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  1. JDK
  2. JDK-8240569

Additional information to JDK-8139152

    Details

    • Subcomponent:
    • Introduced In Version:
      9
    • CPU:
      x86_64
    • OS:
      windows_10

      Description

      ADDITIONAL SYSTEM INFORMATION :
      Windows 10, JDK EA 15 Build 6

      A DESCRIPTION OF THE PROBLEM :
      It's correct that you can pass a MultiResolutionImage to createCustomCursor. However, only the base image is looked at, as is quite obvious from the respective JDK code:

      https://github.com/openjdk/jdk/blob/6bab0f539fba8fb441697846347597b4a0ade428/src/java.desktop/share/classes/sun/awt/CustomCursor.java
      and
      https://github.com/openjdk/jdk/blob/dd570ee6c85ed6f6093755efc17ce21258c538f9/src/java.desktop/windows/classes/sun/awt/windows/WCustomCursor.java

      Providing a large image (e.g. 64x64 according to getBestCursorSize) indeed gives you a HiDPI cursor. However, having attached both a HiDPI (200% scaling) screen and a regular screen (100% scaling) at the same time, this makes the cursor appear at double size on the regular screen.

      If you consider this a different problem than JDK-8139152, please open a new bug.

      STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
      Run the attached test program and hover the mouse over the opened window.

      EXPECTED VERSUS ACTUAL BEHAVIOR :
      EXPECTED -
      A HiDPI cursor on the HiDPI screen, a normal DPI cursor on the regular screen, both having about the same size.
      ACTUAL -
      A HiDPI cursor on the HiDPI resolution, a normal DPI cursor on the normal DPI screen, the latter having twice the size.
      (Too bad no screenshots can be attached here.)

      ---------- BEGIN SOURCE ----------
      import java.awt.*;
      import java.awt.event.MouseEvent;
      import java.awt.event.MouseListener;
      import java.awt.image.BaseMultiResolutionImage;
      import java.awt.image.BufferedImage;

      public class CustomCursorResolution {
          public static void main(String[] args)
          {
              Dimension bestCursorSize = Toolkit.getDefaultToolkit().getBestCursorSize(32, 32);
              assert bestCursorSize.width == bestCursorSize.height; // effectively 64 for systems with (also) a HiDPI screen

              final int cursorSize = bestCursorSize.width;

              // construct framed haircross
              BufferedImage bufferedImageLowRes = createCursorImage(cursorSize / 2);
              BufferedImage bufferedImageHighRes = createCursorImage(cursorSize);

              Frame frame = new Frame();
              BaseMultiResolutionImage mrImage = new BaseMultiResolutionImage(bufferedImageHighRes, bufferedImageLowRes);
              frame.setCursor(Toolkit.getDefaultToolkit().createCustomCursor(
                      mrImage, new Point(cursorSize / 2, cursorSize / 2), "haircross"));
              frame.setSize(new Dimension(500, 500));
              frame.setVisible(true);
          }

          private static BufferedImage createCursorImage(int cursorSize) {
              BufferedImage bufferedImage = new BufferedImage(cursorSize, cursorSize, BufferedImage.TYPE_INT_ARGB);
              Graphics2D bg = bufferedImage.createGraphics();
              bg.setBackground(new Color(1.0f, 1.0f, 1.0f, 0.0f));
              bg.clearRect(0, 0, cursorSize, cursorSize);
              bg.setColor(Color.BLACK);
              bg.drawRect(0, 0, cursorSize - 1, cursorSize - 1);
              bg.setStroke(new BasicStroke(2));
              bg.drawLine(cursorSize / 2, 0, cursorSize / 2, cursorSize);
              bg.drawLine(0, cursorSize / 2, cursorSize, cursorSize / 2);
              return bufferedImage;
          }
      }

      ---------- END SOURCE ----------

      FREQUENCY : always

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              • Assignee:
                pardesha Pardeep Sharma
                Reporter:
                pnarayanaswa Praveen Narayanaswamy
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                • Created:
                  Updated:
                  Resolved: