RFR: 8276849: Refresh the window icon on graphics configuration changes [v3]

[Alexey Ivanov]

On Mon, 21 Feb 2022 07:57:32 GMT, Emmanuel Bourg <duke at 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?
>
> Emmanuel Bourg has updated the pull request incrementally with five additional commits since the last revision:
> 
>  - Test case for the window icon update on DPI change (other changes)
>  - Test case for the window icon update on DPI change (@compile not needed)
>  - Test case for the window icon update on DPI change (center the frame)
>  - Test case for the window icon update on DPI change (specific message for timeouts)
>  - Test case for the window icon update on DPI change (icon with a white background and centered text)

Changes requested by aivanov (Reviewer).

test/jdk/java/awt/Window/WindowIconUpdateOnDPIChanging/WindowIconUpdateOnDPIChangingTest.java line 79:

> 77:         SwingUtilities.invokeLater(WindowIconUpdateOnDPIChangingTest::createUI);
> 78:         if (!countDownLatch.await(15, TimeUnit.MINUTES)) {
> 79:             frame.dispose();

It must be called on EDT.
Suggestion:

            SwingUtilities.invokeAndWait(() -> frame.dispose());

test/jdk/java/awt/Window/WindowIconUpdateOnDPIChanging/WindowIconUpdateOnDPIChangingTest.java line 98:

> 96:         frame.getContentPane().add(createInstrumentsPane(), BorderLayout.CENTER);
> 97:         frame.getContentPane().add(createControlPanel(), BorderLayout.SOUTH);
> 98:         frame.setIconImages(IntStream.rangeClosed(16, 32).mapToObj(size -> createIcon(size)).toList());

In fact, I liked the version with method reference better even though the line is longer.

But I still suggest wrapping the line at each dot to make it clearer what operations are performed on the stream.
Suggestion:

        frame.setIconImages(IntStream.rangeClosed(16, 32)
                                     .mapToObj(size -> createIcon(size))
                                     .toList());

It fits into 80 column limit. If it's replaced with method reference as it was before, it doesn't fit but I don't see it as big problem.

Alternatively, you can wrap the start of the stream too:
Suggestion:

        frame.setIconImages(
                IntStream.rangeClosed(16, 32)
                         .mapToObj(WindowIconUpdateOnDPIChangingTest::createIcon)
                         .toList());

The line with method reference takes 82 columns, I'm sure it's acceptable.

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

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