RFR: 8306707: Support pluggable image loading via javax.imageio [v20]

[Andy Goryachev]

On Wed, 13 Nov 2024 18:33:27 GMT, Michael Strauß <mstrauss at openjdk.org> wrote:

>> This PR is an improved version of #1093.
>> 
>> JavaFX can load BMP, GIF, PNG, and JPEG images with its built-in image loaders. It has been a long-standing request to support more image formats, most notably (but not limited to) SVG. However, adding more built-in image loaders is a significant effort not only in creating the functionality, but also in maintaining the additional dependencies.
>> 
>> This will probably not happen any time soon, so we are left with three alternatives:
>> 1. Accept the fact that JavaFX will never be able to load additional image formats.
>> 2. Create a public image loader API, and hope that developers in the JavaFX ecosystem will create image loader plugins.
>> 3. Leverage the existing Java Image I/O API.
>> 
>> From these options, I think we should simply support existing Java APIs; both because it is the shortest and most realistic path forward, but also because I don't think it is sensible to bifurcate pluggable image loading in the Java ecosystem.
>> 
>> Of course, Java Image I/O is a part of the `java.desktop` module, which as of now, all JavaFX applications require. However, it has been noted in the previous PR that we shouldn't lock JavaFX into the `java.desktop` dependency even further.
>> 
>> I've improved this PR to not permanently require the `java.desktop` dependency: if the module is present, then JavaFX will use Image I/O for image formats that it can't load with the built-in loaders; if the module is not present, only the built-in loaders are available.
>> 
>> I have prepared a small sample application that showcases how the feature can be used to load SVG images in a JavaFX application: https://github.com/mstr2/jfx-imageio-sample
>
> Michael Strauß has updated the pull request incrementally with one additional commit since the last revision:
> 
>   include image size in exception message

too late to the party, but


Description	Resource	Type	Path	Location
The method load(int, double, double, boolean, boolean, float, float) of type GIFImageLoader2 should be tagged with @Override since it actually overrides a superinterface method	GIFImageLoader2.java	Java Problem	/graphics/src/main/java/com/sun/javafx/iio/gif	line 201

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PR Comment: https://git.openjdk.org/jfx/pull/1593#issuecomment-2474965062