Ok, found this for X windows:
FVWM Forums • View topic - Thumbnailing a Window on another Viewport
As to why you can't access a window (that is, take a picture of it when it is not on the same desk/page as the current viewport) is because windows that are not on the current page are unmapped. This is true when one changes pages/desks -- the windows are unmapped, and the windows on the current viewport are remapped.
So, I guess that means what I want is impossible? Although there are two workarounds:
- use
xrandr to increase the virtual size of (each of the four) viewports
This is what works for me - first query to see which output you want, then execute:
$ xrandr -q
Screen 0: minimum 320 x 200, current 1024 x 600, maximum 4096 x 4096
LVDS1 connected 1024x600+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
1024x600 60.0*+
800x600 60.3 56.2
640x480 59.9
VGA1 disconnected (normal left inverted right x axis y axis)
$ xrandr --output LVDS1 --panning 1600x768
... see also X/Config/Resolution - Ubuntu Wiki
- Use
xvfb for virtual render
Got this via x11 - Remote offscreen rendering - Server Fault, also see Xvfb - Wikipedia, the free encyclopedia for examples. This is what worked for me - each command goes in own terminal (as some of them are meant to be services)
# start xvfb as display 1 - note the "screen 0" there refers to "its own" screen 0; should set it to 24-bit color
Xvfb :1 -screen 0 1600x1200x24 -pixdepths 3 -fp /usr/share/fonts/X11/Type1
# start metacity on display 1 (would start gdm, but [Bug #598848: gdm no longer works with xvfb](https://bugs.launchpad.net/bugs/598848)
# needed to we have title bars, and possibility to move windows around
DISPLAY=:1 metacity
# start application (here web-browser arora) again on display 1
DISPLAY=:1 arora
# start vnc server, which will bridge display 1 to port 5900
# note - this command exists, however starts a server in background
x11vnc -display :1 -bg -nopw -listen localhost -xkb
# start vnc viewer on port 5900 - so we can see display 1:
# note also - when vncviewer exits, it also will kill the x11vnc server
vncviewer -FullColor=1 localhost:5900
The problem here is that not all parts of the OS are initialized - so there are no window decoration, and only basic X fonts; although, apps may find their own fonts, as seen below:
xvfb looks almost ideal to me - since I could basically set up an "invisible" environment, as big as I want, and take screenshots directly from it (using xwd). The problem is that I cannot have a window on "my" DISPLAY=:0, then switch it to the 'virtual' DISPLAY=:1 for screenshotting, then bring it back to DISPLAY=:0. Then one must set up an application specifically for xvfb; and if so happens you need more size - then the whole chain above needs to be restarted.
On the other hand, I find working with 4 workspaces and large viewports (shwere the mouse moves you around within a viewport) a bit confusing - then again, can change the size there on the fly and nothing needs to be restarted; and plus I can use any of the usual screenshot tools (but I'd still have to switch viewports).
Needless to say, I'd still love to hear about a possible command line solution that could do this kind of screenshotting in one go :)
It seems things may have changed... This is what I did:
First select Tools > Web Developer > Inspector.
Look for the little cog-wheel with Toolbox options as its tooltip. Click on the cog-wheel to open the Toolbox options.
Scroll down to Available Toolbox Buttons and look for "Take a screenshot of the entire page". Check its box. A little camera icon should now appear to the left of the Toolbox options cog-wheel. If you don't see it, close the Inspector window and reopen it.
Best Answer