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?
-------------
Commit messages:
- Refresh the window icon on graphics configuration changes
Changes: https://git.openjdk.java.net/jdk/pull/6180/files
Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6180&range=00
Issue: https://bugs.openjdk.java.net/browse/JDK-8276849
Stats: 4 lines in 3 files changed: 4 ins; 0 del; 0 mod
Patch: https://git.openjdk.java.net/jdk/pull/6180.diff
Fetch: git fetch https://git.openjdk.java.net/jdk pull/6180/head:pull/6180
PR: https://git.openjdk.java.net/jdk/pull/6180
