Allow creating of an empty Themes Table on request

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1692211 13f79535-47bb-0310-9956-ffa450edef68

src/ooxml/java/org/apache/poi/xssf/model/StylesTable.java

@@ -35,7 +35,10 @@ import org.apache.poi.ss.usermodel.BuiltinFormats;
 import org.apache.poi.ss.usermodel.FontFamily;
 import org.apache.poi.ss.usermodel.FontScheme;
 import org.apache.poi.xssf.usermodel.XSSFCellStyle;
+import org.apache.poi.xssf.usermodel.XSSFFactory;
 import org.apache.poi.xssf.usermodel.XSSFFont;
+import org.apache.poi.xssf.usermodel.XSSFRelation;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
 import org.apache.poi.xssf.usermodel.extensions.XSSFCellBorder;
 import org.apache.poi.xssf.usermodel.extensions.XSSFCellFill;
 import org.apache.xmlbeans.XmlException;
@@ -57,7 +60,6 @@ import org.openxmlformats.schemas.spreadsheetml.x2006.main.CTXf;
 import org.openxmlformats.schemas.spreadsheetml.x2006.main.STPatternType;
 import org.openxmlformats.schemas.spreadsheetml.x2006.main.StyleSheetDocument;
 
-
 /**
  * Table of styles shared across all sheets in a workbook.
  */
@@ -79,6 +81,7 @@ public class StylesTable extends POIXMLDocumentPart {
     private static final int MAXIMUM_STYLE_ID = SpreadsheetVersion.EXCEL2007.getMaxCellStyles();
 
     private StyleSheetDocument doc;
+    private XSSFWorkbook workbook;
     private ThemesTable theme;
 
     /**
@@ -96,7 +99,17 @@ public class StylesTable extends POIXMLDocumentPart {
         super(part, rel);
         readFrom(part.getInputStream());
     }
+    
+    public void setWorkbook(XSSFWorkbook wb) {
+        this.workbook = wb;
+    }
 
+    /**
+     * Get the current Workbook's theme table, or null if the
+     *  Workbook lacks any themes.
+     * <p>Use {@link #ensureThemesTable()} to have a themes table
+     *  created if needed
+     */
     public ThemesTable getTheme() {
         return theme;
     }
@@ -113,6 +126,17 @@ public class StylesTable extends POIXMLDocumentPart {
             border.setThemesTable(theme);
         }
     }
+    
+    /**
+     * If there isn't currently a {@link ThemesTable} for the
+     *  current Workbook, then creates one and sets it up.
+     * After this, calls to {@link #getTheme()} won't give null
+     */
+    public void ensureThemesTable() {
+        if (theme != null) return;
+
+        theme = (ThemesTable)workbook.createRelationship(XSSFRelation.THEME, XSSFFactory.getInstance());
+    }
 
     /**
      * Read this shared styles table from an XML file.

src/ooxml/java/org/apache/poi/xssf/model/ThemesTable.java

@@ -17,12 +17,14 @@
 package org.apache.poi.xssf.model;
 
 import java.io.IOException;
+import java.io.OutputStream;
 
 import org.apache.poi.POIXMLDocumentPart;
 import org.apache.poi.openxml4j.opc.PackagePart;
 import org.apache.poi.openxml4j.opc.PackageRelationship;
 import org.apache.poi.xssf.usermodel.XSSFColor;
 import org.apache.xmlbeans.XmlException;
+import org.apache.xmlbeans.XmlOptions;
 import org.openxmlformats.schemas.drawingml.x2006.main.CTColor;
 import org.openxmlformats.schemas.drawingml.x2006.main.CTColorScheme;
 import org.openxmlformats.schemas.drawingml.x2006.main.ThemeDocument;
@@ -34,6 +36,15 @@ import org.openxmlformats.schemas.drawingml.x2006.main.ThemeDocument;
 public class ThemesTable extends POIXMLDocumentPart {
     private ThemeDocument theme;
 
+    /**
+     * Create a new, empty ThemesTable
+     */
+    public ThemesTable() {
+        super();
+        theme = ThemeDocument.Factory.newInstance();
+        theme.addNewTheme().addNewThemeElements();
+    }
+    
     /**
      * Construct a ThemesTable.
      * @param part A PackagePart.
@@ -120,4 +131,24 @@ public class ThemesTable extends POIXMLDocumentPart {
 
