Tab Folder - TabChanging Event

TabChanging happens just before a tab is displayed

Member of Tab Folder (PRIM_TAB)

Parameters

Name

Type

Data Type

Description

OpenPage

*Input

PRIM_TBSH

OpenPage is the tab sheet currently open

OpeningPage

*Input

PRIM_TBSH

Reference to the opening page

CanChangePage

*Both

Boolean

Set to false to prevent the change of page

Details

The TabChanging event is fired the user clicks on a different tab.

The CanChangePage property can be used to prevent a change of tab sheet.

This only applies to tabs in the Center DockPosition.

Example

In this example, the caption of the opening page is shown in the form caption.

The user is prevented from ever turning to Page2.

     Begin_Com Role(*EXTENDS #PRIM_FORM) Caption('Docking Framework Sample') Clientheight(454) Clientwidth(912) Height(493) Left(188) Top(205) Width(928) 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(#LayoutItem1) Column(#Column1) Manage(#Tab1) Parent(#TableLayout1) Row(#Row1) 

        Define_Com Class(#PRIM_TAB) Name(#Tab1) Bottomlayoutpriority(4) Componentversion(2) Displayposition(1) Height(454) Left(0) Leftlayoutpriority(1) Parent(#COM_OWNER) Rightlayoutpriority(2) Tabposition(1) Top(0) Toplayoutpriority(3) Width(912)
        Define_Com Class(#PRIM_TBSH) Name(#Sheet1) Caption('Page1') Displayposition(1) Height(430) Left(0) Parent(#Tab1) Tabposition(1) Tabstop(False) Top(24) Width(912)
        Define_Com Class(#PRIM_TBSH) Name(#Sheet2) Caption('Page2') Displayposition(2) Height(430) Left(0) Parent(#Tab1) Tabposition(2) Tabstop(False) Top(24) Width(912)
        Define_Com Class(#PRIM_TBSH) Name(#Sheet3) Caption('Page3') Displayposition(3) Height(430) Left(0) Parent(#Tab1) Tabposition(3) Tabstop(False) Top(24) Width(912) 

        Evtroutine Handling(#Tab1.TabChanging) Openingpage(#OpeningPage) Canchangepage(#CanChangePage) 

           #com_owner.Caption := #OpeningPage.caption 

           #CanChangePage := (#OpeningPage *IsNotEqualTo #Sheet2) 

        Endroutine 

     End_Com


See also

All Component Classes

Technical Reference

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