Sharp rendering of SVGs passed as InputStream

[ShahzaibIbrahim]

Storing input stream content to be later used for executeOnImageHandleAtBestFittingSize() to sharply render the svg images when created using Image(Display, InputStream)

In addition, on Linux an image can be refreshed for a new zoom (Image#refreshImageForZoom()), which was also not supported for the case that the image is based on an InputStream. Since we are storing the input stream content anyway, this case is should be covered here too.

Contribute to: #2917

How to Test

• Run this Snippet on Windows, Mac and Linux and compare the results:

package org.eclipse.swt.snippets;
import java.nio.file.Path;

import org.eclipse.swt.graphics.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;

public class SVGImageTests {

    public static void main(String[] args) throws Exception {
        final Display display = new Display();

        final Shell shell = new Shell(display);
        shell.setText("SVG Image Test");
        shell.setLayout(new FillLayout());
        shell.setBounds(250, 50, 1000, 400);
        shell.setBackground(new Color(255, 255, 255));

        String imgPath = "eclipse16.svg";
        Path fullPath = Path.of(SVGImageTests.class.getResource(imgPath).toURI());

        // Image loaded in stream
        Image image1 = new Image(display, SVGImageTests.class.getResourceAsStream(imgPath));

        // Image loaded in ImageFileNameProvider
        Image image3 = new Image(display, (ImageFileNameProvider) zoom -> {
            return zoom == 100 ? fullPath.toString() : null;
        });

        shell.addPaintListener(e -> {
            e.gc.drawImage(image1, 20, 10, 300, 300);
            e.gc.drawText("Image(Display, InputStream)", 80, 300);

            e.gc.drawImage(image3, 340, 10, 300, 300);
            e.gc.drawText("Image(Display, String)", 420, 300);
        });

        shell.open();

        while(!shell.isDisposed()) {
            if(!display.readAndDispatch()) {
                display.sleep();
            }
        }

        display.dispose();
    }
}

Use this SVG image for the Snippet:

• Currently, In GTK and Cocoa, an image based on an SVG passed as inputStream to Image(Device, InputStream) was blurry. With the current change it should look as good as ImageFileNameProvider as shown in snippet.

---

Results

Without this PR:

---

After Changes:

GTK:

Cocoa:

To be Tested

[github-actions]

Test Results

  176 files  ±0    176 suites  ±0   26m 57s ⏱️ - 2m 13s
4 676 tests ±0  4 654 ✅ ±0  22 💤 ±0  0 ❌ ±0 
  482 runs  ±0    476 ✅ ±0   6 💤 ±0  0 ❌ ±0 

Results for commit 4cdd05f. ± Comparison against base commit bbb21e5.

♻️ This comment has been updated with latest results.

[laeubi]

@ShahzaibIbrahim please provide a consistent PR description and at best show before/after screenshot.
Also commit descriptions seem not sufficient.

[ShahzaibIbrahim]

@ShahzaibIbrahim please provide a consistent PR description and at best show before/after screenshot. Also commit descriptions seem not sufficient.

Hi @laeubi, This PR is not ready and hence it's currently drafted.

[laeubi]

@ShahzaibIbrahim please provide a consistent PR description and at best show before/after screenshot. Also commit descriptions seem not sufficient.

Hi @laeubi, This PR is not ready and hence it's currently drafted.

I appreciate that it's marked as a draft, but even draft PRs should contain a clear title and meaningful description explaining what you're working on and what the expected outcome is. This helps maintainers understand the context and provide better guidance early in the process.

The SWT repository should have draft PRs that clearly communicate:

• What issue or improvement you're addressing
• What approach you're taking
• What the current state is and what still needs to be done

If you need to run CI checks while developing, you can do that on your fork as well. Please update the PR description before continuing, so we can provide better feedback. Thanks!

[ShahzaibIbrahim]

I appreciate that it's marked as a draft, but even draft PRs should contain a clear title and meaningful description explaining what you're working on and what the expected outcome is. This helps maintainers understand the context and provide better guidance early in the process.

The SWT repository should have draft PRs that clearly communicate:

• What issue or improvement you're addressing
• What approach you're taking
• What the current state is and what still needs to be done

I have updated the PR description with all the sufficient information I currently have.

[laeubi]

Would this not better be part of a supplier instead of part of the image?

[ShahzaibIbrahim]

I need o make it part of Image class because I have to use it in private class CachedImageAtSize#loadImageDataAtExactSize not just in initWithSupplier. Or do you mean something else?

[Phillipus]

Some early feedback on Mac for this one...

Here's a screenshot running this Snippet of the changes in this PR and #2924

@ShahzaibIbrahim Thank-you for your work on this and #2924

[ShahzaibIbrahim]

@HeikoKlare I think tests are fixed. Can you please test my snippet on multiple zoom level on mac to mark this PR ready for review?

[Phillipus]

Mac with latest changes: