RFR: 8276849: Refresh the window icon on graphics configuration changes

[Emmanuel Bourg]

On Tue, 9 Nov 2021 11:17:27 GMT, Aleksey Shipilev <shade at openjdk.org> 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?
>
> Submitted the bug for it, please change the PR title to "8276849: Refresh the window icon on graphics configuration changes" to get it hooked and resolve the jcheck complaint.

@shipilev Thank you for filing the JDK bug

-------------

PR: https://git.openjdk.java.net/jdk/pull/6180