Add style customizer to report action, with excel poi implementation for columnWidths, more cell styles, merged ranges

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/reporting/ExportStreamerInterface.java

@@ -54,6 +54,14 @@ public interface ExportStreamerInterface
       // noop in base class
    }
 
+   /***************************************************************************
+    **
+    ***************************************************************************/
+   default void setExportStyleCustomizer(ExportStyleCustomizerInterface exportStyleCustomizer)
+   {
+      // noop in base class
+   }
+
    /*******************************************************************************
     ** Called once per sheet, before any rows are available.  Meant to write a
     ** header, for example.

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/reporting/ExportStyleCustomizerInterface.java

@@ -0,0 +1,35 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2025.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * 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.kingsrook.qqq.backend.core.actions.reporting;
+
+
+/*******************************************************************************
+ ** interface for classes that can be used to customize visual style aspects of
+ ** exports/reports.
+ **
+ ** Anticipates very different sub-interfaces based on the file type being generated,
+ ** and the capabilities of each.  e.g., excel (bolds, fonts, cell merging) vs
+ ** json (different structure of objects).
+ *******************************************************************************/
+public interface ExportStyleCustomizerInterface
+{
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/reporting/GenerateReportAction.java

@@ -163,6 +163,12 @@ public class GenerateReportAction extends AbstractQActionFunction<ReportInput, R
          reportStreamer = reportFormat.newReportStreamer();
       }
 
+      if(reportInput.getExportStyleCustomizer() != null)
+      {
+         ExportStyleCustomizerInterface styleCustomizer = QCodeLoader.getAdHoc(ExportStyleCustomizerInterface.class, reportInput.getExportStyleCustomizer());
+         reportStreamer.setExportStyleCustomizer(styleCustomizer);
+      }
+
       reportStreamer.preRun(reportInput.getReportDestination(), views);
 
       ////////////////////////////////////////////////////////////////////////////////////////////////
@@ -660,7 +666,7 @@ public class GenerateReportAction extends AbstractQActionFunction<ReportInput, R
          ////////////////////////////////////////////////////////////////////////////////////////////////////////////////
          // if any fields are 'showPossibleValueLabel', then move display values for them into the record's values map //
          ////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-         for(QReportField column : tableView.getColumns())
+         for(QReportField column : CollectionUtils.nonNullList(tableView.getColumns()))
          {
             if(column.getShowPossibleValueLabel())
             {

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/reporting/excel/poi/StreamedSheetWriter.java

@@ -25,7 +25,10 @@ package com.kingsrook.qqq.backend.core.actions.reporting.excel.poi;
 import java.io.IOException;
 import java.io.Writer;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
+import com.kingsrook.qqq.backend.core.model.metadata.reporting.QReportView;
+import com.kingsrook.qqq.backend.core.utils.CollectionUtils;
 import org.apache.poi.ss.util.CellReference;
 
 
@@ -53,13 +56,29 @@ public class StreamedSheetWriter
    /*******************************************************************************
     **
     *******************************************************************************/
-   public void beginSheet() throws IOException
+   public void beginSheet(QReportView view, ExcelPoiStyleCustomizerInterface styleCustomizerInterface) throws IOException
    {
       writer.write("""
          <?xml version="1.0" encoding="UTF-8"?>
-            <worksheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
+            <worksheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">""");
-               <sheetData>""");
 
+      if(styleCustomizerInterface != null && view != null)
+      {
+         List<Integer> columnWidths = styleCustomizerInterface.getColumnWidthsForView(view);
+         if(CollectionUtils.nullSafeHasContents(columnWidths))
+         {
+            writer.write("<cols>");
+            for(int i = 0; i < columnWidths.size(); i++)
+            {
+               writer.write("""
+                  <col min="%d" max="%d" width="%d" customWidth="1"/>
+                  """.formatted(i + 1, i + 1, columnWidths.get(i)));
+            }
+            writer.write("</cols>");
+         }
+      }
+
+      writer.write("<sheetData>");
    }
 