        // All done
     }
+    
+    /**
+     * Write this table out as XML.
+     * 
+     * @param out The stream to write to.
+     * @throws IOException if an error occurs while writing.
+     */
+    public void writeTo(OutputStream out) throws IOException {
+        XmlOptions options = new XmlOptions(DEFAULT_XML_OPTIONS);
+
+        theme.save(out, options);
+    }
+
+    @Override
+    protected void commit() throws IOException {
+        PackagePart part = getPackagePart();
+        OutputStream out = part.getOutputStream();
+        writeTo(out);
+        out.close();
+    }
 }

src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFWorkbook.java

@@ -153,8 +153,6 @@ public class XSSFWorkbook extends POIXMLDocument implements Workbook, Iterable<X
      */
     private StylesTable stylesSource;
 
-    private ThemesTable theme;
-
     /**
      * The locator of user-defined functions.
      * By default includes functions from the Excel Analysis Toolpack
@@ -337,6 +335,7 @@ public class XSSFWorkbook extends POIXMLDocument implements Workbook, Iterable<X
             WorkbookDocument doc = WorkbookDocument.Factory.parse(getPackagePart().getInputStream());
             this.workbook = doc.getWorkbook();
 
+            ThemesTable theme = null;
             Map<String, XSSFSheet> shIdMap = new HashMap<String, XSSFSheet>();
             Map<String, ExternalLinksTable> elIdMap = new HashMap<String, ExternalLinksTable>();
             for(POIXMLDocumentPart p : getRelations()){
@@ -362,6 +361,7 @@ public class XSSFWorkbook extends POIXMLDocument implements Workbook, Iterable<X
                     stylesSource = (StylesTable)createRelationship(XSSFRelation.STYLES, XSSFFactory.getInstance());
                 }
             }
+            stylesSource.setWorkbook(this);
             stylesSource.setTheme(theme);
 
             if (sharedStringSource == null) {
@@ -428,6 +428,7 @@ public class XSSFWorkbook extends POIXMLDocument implements Workbook, Iterable<X
 
         sharedStringSource = (SharedStringsTable)createRelationship(XSSFRelation.SHARED_STRINGS, XSSFFactory.getInstance());
         stylesSource = (StylesTable)createRelationship(XSSFRelation.STYLES, XSSFFactory.getInstance());
+        stylesSource.setWorkbook(this);
 
         namedRanges = new ArrayList<XSSFName>();
         sheets = new ArrayList<XSSFSheet>();
@@ -1578,7 +1579,8 @@ public class XSSFWorkbook extends POIXMLDocument implements Workbook, Iterable<X
      * Returns the Theme of current workbook.
      */
     public ThemesTable getTheme() {
-        return theme;
+        if (stylesSource == null) return null;
+        return stylesSource.getTheme();
     }
 
     /**

src/ooxml/testcases/org/apache/poi/xssf/model/TestThemesTable.java

@@ -18,6 +18,7 @@
 package org.apache.poi.xssf.model;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
 
 import java.io.FileOutputStream;
 
@@ -29,6 +30,7 @@ import org.apache.poi.xssf.usermodel.XSSFCellStyle;
 import org.apache.poi.xssf.usermodel.XSSFColor;
 import org.apache.poi.xssf.usermodel.XSSFFont;
 import org.apache.poi.xssf.usermodel.XSSFRow;
+import org.apache.poi.xssf.usermodel.XSSFSheet;
 import org.apache.poi.xssf.usermodel.XSSFWorkbook;
 import org.junit.Test;
 
@@ -75,4 +77,24 @@ public class TestThemesTable {
             fos.close();
         }
     }
+    
+    @Test
+    public void testAddNew() throws Exception {
+        XSSFWorkbook wb = new XSSFWorkbook();
+        XSSFSheet s = wb.createSheet();
+        assertEquals(null, wb.getTheme());
+        
+        StylesTable styles = wb.getStylesSource();
+        assertEquals(null, styles.getTheme());
+        
+        styles.ensureThemesTable();
+        
+        assertNotNull(styles.getTheme());
+        assertNotNull(wb.getTheme());
+        
+        wb = XSSFTestDataSamples.writeOutAndReadBack(wb);
+        styles = wb.getStylesSource();
+        assertNotNull(styles.getTheme());
+        assertNotNull(wb.getTheme());
+    }
 }