AltDragging a window to a second monitor causes it to become very large: Windows 8.1

[yummysoup]

I have a dual-monitor set up.

Altdrag works great when dragging windows within one monitor, but when I drag a window between monitors, it becomes very large as soon as it goes beyond the edge of one screen and onto the next, with each nudge of the mouse causing the window to grow even bigger as long as it spans more than one monitor. If I pull the window back to one monitor while dragging, I can continue to move it around without it growing further (beyond its now huge size).

Windows 8.1 introduces some new scaling options and one of my screens has a higher dpi than the other. There might be some trickery going on because of that.

AltDrag 1.0 Windows 8.1 Pro 64 Screen 1: 1920x1080 14" (internal laptop screen) Screen 2: 1920x1080 24" (external)

[stefansundin]

So when you drag a window across to another monitor, AltDrag will "Aero Snap"-ify the window right at the monitor edges. This can be disabled in the settings, but you can't customize it to not happen between monitors (Windows disables Aero Snap between monitors, and perhaps I should introduce that as a setting). I personally think that if you're dragging the window fast enough it isn't that annoying.

I have not tested the new DPI thing on Win8.1 so I don't know if that is making it worse or breaking something. It's a shame I don't have a multi-monitor setup myself.

[yummysoup]

I'm not sure if it's the "Aero Snap"-ish behaviour that's causing this: I disabled the option to "Enable snapping when normally moving windows", and it happens only when the window crosses the boundary between screens, not when it's near.

Here are some relevant-looking settings from my .ini file:

Aero=0 AutoSnap=0

I'm going to play around with some of the Windows 8.1 scaling options to see if certain combinations cause this while others don't.

On 2014-02-05 10:26 PM, Stefan Sundin wrote:

So when you drag a window across to another monitor, AltDrag will "Aero Snap"-ify the window right at the monitor edges. This can be disabled in the settings, but you can't customize it to not happen between monitors (Windows disables Aero Snap between monitors, and perhaps I should introduce that as a setting). I personally think that if you're dragging the window fast enough it isn't that annoying.

I have not tested the new DPI thing on Win8.1 so I don't know if that is making it worse or breaking something. It's a shame I don't have a multi-monitor setup myself.

— Reply to this email directly or view it on GitHub https://github.com/stefansundin/altdrag/issues/1#issuecomment-34288794.

[yummysoup]

The problem only happens if I uncheck the box "Let me choose one scaling level for all my displays" in the Display control panel (Control Panel > Appearance and Personalization > Display)

If that checkbox is not checked, the problem happens regardless of the scaling level I choose.

If the checkbox is checked, AltDrag behaves as expected when moving windows between monitors.

[stefansundin]

Okay. I might be able to use bootcamp on my mac and use my desktop monitor as my second monitor. That should be doable. TBD when though.

[stefansundin]

Okay, I've installed bootcamp on my mac now, so I can test multiple monitors. I've been playing around for 10 minutes or so but I haven't been able to reproduce the problem.

I've unchecked Let me choose one scaling level for all my displays, and the slider above is in the middle. I've tried both left-to-right and top-to-bottom configurations.

My mac has the resolution 1440x900 and my other monitor is 1920x1080.

If possible, could you record it and put it on YouTube? Thanks!

[yummysoup]

I've created a video here that shows the behaviour:

http://files.yummysoup.com/altdrag/altdrag_1.0_hidpi_bug.mp4

In putting this together, I realized that this only happens on apps for which I "Disable display scaling on high DPI settings".

I.e., in the video, I notice the bug with Chrome, for which I have that checkbox checked, but not for Windows Explorer or cmd.exe for which I don't.

Here are some details of my setup:

• the left monitor is High DPI, the right is standard DPI
• both are 1920x1080
• I've left the "Let me choose one scaling level for all my displays" unchecked
• chrome was set to "Disable display scaling on high DPI settings". The other apps were not
• when the cursor was on the title bar, I moved the window by dragging the title bar.
• when I had the cursor in the content area of the window, I moved it via alt-drag
• I'm using Alt Drag 1.0
• while there's some weird-looking behaviour when I move the Windows Explorer and cmd.exe windows very slowly across the screen boundary, the real problem is with the Chrome window which grows vertically when I go from High DPI to Low DPI, mainly horizontally when I move it from Low DPI to High DPI.
• I've tested it with other apps for which I "Disable display scaling on high DPI settings". I didn't include any in the video, but they behave the same way as Chrome

[stefansundin]

That video is really well done, thank you! I will try to reproduce it again this weekend.

[MartinBriza]

I have problems with scaling as well. The problem seems to be caused by the fact AltDrag assumes non-scaled coordinates while the window are actually bigger (and translated). For example, when I'm operating on a 4k monitor with x2 scaling, mouse wheel scrolling only works in the top left quarter of the screen and affects windows over the whole screen. Can provide more information, just ask me. Not sure if I made myself clear comprehensibly.