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Mid-Michigan Computer Consultants, Inc. 509 Center Bay City, Michigan Sales (989) 892-9242             Support (989) 686-8860 ANSI Standard PL/B Language TREEVIEW

TREEVIEW

4/22/2002... just starting this section.

Testing is being done in the Utilities system under TV-MMCC.

PROCESSING TREEVIEW EVENTS

Like Listviews, there is an important thing to know about treeviews built in the designer. Events generate a series of values which are stored by the form in local variables. To get these back into a mainline program you have to move them from the local variable to a general variable which the mainline can see.

For example Clicking on an item in the TreeView generates a CLICK event. If you want to know the details of this click you must capture the data within the code in the form itself.

We use the following code on each event that we want to process.

       MOVE    #EventType,   EventType 
       MOVE    #EventResult, EventResult  (the row number)
       MOVE    #EventObjId,  EventObjId
       MOVE    #EventChar,   EventChar
       MOVE    #EventMod,    EventMod

TREEVIEW DRAG DROP

There is no specific drag drop. But you can simulate the action by using the MOUSEDOWN and MOUSEUP events. On each of these you grab EventResult and split it up to get the H:V positions of the mouse. Then you use the ItemHitTest method to translate that H:V coordinate into the handle of the line clicked on. Using that data you can get data from the lines.

tv_mousedown DISPLAY   "TV MOUSE DOWN  "
         CALL  CLEAR_PENDING_INFO       ;Start over on any mouse DOWN
         CALL  GET_EVENT_STUFF          ;get the associated data
         MOVE  TV_HANDLE,FROM_HANDLE        ;the new position.
         RETURN
.
tv_mouseup   DISPLAY   "TV MOUSE UP    ";   ;this is same as a DROP
         CALL  GET_EVENT_STUFF              ;identify line they DROPPED on
         MOVE  TV_HANDLE,TO_HANDLE          ;this is line handle
         CALL  DROP_ON_PRESS_LINE
         RETURN
.
get_event_stuff
         MOVE      EventResult,WORK11
         UNPACK    WORK11,WORK03,#H,#V
         F_TV1.ItemHitTest GIVING TV_HANDLE:
                           USING  #H, #V
         F_TV1.GetItemText GIVING TV_DATA USING TV_HANDLE
         RETURN

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Here's a routine from Gerhard Weiss as it appeared on the Sunbelt message board. This was posted by Matthew in response to a request from Paul Fuh:

Bored? Itching for a challenge? How about creating a robust routine FindItem for Treeview similar to Listview.FindItem. Routine should try not have limitations on tree levels. Maybe the only limitation allowed is 65535 tree levels.

I'm posting it here without review. Just don't want to lose track of it:

Gerhard may recognize this logic (its plagiarized from the movetree logic done a long time ago). Matthew

FText           DIM     ^
FHandle         INTEGER ^
PStructTV       TREEVIEW        ^
rlngFromHWnd    INTEGER         4
rlngToHWnd      INTEGER         4
.
lngFromChildItemHWnd INTEGER 4
lngToInsertItemHWnd INTEGER 4
.
strItemText     DIM             ^80
.
lngFromRootHWnd INTEGER         4
Findtree ROUTINE PStructTV,FText,FHandle
     DEBUG
          PStructTV.GetNextItem   GIVING lngFromRootHWnd USING 0,0 ;root item
          MOVE    lngFromRootHWnd,rlngFromHWnd
.
       LOOP
          PStructTV.GetItemText GIVING strItemText USING *Item=rlngFromHWnd
          IF (strItemText = FText)
              MOVE    rlngFromHWnd, FHandle
              SETFLAG EQUAL
              BREAK
          ENDIF
.
          PStructTV.GetNextItem GIVING lngFromChildItemHWnd:
                                USING *Item=rlngFromHWnd:
                               *Code=4 ; child
.
          IF        (lngFromChildItemHWnd!=0)
               MOVE      lngFromChildItemHWnd,rlngFromHWnd
               MOVE      lngToInsertItemHWnd,rlngToHWnd
             ELSE
               LOOP
                 UNTIL     (rlngFromHWnd=lngFromRootHWnd)
                   MOVE      rlngFromHWnd,lngFromChildItemHWnd
                   PStructTV.GetNextItem GIVING rlngFromHWnd:
                                         USING *Item=rlngFromHWnd:
                                         *Code=1 ; next
                 UNTIL     (rlngFromHWnd!=0)
.
                 PStructTV.GetNextItem GIVING rlngFromHWnd:
                                       USING *ITem=lngFromChildItemHWnd:
                                       *Code=TVGN_PARENT
.
                 PStructTV.GetNextItem GIVING rlngToHWnd:
                                       USING *Item=rlngToHWnd:
                                       *Code=TVGN_PARENT
.
                REPEAT
            ENDIF
            IF ( lngFromRootHWnd = rlngFromHWnd )
                PStructTV.GetNextItem GIVING lngFromRootHWnd:
                                      USING *Item=rlngFromHWnd:
                                      *Code=1 ; next
                MOVE    lngFromRootHWnd,rlngFromHWnd
            ENDIF
            IF ( rlngFromHWnd = 0)
                SETFLAG NOT EQUAL
                BREAK
            ENDIF
       REPEAT
       RETURN

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