#64716 - wmf display error

EMF: workaround for invalid EMF header bounds
EMF: add option to PPTX2PNG / DrawableHint to fallback to force EMF header bounds 
EMF: use RGB instead of HSL gradiants

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1883051 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 56 insertions, 8 deletions

diff --git a/src/java/org/apache/poi/common/usermodel/PictureType.java b/src/java/org/apache/poi/common/usermodel/PictureType.java
index 4aceb624a0..d3ed67fc2e 100644
--- a/src/java/org/apache/poi/common/usermodel/PictureType.java
+++ b/src/java/org/apache/poi/common/usermodel/PictureType.java
@@ -17,6 +17,8 @@
 
 package org.apache.poi.common.usermodel;
 
+import org.apache.poi.poifs.filesystem.FileMagic;
+
 /**
  * General enum class to define a picture format/type
  *
@@ -65,4 +67,37 @@ public enum PictureType {
         this.contentType = contentType;
         this.extension = extension;
     }
+
+    public String getContentType() {
+        return contentType;
+    }
+
+    public String getExtension() {
+        return extension;
+    }
+
+    public static PictureType valueOf(FileMagic fm) {
+        switch (fm) {
+            case BMP:
+                return PictureType.BMP;
+            case GIF:
+                return PictureType.GIF;
+            case JPEG:
+                return PictureType.JPEG;
+            case PNG:
+                return PictureType.PNG;
+            case XML:
+                // this is quite fuzzy, to suppose all XMLs are SVGs when handling pictures ...
+                return PictureType.SVG;
+            case WMF:
+                return PictureType.WMF;
+            case EMF:
+                return PictureType.EMF;
+            case TIFF:
+                return PictureType.TIFF;
+            default:
+            case UNKNOWN:
+                return PictureType.UNKNOWN;
+        }
+    }
 }
diff --git a/src/java/org/apache/poi/sl/draw/DrawPictureShape.java b/src/java/org/apache/poi/sl/draw/DrawPictureShape.java
index 695f4ec708..2e25d75a6a 100644
--- a/src/java/org/apache/poi/sl/draw/DrawPictureShape.java
+++ b/src/java/org/apache/poi/sl/draw/DrawPictureShape.java
@@ -27,6 +27,8 @@ import java.util.ServiceLoader;
 import java.util.function.Supplier;
 import java.util.stream.StreamSupport;
 
+import org.apache.poi.common.usermodel.PictureType;
+import org.apache.poi.poifs.filesystem.FileMagic;
 import org.apache.poi.sl.usermodel.PictureData;
 import org.apache.poi.sl.usermodel.PictureShape;
 import org.apache.poi.sl.usermodel.RectAlign;
@@ -36,11 +38,6 @@ import org.apache.poi.util.POILogger;
 
 public class DrawPictureShape extends DrawSimpleShape {
     private static final POILogger LOG = POILogFactory.getLogger(DrawPictureShape.class);
-    private static final String[] KNOWN_RENDERER = {
-        "org.apache.poi.hwmf.draw.HwmfImageRenderer",
-        "org.apache.poi.hemf.draw.HemfImageRenderer",
-        "org.apache.poi.xslf.draw.SVGImageRenderer"
-    };
 
     public DrawPictureShape(PictureShape<?,?> shape) {
         super(shape);
@@ -60,10 +57,14 @@ public class DrawPictureShape extends DrawSimpleShape {
             }
 
             try {
-                String ct = data.getContentType();
+                byte[] dataBytes = data.getData();
+
+                PictureType type = PictureType.valueOf(FileMagic.valueOf(dataBytes));
+                String ct = (type == PictureType.UNKNOWN) ? data.getContentType() : type.getContentType();
+
                 ImageRenderer renderer = getImageRenderer(graphics, ct);
                 if (renderer.canRender(ct)) {
-                    renderer.loadImage(data.getData(), ct);
+                    renderer.loadImage(dataBytes, ct);
                     renderer.drawImage(graphics, anchor, insets);
                     return;
                 }
@@ -92,7 +93,7 @@ public class DrawPictureShape extends DrawSimpleShape {
 
         // the fallback is the BitmapImageRenderer, at least it gracefully handles invalid images
         final Supplier<ImageRenderer> getFallback = () -> {
-            LOG.log(POILogger.WARN, "No suiteable image renderer found for content-type '"+
+            LOG.log(POILogger.WARN, "No suitable image renderer found for content-type '"+
             contentType+"' - include poi-scratchpad (for wmf/emf) or poi-ooxml (for svg) jars!");
             return fallback;
         };
diff --git a/src/java/org/apache/poi/sl/draw/Drawable.java b/src/java/org/apache/poi/sl/draw/Drawable.java
index 919e1a6f25..cb5f8592f9 100644
--- a/src/java/org/apache/poi/sl/draw/Drawable.java
+++ b/src/java/org/apache/poi/sl/draw/Drawable.java
@@ -49,6 +49,7 @@ public interface Drawable {
             case 12: return "CURRENT_SLIDE";
             case 13: return "BUFFERED_IMAGE";
             case 14: return "DEFAULT_CHARSET";
+            case 15: return "EMF_FORCE_HEADER_BOUNDS";
             default: return "UNKNOWN_ID "+intKey();
             }
         }
@@ -153,6 +154,17 @@ public interface Drawable {
      */
     DrawableHint DEFAULT_CHARSET = new DrawableHint(14);
 
+    /**
+     * A boolean value to force the usage of the bounding box, which is specified in the EMF header.
+     * Defaults to {@code FALSE} - in this case the records are scanned for window and
+     * viewport records to determine the initial bounding box by using the following
+     * condition: {@code isValid(viewport) ? viewport : isValid(window) ? window : headerBounds }
+     * <p>
+     * This is a workaround switch, which might be removed in future releases, when the bounding box
+     * determination for the special cases is fixed.
+     * In most cases it's recommended to leave the default value.
+     */
+    DrawableHint EMF_FORCE_HEADER_BOUNDS = new DrawableHint(15);
 
     /**
      * Apply 2-D transforms before drawing this shape. This includes rotation and flipping.