DR800 TechPDF: Yet another PDF reader (technology preview)

[GregorRichards]

Knowing in advance that I would be dissatisfied with the PDF reading on the IREX, I planned to write my own. And now I have! This is a PDF reader aimed towards those who usually read technical papers.

Features:

• Rather than using general-purpose pan and zoom, uses a set of predefined "strategies". This simplifies use at the cost of generality.
• One strategy is two-column mode, with which it splits columns. That is, the page will be viewed in two parts (landscape mode), the first part will be the top-left and bottom-left of the original page, and the second part will be the top-right and bottom-right of the original page. This way, two-column pages can be read completely with only one refresh.
• Since the strategies always define exactly how much to move, moving about the page never depends on exactly how much you've zoomed. For example, the "half page" and "two-column" strategies will always get from one page to the next in two steps.
• Margins are eliminated before display, utilizing as much screen space as is feasible.

Unfeatures (features I don't have, and may or may not have in the future):

• No explicit pan and zoom. The main reason for adding this feature to TechPDF (the entire point of which is to NOT have explicit pan and zoom) would be for the occasional graph or figure that spans the page in an unusual, strategy-defiant way.
• No annotations/scribbling.
• No bookmarks or other such memory.
• No support for PDFs with DRM.
• No memory of what file or page you left on, what strategy you last used, etc. This would be nice for the common case of re-viewing the same file.

Bugs:

• FIXED in alpha5: Doesn't use the nice DR800 menu in any way, instead uses its own bar at the top of the screen.
• FIXED in alpha2: Screen refreshes more often than it ought to (two refreshes for every page turn)
• Sorta FIXED in alpha2: The initial file selection dialog is tiny and not easy to use.
• FIXED (whatever that means) in alpha5: The code is hideously ugly, as it's a horrible amalgam of gtk-splash-test.cc from poppler and my weird strategy system. Needs some rearchitecting.
• Many, many more!

This is just a technology preview. I am not finished with this, but I'm at a point where it works so I'd like to show it off and ask other peoples' opinions. Here's the basic usage:

Extract the .zip to your SD card. When TechPDF is run, it presents the user with a dialog to select a PDF file. It will normally look in the Books directory, but if you have a Books/TechPDF directory or TechPDF directory, it will prefer those (so you can organize as you please). When you've selected a file, it displays it in full-page mode, which is more-or-less exactly like the default in the standard IREX PDF viewer. You may at this point rotate as you please, and choose a strategy from the menu. When a strategy is chosen, it will refresh the screen into that strategy (duh). You can skip pages with the "go to page" optoin, and close the application also from the menu. Navigation is as per normal, flipbar or onscreen.

If anybody finds this interesting or has comments or suggestions, feel free, I'd love your input.

Source and binaries available at https://dev.mobileread.com/trac/tech...rsion0.0Alpha8

Change log:

• 0.0 alpha 8: Fixed a memory leak and some inefficient use of memory
• 0.0 alpha 7: Mainly speed improvements (still not as fast as the builtin one, or even close to ... )
• 0.0 alpha 6: Fixed a bug causing the two-column mode to display improperly
• 0.0 alpha 5: Now uses the DR's standard menu rather than building its own
• 0.0 alpha 4: Added margin elimination.

[ericshliao]

Originally Posted by GregorRichards

Screen refreshes more often than it ought to (two refreshes for every page turn)

Maybe this line can help:
GTK_WIDGET_UNSET_FLAGS (widget, GTK_DOUBLE_BUFFERED);

The problem of flickering also happens on iLiad. And it's still mysterious for me after so many trial and error. Sometimes, I can solve it with certain technique, sometimes, I can't.

[Iñigo]

Originally Posted by GregorRichards

Knowing in advance that I would be dissatisfied with the PDF reading on the IREX, I planned to write my own. And now I have! This is a PDF reader aimed towards those who usually read technical papers.

Features:

• Rather than using general-purpose pan and zoom, uses a set of predefined "strategies". This simplifies use at the cost of generality.
• One strategy is two-column mode, with which it splits columns. That is, the page will be viewed in two parts (landscape mode), the first part will be the top-left and bottom-left of the original page, and the second part will be the top-right and bottom-right of the original page. This way, two-column pages can be read completely with only one refresh.
• Since the strategies always define exactly how much to move, moving about the page never depends on exactly how much you've zoomed. For example, the "half page" and "two-column" strategies will always get from one page to the next in two steps.

Unfeatures (features I don't have, and may or may not have in the future):

• No explicit zoom. Margins can, as such, be annoying. This goes against the design intent, but some smart margin elimination may be nice.
• No annotations/scribbling.
• No bookmarks or other such memory.
• No support for PDFs with DRM.

