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Hi,
I came across some phenomena of GRAPHIC WINDOW which I would like to discuss.
(1) You can get the mouse coordinates easily without subclassing the GW: GetCursorPos(lpPoint)
(2) When you work in a GW it is difficult to get the exact location of the GW client area.
The GRAPHIC GET LOC statement only gives you the top left corner of the GW INCLUDING the
window edge and the caption bar. It becomes obvious when the caption is used
(in my case: 3 pixel edge and 29 pixel caption bar).
Still, without the caption you are offset by one pixel!
The width and height of GRAPHIC GET CLIENT are correct.
The goal is to get the exact location of the client area of a GW, i.e. the area in which you can draw.
The code below shows that x0, y0 are not good enough for that purpose.
Using the Api call GetWindowRect() and a bit of calculation gives us the correct client coordinates x1 and y1.
This also reveals that a GW without caption has a 1 pixels frame that can be corrected using x1 and y1.
I had used this method already in the "Graphic Buttons for PB/CC 5.0" for getting the hover effect right.
(3) On my two computers (PC and laptop, both Win XP) moving the scroll wheel crashes the program (without any leftovers, I hope).
In my discussion with PB support they claimed that it could possibly be caused by my mouse driver(s).
Does any one else also see that effect?
With the code below you can test the situation with/without caption and checking if the mouse is within x0/y0 or x1/y1.
I used the spaces in the print statement because I am too lazy to erased the old text exactly ...
Regards,
Gert Voland.
I came across some phenomena of GRAPHIC WINDOW which I would like to discuss.
(1) You can get the mouse coordinates easily without subclassing the GW: GetCursorPos(lpPoint)
(2) When you work in a GW it is difficult to get the exact location of the GW client area.
The GRAPHIC GET LOC statement only gives you the top left corner of the GW INCLUDING the
window edge and the caption bar. It becomes obvious when the caption is used
(in my case: 3 pixel edge and 29 pixel caption bar).
Still, without the caption you are offset by one pixel!
The width and height of GRAPHIC GET CLIENT are correct.
The goal is to get the exact location of the client area of a GW, i.e. the area in which you can draw.
The code below shows that x0, y0 are not good enough for that purpose.
Using the Api call GetWindowRect() and a bit of calculation gives us the correct client coordinates x1 and y1.
This also reveals that a GW without caption has a 1 pixels frame that can be corrected using x1 and y1.
I had used this method already in the "Graphic Buttons for PB/CC 5.0" for getting the hover effect right.
(3) On my two computers (PC and laptop, both Win XP) moving the scroll wheel crashes the program (without any leftovers, I hope).
In my discussion with PB support they claimed that it could possibly be caused by my mouse driver(s).
Does any one else also see that effect?
With the code below you can test the situation with/without caption and checking if the mouse is within x0/y0 or x1/y1.
I used the spaces in the print statement because I am too lazy to erased the old text exactly ...
Regards,
Gert Voland.
Code:
'test_coordinates.bas, Gert Voland, 11. Nov. 2008
#COMPILE EXE
#DIM ALL
#BREAK ON
#CONSOLE OFF
#INCLUDE "Win32Api.inc"
'----------------------------------------------------------------------------------------------
FUNCTION PBMAIN
LOCAL z$
LOCAL hGW AS LONG
LOCAL x0, y0, x1, y1 AS LONG
LOCAL deltax, deltay AS SINGLE
LOCAL x, y, w, h AS SINGLE
LOCAL xold, yold AS SINGLE
LOCAL lpPoint AS POINTAPI ' Pointer type defined in Win32Api
LOCAL GWRect AS RECT ' Data structure defined in Win32Api
LOCAL grstat AS LONG
x0 = 350
y0 = 450
w = 400
h = 200
'' GRAPHIC WINDOW "", x0, y0, w, h TO hGW ' Without caption
GRAPHIC WINDOW "test_coordinates", x0, y0, w, h TO hGW
GRAPHIC ATTACH hGW, 0, REDRAW
GRAPHIC SET POS (10, 10) : GRAPHIC PRINT "Test the coordinates. Press ESC to quit"
GRAPHIC SET POS (10, 30) : GRAPHIC PRINT "Move scroll wheel -> Crash?"
DO ' Update the coordinates when GW is moved
GRAPHIC GET LOC TO x0, y0 ' Absolute pixels of the left top corner of the GW bounding rectangle
GetWindowRect(hGW, GWRect) ' API call: absolute coordinates of the GW bounding rectangle
deltax = (GWRect.nRight - GWRect.nLeft - w)/2 ' Half of: Width of the total GW - desired width (= edge of GW)
deltay = GWRect.nBottom - GWRect.nTop - h - deltax ' Height of the total GW - desired height - edge (= width of caption bar)
x1 = GWRect.nLeft + deltax ' x of the GW client area, absolute pixels
y1 = GWRect.nTop + deltay ' y of the GW client area, absolute pixels
GetCursorPos(lpPoint) ' API call: absolute x/y coordinates
x = lpPoint.x
y = lpPoint.y
IF x <> xold OR y <> yold THEN ' Update GW whenever the mouse is moved
GRAPHIC SET POS (10, 60) : GRAPHIC PRINT "Position of GW: "; x0; y0; SPACE$(10); "Width and Height: ";w; h
GRAPHIC SET POS (10, 80) : GRAPHIC PRINT "Absolute mouse coordinates: "; x ;y; SPACE$(10)
''' IF x >= x0 AND x <= x0 + w AND y >= y0 AND y <= y0 + h THEN ' Using the GET LOC data: we are not in the client area of GW
IF x >= x1 AND x <= x1 + w AND y >= y1 AND y <= y1 + h THEN ' Using the API call: now inside the client area, independent of caption
GRAPHIC SET POS ( 10, 120) : GRAPHIC PRINT "Relative coordinates - GRAPHIC GET LOC : ";
GRAPHIC SET POS (220, 120) : GRAPHIC PRINT x - x0; y - y0; SPACE$(10)
GRAPHIC SET POS ( 10, 140) : GRAPHIC PRINT "Relative coordinates - Corrected: ";
GRAPHIC SET POS (220, 140) : GRAPHIC PRINT x - x1; y - y1; SPACE$(10)
ELSE
GRAPHIC SET POS (10, 120) : GRAPHIC PRINT SPACE$(100)
GRAPHIC SET POS (10, 140) : GRAPHIC PRINT SPACE$(100)
END IF
xold = x
yold = y
END IF
GRAPHIC INSTAT TO grstat
IF ISTRUE grstat THEN
GRAPHIC INKEY$ TO z$
GRAPHIC SET POS (10, 180) : GRAPHIC PRINT "Pressed key: "; z$ ; SPACE$(10)
END IF
GRAPHIC REDRAW
LOOP UNTIL z$ = $ESC
GRAPHIC WINDOW END
END FUNCTION
'---end of file ------------------------------------------------------------------------------------
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