Add background size support

DEVSIX-1708

Author: Artyom Yanchevsky

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

@@ -68,28 +68,31 @@ public class BackgroundImage {
      */
     @Deprecated
     protected boolean repeatY;
-
     protected AbstractLinearGradientBuilder linearGradientBuilder;
 
     private BlendMode blendMode = DEFAULT_BLEND_MODE;
 
     private BackgroundPosition position;
+    private BackgroundSize backgroundSize;
 
     /**
      * Creates a new {@link BackgroundImage} instance.
      *
      * @param image                 background-image property. {@link PdfXObject} instance.
      * @param repeat                background-repeat property. {@link BackgroundRepeat} instance.
      * @param position              background-position property. {@link BackgroundPosition} instance.
+     * @param backgroundSize        background-size property. {@link BackgroundSize} instance.
      * @param linearGradientBuilder background-image property. {@link AbstractLinearGradientBuilder} instance.
      * @param blendMode             the image's blend mode. {@link BlendMode} instance.
      */
     protected BackgroundImage(PdfXObject image, BackgroundRepeat repeat, BackgroundPosition position,
-                              AbstractLinearGradientBuilder linearGradientBuilder, BlendMode blendMode) {
+                              BackgroundSize backgroundSize, AbstractLinearGradientBuilder linearGradientBuilder,
+                              BlendMode blendMode) {
         this.image = image;
         this.repeatX = repeat.isRepeatX();
         this.repeatY = repeat.isRepeatY();
         this.position = position;
+        this.backgroundSize = backgroundSize;
         this.linearGradientBuilder = linearGradientBuilder;
         if (blendMode != null) {
             this.blendMode = blendMode;
@@ -106,7 +109,7 @@ protected BackgroundImage(PdfXObject image, BackgroundRepeat repeat, BackgroundP
      */
     @Deprecated
     public BackgroundImage(final PdfImageXObject image, final BackgroundRepeat repeat, final BlendMode blendMode) {
-        this(image, repeat, new BackgroundPosition(), null, blendMode);
+        this(image, repeat, new BackgroundPosition(), new BackgroundSize(), null, blendMode);
     }
 
     /**
@@ -119,7 +122,7 @@ public BackgroundImage(final PdfImageXObject image, final BackgroundRepeat repea
      */
     @Deprecated
     public BackgroundImage(final PdfFormXObject image, final BackgroundRepeat repeat, final BlendMode blendMode) {
-        this(image, repeat, new BackgroundPosition(), null, blendMode);
+        this(image, repeat, new BackgroundPosition(), new BackgroundSize(), null, blendMode);
     }
 
     /**
@@ -131,7 +134,7 @@ public BackgroundImage(final PdfFormXObject image, final BackgroundRepeat repeat
      */
     @Deprecated
     public BackgroundImage(final PdfImageXObject image, final BackgroundRepeat repeat) {
-        this(image, repeat, new BackgroundPosition(), null, DEFAULT_BLEND_MODE);
+        this(image, repeat, new BackgroundPosition(), new BackgroundSize(), null, DEFAULT_BLEND_MODE);
     }
 
     /**
@@ -143,7 +146,7 @@ public BackgroundImage(final PdfImageXObject image, final BackgroundRepeat repea
      */
     @Deprecated
     public BackgroundImage(final PdfFormXObject image, final BackgroundRepeat repeat) {
-        this(image, repeat, new BackgroundPosition(), null, DEFAULT_BLEND_MODE);
+        this(image, repeat, new BackgroundPosition(), new BackgroundSize(), null, DEFAULT_BLEND_MODE);
     }
 
     /**
@@ -154,7 +157,7 @@ public BackgroundImage(final PdfFormXObject image, final BackgroundRepeat repeat
      */
     @Deprecated
     public BackgroundImage(final PdfImageXObject image) {
-        this(image, new BackgroundRepeat(), new BackgroundPosition(), null, DEFAULT_BLEND_MODE);
+        this(image, new BackgroundRepeat(), new BackgroundPosition(), new BackgroundSize(), null, DEFAULT_BLEND_MODE);
     }
 
     /**
@@ -165,7 +168,7 @@ public BackgroundImage(final PdfImageXObject image) {
      */
     @Deprecated
     public BackgroundImage(final PdfFormXObject image) {
-        this(image, new BackgroundRepeat(), new BackgroundPosition(), null, DEFAULT_BLEND_MODE);
+        this(image, new BackgroundRepeat(), new BackgroundPosition(), new BackgroundSize(), null, DEFAULT_BLEND_MODE);
     }
 
     /**
@@ -178,7 +181,8 @@ 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(), null, DEFAULT_BLEND_MODE);
+        this(image, new BackgroundRepeat(repeatX, repeatY), new BackgroundPosition(), new BackgroundSize(),
+                null, DEFAULT_BLEND_MODE);
     }
 
