PRS-500 Create LRS and LRF files from Python with pylrs

[EatingPie]

Thanks Kov.

Turns out there's a quick reference online that is far better than the one I linked above. I figured out a lot of stuff, including how to implement my curly quote algorithm. Now I can move on to questions more directly related to pylrs.

I have two questions off the bat...

(1) How do you set the BOTTOM MARGIN in pylrs?

Using the default Text and Page objects, the text flows beyond the end of the screen, leaving the last sentence on the page partially obscured. I've been able to set top and side margin, but not bottom. If you add more text to the formatting.py example, you will see this behaviour.

(2) Anyone know what font size matches that of makelrf3?

For me, makelrf3 had the font size bullseyed... even better than the Sony Connect books. Pylrs uses a font that's too big for my tastes.

-Pie

[kovidgoyal]

I've added support for inline graphics to pylrs. Attached is a demo with the python code to create it.

@Falstaff The patch is available at
pylrs.py
https://libprs500.kovidgoyal.net/cha...lrs.py&new=235
pylrf.py
https://libprs500.kovidgoyal.net/cha...lrf.py&new=235

Here's the python code to create helloworld.lrf

from libprs500.lrf.pylrs.pylrs import *

"""
    TextBlocks can be added to any page at any time, since the entire book is
    kept in memory.  Text can also be added to any paragraph at any time.
"""

def helloworld():
    # create the book
    book = Book()

    # add a page to the book using the default page style
    page = book.Page()
    page.TextBlock().Paragraph('Demonstration of embedded graphics').CR()
    

    # add a textblock to the page using defaults for TextStyle and BlockStyle 
    textBlock = page.TextBlock()
    textBlock.blockStyle = BlockStyle(blockrule='horz-fixed', blockwidth='575')

    # add a paragraph to the text block 
    istr = ImageStream('/tmp/try/cherubs.jpg')
    im = Image(istr, x0=0, y0=0, x1=300, y1=300, xsize=100, ysize=100)
    p = Paragraph('This line of text is before the graphic. ')
    dc = DrawChar(lines=3)
    dc.append(Plot(im, xsize=450, ysize=450))
    p.append(dc)
    textBlock.append(p)
    textBlock.Paragraph('This line of text is after the graphic. It needs to be long enough to ensure that the graphic is not cut-off.')
    
    

    # generate the lrf file
    book.renderLrs("/tmp/helloworld.lrs")
    book.renderLrf("/home/kovid/helloworld.lrf")


if __name__ == "__main__":
    helloworld()

[kovidgoyal]

Originally Posted by EatingPie

(1) How do you set the BOTTOM MARGIN in pylrs?

Using the default Text and Page objects, the text flows beyond the end of the screen, leaving the last sentence on the page partially obscured. I've been able to set top and side margin, but not bottom. If you add more text to the formatting.py example, you will see this behaviour.

I use the following code to keep the text from creeping off the edges.

Book(pagestyledefault=dict(textwidth=575, textheight=747))

Alternatively, if you use the pylrs from the libprs500 svn the defaults have been fixed to prevent this.

[kovidgoyal]

Here's a more complete example of using inline images. I had to Refactor the inheritance rules in pylrs a bit.

from libprs500.lrf.pylrs.pylrs import *

"""
    TextBlocks can be added to any page at any time, since the entire book is
    kept in memory.  Text can also be added to any paragraph at any time.
"""

def helloworld():
    book = Book()
    istr = ImageStream('/tmp/try/cherubs.jpg')
    im = Image(istr, x0=0, y0=0, x1=300, y1=300, xsize=100, ysize=100)

    
    page = book.Page()
    page.TextBlock().Paragraph(Span('Demonstration of embedded graphics', fontsize='180')).CR()
    p = page.TextBlock().Paragraph('The image: ')
    p.append(Plot(im, xsize=550, ysize=550))
    page.TextBlock(TextStyle(), BlockStyle(blockrule='vert-fixed'))    
    page.TextBlock().Paragraph(Bold('Drop caps')).CR()
    textBlock = page.TextBlock()
    textBlock.blockStyle = BlockStyle(blockrule='horz-fixed', blockwidth='575')
    p = Paragraph('This line of text is before the graphic. ')
    dc = DropCaps(lines=3)
    dc.append(Plot(im, xsize=450, ysize=450))
    p.append(dc)
    textBlock.append(p)
    textBlock.Paragraph('This line of text is after the graphic. It needs to be long enough to ensure that the graphic is not cut-off.')
    page.TextBlock().Paragraph(Bold('Inline graphic')).CR()
    page.TextBlock(TextStyle(), BlockStyle(blockrule='vert-fixed'))
    tb = page.TextBlock()
    
    p = tb.Paragraph('This line of text is before the graphic.')
    p.append(Plot(im, xsize=350, ysize=350))
    p.append('This line of text is after the graphic.')
    
    
    book.renderLrs("/tmp/helloworld.lrs")
    book.renderLrf("/home/kovid/helloworld.lrf")


if __name__ == "__main__":
    helloworld()

[Falstaff]

Nice work, kovidgoyal. I didn't look too closely yet, but I think you might have replaced the LrsDrawChar class -- this class is used to control what can nest inside of other classes (following the LRS specification). As I see you found out, the LRS spec uses the word DrawChar for two different things. I think there needs to be both the DrawChar class that you wrote and the empty LrsDrawChar that is used to enforce the nesting rules from the LRS spec.

LrsDrawChar and LrsSimpleChar1 are used just to identify the different types of things so that the code can complain if you try to put a LrsDrawChar where only a LrsSimpleChar1 is allowed. I forget why, but I didn't need LrsSimpleChar2...

I should have put in some comments to explain that strange usage of the empty classes. But I didn't. Sorry.

[kovidgoyal]

Thanks. Yeah in svn I've renamed DrawChar to DropCaps. I didn't put back LrsDrawChar though. As far as I can tell things work with just LrsSimpleChar1. At some point I should go through all the inheritance rules carefully and fix things.

[ashkulz]

Falstaff, can you create some sort of "official" development area where patches could be sent? You have the original release, I have the same (with a few minor changes) and looks like kovidgoyal has a more different version ...

[kovidgoyal]

Originally Posted by ashkulz

Falstaff, can you create some sort of "official" development area where patches could be sent? You have the original release, I have the same (with a few minor changes) and looks like kovidgoyal has a more different version ...

I can volunteer my SVN server.

[kovidgoyal]

@Falstaff
I made some more changes to pylrs for functionality I needed in html2lrf
Here's the combined diff
https://libprs500.kovidgoyal.net/cha...%2Flrf%2Fpylrs

[EatingPie]

Does pylrs have a function to add a per-page heading, like books from the CONNECT store? The CONNET store books have a the book title at the top/right of the page in small text. Very handy.

-Pie

[EatingPie]

Another Python question.

Unicode characters (binary) kill my app. Is there a way to convert unicode to text? Or to convert unicode to Pythons u"\0020" format?

-Pie

[kovidgoyal]

yes it does have support for headers. See html2lrf

[EatingPie]

I think I'm missing something here...

I have HTMLtoLRF-1.0 and it's a C++ program that requires a Windows DLL. Is there another version?

Also, I think I need some explanation of libprs500 vs. pylrf-1.0.0. You've mentioned the former several times in this thread. What's the difference between these two libraries? Is libprs500 an extension of pylrf-1.0.0?

-Pie

[kovidgoyal]

Originally Posted by EatingPie

I think I'm missing something here...

I have HTMLtoLRF-1.0 and it's a C++ program that requires a Windows DLL. Is there another version?

Also, I think I need some explanation of libprs500 vs. pylrf-1.0.0. You've mentioned the former several times in this thread. What's the difference between these two libraries? Is libprs500 an extension of pylrf-1.0.0?

-Pie

libprs500 is my set of python tools for working with the SONY reader. It includes converters called html2lrf and txt2lrf. The converters are based on an improved version of pylrs.

[EatingPie]

In figuring out the header stuff, I did some diffs between libprs500's pylrs and Falstaff's pylrs-1.0.0. Are there any plans to merge the codebases?

I didn't do extensive diffing, but it looks like Kovidgoyal added the pylrs-1.0.0 -- for example Image support -- rather than making changes to existing code. I think it would benefit the community extensively to have an update to the pylrs code base with Kovidgoyal's changes.

-Pie