Optional events: Information retrieved

ONLINE HELP
WINDEV, WEBDEV AND WINDEV MOBILE

Version:

Home | Sign in | English

This content has been translated automatically. Click here to view the French version.

Help / Developing an application or website / Controls, windows and pages / Controls: Options and actions

Overview
Actions performed by the user
MK_XX constants
VK_XX constants
SB_XXX constants
SIZE_XXX constants
Examples

WINDEV

WEBDEV

WINDEV Mobile

Others

See also

Optional events: Information retrieved

Overview

In WINDEV, you can add optional events in the code of the different elements of an application. For more details, see Optional events.

Depending on the optional event used, specific information can be retrieved via the _EVE.LPARAM and _EVE.WPARAM variables.

Actions performed by the user

The table below presents the information returned in the different optional events:

Optional event	Information returned in the _EVE.LParam variable	Information returned in the _EVE.WParam variable

Mouse hover (WM_MOUSEMOVE) Left mouse button down (WM_LBUTTONDOWN) Left mouse button up (WM_LBUTTONUP) Double click with the left mouse button (WM_LBUTTONDBLCLK) Right mouse button down (WM_RBUTTONDOWN) Right mouse button up (WM_RBUTTONUP) Double click with the right mouse button (WM_RBUTTONDBLCLK)	*High weight* (known by function HiWord): Vertical position (Y) of mouse cursor relative to the field or window in question (equivalent to function MouseYPos). *Low weight* (known by function LoWord): Horizontal position (X) of mouse cursor relative to the field or window in question (equivalent to function MouseXPos).	Key pressed in the format of a *MK_XXX constant*
Mouse wheel (WM_MOUSEWHEEL)	*High weight* (known by function HiWord): Vertical position (Y) of mouse cursor relative to the field or window in question (equivalent to function MouseYPos). *Low weight* (known by function LoWord): Horizontal position (X) of mouse cursor relative to the field or window in question (equivalent to function MouseXPos).	*High weight* (known by function HiWord): Castor rotation direction (positive number: upward movement; negative number: downward movement) *Low weight* (known by function LoWord): Key Pushed as *constant MK_XXX*
Key down (WM_KEYDOWN) Key up (WM_KEYUP)		Key pressed in the format of a *VK_XXX constant*
Key pressed (WM_CHAR)		ASCII code of the key pressed (can be handled by Charact)
System key down (WM_SYSKEYDOWN) System key up (WM_SYSKEYUP)		Key pressed in the format of a *VK_XXX constant*
System key pressed (WM_SYSCHAR)		ASCII code of the system key pressed
Horizontal scrollbar (WM_HSCROLL) Vertical scrollbar (WM_VSCROLL)	Handle of scrollbar	*High weight* (known by function HiWord): Elevator shaft position *Low weight* (known by function LoWord): Method used to move the elevator shaft, in the form of an *constant SB_XXX*
Display of context menu (WM_CONTEXTMENU)	*High weight* (known by function HiWord): Vertical position (Y) of mouse cursor relative to the field or window in question (equivalent to function MouseYPos). *Low weight* (known by function LoWord): Horizontal position (X) of mouse cursor relative to the field or window in question (equivalent to function MouseXPos). Note: If these values are equal to -1, the context menu has been opened using the Windows open context menu key.	Handle of window or control from which the context menu is called
Move (WM_MOVE)	*High byte* (returned by HiWord): vertical position of the upper-left corner of the window relative to the upper-left corner of the screen (equivalent to the Y property) vertical position of the upper-left corner of the control relative to the upper-left corner of the window client area (equivalent to the Y property). *Low byte* (returned by LoWord): horizontal position of the upper-left corner of the window relative to the upper-left corner of the screen (equivalent to the X property) horizontal position of the upper-left corner of the control relative to the upper-left corner of the client area of the window (equivalent to the X property).
Resize (WM_SIZE)	*High weight* (known by function HiWord): Field or window height (equivalent to property Height). *Low weight* (known by function LoWord): Field or window width (equivalent to property Width).	Display mode of window (minimized, maximized, ...) in the format of a *SIZE_XXX constant* (equivalent to WinSize).
Gain focus (WM_SETFOCUS)		Handle of window or control that gained focus.
Lose focus (WM_KILLFOCUS)		Handle of window or control that gained focus.