     /**
@@ -191,7 +195,8 @@ 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(), null, DEFAULT_BLEND_MODE);
+        this(image, new BackgroundRepeat(repeatX, repeatY), new BackgroundPosition(), new BackgroundSize(),
+                null, DEFAULT_BLEND_MODE);
     }
 
     /**
@@ -216,7 +221,8 @@ public BackgroundImage(final AbstractLinearGradientBuilder linearGradientBuilder
      */
     @Deprecated
     public BackgroundImage(final AbstractLinearGradientBuilder linearGradientBuilder, final BlendMode blendMode) {
-        this(null, new BackgroundRepeat(false, false), new BackgroundPosition(), linearGradientBuilder, blendMode);
+        this(null, new BackgroundRepeat(false, false), new BackgroundPosition(), new BackgroundSize()
+                , linearGradientBuilder, blendMode);
     }
 
     public PdfImageXObject getImage() {
@@ -252,10 +258,45 @@ public boolean isRepeatY() {
         return repeatY;
     }
 
+    /**
+     * Gets the background size property.
+     *
+     * @return {@link BackgroundSize} instance
+     */
+    public BackgroundSize getBackgroundSize() {
+        return backgroundSize;
+    }
+
+    /**
+     * Gets initial image width.
+     */
+    public float getImageWidth() {
+        return (float) image.getWidth();
+    }
+
+    /**
+     * Gets initial image height.
+     */
+    public float getImageHeight() {
+        return (float) image.getHeight();
+    }
+
+    /**
+     * Gets initial image width.
+     *
+     * @deprecated To be removed in 7.2. Use {@link BackgroundImage#getImageWidth()} instead.
+     */
+    @Deprecated
     public float getWidth() {
         return (float) image.getWidth();
     }
 
+    /**
+     * Gets initial image height.
+     *
+     * @deprecated To be removed in 7.2. Use {@link BackgroundImage#getImageHeight()} instead.
+     */
+    @Deprecated
     public float getHeight() {
         return (float) image.getHeight();
     }
@@ -279,6 +320,7 @@ public static class Builder {
         private BackgroundPosition position = new BackgroundPosition();
         private BackgroundRepeat repeat = new BackgroundRepeat();
         private BlendMode blendMode = DEFAULT_BLEND_MODE;
+        private BackgroundSize backgroundSize = new BackgroundSize();
 
         public Builder() {
         }
@@ -347,13 +389,26 @@ public Builder setBackgroundBlendMode(BlendMode blendMode) {
             return this;
         }
 
+        /**
+         * Set the image's backgroundSize.
+         *
+         * @param backgroundSize {@link BackgroundSize} to be set.
+         * @return this {@link Builder}.
+         */
+        public Builder setBackgroundSize(BackgroundSize backgroundSize) {
+            if (backgroundSize != null) {
+                this.backgroundSize = backgroundSize;
+            }
+            return this;
+        }
+
         /**
          * Builds new {@link BackgroundImage} using set fields.
          *
          * @return new {@link BackgroundImage}.
          */
         public BackgroundImage build() {
-            return new BackgroundImage(image, repeat, position, linearGradientBuilder, blendMode);
+            return new BackgroundImage(image, repeat, position, backgroundSize, linearGradientBuilder, blendMode);
         }
     }
 }

