macOS: ImageResource for https://josm.openstreetmap.de/logo-macos.png is wasting 25MB on the heap

[simon04]

Regression of r17488. https://josm.openstreetmap.de/logo-macos.png has a dimension 1024x1024.

• Why do we need to download an essential image via HTTP?
• Why does the icon need to be so huge? 1024x1024
• Why cannot we use an SVG?

Due to HiDPI upscaling the icon to 2x, in addition, a 2048x2048 variant is stored in memory. This is is useless and simple to fix.

[simon04]

In 17728/josm:

see #20733 - ImageProvider: do not upscale non SVG images for HiDPI

[simon04]

In 17729/josm:

fix #20733 - PlatformHookOsx: use logo.svg in 256x256 size

• Avoids downloading/caching https://josm.openstreetmap.de/logo-macos.png (79k)
• Avoids loading/caching a buffered image of size 1024x1024

[Stereo]

The live downloading was done at @don-vip's request. I'd be happy with either philosophically, and 25MB of heap to save a 79K download does indeed sound like a bad tradeoff to me.

If I understand your change correctly, you're using the default logo.svg instead of the macOS icon. logo-macos.png or the svg version should be bundled and used instead.

[simon04]

@Stereo, which resolution is required for logo-macos.png – 1024x1024 seems to be an overkill?

[simon04]

In 17826/josm:

fix #20733 - PlatformHookOsx: use logo_macOS.png in 256x256 size

[simon04]

In 17827/josm:

see #20733 - ImageProvider: do not rescale non SVG images when already correctly sized

[Stereo]

Sorry I missed this. Icons on macOS can indeed be quite large in pixels, especially when navigating in the Preview panel in the Finder. On a retina display, 512x512 gets upscaled to 1024.

This png icon isn't the app icon shown in the Finder though - it is used after startup, to set the icon in the dock. We already bundle a perfectly good icon pack in the .app (JOSM.icns), but the minority of users who use the .jar won't have it.

I wonder if there would be a way to detect how JOSM is being launched, to only substitute the low-res icon if strictly necessary.

[simon04]

Please leave this ticket closed as its mentioned in the milestone changelogs and contributed major heap savings. For further improvements, please open a separate longterm ticket. Thank you!