MK_XX constants

The MK_XXX constants are as follows:


MK_CONTROL	8	Ctrl key down.
MK_LBUTTON	1	Left mouse button down.
MK_MBUTTON	16	Middle mouse button down.
MK_RBUTTON	2	Right mouse button down.
MK_SHIFT	4	Shift key down

Before using these constants, you must enter the following lines of code:

CONSTANT
MK_CONTROL=8
MK_LBUTTON=1
MK_MBUTTON=16
MK_RBUTTON=2
MK_SHIFT=4
END

VK_XX constants

The details of the VK_XXX constants are stored in the "KeyConst.WL" file in the "Personal\External" subdirectory of the WINDEV installation directory.

Before using these constants, you must enter the following line of code:

EXTERN "KeyConst.WL"

SB_XXX constants

The SB_XXX constants are as follows:

		The scrollbar box was moved by:

SB_LINEDOWN	1	the spin button at the bottom
SB_LINEUP	0	the spin button at the top
SB_LINELEFT	0	the spin button on the left
SB_LINERIGHT	1	the spin button on the right
SB_PAGEDOWN	3	the scrollbar below the scrollbar box
SB_PAGEUP	2	the scrollbar above the scrollbar box
SB_PAGELEFT	2	the scrollbar on the left of the scrollbar box
SB_PAGERIGHT	3	the scrollbar on the right of the scrollbar box
SB_THUMBPOSITION	4	the scrollbar box
SB_THUMBTRACK	5	the scrollbar box

Before using these constants, you must enter the following lines of code:

CONSTANT
SB_LINEDOWN=1
SB_LINEUP=0
SB_LINELEFT=0
SB_LINERIGHT=1
SB_PAGEDOWN=3
SB_PAGEUP=2
SB_PAGELEFT=2
SB_PAGERIGHT=3
SB_THUMBPOSITION=4
SB_THUMBTRACK=5
END

SIZE_XXX constants

The SIZE_XXX constants are as follows:


SIZE_MAXIMIZED	2	The window is maximized
SIZE_MINIMIZED	1	The window is minimized
SIZE_RESTORED	0	The window is restored

Before using these constants, you must enter the following line of code:

CONSTANT
SIZE_RESTORED=0
SIZE_MINIMIZED=1
SIZE_MAXIMIZED=2
END

Examples

The following example is used to find out the rotational direction of the mouse wheel:

// -- Optional Event: Mouse wheel 
Direction is int 
Direction = HiWord(_EVE.wParam) 
IF Direction < 0 THEN 
	Trace("The mouse wheel is going to the bottom") 
ELSE 
	Trace("The mouse wheel is going to the top") 
END

The following example is used to add the window icon into the task bar when the window is minimized and to remove it when the window is maximized.

// -- Optional Event: Size change 
// Declare the constants 
CONSTANT 
	SIZE_RESTORED=0 
	SIZE_MINIMIZED=1 
	SIZE_MAXIMIZED=2
END 

// Add the "C:\Icons\Icon.ICO" icon to the taskbar 
// when the window is minimized 
IF _EVE.wParam = SIZE_MINIMIZED THEN 
	SysIconAdd("C:\Icons\Icon.ICO") 
END 

// Delete the "C:\Icons\Icon.ICO" icon 
// when the window is restored 

IF _EVE.wParam = SIZE_RESTORED THEN SysIconDelete()

The following example is used to delete the current row from a table when the Del key is pressed:

// -- Optional Event: Key released 
// Include the "KeyConst.wl" file that contains 
// the standard Windows constants 
EXTERN "KeyConst.WL" 

// [Del] key up? 
IF _EVE.wParam = VK_DELETE THEN 
	// Delete the current row? 
		IF YesNo("Delete the current row?") = Yes THEN 
			TableDelete(MySelf) 
		END 
END