[SOLVED] VirtualStringTree-set Checkbox from Code not propagating back to Parent

[Zvoni]

Hi Folks,
first time using VTV as VirtualStringTree with Checkboxes (CheckType=TriState)
User opens Form, VST is filled from a Database - 3 Levels deep

User can now check/uncheck Nodes as he wishes, with the State of the 2 higher-order nodes being set automagically (as it should be):
All Childnodes checked, "some" childnodes checked (This "Half-State"), no childnodes checked (See screenshot 1)

Now, only checks/unchecks on Level 3 are being saved back to the Database in Real-Time (I'm using the OnChecked-Event)

This works as it should

Now: Next day, user wants to continue, and after the VST is filled, i pull the already checked Level-3-Nodes from the Database.
I iterate over the nodes looking for my identifier, and when found do

Code: Pascal  [Select][+][-]

1. Node^.CheckState:=csCheckedNormal;

Works as it should

BUT: The newly set CheckState of that Level-3-Node doesn't propagate back to its 2 higher-order Nodes
(Screen shot 2)

What am i missing?
It's not "vst.Refresh;" --> already tried that.

[zeljko]

It is in your code, do you use vt.BeginUpdate / vt.EndUpdate when populating nodes from db ? Where is code which reacts on checkstate change of node ?

[Zvoni]

It is in your code, do you use vt.BeginUpdate / vt.EndUpdate when populating nodes from db ? Where is code which reacts on checkstate change of node ?

Hi fellow countryman.
No i don't use begin/End-Update


This is my OnChecked-Code.
But it doesn't fire, when i set CheckBox from code (already tested).
Only fires when user clicks

Code: Pascal  [Select][+][-]

1. procedure TFormCatalogue.vstCompetencesChecked(Sender: TBaseVirtualTree;
2.   Node: PVirtualNode);
3. Var
4.   s:String;
5.   Level:Integer;
6.   Q:Integer;
7. begin
8.   Level:=StrToInt(vstCompetences.Text[Node,2]);
9.   If Level=3 Then
10.     Begin
11.       Case Node^.CheckState Of
12.         csCheckedNormal : Begin  //Insert
13.                             If optPoweruser.Checked Then
14.                               Q:=SQL_INSERT_POWERUSER_COMPETENCE
15.                             Else
16.                               Q:=SQL_INSERT_EMPLOYEE_COMPETENCE;
17.                           end;
18.         csUncheckedNormal : Begin //Delete
19.                               If optPoweruser.Checked Then
20.                                 Q:=SQL_DELETE_POWERUSER_COMPETENCE
21.                               Else
22.                                 Q:=SQL_DELETE_EMPLOYEE_COMPETENCE;
23.  
24.                             end;
25.       End;
26.       s:=GetSQLStatement(Q);
27.       SQLQuery.Close;
28.       SQLQuery.SQL.Clear;
29.       SQLQuery.SQL.Text:=s;
30.       SQLQuery.ParamByName('pCID').AsInteger:=StrToInt(vstCompetences.Text[Node,1]);
31.       SQLQuery.ParamByName('pUID').AsInteger:=UserID;
32.       SQLQuery.ExecSQL;
33.       SQLQuery.SQLTransaction.CommitRetaining;
34.     end;
35. end;                                                                

EDIT: Using Begin/End-Update before populating/after setting Checkboxes makes no difference.
Meaning
BeginUpdate
Populate VST
Iterate over VST and set Checkboxes where necessary
EndUpdate

No difference

I'm sure i'm missing something simple

EDIT2: I'm not using Event OnChecking whatsoever
(I know that's the event in which you can actually "prevent" a Checkmark being set)

EDIT3: The reason why i would like that "feature":
The Form with VST shows up in collapsed state, so the user actually only sees the (currently) 4 root-Nodes, and it would be like
"In that root-node you already have some selections, in that root-node you have none" etc...

