PageRanges

[Janschenkel]

Hi All,

Back in January 2012, there was a request by Hugh Senior on the livecode-dev mailing list for 'pageChars' and 'pageChunks' field properties to complement the 'pageHeights' property. I seconded that request, but the RunRev team couldn't fit it in the schedule. But now that LiveCode is open source, I can do it for us all instead

Perhaps some clarification is in order for those who haven't a clue what this is about...

Fields have a property 'pageHeights' which helps to determine the page breaks when printing the field over multiple pages, taking into account the fixed line height property and the height of the individual blocks of text within the field.
Its output is a return-delimited list of integers.
Example:

Code: Select all

168
340
280

Unfortunately, it is difficult to map these onto the character offsets.
Therefore I'd like to add a 'pageRanges' property which maps these page breaks onto the exact character offsets.
Its output would be a return-and-comma delimited list of integers, where each line gives the offset of the first and last characters of the page.
Example:

Code: Select all

1,80
81,168
169,200

This would allow for a nice way to extract the individual pages:

Code: Select all

function getPageHtmlText pSourceField, pPage
  get line pPage of the pageRanges of fld pSourceField
  put item 1 of it into tStartChar
  put item 2 of it into tEndChar
  return the htmlText of char tStartChar to tEndChar of fld pSourceField
end getPageHtmlText

Last week I took a stab at it, and with the help of the RunRev staff at the conference, I now have a working version.
So what's the next step to contribute this back?

Should I file an entry at quality.runrev.com first?
Or just issue a pull request for the team?

TIA,

Jan Schenkel.

[LCMark]

Just send a pull request to the runrev repo and it will be put in the queue for integration

[Janschenkel]

Pull request submitted

Jan Schenkel.

[malte]

Where is the like button?

[BvG]

Quick, report Malte, he's a bot!

[monte]

Cool feature Jan. It will definitely come in handy!

[Janschenkel]

Update: it's been accepted and merged into the 'develop' branch so will be available in the next major version...

Cheers,

Jan Schenkel.

[mwieder]

@Jan- this is great! I just pasted 5k of text into a field and the pageRanges gives me a nice list. But the name...
I think I'd like to see "pageChars" instead of "pageRanges", to allow for "pageLines" as well. I can currently get this with

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put empty into tPageLines
put the pageRanges of field 1 into tRanges
repeat for each line tLine in tRanges
  put item 1 of tLine into tStartChar
  put item 2 of tLine into tEndChar
  put the number of lines in char 1 to tStartChar of field 1 into tStartLine
  put the number of lines in char 1 to tEndChar of field 1 into tEndLine
  put tStartLine,tEndLine & cr after tPageLines
end repeat

so there's a workaround, but it's awkward. It would be nice to say

Code: Select all

put the pageChars of field 1 into tPageChars
put the pageLines of field 1 into tPageLines

[trevordevore]

Mark,

put the lineIndex of char X of field Y

lineIndex and charIindex were added in 5.5 DP1. They convert line/char references back and forth.

--
Trevor DeVore
Blue Mango Learning Systems
www.clarify-it.com - www.screensteps.com

[mwieder]

@Trevor- thanks, I missed that in the release notes. Still would like pageLines and pageChars, though.

[Janschenkel]

@mwieder
PageRanges was sufficient for my goals, Mark - but if you want to expand on its ideas, you now have a good place to start from

Cheers,

Jan Schenkel.

[mwieder]

@Jan- Dang. I was hoping to make you do all the work.

[LCMark]

I think the 'pageRanges' property is pretty balanced both in terms of name and in terms of function. The name 'pageChars' doesn't really fit because it's a list of char ranges and not char indices, and 'pageLines' doesn't make a great deal of sense in terms of what the action is because you can't actual get an accurate list of line indices which should be used to paginate - remember that pagination takes into account soft line-breaks. i.e. The formatted list of lines is distinct from the list of lines.

Update: Although perhaps it should be 'pageCharRanges'...

[Janschenkel]

I pondered the property name for a while before I coded it; originally I had thought of 'pageChunks' but that would have implied that the output would have been something along the lines of

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char 1 to 490
char 491 to 587
char 588 to 675

but that looked awkward and difficult to use further on.
Another option that crossed my mind was 'pageOffsets' with an output along the lines of

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1
491
588

but that would have been equally difficult to use further on.
Eventually I settled for 'pageRanges' instead of 'pageCharRanges' as I didn't think we'd need 'pageItemRanges' or 'pageWordRanges'

That's my story and I'm sticking to it

Jan Schenkel.

[LCMark]

@Janschenkel: I'll retract my musing on 'pageCharRanges' - after all we have 'flaggedRanges' - which are char ranges (which I remembered yesterday afternoon whilst investigating a bug Trevor reported)