 
@@ -67,11 +86,25 @@ public class StreamedSheetWriter
    /*******************************************************************************
     **
     *******************************************************************************/
-   public void endSheet() throws IOException
+   public void endSheet(QReportView view, ExcelPoiStyleCustomizerInterface styleCustomizerInterface) throws IOException
    {
-      writer.write("""
+      writer.write("</sheetData>");
-            </sheetData>
+
-         </worksheet>""");
+      if(styleCustomizerInterface != null && view != null)
+      {
+         List<String> mergedRanges = styleCustomizerInterface.getMergedRangesForView(view);
+         if(CollectionUtils.nullSafeHasContents(mergedRanges))
+         {
+            writer.write(String.format("<mergeCells count=\"%d\">", mergedRanges.size()));
+            for(String range : mergedRanges)
+            {
+               writer.write(String.format("<mergeCell ref=\"%s\"/>", range));
+            }
+            writer.write("</mergeCells>");
+         }
+      }
+
+      writer.write("</worksheet>");
    }
 
 
@@ -151,7 +184,7 @@ public class StreamedSheetWriter
             {
                rs.append("&quot;");
             }
-            else if (c < 32 && c != '\t' && c != '\n')
+            else if(c < 32 && c != '\t' && c != '\n')
             {
                rs.append(' ');
             }

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/actions/reporting/ReportInput.java

@@ -28,6 +28,7 @@ import java.util.Map;
 import java.util.function.Supplier;
 import com.kingsrook.qqq.backend.core.actions.reporting.ExportStreamerInterface;
 import com.kingsrook.qqq.backend.core.model.actions.AbstractTableActionInput;
+import com.kingsrook.qqq.backend.core.model.metadata.code.QCodeReference;
 import com.kingsrook.qqq.backend.core.model.metadata.reporting.QReportMetaData;
 
 
@@ -44,6 +45,7 @@ public class ReportInput extends AbstractTableActionInput
    private ReportDestination reportDestination;
 
    private Supplier<? extends ExportStreamerInterface> overrideExportStreamerSupplier;
+   private QCodeReference                              exportStyleCustomizer;
 
 
 
@@ -208,4 +210,35 @@ public class ReportInput extends AbstractTableActionInput
       return (this);
    }
 
+
+
+   /*******************************************************************************
+    ** Getter for exportStyleCustomizer
+    *******************************************************************************/
+   public QCodeReference getExportStyleCustomizer()
+   {
+      return (this.exportStyleCustomizer);
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for exportStyleCustomizer
+    *******************************************************************************/
+   public void setExportStyleCustomizer(QCodeReference exportStyleCustomizer)
+   {
+      this.exportStyleCustomizer = exportStyleCustomizer;
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for exportStyleCustomizer
+    *******************************************************************************/
+   public ReportInput withExportStyleCustomizer(QCodeReference exportStyleCustomizer)
+   {
+      this.exportStyleCustomizer = exportStyleCustomizer;
+      return (this);
+   }
+
 }

qqq-backend-core/src/test/java/com/kingsrook/qqq/backend/core/actions/reporting/excel/TestExcelStyler.java

@@ -0,0 +1,76 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2025.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * 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.kingsrook.qqq.backend.core.actions.reporting.excel;
+
+
+import java.util.List;
+import java.util.Map;
+import com.kingsrook.qqq.backend.core.actions.reporting.excel.poi.ExcelPoiStyleCustomizerInterface;
+import com.kingsrook.qqq.backend.core.model.metadata.reporting.QReportView;
+import org.apache.poi.ss.usermodel.CreationHelper;
+import org.apache.poi.ss.usermodel.Font;
+import org.apache.poi.xssf.usermodel.XSSFCellStyle;
+import org.apache.poi.xssf.usermodel.XSSFWorkbook;
+
+
+/*******************************************************************************
+ **
+ *******************************************************************************/
+public class TestExcelStyler implements ExcelPoiStyleCustomizerInterface
+{
+
+   /***************************************************************************
+    **
+    ***************************************************************************/
+   @Override
+   public List<Integer> getColumnWidthsForView(QReportView view)
+   {
+      return List.of(60, 50, 40);
+   }
+
+
+
+   /***************************************************************************
+    **
+    ***************************************************************************/
+   @Override
+   public List<String> getMergedRangesForView(QReportView view)
+   {
+      return List.of("A1:B1");
+   }
+
+
+
+   /***************************************************************************
+    **
+    ***************************************************************************/
+   @Override
+   public void customizeStyles(Map<String, XSSFCellStyle> styles, XSSFWorkbook workbook, CreationHelper createHelper)
+   {
+      Font font = workbook.createFont();
+      font.setFontHeightInPoints((short) 16);
+      font.setBold(true);
+      XSSFCellStyle cellStyle = workbook.createCellStyle();
+      cellStyle.setFont(font);
+      styles.put("header", cellStyle);
+   }
+}