Tree View (PRIM_TRVW)
Hierarchical display of data
Ancestors - Control (PRIM_CTRL)Object (PRIM_OBJT)
Details
A TreeView is a hierarchical display of data showing items within item within items. TreeView is a typical LANSA list control managed by the LANSA list commands, such as ADD_ENTRY, GET_ENTRY, SELECTLIST etc. Columns are added to the tree. Each has a Source and data values are mapped in and out of the list as items are used. TreeView has two variation based on the ViewStyle property. 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.
Example
In this example, an unlevelled tree adds 4 child items to the expanding item. The first column shows the item number for the branch while the second shows the underlying list entry number.
Function Options(*DIRECT)
Begin_Com Role(*EXTENDS #PRIM_FORM) Clientwidth(480) Clientheight(398) Left(259) Top(261) Height(437) Width(496) Layoutmanager(#TableLayout1)
Define_Com Class(#PRIM_TBLO) Name(#TableLayout1)
Define_Com Class(#PRIM_TBLO.Column) Name(#Column1) Displayposition(1) Parent(#TableLayout1)
Define_Com Class(#PRIM_TBLO.Row) Name(#Row1) Displayposition(1) Parent(#TableLayout1)
Define_Com Class(#PRIM_TBLO.Item) Name(#TreeView1Item1) Column(#Column1) Manage(#Tree) Parent(#TableLayout1) Row(#Row1)
Define_Com Class(#PRIM_TRVW) Name(#Tree) Columnbuttonheight(19) Componentversion(2) Displayposition(1) Height(398) Keyboardpositioning(SortColumn) Left(0) Parent(#COM_OWNER) Tabposition(1) Top(0) Width(480) Viewstyle(UnLevelled) Fullrowselect(True)
Define_Com Class(#PRIM_TVCL) Name(#TreeViewColumn2) Displayposition(1) Level(2) Parent(#Tree) Source(#STD_NUM) Width(28) Captiontype(Caption) Caption('Item number')
Define_Com Class(#PRIM_TVCL) Name(#TreeViewColumn3) Displayposition(2) Level(2) Parent(#Tree) Source(#STD_IDNO) Width(32) Captiontype(Caption) Caption('List Entry')
Evtroutine Handling(#Com_owner.CreateInstance)
#Com_Self.Add4Items
Endroutine
Mthroutine Name(Add4Items)
Define_Map For(*input) Class(#Prim_tvit) Name(#ParentItem) Mandatory(*Null) Pass(*By_reference)
Begin_Loop Using(#Std_num) To(4)
Add_Entry To_List(#Tree)
#std_idno := #Tree.CurrentItem.Entry
Upd_Entry In_List(#Tree)
#Tree.CurrentItem.ParentItem <= #ParentItem
#Tree.CurrentItem.HasChildren := Unknown
End_Loop
Endroutine
Evtroutine Handling(#Tree.ItemExpanding)
If (#Tree.CurrentItem.HasChildren <> Yes)
#Com_Self.Add4Items( #Tree.currentitem )
Endif
Endroutine
End_Com
Properties
| Name | Description |
|---|---|
| BusyUpdates | BusyUpdates specifies how the control updates itself Inherited from Control (PRIM_CTRL) |
| BusyUpdatesOfParent | BusyUpdatesOfParent specifies whether the parent controls updates Inherited from Control (PRIM_CTRL) |
| CanFocus | CanFocus returns a value indicating whether the control can receive keyboard focus Inherited from Control (PRIM_CTRL) |
| ColumnButtonHeight | Specifies the height of the buttons shown at the top of the list |
| ColumnEllipses | Show ellipses for truncated text |
| ColumnHeaders | ColumnHeaders sets column headers on and off |
| ColumnResize | Specifies whether the column can be manually resized |
| Columns | Columns gives you access to the properties of the columns |
| ComponentClassName | ComponentClassName is the name of the component's class. Inherited from Object (PRIM_OBJT) |
| ComponentMembers | ComponentMembers provides access to all the member components of this component Inherited from Object (PRIM_OBJT) |
| ComponentPatternName | ComponentPatternName is used to qualify the class of the component. Inherited from Object (PRIM_OBJT) |
| ComponentTag | Generic space allowing a value to be stored for the instance Inherited from Object (PRIM_OBJT) |
| ComponentType | ComponentType gives you access to the type information about the component Inherited from Object (PRIM_OBJT) |
| ComponentTypeName | ComponentTypeName is the fully qualified name of the component's class. Inherited from Object (PRIM_OBJT) |
| ComponentVersion | Variant of the control being used |
| CurrentItem | The last item in the list touched either in the UI or via a list related command |
| Cursor | Cursor sets the cursor image Inherited from Control (PRIM_CTRL) |
| DisplayPosition | DisplayPosition determines the order in which components are shown Inherited from Control (PRIM_CTRL) |
| DragColumns | Allow columns to be reordered |
| DragStyle | DragStyle determines how a component can be dragged Inherited from Control (PRIM_CTRL) |
| Enabled | Enable activates/deactivates the component Inherited from Control (PRIM_CTRL) |
| Entries | The number of entries in the underlying data list |
