Implement supporting background-repeat CSS property

DEVSIX-4370

Author: introfog

kernel/src/main/java/com/itextpdf/kernel/geom/Rectangle.java

@@ -260,24 +260,44 @@ public boolean contains(Rectangle rect) {
     /**
      * Check if this rectangle and the passed rectangle overlap
      *
-     * @param rect a rectangle which is to be checked if it overlaps the passed rectangle.
+     * @param rect a rectangle which is to be checked if it overlaps the passed rectangle
      * @return true if there is overlap of some kind
      */
-    public boolean overlaps(Rectangle rect) {
-        // Two rectangles do not overlap if any of the following holds
-        // 1. the lower left corner of the second rectangle is to the right of the upper-right corner of the first.
-        return !((rect.getX() - (this.getX() + this.getWidth()) > EPS)
+    public boolean overlaps(final Rectangle rect) {
+        return overlaps(rect, -EPS);
+    }
 
-                // 2. the lower left corner of the second rectangle is above the upper right corner of the first.
-                || (rect.getY() - (this.getY() + this.getHeight()) > EPS)
+    /**
+     * Check if this rectangle and the passed rectangle overlap
+     *
+     * @param rect a rectangle which is to be checked if it overlaps the passed rectangle
+     * @param epsilon if greater than zero, then this is the maximum distance that one rectangle can go to another, but
+     *               they will not overlap, if less than zero, then this is the minimum required distance between the
+     *                rectangles so that they do not overlap
+     * @return true if there is overlap of some kind
+     */
+    public boolean overlaps(final Rectangle rect, final float epsilon) {
+        // Two rectangles do not overlap if any of the following holds
 
-                // 3. the upper right corner of the second rectangle is to the left of the lower-left corner of the first.
-                || (this.getX() - (rect.getX() + rect.getWidth()) > EPS)
+        // The first rectangle lies to the left of the second rectangle or touches very slightly
+        if ((this.getX() + this.getWidth()) < (rect.getX() + epsilon)) {
+            return false;
+        }
+        // The first rectangle lies to the right of the second rectangle or touches very slightly
+        if ((this.getX() + epsilon) > (rect.getX() + rect.getWidth())) {
+            return false;
+        }
 
-                // 4. the upper right corner of the second rectangle is below the lower left corner of the first.
-                || (this.getY() - (rect.getY() + rect.getHeight()) > EPS)
-        );
+        // The first rectangle lies to the bottom of the second rectangle or touches very slightly
+        if ((this.getY() + this.getHeight()) < (rect.getY() + epsilon)) {
+            return false;
+        }
+        // The first rectangle lies to the top of the second rectangle or touches very slightly
+        if ((this.getY() + epsilon) > (rect.getY() + rect.getHeight())) {
+            return false;
+        }
 
+        return true;
     }
 
     /**

kernel/src/test/java/com/itextpdf/kernel/geom/RectangleTest.java

@@ -51,15 +51,68 @@ This file is part of the iText (R) project.
 import com.itextpdf.test.annotations.type.UnitTest;
 
 import java.io.ByteArrayOutputStream;
+
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+
 import org.junit.Assert;
 import org.junit.Test;
 import org.junit.experimental.categories.Category;
 
