Improve zoom and pan behavior
Submitted by dredmorbius
Link to original bug (#725395)
Description
Background: I use Evince to read PDFs on a Thinkpad T520i laptop with a 2910x1080 (16:9 ratio) display. Even at full-screen, font size on many documents is too small to read clearly. Unfortunately the zoom, page centering, and navigation features of evince make it less than optimal for online reading.
Requests:
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Provide an "autocrop zoom" option. This would zoom a page such that text fills the screen to the maximum extent possible. See applications such as the GIMP and its image autocrop feature (http://docs.gimp.org/en/plug-in-autocrop.html), or the Internet Archive's online book reader, image: http://i.imgur.com/Reg8KLB.png and URL: http://archive.org/stream/industrialrevol00toyngoog#page/n6/mode/2up Note that the zoom level is set to just enclose the text on the page. As much as I generally dislike Web apps, the IA bookreader is hands down the best interface I've found for reading formatted text material online, and it's a very strongly recommended study in UI/UX.
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Center the page when zooming. In most cases, the text of interest will be at the center of the page, not at the top left. Positioning the page to center is preferable to a TL positioning, particularly when autocropping zoom level is set and/or it's observed that the viewpane size is set to accomodate all visible text on the page(s) displayed. Having to manually reposition each page as it's read is spectacularly tedious.
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Preserve page positioning when flipping through pages with left/right arrows. Note that this is the behavior for the Internet Archive's reader.
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Consider a gv-style navigation motif for higher zoom levels. Under the gv postscript document viewer, using the spacebar to advance the page first top to bottom, then left to right, allowing reasonably effective reading of large-format documents even on smaller displays. I've long relied on gv for reading documents despite its otherwise primitive features simply because its navigation is so intuitive.
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Alter navigation keybindings. PageUp / PageDown should navigate by pages. Up/down arrows should navigate within pages. Spacebar should navigate sensibly through the document, panning top->bottom, then left -> right (for ltr languages, consider swapping for rtl). Again, gv gets this right. Presently, Evince will first advance top -> bottom, then left -> right, but fails to return to the left side of the document when a page is advanced. I find Internet Archive's use of left/right arrows for page navigation useful, though given the possible need for intra-page positioning, that's possibly not desirable.
Possibly related bugs: 722147, 614748, 663848
Version: 3.10.x