The LA Fox Developer Newsletter

February 1997

VFP Forms for Any

Screen Resolution

By Nelson M. Johnson, CCP

While I was learning MS Access, I saw a really cool demonstration of a form that would proportionally resize all the controls on the form each time the form size was changed so that no matter how small or large the form was, the user could still use all the controls. I was stunned. This was the answer to my Windows- client prayers. Now I could develop a form for one resolution and regardless of what screen resolution the user had, my form would always look right. I initially tried copying the code into the forms I wanted to have this ability, but reality struck. Access has this nasty requirement that ALL procedure names throughout the application must be unique. This meant that if I really wanted this to work, I would have to do some serious re-writing.

Along comes Visual FoxPro. I wrote a simplified procedure to do this very trick and have included it below. There are four properties you will need to add to your form: PrevHeight, PrevWidth, BaseWidth, and BaseFontSize. You should manually set the BaseFontSize to whatever font size is your default for the form. Then add these two procedures to your form and you are off. There are a couple things you need to be aware of:

This will not handle container objects such as option groups and page frames. Also, some controls have an AutoSize property which this will set to .T., but the ones that don’t (like text boxes) will have problems in the handling of the height property because rounding error will cause the size to “creep” if you resize the form several times. I started to address this problem in fonts by tracking the original base font size and then use an absolute scaling factor, but I haven’t perfected it - I will leave that to you to share with us. Unlike its Access cousin, this code should allow you to drop it into many forms or classes and impress your clients and coworkers, especially if they have been using an FPW application.

Procedure Form.lnit() this.prevHeight = this.height this.prevWldth = this.width this.BaseWidth = this.width

Procedure Form.Resize() local InI && a loop counter

local lcName && the name of the object local InScaleFactor && a relative scale factor local InBaseScaleFactor && an absolute scale factor local IcError

IcError = on(’error’)

InScaleFactor = this.width I this.prevWidth this.prevWidth = this.width this.height = this.prevHeight * InScaleFactor

&& the height of the form isa

&& fixed function of the width

this.prevHeight = this.height

InBaseScaleFactor = this.width / this.BaseWidth on error * && some objects don’t have

&& FontSize or AutoSize Property

(Con't, next column)

Forum Hot Tip

Corrupted Table

/ have a small corrupted datebase which I’d like to fix and I understand that! should use a Foxpro compatible program to make the changes.

The Software program is Navcis 1.76, a Compusetve "offline reader” The specific database which is couurpted is the address book. It is about 70 kb in size and consists of 314 records. Each record is assigned a number. The numbers should run from 1-314. Howe ver somehow the db got corru pted and actually reads from 1 to about 150 and then starts over, again running from about I - 150. I understand that I simply need to open the db and manually change the numbering to I - 314. Any suggestions?

Bob

Hi Bob,

Try this-

First create a table with an exact structure like your

‘corrupted_table’.

Then-

SELECT ‘corrupted_table’

COPY TO ARRAY anyname

SELECT new_table’

APPEND FROM ARRAY anyname

VFP Forms (Con? from prey, column)

=amembers(laMembers,this,2) && get a list of object names

&& (ignore nested objects)

this.lockscreen = .t. && this will make form updates && wait until we are done

for InI = I to alen(laMembers)

IcName = laMembers[lnl]

with this.&lcName .AutoSize .t. .width .wldth * InScaleFactor .height = height * lnScaleFactor .top = .top * InScaleFactor .left = .left * InScaleFactor

.FontSize int(this.BaseFontSize * lnBaseScaleFactor)

endwith

next

thls.lockscreen = .f. && allow form to udpate

on error &lcError

[Ed. Note: Nelson M. Johnson, Certified Computer Professional, is a member of the Potomac Area FoxPro Group. To contact him, send e-mail to consult@i-t-works-inc.com. Copyright © 1996 i.t. Works, Inc.)

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