| EntriesAtRoot | Number of items at the root level of the tree |
| FixedPosition | Fix the control position so that it does not move if the parent is scrolled Inherited from Control (PRIM_CTRL) |
| Focus | Focus tells whether the component has focus Inherited from Control (PRIM_CTRL) |
| FocusedStyle | Reference to a style to be applied when the control is focus Inherited from Control (PRIM_CTRL) |
| FocusedStyles | Collection of styles to be applied when the control is focus Inherited from Control (PRIM_CTRL) |
| FocusItem | Reference to the focus item in the list |
| FullRowSelect | Show item selection as the whole row or just the item text |
| Handle | Returns the Windows handle in desktop applications Inherited from Control (PRIM_CTRL) |
| HasButtons | Show the expand and collapse image |
| HasLines | Show the lines that join parent and child nodes |
| Height | The height of the control in pixels Inherited from Control (PRIM_CTRL) |
| Hint | Caption displayed when the mouse hovers over the control Inherited from Control (PRIM_CTRL) |
| HintPopup | HintPopup allows a PopupPanel instance to be used instead of the default hint text box Inherited from Control (PRIM_CTRL) |
| HintShow | Enabled or disable the appearance of hints Inherited from Control (PRIM_CTRL) |
| HintShowOfParent | Delegate hints appearance to the parent control Inherited from Control (PRIM_CTRL) |
| HintTitle | HintTitle defines the text shown at the top of the hint window in emphasized text Inherited from Control (PRIM_CTRL) |
| IsAnimating | IsAnimating indicates that a control is currently being animated Inherited from Control (PRIM_CTRL) |
| IsRealized | True if the control is currently realized Inherited from Control (PRIM_CTRL) |
| Items | Collection of items in the component |
| KeyboardPositioning | Determines how the list will position based on keyboard input |
| Left | Position of the control relative to the left boundary of its parent Inherited from Control (PRIM_CTRL) |
| LinesAtRoot | Show parent child lines to the left of root level nodes |
| ManageChildren | ManageChildren controls what happens when a tree item is collapsed |
| Modified | Modified indicates that the contents of the component have changed Inherited from Control (PRIM_CTRL) |
| ModifiedRules | Controls when the Modified property is set to True |
| MouseOver | MouseOver determines whether the mouse is directly over a control Inherited from Control (PRIM_CTRL) |
| MouseOverPart | True if the cursor is within the bounds of a child component |
| MouseOverStyle | MouseOverStyle defines the style to be applied to a control when the mouse is over it Inherited from Control (PRIM_CTRL) |
| MouseOverStyles | MouseOverStyles is a collection of styles to be applied to a control when the mouse is over it Inherited from Control (PRIM_CTRL) |
| MultipleSelectStyle | Specifies how selection works across different branches |
| Name | Name identifies the component Inherited from Object (PRIM_OBJT) |
| NotificationStyle | NotificationStyle controls how events are triggered |
| Opacity | Opacity denotes the appearance of a control in terms of its interaction with its background Inherited from Control (PRIM_CTRL) |
| Owner | Owner owns this component Inherited from Object (PRIM_OBJT) |
| Parent | Reference to the control in which this control is visually positioned Inherited from Control (PRIM_CTRL) |
| Popup | Popup allows a PopupPanel instance to be used instead of the typical right click popup menu Inherited from Control (PRIM_CTRL) |
| PopupMenu | Reference to a PopupMenu to be shown on a right click Inherited from Control (PRIM_CTRL) |
| PopupMenuFocusSelect | Set focus to the list item when a context menu is displayed |
| Rotation | Rotation allows a control to rotate a number of degrees about a given origin Inherited from Control (PRIM_CTRL) |
| RotationOriginLeft | RotationOriginLeft defines the left coordinate of an imaginary point around which a control will rotate Inherited from Control (PRIM_CTRL) |
| RotationOriginTop | RotationOriginTop defines the top coordinate of an imaginary point around which a control will rotate Inherited from Control (PRIM_CTRL) |
| RowHeight | Height of an item in pixels |
| ScaleHeight | ScaleHeight is the percentage of the height to use in the visual appearance of a control Inherited from Control (PRIM_CTRL) |
| ScaleOriginLeft | ScaleOriginLeft defines the left coordinate of an imaginary point from which a control will scale Inherited from Control (PRIM_CTRL) |
| ScaleOriginTop | ScaleOriginTop defines the top coordinate of an imaginary point from which a control will scale Inherited from Control (PRIM_CTRL) |
