bug 61454: add column width to example Spreadsheet ToHtml; thanks to Christian Froehler

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1808816 13f79535-47bb-0310-9956-ffa450edef68

src/examples/src/org/apache/poi/ss/examples/html/ToHtml.java

@@ -30,6 +30,7 @@ import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;
+import java.util.TreeMap;
 
 import org.apache.poi.hssf.usermodel.HSSFWorkbook;
 import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
@@ -95,6 +96,10 @@ public class ToHtml {
             BorderStyle.SLANTED_DASH_DOT, "dashed 2pt",
             BorderStyle.THICK, "solid 3pt",
             BorderStyle.THIN, "dashed 1pt");
+    
+    private static final int IDX_TABLE_WIDTH = -2;
+    private static final int IDX_HEADER_COL_WIDTH = -1;
+    
 
     @SuppressWarnings({"unchecked"})
     private static <K, V> Map<K, V> mapFor(Object... mapping) {
@@ -355,17 +360,61 @@ public class ToHtml {
 
     public void printSheet(Sheet sheet) {
         ensureOut();
-        out.format("<table class=%s>%n", DEFAULTS_CLASS);
-        printCols(sheet);
+        Map<Integer, Integer> widths = computeWidths(sheet);
+        int tableWidth = widths.get(IDX_TABLE_WIDTH); 
+        out.format("<table class=%s style=\"width:%dpx;\">%n", DEFAULTS_CLASS, tableWidth);
+        printCols(widths);
         printSheetContent(sheet);
         out.format("</table>%n");
     }
+    
+    /**
+     * computes the column widths, defined by the sheet. 
+     * 
+     * @param sheet
+     * @return Map with key: column index; value: column width in pixels
+     *     <br>special keys: 
+     *     <br>{@link #IDX_HEADER_COL_WIDTH} - width of the header column
+     *     <br>{@link #IDX_TABLE_WIDTH} - width of the entire table 
+     */
+    private Map<Integer, Integer> computeWidths(Sheet sheet) {
+        Map<Integer, Integer> ret = new TreeMap<Integer, Integer>();
+        int tableWidth = 0;
 
-    private void printCols(Sheet sheet) {
-        out.format("<col/>%n");
         ensureColumnBounds(sheet);
+        
+        // compute width of the header column
+        int lastRowNum = sheet.getLastRowNum();
+        int headerCharCount = String.valueOf(lastRowNum).length();
+        int headerColWidth = widthToPixels((headerCharCount + 1) * 256);
+        ret.put(IDX_HEADER_COL_WIDTH, headerColWidth);
+        tableWidth += headerColWidth;
+
+        for (int i = firstColumn; i < endColumn; i++) {
+            int colWidth = poiWidthToPixels(sheet.getColumnWidth(i));
+            ret.put(i, colWidth);
+            tableWidth += colWidth;
+        }
+        
+        ret.put(IDX_TABLE_WIDTH, tableWidth);
+        return ret ;
+    }
+    
+    /**
+     * Probably platform-specific, but appears to be a close approximation on some systems
+     * @param widthUnits POI's native width unit (twips)
+     * @return the approximate number of pixels for a typical display
+     */
+    protected int widthToPixels(final double widthUnits) {
+        return (int) (Math.round(widthUnits * 9 / 256));
+    }
+
+    private void printCols(Map<Integer, Integer> widths) {
+        int headerColWidth = widths.get(IDX_HEADER_COL_WIDTH);
+        out.format("<col style=\"width:%dpx\"/>%n", headerColWidth);
         for (int i = firstColumn; i < endColumn; i++) {
-            out.format("<col/>%n");
+            int colWidth = widths.get(i);
+            out.format("<col style=\"width:%dpx;\"/>%n", colWidth);
         }
     }
 
@@ -462,4 +511,4 @@ public class ToHtml {
         }
         return "";
     }
-}
+}

src/examples/src/org/apache/poi/ss/examples/html/excelStyle.css

@@ -30,7 +30,7 @@
 	text-indent: 0;
 	letter-spacing: 0;
 	word-spacing: 0;
-	white-space: normal;
+	white-space: pre-wrap;
 	unicode-bidi: normal;
 	vertical-align: 0;
 	background-image: none;
@@ -40,7 +40,6 @@
 	padding: 0;
 	margin: 0;
 	border-collapse: collapse;
-	white-space: pre;
 	vertical-align: bottom;
 	font-style: normal;
 	font-family: sans-serif;
@@ -48,6 +47,9 @@
 	font-weight: normal;
 	font-size: 10pt;
 	text-align: right;
+	table-layout: fixed;
+	word-wrap: break-word;
+	overflow-wrap: break-word;
 }
 
 .excelDefaults td {