Bugs:

• Doesn't use the nice DR800 menu in any way, instead uses its own bar at the top of the screen.
• FIXED in alpha2: Screen refreshes more often than it ought to (two refreshes for every page turn)
• Partially FIXED in alpha2: The initial file selection dialog is tiny and not easy to use.
• The code is hideously ugly, as it's a horrible amalgam of gtk-splash-test.cc from poppler and my weird strategy system. Needs some rearchitecting.
• Many, many more!

This is just a technology preview. I am not finished with this, but I'm at a point where it works so I'd like to show it off and ask other peoples' opinions. Here's the basic usage:

Extract the .zip to your SD card. When TechPDF is run, it presents the user with a dialog to select a PDF file. This starts in the "TechPDF" directory on the SD card. (I didn't want to take one of the preexisting directories :P). When you've selected a file, it displays it in full-page mode, which is more-or-less exactly like the default in the standard IREX PDF viewer. You may at this point rotate as you please, and choose a strategy from the menu at the top of the screen. When a strategy is chosen, it will refresh the screen into that strategy (duh). You can skip pages with the "go to page" button, and close the application with the "X" button.

If anybody finds this interesting or has comments or suggestions, feel free, I'd love your input.

Source and binaries available at https://dev.mobileread.com/trac/tech...rsion0.0Alpha2

This, and your previous ports for DR800, look fantastic.
One note: if you don't use iRex bottom bar maybe you could make your app fullscreen.

Iñigo

[javifields]

Thank you GregorRichards!
One question: what is the path (starting from / ) to the books folder of the SD card?
(I am not able to find the pdf files)

[Iñigo]

Originally Posted by javifields

Thank you GregorRichards!
One question: what is the path (starting from / ) to the books folder of the SD card?
(I am not able to find the pdf files)

/media/mmcblk0p1/Books

[javifields]

Thanks! It works nicely for reading two column papers!

[GregorRichards]

Originally Posted by Iñigo

This, and your previous ports for DR800, look fantastic.
One note: if you don't use iRex bottom bar maybe you could make your app fullscreen.

Iñigo

I'd rather just make it use the bottom bar

[GregorRichards]

Originally Posted by GregorRichards

I'd rather just make it use the bottom bar

It's just occurred to me how ridiculous this is ... why do I care whether it's /their/ bar or /my/ bar? Changed my mind, thanks for the suggestion, I'll just take over for now.

[GregorRichards]

Just released alpha 4, which adds margin elimination. This is gettin' pretty OK

[Iñigo]

Hi GregorRichards,

What's the purpose of "/media/mmcblk0p1/TechPDF" directory created in the shell script?

I presume is the place you store the scientific .pdf files you aim to read with TechPDF.
If it is, I think is a bad idea because it pollutes the SD file system.

Another approach could be to pass an argument in the shell script with the initial path.

[GregorRichards]

Originally Posted by Iñigo

I presume is the place you store the scientific .pdf files you aim to read with TechPDF.
If it is, I think is a bad idea because it pollutes the SD file system.

That's the idea. It's a matter of organization ... they're not books, they're not personal documents, they're not news, and they're not something that I (at least, me personally) want to pollute the /rest/ of the SD filesystem. Perhaps the superior option would be to use TechPDF iff it exists, otherwise start in Books?

[Iñigo]

Originally Posted by GregorRichards

That's the idea. It's a matter of organization ... they're not books, they're not personal documents, they're not news, and they're not something that I (at least, me personally) want to pollute the /rest/ of the SD filesystem. Perhaps the superior option would be to use TechPDF iff it exists, otherwise start in Books?

I use a some custom directories in "Personal Documents", but it's a matter of personal preferences.

[Mackx]

Originally Posted by GregorRichards

Just released alpha 4, which adds margin elimination. This is gettin' pretty OK

Hi GregorRichards,

Great to see how much effort you spend on improving your application. Did you also have a look at the (old) pdf viewer implementation of iRex which was used in the R1.7 firmware of the DR1000 (also uses poppler)? See the published source code: document-viewer-plugins\plugins\pdf. The file src/pdf_page.cpp, for example, also contains code to calculate the bounding box (PDFPage::get_content_from_bitmap) maybe there is more code you can reuse?

[GregorRichards]

Originally Posted by Mackx

Hi GregorRichards,

Great to see how much effort you spend on improving your application. Did you also have a look at the (old) pdf viewer implementation of iRex which was used in the R1.7 firmware of the DR1000 (also uses poppler)? See the published source code: document-viewer-plugins\plugins\pdf. The file src/pdf_page.cpp, for example, also contains code to calculate the bounding box (PDFPage::get_content_from_bitmap) maybe there is more code you can reuse?

Feh, I knew the code would be laying around somewhere, but I couldn't find it ... I'll look in to it.

[GregorRichards]

Just released alpha 5, which properly uses the DR's menu system, hooray