double-click on GRAPHIC WINDOW

[Chris Holbrook]

Could someone tell me how to detect a double-click on a GRAPHIC window? Using the GRAPHIC WINDOW stuff that is. Thanks!

[Chris Holbrook]

Trying a loop around GRAPHIC WINDOW CLICK, I found that to get a count of 2 clicks I had to click three times or more. But increasing the sampling window I found that two actual clicks could be recorded as such providing that there was mouse movement in between the clicks.

So GRAPHIC WINDOW CLICK seems to ignore successive clicks in the same place, which makes detection a double-click rather difficult.

Anyone?

#COMPILE EXE
#DIM ALL
#INCLUDE "WIN32API.INC"
FUNCTION PBMAIN () AS LONG
    LOCAL clicked, clickX, clickY, clickcount, lstart, lend AS LONG
    LOCAL hGW AS DWORD
    LOCAL skey AS STRING
    
    GRAPHIC WINDOW "counting clicks", 300, 300, 200, 200 TO hGW
    GRAPHIC ATTACH hGW, 0
    GRAPHIC PRINT "click mouse, watch count"
    GRAPHIC PRINT "ESC to exit"
    WHILE 1 = 1
        clickcount = 0
        clicked = 0
        lstart = gettickcount
        lend = lstart + 5000
        WHILE gettickcount < lend
            GRAPHIC WINDOW CLICK TO clicked, clickX, clickY
            IF clicked THEN
                INCR clickcount
                clicked = 0
            END IF
        WEND
        GRAPHIC SET POS (50, 50)

        GRAPHIC PRINT STR$(clickcount) + " clicks detected"
    WEND
    GRAPHIC WINDOW END
'
END FUNCTION

[Guy Dombrowski]

Double click

Chris,

I simplified your double click demo to try to better illustrate the failure to detect a double click.
If you start clicking slowly and increase progressively the tempo, it become evident that there is a time delay built in that function.
If you do it while moving the mouse around, it can catch rapid click but you would have to add a timing loop to detect a double click.
Conclusion, you need to subclass the mouse handling to use it when writing graphic code like I did in my Graphic Console Demo.

#COMPILE EXE
#CONSOLE OFF
#DIM ALL

FUNCTION PBMAIN () AS LONG
  LOCAL clicked, clickX, clickY, clickcount AS LONG
  LOCAL hGW AS DWORD: LOCAL skey AS STRING
  GRAPHIC WINDOW "counting clicks", 300, 300, 600, 600 TO hGW
  GRAPHIC ATTACH hGW, 0
  GRAPHIC PRINT "click mouse, watch count.   Esc or  [x]  to exit"
    WHILE skey<>CHR$(27)
      GRAPHIC GET DC TO hgw: IF hgw=0 THEN END
      GRAPHIC WINDOW CLICK TO clicked, clickX, clickY
      IF clicked THEN INCR clickcount
      GRAPHIC SET POS (50, 50): GRAPHIC PRINT STR$(clickcount) + " clicks detected"
      GRAPHIC INKEY$ TO skey
    WEND
  GRAPHIC WINDOW END
END FUNCTION

[Chris Holbrook]

...it become evident that there is a time delay built in that function.

Thanks Guy - I feel an email to [email protected] coming on.

(later) OK I've reported it.

[Michael Mattias]

The time to recognize a "double click" versus two "single clicks" is a System Parameters Setting.

Direct WinAPI functions:

GetDoubleClickTime Function

--------------------------------------------------------------------------------

The GetDoubleClickTime function retrieves the current double-click time for the mouse. A double-click is a series of two clicks of the mouse button, the second occurring within a specified time after the first. The double-click time is the maximum number of milliseconds that may occur between the first and second click of a double-click.
[....]
SetDoubleClickTime Function

--------------------------------------------------------------------------------

The SetDoubleClickTime function sets the double-click time for the mouse. A double-click is a series of two clicks of a mouse button, the second occurring within a specified time after the first. The double-click time is the maximum number of milliseconds that may occur between the first and second clicks of a double-click.

You may alternately use SystemParametersInfo() function with either the SPI_GETDOUBLECLICKTIME or SPI_SETDOUBLECLICKTIME constants.

Reading the doc...

GRAPHIC WINDOW CLICK checks whether the specified GRAPHIC WINDOW has been clicked since the last time this statement was executed on this window.

You might want to try doing GRAPHIC WINDOW CLICK twice with a delay of the current system setting between tests.. something like...

FUNCTION WasDoubleClicked  (hWin AS LONG) AS LONG 

   LOCAL dwDTTime AS LONG 
   dwDTTime = GetDoubleClickTime()
  GRAPHIC WINDOW CLICK    hWin TO click&, X, Y 
  SLEEP dwDtTime 
  GRAPHIC WINDOW CLICK  hWnd TO Click&, X, Y 
  FUNCTION = (Click& = 1)   ' window WAS clicked since last time this window  was clicked
..

I know this is incorrect logic but I think I have all the pieces there and they can be rearranged somehow to get desired result.

MCM

[Chris Holbrook]

The time to recognize a "double click" versus two "single clicks" is a System Parameters Setting.

That value might be enough for Windows but is not enough for GRAPHIC WINDOW CLICK. On my PC it is 500, for me the threshold window for counting two clicks with movement is 600, without movement I have gone up to 5000 which is too long a delay to be practical, and still not got an accurate count, unless the mouse is moved between clicks. See code in post #2.

Its as if there was some debouncing going on inside PBCC using a longer time interval than doubleclicktime, but - who knows.

For the time being, I will live with it pending PB's reply. If pressed I can subclass the control etc etc like Guy has done.

[Guy Dombrowski]

Subclassing

Anyway,
If you want to catch all 3 buttons and also mouse moves, you have to subclass.
Would have been nice to have those in PBCC5

[Chris Holbrook]

...If you want to catch all 3 buttons and also mouse moves, you have to subclass...

I know, but not now - my cup runneth over!

[Michael Mattias]

If you want to catch all 3 buttons and also mouse moves, you have to subclass.
Would have been nice to have those in PBCC5

PB/CC 5 supports creating and subclassing windows.

For that matter, so did PB/CC 4, PB/CC 3, PB/CC 2 and PB/CC 1

[Richard Angell]

Michael,

I believe Guy was referring to not having GRAPHIC commands for the 3 functions he desired all in PBCC5, so he would not have to subclass. He was not trying to say, as I read it, that subclassing was not possible in PBCC versions.

[Guy Dombrowski]

Subclassing

Rick,

You are right, It would have been nice to have those in PBCC5 without having to subclass.
But I guess I will have to learn more Window programming in order to do what I want.

[Michael Mattias]

You are right, It would have been nice to have those in PBCC5 without having to subclass

Send new feature suggestions directly to publisher at [email protected]

[Chris Holbrook]

...OK I've reported it.

reply today from Jeff Daniels, PowerBasic:

I have logged a request for the ability to catch double clicks from a graphic window.

That'll do for me!

[Michael Mattias]

PB is really good about acknowledging NFSs.

It's nice to know know someone is going to look at your suggestion on "Let's pick the features for the next release" days in Venice FL.

[Guy Dombrowski]

Nsf

I also added my wish for full mouse control.