On Sun, 31 Oct 2021 08:21:58 GMT, Emmanuel Bourg <d...@openjdk.java.net> wrote:
> When a list of icons is set on a window, the most appropiate icon is selected
> depending on the graphics configuration. But if the graphics configuration
> changes (because the window is moved to a different screen, or because the
> DPI settings of the screen is changed), the frame icon isn't updated.
>
> Here is an example illustrating the issue:
>
> public static void main(String[] args) throws Exception {
> SwingUtilities.invokeLater(() -> {
> JFrame frame = new JFrame("Window Icon Test");
> frame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
> frame.setSize(400, 300);
> frame.setVisible(true);
>
> List<Image> images = new ArrayList<>();
> for (int size = 16; size <= 32; size++) {
> // create an image displaying the size used
> BufferedImage image = new BufferedImage(size, size,
> BufferedImage.TYPE_INT_ARGB);
> Graphics2D g = image.createGraphics();
> g.setFont(new Font("dialog", Font.BOLD, 12));
> g.setColor(Color.BLACK);
> g.drawString(String.valueOf(size), 0, size - (size -
> g.getFont().getSize()) / 2);
> images.add(image);
> }
>
> frame.setIconImages(images);
> });
> }
>
> On Windows if the screen scaling is set to 100% the 16x16 icon is picked from
> the list. If the scaling of the screen is set to 150% while the application
> is running, the 16x16 icon is upscaled and looks blurry.
>
> A way to work around this issue is to listen for graphics configuration
> changes with:
>
> frame.addPropertyChangeListener("graphicsConfiguration", event ->
> frame.setIconImages(frame.getIconImages()));
>
>
> Ideally this should be done automatically by the JDK. Maybe the `WindowPeer`
> could call `updateIconImages()` when `updateGraphicsData()` or
> `displayChanged()` is invoked?
1. Run the test code on a screen with DPI scaling set to 100%, the frame icon
displayed should be "16"
2. Change the DPI scaling of the screen (or move the frame to a secondary
screen with a different scaling), the frame icon should change ("20" at 125%,
"24" at 150%)
-------------
PR: https://git.openjdk.java.net/jdk/pull/6180
