Tree View - ViewStyle Property
ViewStyle sets the way the list or tree is shown
Member of Tree View (PRIM_TRVW)
Data Type - Enumeration

Details

Levelled tree uses the KeyPosition property of columns to determine the hierarchy. Changes to data values automatically cause nesting of child items. However, only one value can be see for each item in the tree and the number of level is governed by the number of columns added.
Unlevelled trees have no such automation, requiring that the user control the nesting of items via the ParentItem property. Unlevelled trees can have many levels and can show many columns of data. While they are less automated, they are far more flexible and powerful.
Unlevelled tree views are used extensively in the LANSA IDE, for example the Fields page in an open File or the Repository Browser

Allowed Values

Example

This example shows a 4 level unlevelled tree.
Function Options(*DIRECT)
Begin_Com Role(*EXTENDS #PRIM_FORM) Caption('Multi-column tree') Clientheight(397) Clientwidth(907) Height(436) Layoutmanager(#TableLayout_1) Left(140) Top(203) Width(923)
Define_Com Class(#PRIM_TBLO) Name(#TableLayout_1)
Define_Com Class(#PRIM_TBLO.Row) Name(#Row_1) Displayposition(1) Parent(#TableLayout_1)
Define_Com Class(#PRIM_TBLO.Column) Name(#Column_1) Displayposition(1) Parent(#TableLayout_1)
Define_Com Class(#PRIM_TBLO.Item) Name(#Item_1) Column(#Column_1) Manage(#Tree) Parent(#TableLayout_1) Row(#Row_1)
Define_Com Class(#PRIM_TRVW) Name(#Tree) Columnbuttonheight(20) Componentversion(2) Displayposition(1) Fullrowselect(True) Haslines(False) Height(397) Left(0) Parent(#COM_OWNER) Tabposition(1) Top(0) Viewstyle(UnLevelled) Width(907)
Define_Com Class(#PRIM_TVCL) Name(#TVCL_1) Captiontype(Caption) Displayposition(1) Level(1) Parent(#Tree) Sortonclick(True) Source(#xDemoUnicode128) Width(21) Widthtype(Fixed)
Define_Com Class(#PRIM_TVCL) Name(#TVCL_2) Captiontype(Caption) Displayposition(2) Level(1) Parent(#Tree) Sortonclick(True) Source(#xDemoUnicode128_2) Width(36) Widthtype(Fixed)
Define_Com Class(#PRIM_TVCL) Name(#TVCL_3) Captiontype(Caption) Displayposition(3) Level(1) Parent(#Tree) Sortonclick(True) Source(#xDemoUnicode128_3) Width(40) Widthtype(Fixed)
Evtroutine Handling(#Com_owner.CreateInstance)
#Com_owner.AddDepartments
Endroutine
Mthroutine Name(AddDepartments)
Select Fields(*All) From_File(Deptab)
#Com_owner.AddEntry( #Deptment #Deptdesc "" #xImageDepartment32 )
#Com_Owner.AddSections( #Tree.Currentitem )
Endselect
Endroutine
Mthroutine Name(AddSections) Access(*private)
Define_Map For(*Input) Class(#prim_tvit) Name(#ParentItem) Pass(*by_reference)
Select Fields(*All) From_File(Sectab) With_Key(#Deptment)
#Com_owner.AddEntry( #section #secdesc "" #xImageSection32 #ParentItem )
#Com_Owner.AddEmployees( #Tree.Currentitem )
Endselect
Endroutine
Mthroutine Name(AddEmployees) Access(*private)
Define_Map For(*Input) Class(#prim_tvit) Name(#ParentItem) Pass(*by_reference)
Select Fields(*All) From_File(Pslmst1) With_Key(#Deptment #Section)
#Com_owner.AddEntry( #empno #Surname #GiveName #xImageEmployee32 #ParentItem )
#Com_Owner.AddSkills( #Tree.Currentitem )
Endselect
Endroutine
Mthroutine Name(AddSkills) Access(*private)
Define_Map For(*Input) Class(#prim_tvit) Name(#ParentItem) Pass(*by_reference)
Select Fields(*All) From_File(Pslskl) With_Key(#empno)
Fetch Fields(#skildesc) From_File(skltab) With_Key(#skilcode)
#Com_owner.AddEntry( #Skilcode #Skildesc "" #xImageSkill32 #ParentItem )
Endselect
Endroutine
Mthroutine Name(AddEntry) Access(*private)
Define_Map For(*Input) Class(#xDemoAlpha128) Name(#Column1)
Define_Map For(*Input) Class(#xDemoUnicode128) Name(#Column2) Mandatory("")
Define_Map For(*Input) Class(#xDemoUnicode128) Name(#Column3) Mandatory("")
Define_Map For(*Input) Class(#prim_flbx) Name(#Image) Mandatory(*null) Pass(*by_reference)
Define_Map For(*Input) Class(#prim_tvit) Name(#ParentItem) Mandatory(*null) Pass(*by_reference)
Define_Map For(*Result) Class(#prim_tvit) Name(#Result) Mandatory(*null) Pass(*by_reference)
#xDemoUnicode128 := #Column1
#xDemoUnicode128_2 := #Column2
#xDemoUnicode128_3 := #Column3
Add_Entry To_List(#Tree)
#Tree.Currentitem.ParentItem <= #ParentItem
#Tree.Currentitem.image <= #Image
#Result <= #Tree.Currentitem
Endroutine
End_Com

See also

All Component Classes
Technical Reference