fix!: keep sub-percent precision in crop values

src/main/java/com/flowingcode/vaadin/addons/imagecrop/Crop.java

@@ -34,7 +34,7 @@
  * @param width  the width of the cropped area
  * @param height the height of the cropped area
  */
-public record Crop(String unit, int x, int y, int width, int height) {
+public record Crop(String unit, double x, double y, double width, double height) {
 
     /**
      * Returns a string representation of the Crop object.

src/main/java/com/flowingcode/vaadin/addons/imagecrop/ImageCrop.java

@@ -223,9 +223,9 @@ public void setCrop(Crop crop) {
    * <p>
    * Once the image has loaded, the crop is normalized to a percentage of the
    * image's natural size, so the returned unit is {@code %} even when
-   * {@link #setCrop(Crop)} was given a {@code px} crop. Because {@link Crop} holds
-   * integer values, those percentages are rounded to whole units, which on a large
-   * image is coarser than the configured pixel values.
+   * {@link #setCrop(Crop)} was given a {@code px} crop. The percentages keep their
+   * fractional part, so passing the returned crop back to {@link #setCrop(Crop)}
+   * does not move the selection.
    *
    * @return the crop dimensions
    */

src/test/java/com/flowingcode/vaadin/addons/imagecrop/test/ImageCropTest.java

@@ -21,7 +21,6 @@
 import com.vaadin.flow.component.UI;
 import com.vaadin.flow.server.streams.DownloadHandler;
 import com.vaadin.flow.server.streams.DownloadResponse;
-
 public class ImageCropTest {
 
   private ImageCrop imageCrop;
@@ -89,6 +88,20 @@ public void testSetAndGetCrop() {
     assertEquals(expectedCrop, imageCrop.getCrop());
   }
 
+  @Test
+  public void testGetCropKeepsSubPercentPrecision() {
+    // the client syncs the crop as a "%" crop with fractional values; on a
+    // 4000px-wide image 1% is 40px, so dropping the fraction moves the selection
+    Crop expectedCrop = new Crop("%", 12.3456, 7.89, 33.3333, 50.125);
+    imageCrop.setCrop(expectedCrop);
+
+    Crop crop = imageCrop.getCrop();
+    assertEquals(expectedCrop, crop);
+
+    imageCrop.setCrop(crop);
+    assertEquals(crop, imageCrop.getCrop());
+  }
+
   @Test
   public void testSetAndGetAspect() {
     Double expectedAspect = 16.0 / 9.0;