Hex constants for Colors data type?

questions
#1

I have a problem that needs some support. In a report I simulate zebra paper how it was used in earlier times. Using f3 as record counter I change the background color on every second record from white to some nice background:

f3=f3+1
report$?detail{prop:color} = 0FFF0F5H !LavenderBlush (CSS color name)
if f3 % 2 = 0 then
report$?detail{prop:color} = 0FFFFFFH !White
end

This works fine so far. Now I would like to manage the color value by using a variable which I could then set in my default settings of my app.

The problem is: I don’t know what type of variable I should use for that since in my example I am using hex constants.

Any ideas?

#2

You want to use a LONG.

1 Like
#3

As @Rick_UpperPark said a LONG is the type for colors …

If the Settings are on a Window where you would like to have an ENTRY() to type the colors, and you use a LONG as the type, then you must enter the color as an ENTRY(@n10) Long. That means you enter 16,773,215 for FFF0F5h.

Another option would be to make it a HexColor STRING(6) so you could type ‘FFF0F5’ . You must validate that it was all hex digits 0-9 A-F entered. You can convert to a Long using LongColor=EVALUATE('0' & CLIP(HexColor) & 'h' ). I would store both the STRING and the LONG in the Settings file so can use the Long color in all the code setting up colors.

I do have a Long to Hex function in the below GIST. Similar functions are in LibSrc CWUtil.clw. You could use that to store only a LONG in the file, but convert to String of hex digits for an Entry(@s6).

#4

They look like 32bit hex values which will work fine with the 32bit long, and it looks like CSS hex which means its a hex representation of Red Green Blue (RGB) so should remain 32bit, but if it didnt and you had to have 64bit hex values, you’d need a data type for 64bit values, and then String would be an easy data type to use.

#5

Thank you very much for your support. I also played along in the meantime and came up with this solution:

hex2dec routine

!Convert hex color code to decimal value
hex = zebraColor !cstring(7)
j = 0 !short
dec = 0 !short
pwr = 0 !short
decTotal = 0 !long
hexChars = ‘0123456789ABCDEF’ !cstring(17)

loop j=1 to 6
dec=instring(sub(hex,j,1),hexChars,1) - 1
pwr=6-j
decTotal = decTotal + dec * 16 ^ pwr
end

zebraColorLong = decTotal

exit

#6

You can use EVALUATE(‘0FF00FFh’)

#7

Perfect. Saves me a whole routine although it was fun to write it :slight_smile:

#8

If you select the Code you paste then click the <\> icon it will be formatted as Fixed Width Font Code. It also preserves indenting and quotes so looks nicer to read.

Below is the pasted code on the Left and formatted on the Right:

image
image934×211 21 KB

Your code formatted with <\>

hex2dec routine

    !Convert hex color code to decimal value
    hex = zebraColor !cstring(7)
    j = 0 !short
    dec = 0 !short
    pwr = 0 !short
    decTotal = 0 !long
    hexChars = '0123456789ABCDEF' !cstring(17)

    loop j=1 to 6
    dec=instring(sub(hex,j,1),hexChars,1) - 1
    pwr=6-j
    decTotal = decTotal + dec * 16 ^ pwr
    end

    zebraColorLong = decTotal

    exit
#9 
x= 'Cool. Thank you.'
message(x)