the Picture object acts as an interface to the StdPicture class object, but is not technically a (co)class object in itself. Hence, trying to use TypeName to describe it will result in an error because it is not a Picture per se but an interface to one.

Hence, transferring the frm1.Picture object to a Variant with transfer it as an Interface because a Variant can hold a COM Interface, whereas converting it to a control or object first should transfer the object in frm1.Picture as a picture (either an Image control or StdPicture object).

That's the theory, anyway...

I hope that helps.

[(X)]

Thanks dj,

I know just a little about the interface concept, the more I read about it, the more I realize it is important and fundamental, it's just not the first concepts one has to master before writing a "Hello World!" program in BASIC.

I find it all fascinating.