| ScaleWidth | ScaleWidth is the percentage of the width to use in the visual appearance of a control Inherited from Control (PRIM_CTRL) |
| ScreenLeft | ScreenLeft sets the distance from the left of the screen Inherited from Control (PRIM_CTRL) |
| ScreenTop | ScreenTop sets the distance from the top of the screen Inherited from Control (PRIM_CTRL) |
| ScrollLeft | Left position of a horizontally scrolled child control relative to its parent control Inherited from Control (PRIM_CTRL) |
| ScrollTop | Top position of a vertically scrolled child control relative to its parent control Inherited from Control (PRIM_CTRL) |
| SelectionStyle | Specifies the rules for item selection within the list |
| ShowItemHint | Enable hints for the item |
| ShowSelection | Show selection when the control does not have focus |
| SkewLeft | SkewLeft defines the angle at which to skew the control horizontally Inherited from Control (PRIM_CTRL) |
| SkewOriginLeft | SkewOriginLeft defines the left coordinate of an imaginary point from which a control will skew Inherited from Control (PRIM_CTRL) |
| SkewOriginTop | SkewOriginTop defines the top coordinate of an imaginary point from which a control will skew Inherited from Control (PRIM_CTRL) |
| SkewTop | SkewTop defines the angle at which to skew the control vertically Inherited from Control (PRIM_CTRL) |
| SplitStyle | SplitStyle enables independent pane scrolling |
| Style | Style defines the style to be applied to a control Inherited from Control (PRIM_CTRL) |
| Styles | Collection of styles to be applied to the control Inherited from Control (PRIM_CTRL) |
| TabPosition | TabPosition sets the order of focus when the Tab key is used Inherited from Control (PRIM_CTRL) |
| TabStop | Set to false to stop focus being given to the control via the Tab key Inherited from Control (PRIM_CTRL) |
| ThemeDrawStyle | Name of the Theme DrawStyle to be applied to the control Inherited from Control (PRIM_CTRL) |
| Top | Position of the control relative to the top boundary of its parent Inherited from Control (PRIM_CTRL) |
| TouchMove | Determines how the control will respond to touch move processing Inherited from Control (PRIM_CTRL) |
| TouchRotate | Determines how the control will respond to touch rotation Inherited from Control (PRIM_CTRL) |
| TouchScale | Determines how the control will respond to touch scaling Inherited from Control (PRIM_CTRL) |
| TouchScroll | Specifies how the control will respond to touch input for scrolling |
| TouchSize | Determines whether a control can be resized Inherited from Control (PRIM_CTRL) |
| ValueAt | Value at the specified location |
| ViewPopupMenu | ViewpopupMenu specifies the popup menu for the view area |
| ViewStyle | ViewStyle sets the way the list or tree is shown |
| Visible | Show or hide the control Inherited from Control (PRIM_CTRL) |
| VisualStyle | VisualStyle sets the appearance Inherited from Control (PRIM_CTRL) |
| VisualStyleOfParent | Adopt the Visual style from the parent control Inherited from Control (PRIM_CTRL) |
| Width | Width of the component in pixels Inherited from Control (PRIM_CTRL) |
Events
| Name | Description |
|---|---|
| AnimationEnded | Fired when an animation is ended Inherited from Control (PRIM_CTRL) Cancelled |
| Changed | Changed is a change in the component |
| CreateInstance | CreateInstance is signalled when an instance of a component is created Inherited from Control (PRIM_CTRL) |
| DestroyInstance | DestroyInstance is signalled when an instance of a component is about to be destroyed Inherited from Control (PRIM_CTRL) |
| DoubleClick | Fired when the user double clicks
ExpandItem |
| DragDrop | Fired on mouse up to signify the end of a drag process Inherited from Control (PRIM_CTRL) PosX, PosY, Source, Payload, AggregatedSource, Origin, Handled, DragResult |
| DragOver | Fired during the drag and drop process when the cursor moves over the control Inherited from Control (PRIM_CTRL) PosX, PosY, Source, Payload, DragState, AcceptDrop, DragCursor, ShowDropHilight, AggregatedSource, Origin, Handled |
| EditorChanged | Fired when the user changes a value in an editable cell
Value |
| EndDrag | Fired when the drag and drop process has completed Inherited from Control (PRIM_CTRL) Source, Payload, DragResult, AggregatedSource, Origin, Handled |
| Enter | Fired when the Enter key is pressed
KeyCode, Char, IsAltDown, IsControlDown, IsShiftDown, Handled |
| GotFocus | Fired when the control receives the focus |
| Initialize | Fired after a component has been realized for the first time Inherited from Control (PRIM_CTRL) |
