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Author
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Topic: Notifications
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Jeffrey Smith
Member
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posted 03-06-2008 02:25 PM
  
I'm trying to catch the cursor and mouse messages to create a selection area on a EGRID control. In the documentation for EGRID it says: "If The notification message returns TRUE, then no further actions will be taken". I thought all I had to do was set Cancel& = TRUE in the control events sub. I'm trying to prevent egrid from automatically resetting the cursor location when I hold down the shift key and cursor.code:
SUB DE_EGRID1_Events( MyID&, CMsg&, CVal&, Cancel&)
STATIC SHIFTKey&, CTRLKey&, RangeX1 AS LONG, RangeY1 AS LONG, RangeX2 AS LONG, RangeY2 AS LONG, RangeState AS INTEGER
LOCAL MYRECT AS RECT, MaxCols AS INTEGER, MaxRows AS INTEGER, TLong& SELECT CASE CMsg&
CASE %EGN_SELECTIONCHANGED
MSGBOX "changed" 'This doesn't work
CASE %EZ_Click
CASE %EZ_KeyDown
SHIFTKey&=EZ_GetKeyState(%EZK_SHIFT,0) AND 1
IF ShiftKey& = 1 THEN
RangeX1& = EZ_SENDMESSAGER("DE",MyID&, %EG_GETFOCUSEDCELLX, 0, 0)
RangeY1& = EZ_SENDMESSAGER("DE",MyID&, %EG_GETFOCUSEDCELLY, 0, 0)
END IF CTRLKey&=EZ_GetKeyState(%EZK_CTRL,0) AND 1
CASE %EZ_KeyUp
IF CVal& =>37 AND CVal& =< 40 AND ShiftKey& = 1 THEN
CANCEL& = %TRUE
RangeX2& = EZ_SENDMESSAGER("DE",MyID&, %EG_GETFOCUSEDCELLX, 0, 0)
RangeY2& = EZ_SENDMESSAGER("DE",MyID&, %EG_GETFOCUSEDCELLY, 0, 0)
'msgdp "1:" & STR$(RangeX1&) & " " & STR$(RangeY1&)
'msgdp "2:" & STR$(RangeX2&) & " " & STR$(RangeY2&)
IF RangeX2& - RangeX1 < 0 THEN
TLong& = RangeX1
RangeX1 = RangeX2
RangeX2 = TLong&
END IF
IF RangeY2 - RangeY1 < 0 THEN
TLong& = RangeY1
RangeY1 = RangeY2
RangeY2 = TLong&
END IF
SETRECT MYRECT, RangeX1&, RangeY1&, RangeX2&, RangeY2&
EZ_SENDMESSAGE "DE", MyID&, %EG_SETINTERNALSELECTION, VARPTR(MYRECT), 0
Result& = EZ_SENDMESSAGER("DE", MyID&, %EG_INTERNTOVISIBLE, 0, 0)
EZ_SENDMESSAGE "DE", MyID&, %EG_REFRESHALL, 0, 0
END IF
'IF CVal& =>37 AND CVal& =< 40 AND CTRLKey& = 1 THEN
CASE %EZ_KeyPress
CASE %EZ_RButtonUp
CASE %EZ_LButtonDown
CASE %EZ_LButtonUp
CASE %EZ_Loaded
CASE %EZ_Loading
CASE ELSE
END SELECT
END SUB
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Chris Boss
Administrator
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posted 03-06-2008 11:53 PM
If you set Cancel& to true, it simply prevents the message from being passed to Windows default processing.To return a value, you have to pass the return value in CVal&. ie. code:
Cancel&=1 ' tell EZGUI not to let Windows process message
CVal&=1 ' this is the return value for WM_NOTIFY message
Make sure you don't attempt to use CVal& anymore, after you change its value for the return value.
[This message has been edited by Chris Boss (edited 03-06-2008).] |
Chris Boss
Administrator
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posted 03-06-2008 11:58 PM
One rule with %EZ_Notify:Never change the value of CVal& (the return value) unless you also set Cancel& to non-zero (1). Also never use CVal& (as a pointer) after you change its value in %EZ_Notify. | |
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