As pointed out in the Technical Tip Customizing the style and color of rows in a selection based list box project methods can be entered in the List Box Property List to be called to customize Row Styles, Row Font Colors, and Row Background Colors. If the values in method need to be tested and modified it is important to know when these methods are called so values, such as colors, can be set.



It is important to know that these methods are called before the earliest object or form event, On Load. If any values, such as process variables, in these methods need to be set based on values in the records to be presented, these values need to be set before the window is loaded with the Dialog, Modify Selection, or Display Record commands.

Assume the method below will be called to colorize List Box rows based on the numeric value in a field. Based on customer desire the thresholds and colors can be changed dynamically.

$AcctBal_R:=$1 $SRN:=Selected record number([Account]) //======================== Method Actions ================================== Case of     : ($AcctBal_R>=Level_1_R)     $0:=ACCT_Level_1 // green    Else      If ($AcctBal_R<Level_2_R)        Case of          : ($AcctBal_R>Level_3_R)            $0:=ACCT_Level_3 // yellow          : ($AcctBal_R>Level_4_R)            $0:=ACCT_Level_4 // orange          Else            $0:=ACCT_Level_5 // red        End case      Else        // Account balances > Level_2_R and < Level_1_R        //        If ($SRN %2 # 0)          $0:=CLR_OddRow_L // white        Else          $0:=CLR_EvenRow_L // pale blue        End if    End if End case

The method below would be called during the process but before the window that will display the List Box is opened to set the values that will be used.

$Table_P:=$1 Case of    : ($Table_P=(->[Table_1]))      C_LONGINT(ACCT_Level_1;ACCT_Level_2;ACCT_Level_3;ACCT_Level_4;ACCT_Level_5)      C_LONGINT(CLR_EvenRow_L;CLR_OddRow_L)      C_REAL(Level_1_R;Level_2_R;Level_3_R;Level_4_R;Level_5_R)      ACCT_Level_1:=0xFF00 // green      ACCT_Level_2:=0 // no coloring      ACCT_Level_3:=0x00FFDE24 // yellow      ACCT_Level_4:=0x00FFA600 // orange      ACCT_Level_5:=0x00FF0000 //Red      CLR_EvenRow_L:=0x00DEECFE // pale blue      CLR_OddRow_L:=0x00FFFFFF // white      Level_1_R:=10000      Level_2_R:=500      Level_3_R:=250      Level_4_R:=50      Level_5_R:=0    : ($Table_P=(->[Table_2]))    Else      ALERT("Unknow table pointer") End case

Once the List Box exists on the form the process variables can be changed and a call to REDRAW(myListBoxVar) will update the colors in the list box.