| ItemChanged | ItemChanged happens when an item is changed |
| ItemChangedAccept | ItemChangedAccept event is triggered when an item is about to be changed
Accept, Reason, Continue, Value |
| ItemCollapsed | ItemCollapsed is the event of a tree view closing up a level of entries |
| ItemExpanding | ItemExpanding is the event of tree view showing the next level entries |
| ItemGotFocus | Fired when an item receives the focus |
| ItemGotFocusAccept | ItemGotFocusAccept is fired when the item gets focus
Accept, Reason |
| ItemGotSelection | Fired when an item in the list becomes selected |
| ItemGotSelectionAccept | Fired when an item in the list is about to become selected
Accept, Reason |
| ItemHintText | Fired when the hint is about to be shown
Caption |
| ItemLostFocus | Fired when the item loses focus |
| ItemLostFocusAccept | Fired when an item in the list is about to lose focus
Accept, Reason |
| ItemLostSelection | ItemLostSelection happens when another item is selected |
| ItemLostSelectionAccept | Fired when an item in the list is about to lose selection
Accept, Reason |
| ItemMouseEnter | The mouse has entered the bounds of the item |
| ItemMouseHover | The mouse is hovering over the item |
| ItemMouseLeave | The mouse has left the bounds of the item |
| KeyPress | Fired when a key is pressed on the keyboard
KeyCode, Char, IsAltDown, IsControlDown, IsShiftDown, Handled |
| LostFocus | LostFocus happens when a component is no longer active |
| MouseEnter | The mouse has entered the bounds of the control Inherited from Control (PRIM_CTRL) |
| MouseHover | The mouse has hovered over the control Inherited from Control (PRIM_CTRL) Origin, Handled |
| MouseLeave | The mouse has left the bounds of the control Inherited from Control (PRIM_CTRL) |
| PrompterAccept | Fired when a value is selected in a prompter
Form, ApplyValue, FocusAction, ReshowPrompter |
| PrompterActivate | Fired when the prompter image is clicked
Form, Continue |
| PrompterDeactivate | Fired when the prompter is closed
Form |
| StartDrag | Fired when the user starts a drag and drop process Inherited from Control (PRIM_CTRL) Source, Payload, Continue, DragList, AggregatedSource, Origin, Handled |
| TouchChange | Fired repeatedly between the TouchStart and TouchEnd boundaries to provide details of the touch events Inherited from Control (PRIM_CTRL) MoveLeft, MoveTop, ScaleWidth, ScaleHeight, Rotation, Continue |
| TouchEnd | Fired when the user stops touching the screen Inherited from Control (PRIM_CTRL) |
| TouchStart | Fired when the user first makes physical contact with the screen Inherited from Control (PRIM_CTRL) Origin, TouchMove, TouchRotate, TouchScale, TouchSize |
| ViewDoubleClick | Fired when the user double clicks in a part of the list not occupied by a list item |
Methods
| Name | Description |
|---|---|
| CollapseAll | Collapse all tree nodes to hide child items |
| ExpandAll | Expand all tree items to show child nodes |
| FadeIn | Animate from invisible to visible Inherited from Control (PRIM_CTRL) Duration, Delay |
| FadeOut | Animate from visible to invisible Inherited from Control (PRIM_CTRL) Duration, Delay, Visible |
| FindItem | Search for an object stored in the item RelatedReference property
Result, RelatedReference, StartItem |
| MoveFrom | Move a control from the specified position to the current position Inherited from Control (PRIM_CTRL) Left, Top, Duration, Delay |
| MoveTo | Animate a move from the specified number of pixels Inherited from Control (PRIM_CTRL) Left, Top, Duration, Delay |
| Realize | Creates the visual portion of dynamically created controls Inherited from Control (PRIM_CTRL) |
| Scale | Animate a change of scale Inherited from Control (PRIM_CTRL) ScaleWidth, ScaleHeight, Duration, Delay |
| SetFocus | Sets the control to be the focus control Inherited from Control (PRIM_CTRL) |
| SetValueAt | Set the value at the specified position
Result, Row, Column, Value |
| ShowMessages | LANSA Internal Use Inherited from Control (PRIM_CTRL) |
| SizeTo | Changes and animates control size changing Inherited from Control (PRIM_CTRL) Width, Height, Duration, Delay |
| StartEdit | StartEdit method is a programmatic way of starting the edit of the current item |
| StartSplit | StartSplit enables independent pane scrolling |
| Unrealize | Destroys the visual portion of dynamically created controls Inherited from Control (PRIM_CTRL) |
| UpdateDisplay | UpdateDisplay updates the display immediately Inherited from Control (PRIM_CTRL) |
See also
LANSA Version 15, April 2020