 @Category(UnitTest.class)
 public class RectangleTest extends ExtendedITextTest {
+    private static final float OVERLAP_EPSILON = 0.1f;
+
+    @Test
+    public void overlapWithEpsilon() {
+        Rectangle first = new Rectangle(0, 0, 10, 10);
+        Rectangle second = new Rectangle(-10, 0, 10.09f, 5);
+
+        Assert.assertFalse(first.overlaps(second, OVERLAP_EPSILON));
+        second.setWidth(10.11f);
+        Assert.assertTrue(first.overlaps(second, OVERLAP_EPSILON));
+
+        second = new Rectangle(5, 9.91f, 5, 5);
+        Assert.assertFalse(first.overlaps(second, OVERLAP_EPSILON));
+        second.setY(9.89f);
+        Assert.assertTrue(first.overlaps(second, OVERLAP_EPSILON));
+
+        second = new Rectangle(9.91f, 0, 5, 5);
+        Assert.assertFalse(first.overlaps(second, OVERLAP_EPSILON));
+        second.setX(9.89f);
+        Assert.assertTrue(first.overlaps(second, OVERLAP_EPSILON));
+
+        second = new Rectangle(5, -10, 5, 10.09f);
+        Assert.assertFalse(first.overlaps(second, OVERLAP_EPSILON));
+        second.setHeight(10.11f);
+        Assert.assertTrue(first.overlaps(second, OVERLAP_EPSILON));
+    }
+
+    @Test
+    public void overlapWithNegativeEpsilon() {
+        Rectangle first = new Rectangle(0, 0, 10, 10);
+        Rectangle second = new Rectangle(-10, 0, 9.89f, 5);
+
+        Assert.assertFalse(first.overlaps(second, -OVERLAP_EPSILON));
+        second.setWidth(9.91f);
+        Assert.assertTrue(first.overlaps(second, -OVERLAP_EPSILON));
+
+        second = new Rectangle(5, 10.11f, 5, 5);
+        Assert.assertFalse(first.overlaps(second, -OVERLAP_EPSILON));
+        second.setY(10.09f);
+        Assert.assertTrue(first.overlaps(second, -OVERLAP_EPSILON));
+
+        second = new Rectangle(10.11f, 0, 5, 5);
+        Assert.assertFalse(first.overlaps(second, -OVERLAP_EPSILON));
+        second.setX(10.09f);
+        Assert.assertTrue(first.overlaps(second, -OVERLAP_EPSILON));
+
+        second = new Rectangle(5, -10, 5, 9.89f);
+        Assert.assertFalse(first.overlaps(second, -OVERLAP_EPSILON));
+        second.setHeight(9.91f);
+        Assert.assertTrue(first.overlaps(second, -OVERLAP_EPSILON));
+    }
 
     @Test
     public void rectangleOverlapTest01() {

layout/src/main/java/com/itextpdf/layout/property/BackgroundImage.java

@@ -46,6 +46,7 @@ This file is part of the iText (R) project.
 import com.itextpdf.kernel.pdf.xobject.PdfFormXObject;
 import com.itextpdf.kernel.pdf.xobject.PdfImageXObject;
 import com.itextpdf.kernel.pdf.xobject.PdfXObject;
+import com.itextpdf.layout.property.BackgroundRepeat.BackgroundRepeatValue;
 
 public class BackgroundImage {
 
@@ -54,26 +55,30 @@ public class BackgroundImage {
     protected PdfXObject image;
 
     /**
-     * Whether the background repeats in the x dimension.
+     * Whether the background-repeat value is not {@link BackgroundRepeatValue#NO_REPEAT} for X axis.
      *
-     * @deprecated Replace this field with {@link BackgroundRepeat} instance.
+     * @deprecated replace this field with {@link BackgroundRepeat} instance
      */
     @Deprecated
     protected boolean repeatX;
 
     /**
-     * Whether the background repeats in the y dimension.
+     * Whether the background-repeat value is not {@link BackgroundRepeatValue#NO_REPEAT} for Y axis.
      *
-     * @deprecated Replace this field with {@link BackgroundRepeat} instance.
+     * @deprecated replace this field with {@link BackgroundRepeat} instance
      */
     @Deprecated
     protected boolean repeatY;
+
     protected AbstractLinearGradientBuilder linearGradientBuilder;
 
     private BlendMode blendMode = DEFAULT_BLEND_MODE;
 
-    private BackgroundPosition position;
-    private BackgroundSize backgroundSize;
+    private BackgroundRepeat repeat;
+
+    private final BackgroundPosition position;
+
+    private final BackgroundSize backgroundSize;
 
