Bug 365681

Vertical displays are useful for document reading usually, but not always, as a secondary display. The current snapping/tiling is targeted solely at the more common horizontal displays, and does not apply well to vertical orientation.

Current behavior when you drag a window to ___ is to tile it at ___:
- Top edge => Full Screen
- Left edge => Left half of screen
- Right edge => Right half of screen


Reproducible: Always

Steps to Reproduce:
1. Grab and drag a window either by the title bar or by Alt+Click.
2. Drag it to an edges of the display.

Actual Results:  
Window tiles (fills) part of the screen:
Top edge => Full screen
Center of left/right edges => left/right half screen
Top/bottom of left/right edges => quarter screen
Bottom edge => does nothing.

Expected Results:  
Dependent on display orientation.

Horizontal display should stay the same, except maybe:
Bottom edge => minimize? (would feel weird if the menu were somewhere else, though...)

Vertical display: remove left/right halves, add top/bottom halves. Maybe something like:
top/bottom edges => top/bottom halves of the screen
center of left/right edges => Full screen
top/bottom part of left/right edges => quarter screen.

While this is a purely cosmetic change I believe it would make vertical displays a little more productive. The current left/right half tiling creates pretty much useless "stripes" (3 pages of unreadable  PDFs) in my current setup. Also placing windows in top/bottom halves requires me to place them in quarter-screen then resize, and takes some time that could be saved.