Subject Re: autodrop in combobox
From Mustansir Ghor <mustan31@hotmail.com>
Date Sun, 15 Jan 2023 16:12:08 -0500
Newsgroups dbase.getting-started

Dear Mervyn Sir

The syntax  given here has helped me a lot. Yet I came across a situation where the combobox becomes the 1st item of the form. In such case I could not simulate the autodrop feature.

I wonder if there is anything that can be done. Meanwhile I added a push button to make it work.

Best Regards
Mustansir

Mervyn Bick Wrote:

> On 2022/06/05 15:09, Mustansir Ghor wrote:
 > > Dear All
 > >
> > I have set autodrop to true in a combobox. When I press Tab key and the combobox gets focus then popup of items comes up. But when I use combobox.setfocus() to get its focus the autodrop feature does not work.
 > >
> > Can anybody assists me on this how to go about.
 >
> A little example form is attached.  To ensure that Windows places the
> cursor over the combobox button prior to simulating a left mouse click
> the form metric needs to be Pixels.
 >
> Most of the Windows API functions needed are contained in
> rmMouseEvents.cc in the dUFLP.
 >
> When getting or setting a cursor's position or simulating a mouse event
> Windows uses the position on the screen rather than the position on the
> form.
 >
> rmMouseEvents.cc uses a form's onMouseMove event handler to establish
> the relationship between a point on a form and the corresponding point
> on the screen. Instead of creating an onMouseMove event handler I've
> used the ClientToScreen() function from the Windows API to do the
> conversion.
 >
> Mervyn.
 >
>
> ** END HEADER -- do not remove this line
 > //
 > // Generated on 2022-06-06
 > //
 > parameter bModal
 > local f
 > f = new force_combox_dropForm()
 > if (bModal)
 >    f.mdi = false // ensure not MDI
 >    f.readModal()
 > else
 >    f.open()
 > endif
 >
> class force_combox_dropForm of FORM
 >    with (this)
 >       onOpen = class::FORM_ONOPEN
 >       metric = 6        // Pixels
 >       height = 352.0
 >       left = 514.0
 >       top = 0.0
 >       width = 280.0
 >       text = ""
 >    endwith
 >
>    this.ENTRYFIELD1 = new ENTRYFIELD(this)
 >    with (this.ENTRYFIELD1)
 >       height = 22.0
 >       left = 94.0
 >       top = 81.0
 >       width = 84.0
 >       value = "Entryfield1"
 >    endwith
 >
>    this.COMBOBOX1 = new COMBOBOX(this)
 >    with (this.COMBOBOX1)
 >       height = 22.0
 >       left = 94.0
 >       top = 132.0
 >       width = 84.0
 >       dataSource = 'array {"a","b","c","d"}'
 >       style = 1        // DropDown
 >       dropDownHeight = 132.0
 >       autoDrop = true
 >    endwith
 >
>    this.ENTRYFIELD2 = new ENTRYFIELD(this)
 >    with (this.ENTRYFIELD2)
 >       height = 22.0
 >       left = 94.0
 >       top = 183.0
 >       width = 84.0
 >       value = "Entryfield2"
 >    endwith
 >
>    this.PUSHBUTTON1 = new PUSHBUTTON(this)
 >    with (this.PUSHBUTTON1)
 >       onClick = class::PUSHBUTTON1_ONCLICK
 >       height = 43.0
 >       left = 85.0
 >       top = 260.0
 >       width = 107.0
 >       text = "Set focus to combobox"
 >    endwith
 >
>    this.TEXT1 = new TEXT(this)
 >    with (this.TEXT1)
 >       height = 33.0
 >       left = 11.0
 >       top = 7.0
 >       width = 241.0
 >       text = "Form metric must be Pixels otherwise Windows can't place the cursor correctly."
 >    endwith
 >
>
>    function PUSHBUTTON1_onClick()
 >       form.combobox1.setfocus() // Not really neccessary.
>       //The programmed click on the combobox button will set focus anyway.
 >       form.drop_list()
 >       return
 >      
>
>    function drop_list
 >        //Place form coordinates that will show the cursor over the combobox button into form.point
 >        //This conversion to screen coordinates needs to be done each time the function is executed
 >        //in case the user has moved the form on the screen
 >       form.point.setx(form.combobox1.left+form.combobox1.width-10) //make sure cursor is in button
 >       form.point.sety(form.combobox1.top+10)
>       //Convert point values to position on screen.
 >       clienttoscreen(form.hwnd,form.point)
>       //Get x and y coordinates for drop button on combobox
 >       form.x_combo = form.point.getx(form.point,0)  
 >       form.y_combo = form.point.gety(form.point,4)
 >       form.rmMouse.screenLeftClick(form.x_combo,form.y_combo )  
 >       return      
 >
>    function form_onOpen()
 >       if type("ClientToScreen") # "FP"
 >           extern clogical ClientToScreen(chandle,cptr) user32
 >       endif
 >       set procedure to :duflp:rmMouseEvents.cc
 >       form.rmMouse = new rmMouseevents(form)
 >       form.point =  new point() // point is a structure to hold the cursor's x and y coordinates
 >       return
 >
> endclass
 >