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

@@ -0,0 +1,143 @@
+/*
+    This file is part of the iText (R) project.
+    Copyright (c) 1998-2020 iText Group NV
+    Authors: iText Software.
+
+    This program is offered under a commercial and under the AGPL license.
+    For commercial licensing, contact us at https://itextpdf.com/sales.  For AGPL licensing, see below.
+
+    AGPL licensing:
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.itextpdf.layout.property;
+
+/**
+ * Class to hold background-size property.
+ */
+public class BackgroundSize {
+
+    /**
+     * Width size for this image. If {@link UnitValue} is in percent, then width depends on the area of the element.
+     */
+    private UnitValue backgroundWidthSize;
+    /**
+     * Height size for this image. If {@link UnitValue} is in percent, then height depends on the area of the element.
+     */
+    private UnitValue backgroundHeightSize;
+    /**
+     * Image covers the entire area and its size may be more than the area.
+     */
+    private boolean cover;
+    /**
+     * Image hsd a maximum size but not larger than the area.
+     */
+    private boolean contain;
+
+    public BackgroundSize() {
+        cover = false;
+        contain = false;
+    }
+
+    /**
+     * Clear all current properties and sets new width and height values.
+     * One of the parameters can be null. Note that in this case CalculationUtil will scale null property
+     * so that it becomes proportionally equals with the not null value.
+     * If both parameters are set to null, that the default image size will be used.
+     *
+     * @param width a {@link UnitValue} object
+     * @param height a {@link UnitValue} object
+     * @see com.itextpdf.layout.renderer.BackgroundSizeCalculationUtil#calculateBackgroundImageSize
+     */
+    public void setBackgroundSizeToValues(UnitValue width, UnitValue height) {
+        clear();
+        this.backgroundWidthSize = width;
+        this.backgroundHeightSize = height;
+    }
+
+    /**
+     * Clears all size values and sets the "contain" property {@code true}.
+     *
+     * @see BackgroundSize#contain
+     */
+    public void setBackgroundSizeToContain() {
+        clear();
+        contain = true;
+    }
+
+    /**
+     * Clears all size values and sets the "cover" property {@code true}.
+     *
+     * @see BackgroundSize#cover
+     */
+    public void setBackgroundSizeToCover() {
+        clear();
+        cover = true;
+    }
+
+    /**
+     * Gets the background width property of the image.
+     *
+     * @return the {@link UnitValue} width for this image.
+     * @see BackgroundSize#backgroundWidthSize
+     */
+    public UnitValue getBackgroundWidthSize() {
+        return backgroundWidthSize;
+    }
+
+    /**
+     * Gets the background height property of the image.
+     *
+     * @return the {@link UnitValue} height for this image.
+     * @see BackgroundSize#backgroundHeightSize
+     */
+    public UnitValue getBackgroundHeightSize() {
+        return backgroundHeightSize;
+    }
+
+    /**
+     * Returns is size has specific property.
+     *
+     * @return {@code true} if size set to "contain" or "cover", otherwise false.
+     */
+    public boolean isSpecificSize() {
+        return contain || cover;
+    }
+
+    /**
+     * Returns value of the "contain" property.
+     *
+     * @return {@code true} if property "contain" is set to the size, otherwise false.
+     * @see BackgroundSize#contain
+     */
+    public boolean isContain() {
+        return contain;
+    }
+
+    /**
+     * Returns value of the "cover" property.
+     *
+     * @return {@code true} if property "cover" is set to the size, otherwise false.
+     * @see BackgroundSize#cover
+     */
+    public boolean isCover() {
+        return cover;
+    }
+
+    private void clear() {
+        contain = false;
+        cover = false;
+        backgroundWidthSize = null;
+        backgroundHeightSize = null;
+    }
+}

layout/src/main/java/com/itextpdf/layout/renderer/AbstractRenderer.java

@@ -567,6 +567,8 @@ private boolean drawBackgroundImagesList(final List<BackgroundImage> backgroundI
     private void drawBackgroundImage(BackgroundImage backgroundImage,
                                      DrawContext drawContext, Rectangle backgroundArea) {
         applyBorderBox(backgroundArea, false);
+        float[] imageWidthAndHeight = BackgroundSizeCalculationUtil.calculateBackgroundImageSize(
+                backgroundImage, backgroundArea.getWidth(), backgroundArea.getHeight());
         PdfXObject backgroundXObject = backgroundImage.getImage();
         if (backgroundXObject == null) {
             backgroundXObject = backgroundImage.getForm();
@@ -583,15 +585,15 @@ private void drawBackgroundImage(BackgroundImage backgroundImage,
             backgroundImage.getBackgroundPosition().calculatePositionValues(0, 0, xPosition, yPosition);
             backgroundXObject = createXObject(gradientBuilder, backgroundArea, drawContext.getDocument());
             imageRectangle = new Rectangle(backgroundArea.getLeft() + xPosition.getValue(),
-                    backgroundArea.getTop() - backgroundXObject.getHeight() - yPosition.getValue(),
-                    backgroundXObject.getWidth(), backgroundXObject.getHeight());
+                    backgroundArea.getTop() - imageWidthAndHeight[1] - yPosition.getValue(),
+                    imageWidthAndHeight[0], imageWidthAndHeight[1]);
         } else {
             backgroundImage.getBackgroundPosition().calculatePositionValues(
-                    backgroundArea.getWidth() - backgroundImage.getWidth(),
-                    backgroundArea.getHeight() - backgroundImage.getHeight(), xPosition, yPosition);
+                    backgroundArea.getWidth() - imageWidthAndHeight[0],
+                    backgroundArea.getHeight() - imageWidthAndHeight[1], xPosition, yPosition);
             imageRectangle = new Rectangle(backgroundArea.getLeft() + xPosition.getValue(),
-                    backgroundArea.getTop() - backgroundImage.getHeight() - yPosition.getValue(),
-                    backgroundImage.getWidth(), backgroundImage.getHeight());
+                    backgroundArea.getTop() - imageWidthAndHeight[1] - yPosition.getValue(),
+                    imageWidthAndHeight[0], imageWidthAndHeight[1]);
         }
         if (imageRectangle.getWidth() <= 0 || imageRectangle.getHeight() <= 0) {
             Logger logger = LoggerFactory.getLogger(AbstractRenderer.class);