The Mac OS X port is already working in this way and is something I'd really love to see working in the Windows side.

This feature is needed for the Steam release:

• when we double-click a .ase file, a new Aseprite.exe is launched
• if there is a Aseprite.exe running, we've to send a command to this instance to open the file, then we are done (we can close the second instance)
• if we are the first Aseprite.exe instance running, we check if we are installed on Steam, in that case we've to launch the appid and close this instance (so the app is initialized from Steam).
• the first running instance has to start in a "server" mode, so other instances can send commands to this instance (e.g. like open a file)

This IPC could be used to solve #533 too.

This can be solved on Windows using DDE. This is an old technology, but it looks like Microsoft Office is still using it, so we can go for it.

Note: The Allegro port cannot handle DDE messages correctly, it looks like only the Skia port will be able to fix this issue. Anyway in the future, when we implement a full COM server, we can remove the DDE processing.

This fix will be available for first time in the beta branch of the Steam release. (It means, using the Skia branch + special registry keys to use DDE.)

I'm reopening this issue to add Linux support.

should this be working on windows now? i have png files associated with aseprite but they always open a new instance of aseprite when opened from the desktop or any other app

i'm on win10 / aseprite v1.2.9x64

This should be working on Windows too, did you use the installer or the portable version? did you associate the .aseprite file format with Aseprite manually?

i installed with the installer. looks like it opens .aseprite files in the same aseprite instance, but not .png files (which I bound to aseprite manually i think)

@daisyowl you can check the details of the #1070 issue to see how to associate other files as the .aseprite type

hmm, i followed the instructions here as best as i could understand and it still doesn't work (opening a .png from the windows explorer or in unity)

ok so, update: after a bunch of fiddling, it will open from unity/file exlorer with my current setup, which is:

• having the registry entry for .png point to AsepriteFile as above
• ALSO setting the file explorer "open with" dialogue to aseprite

without the second step (file explorer dialog) it would keep opening them in new instances of aseprite

I am having this bug after a recent Aseprite update (currently v1.2.11-x64) in Linux Mint 19.1 XFCE (64-bit) and it's really messing with my workflow lately. I like to keep my file browser (Thunar 1.6.15) open in another window as I'm working with a lot of different sprites.

We need a hero for linux users for either this or drag and drop support.

Yeah, if someone want to contribute that would be great (the clipboard part was already a lot of work just for the Linux port compared to Windows and macOS 😢)

You're so nice to us Linux users, dacap. I am not used to it.
In fact I thought you were already a regular user of Linux 😅.
I had no clue you made a whole library for making a cross-platform clipboard in C++. Bravo!!
It's a wonder why it hasn't already been done before.