deloptes composed on 2016-12-01 08:50 (UTC+0100):
Felix Miata wrote:
...from what I know it is not possible to set DPI per application on the same screen/server. It could be that you can change the font size (what we actually already have), but this is a different story.
PS: and I am not teaching, I am just sharing my knowledge and learning something in the same time.
OK, so lets see what might be learned from the screenshot (this is actually part of what the original exercise was/is about):
A-an xterm was opened, and xdpyinfo reported the screen's apparent resolution and logical pixel density
B-xrandr was used to change the current screen's logical pixel density while keeping the same resolution
C-another xterm was opened, so that the impact of the xrandr command could be evaluated, in part by again using xdpyinfo
Observations:
1-image sizes in (what there is of) UI remained unchanged 2-text size in the window decoration (titlebar) remained unchanged 3-other elements of the window decorations also remained unchanged (e.g. titlebar height) 4-xdpyinfo reports logical density increased from 108 to 133 5-text size in the new/2nd xterm application instance increased
Conclusions: a-Window decorations seem to be part of an already running process, so are unaffected. b-Icon sizes (probably all bitmaps here, so sized in px) may be unaffected, but we can't be sure they are not from an already running process, so can't know whether they've been sized in px or pt (or other) c-Server's logical density increase caused text size increase in the new application instance (text sized in "physical" units: pt) d-Nothing other than text size seems to have been changed e-Other??? f-An increase in DPI on session start, all else being equal, can be expected to cause an increase in text sizes, if not in other screen elements g-Use of tdecmshell would probably provide more useful information for my original purpose than does an xterm
As an additional exercise, compare the following (from separate sessions using configurations differing only in configured DPI (xrandr in startup script)). Note that the titlebar's right side's icons are larger, but not the left's (Firefox) icon, and that nothing within the application's web content area seems differently sized (movies, images and most web text are sized in px): http://fm.no-ip.com/SS/dt1680x108.png http://fm.no-ip.com/SS/dt1680x144.png