[zeljko]

Of course it does not trigger when you update Node^.CheckState in code. call vstCompetencesChecked(Sender: TBaseVirtualTree;
  Node: PVirtualNode); whenever you change Node^.CheckState programatically.

[Zvoni]

Of course it does not trigger when you update Node^.CheckState in code. call vstCompetencesChecked(Sender: TBaseVirtualTree;
  Node: PVirtualNode); whenever you change Node^.CheckState programatically.

No cigar.
Had to use a Blocking-Variable "CheckFromCode" within OnChecked to avoid duplicate primary key (Setting a Checkmark invokes an INSERT)

Code: Pascal  [Select][+][-]

1. procedure TFormCatalogue.vstCompetencesChecked(Sender: TBaseVirtualTree;
2.   Node: PVirtualNode);
3. Var
4.   s:String;
5.   Level:Integer;
6.   Q:Integer;
7. begin
8.   Level:=StrToInt(vstCompetences.Text[Node,2]);
9.   If Not CheckFromCode Then
10.     Begin
11.       If Level=3 Then
12.         Begin                            
13. //My SQL-Stuff INSERTING to Database
14.  

Code: Pascal  [Select][+][-]

1. CheckFromCode:=True;
2. //.....
3. If Level=3 Then
4.             Begin
5.               If Data^.RecordID=SQLQuery.FieldByName(FieldID[Level]).AsString Then
6.                 Begin
7.                   Node^.CheckState:=csCheckedNormal;
8.                   vstCompetencesChecked(vstCompetences,Node);
9.                   SQLQuery.Next;
10. //other stuff following that has nothing to do with it
11.  

*sigh*.... so it's not actually something to do with the Checking itself
Interesting: I found this in TBaseVirtualTree

Code: Pascal  [Select][+][-]

1. FCheckPropagationCount: Cardinal;            // nesting level of check propagation (WL, 05.02.2004)

and this

Code: Pascal  [Select][+][-]

1. function TBaseVirtualTree.CheckParentCheckState(Node: PVirtualNode; NewCheckState: TCheckState): Boolean;
2.  
3. // Checks all siblings of node to determine which check state Node's parent must get.      

Which actually might look like what i'm after, but the Function is protected, so how is the actual VST calling that?

EDIT: After looking further through the Source, i'm thinking "DoCheckClick" of BaseVirtualTree is the one i need, but how are the Descendants calling that?

[Zvoni]

SOLVED (On the german forum)

Code: Pascal  [Select][+][-]

1. CheckFromCode:=True;
2. //.....
3. If Level=3 Then
4.             Begin
5.               If Data^.RecordID=SQLQuery.FieldByName(FieldID[Level]).AsString Then
6.                 Begin
7.                   Node^.CheckState:=csCheckedNormal;
8.                   vstCompetencesChecked(vstCompetences,Node);
9.                   SQLQuery.Next;

Remove Line 8
Replace Line 7 -->
Node^.CheckState:=csCheckedNormal;
with
MyVST.CheckState[Node]:=csCheckedNormal;  (In my Case the MyVST's Name is "vstCompetences" --> vstCompetences.CheckState[Node]:=csCheckedNormal;
This one triggers the Propagation-Check.
NICE!!

Nota bene: I had to use a blocking variable, because the Solution fires the OnChecked-Event, and i have to prevent Duplicate INSERTS.


Reasoning as follows (which in hindsight is completely logical):
Setting the CheckState via
Node^.CheckState:=csCheckedNormal;
sets the State ONLY for the Node --> Its Tree doesn't know about it

But
MyTree.CheckState[Node]:=csCheckedNormal;
tells the tree itself: "Hey, set the Checkmark for this node, and then check everything else"

[zeljko]

Glad to se you fixed your problem

[Zvoni]

and i even removed the need for the Blocking-Variable.

Just changed the INSERT-Statement to "INSERT OR IGNORE blablaha"