     /**
      * Creates a new {@link BackgroundImage} instance.
@@ -89,8 +94,9 @@ protected BackgroundImage(PdfXObject image, BackgroundRepeat repeat, BackgroundP
                               BackgroundSize backgroundSize, AbstractLinearGradientBuilder linearGradientBuilder,
                               BlendMode blendMode) {
         this.image = image;
-        this.repeatX = repeat.isRepeatX();
-        this.repeatY = repeat.isRepeatY();
+        this.repeatX = !repeat.isNoRepeatOnXAxis();
+        this.repeatY = !repeat.isNoRepeatOnYAxis();
+        this.repeat = repeat;
         this.position = position;
         this.backgroundSize = backgroundSize;
         this.linearGradientBuilder = linearGradientBuilder;
@@ -181,8 +187,9 @@ public BackgroundImage(final PdfFormXObject image) {
      */
     @Deprecated
     public BackgroundImage(final PdfImageXObject image, final boolean repeatX, final boolean repeatY) {
-        this(image, new BackgroundRepeat(repeatX, repeatY), new BackgroundPosition(), new BackgroundSize(),
-                null, DEFAULT_BLEND_MODE);
+        this(image, new BackgroundRepeat(repeatX ? BackgroundRepeatValue.REPEAT : BackgroundRepeatValue.NO_REPEAT,
+                repeatY ? BackgroundRepeatValue.REPEAT : BackgroundRepeatValue.NO_REPEAT), new BackgroundPosition(),
+                new BackgroundSize(), null, DEFAULT_BLEND_MODE);
     }
 
     /**
@@ -195,8 +202,9 @@ public BackgroundImage(final PdfImageXObject image, final boolean repeatX, final
      */
     @Deprecated
     public BackgroundImage(final PdfFormXObject image, final boolean repeatX, final boolean repeatY) {
-        this(image, new BackgroundRepeat(repeatX, repeatY), new BackgroundPosition(), new BackgroundSize(),
-                null, DEFAULT_BLEND_MODE);
+        this(image, new BackgroundRepeat(repeatX ? BackgroundRepeatValue.REPEAT : BackgroundRepeatValue.NO_REPEAT,
+                repeatY ? BackgroundRepeatValue.REPEAT : BackgroundRepeatValue.NO_REPEAT), new BackgroundPosition(),
+                new BackgroundSize(), null, DEFAULT_BLEND_MODE);
     }
 
     /**
@@ -221,8 +229,8 @@ public BackgroundImage(final AbstractLinearGradientBuilder linearGradientBuilder
      */
     @Deprecated
     public BackgroundImage(final AbstractLinearGradientBuilder linearGradientBuilder, final BlendMode blendMode) {
-        this(null, new BackgroundRepeat(false, false), new BackgroundPosition(), new BackgroundSize()
-                , linearGradientBuilder, blendMode);
+        this(null, new BackgroundRepeat(BackgroundRepeatValue.NO_REPEAT), new BackgroundPosition(),
+                new BackgroundSize(), linearGradientBuilder, blendMode);
     }
 
     public PdfImageXObject getImage() {
@@ -250,10 +258,12 @@ public boolean isBackgroundSpecified() {
         return image instanceof PdfFormXObject || image instanceof PdfImageXObject || linearGradientBuilder != null;
     }
 
+    @Deprecated
     public boolean isRepeatX() {
         return repeatX;
     }
 
+    @Deprecated
     public boolean isRepeatY() {
         return repeatY;
     }
@@ -301,6 +311,23 @@ public float getHeight() {
         return (float) image.getHeight();
     }
 
+    /**
+     * Gets image {@link BackgroundRepeat} instance.
+     *
+     * @return the image background repeat
+     */
+    public BackgroundRepeat getRepeat() {
+        // Remove this if-blocks after removing repeatX and repeatY
+        if (repeatX == repeat.isNoRepeatOnXAxis()) {
+            repeat = new BackgroundRepeat(repeatX ? BackgroundRepeatValue.REPEAT : BackgroundRepeatValue.NO_REPEAT, repeat.getYAxisRepeat());
+        }
+        if (repeatY == repeat.isNoRepeatOnYAxis()) {
+            repeat = new BackgroundRepeat(repeat.getXAxisRepeat(), repeatY ? BackgroundRepeatValue.REPEAT : BackgroundRepeatValue.NO_REPEAT);
+        }
+
+        return repeat;
+    }
+
     /**
      * Get the image's blend mode.
      *
@@ -349,7 +376,7 @@ public Builder setImage(PdfXObject image) {
          */
         public Builder setLinearGradientBuilder(AbstractLinearGradientBuilder linearGradientBuilder) {
             this.linearGradientBuilder = linearGradientBuilder;
-            this.repeat = new BackgroundRepeat(false, false);
+            this.repeat = new BackgroundRepeat(BackgroundRepeatValue.NO_REPEAT);
             this.image = null;
             return this;
         }