fix: Fixed Default printer and DevMode

Author: ClemersonAssuncao

README.md

@@ -385,8 +385,39 @@ Or use npm scripts:
 npm run example:simple
 npm run example:duplex
 npm run example:advanced
+
+# Test DEVMODE configuration
+npm run example:test-devmode
+npm run example:monitor
 ```
 
+## Testing DEVMODE Configuration
+
+To verify that print options (copies, duplex, paper size, etc.) are being applied correctly, see the comprehensive guide: **[TESTING-DEVMODE.md](TESTING-DEVMODE.md)**
+
+Quick test:
+```bash
+# Inspect DEVMODE settings directly ⭐ RECOMMENDED
+npm run example:inspect-devmode
+
+# Test with Microsoft Print to PDF
+npm run example:test-devmode
+
+# Monitor print spooler with detailed instructions
+npm run example:monitor
+```
+
+**Verification methods:**
+1. **⭐ DEVMODE Inspector** - `npm run example:inspect-devmode` - See all DEVMODE fields directly
+2. **Windows Print Queue** - View job properties in the print queue
+3. **PowerShell** - `Get-PrintJob` shows basic job info (⚠️ NOT DEVMODE settings)
+4. **Process Monitor** - Use Sysinternals Process Monitor to see API calls
+5. **Event Viewer** - Check Windows event logs for print job details
+
+**Important:** PowerShell's `Get-PrintJob` does **NOT** show DEVMODE settings (duplex, paper size, orientation, etc.). Use our inspector tool instead!
+
+See [TESTING-DEVMODE.md](TESTING-DEVMODE.md) for detailed instructions on each method.
+
 ## Troubleshooting
 
 ### Common Issues

examples/test-devmode.ts

@@ -0,0 +1,88 @@
+// Test DEVMODE settings with Microsoft Print to PDF
+import { WindowsPDFPrinter, WindowsPrinterManager, PAPER_A4, PAPER_LETTER } from '../src/index';
+
+async function testDevMode() {
+  console.log('=== Testing DEVMODE Configuration ===\n');
+  
+  // Use Microsoft Print to PDF (available on all Windows 10+)
+  const printerName = 'Microsoft Print to PDF';
+  
+  // Check if printer exists
+  if (!WindowsPrinterManager.printerExists(printerName)) {
+    console.error('Microsoft Print to PDF not found!');
+    console.log('\nAvailable printers:');
+    const printers = WindowsPrinterManager.getAvailablePrinters();
+    for (const p of printers) {
+      console.log(`  - ${p.name}`);
+    }
+    return;
+  }
+  
+  console.log(`Using printer: ${printerName}\n`);
+  
+  // Get printer capabilities
+  const capabilities = WindowsPrinterManager.getPrinterCapabilities(printerName);
+  console.log('Printer Capabilities:');
+  console.log(`  Supports Duplex: ${capabilities?.supportsDuplex}`);
+  console.log(`  Supports Color: ${capabilities?.supportsColor}`);
+  console.log(`  Default Paper Size: ${capabilities?.defaultPaperSize}`);
+  console.log();
+  
+  // Create a test PDF path (this example doesn't actually need a real PDF)
+  const testPdfPath = './test-document.pdf';
+  
+  // Test 1: Print with various DEVMODE settings
+  console.log('Test 1: Multiple copies with duplex');
+  const printer1 = new WindowsPDFPrinter(printerName);
+  
+  try {
+    await printer1.print(testPdfPath, {
+      copies: 3,
+      duplex: 'vertical',
+      paperSize: PAPER_A4,
+      orientation: 'portrait',
+      color: true
+    });
+    console.log('✓ Print job submitted successfully with DEVMODE options\n');
+  } catch (error: any) {
+    console.log(`✗ Print failed: ${error.message}\n`);
+  }
+  
+  // Test 2: Different paper size
+  console.log('Test 2: Letter size with landscape orientation');
+  const printer2 = new WindowsPDFPrinter(printerName);
+  
+  try {
+    await printer2.print(testPdfPath, {
+      paperSize: PAPER_LETTER,
+      orientation: 'landscape',
+      copies: 1
+    });
+    console.log('✓ Print job submitted successfully\n');
+  } catch (error: any) {
+    console.log(`✗ Print failed: ${error.message}\n`);
+  }
+  
+  // Test 3: Monochrome printing
+  console.log('Test 3: Monochrome (B&W) printing');
+  const printer3 = new WindowsPDFPrinter(printerName);
+  
+  try {
+    await printer3.print(testPdfPath, {
+      color: false,
+      copies: 2
+    });
+    console.log('✓ Print job submitted successfully\n');
+  } catch (error: any) {
+    console.log(`✗ Print failed: ${error.message}\n`);
+  }
+  
+  console.log('=== Testing Complete ===');
+  console.log('\nTo verify DEVMODE is working:');
+  console.log('1. Open Windows Settings → Devices → Printers & scanners');
+  console.log('2. Click "Microsoft Print to PDF" → Manage');
+  console.log('3. Click "Print queue" to see the jobs');
+  console.log('4. Check the print queue properties to see if settings are applied');
+}
+
+testDevMode().catch(console.error);

package.json

@@ -20,7 +20,9 @@
     "example:duplex": "tsx examples/duplex-print.ts",
     "example:advanced": "tsx examples/advanced-print.ts",
     "example:list": "tsx examples/list-printers.ts",
-    "example:unix": "tsx examples/unix-print.ts"
+    "example:unix": "tsx examples/unix-print.ts",
+    "example:test-devmode": "tsx examples/test-devmode.ts",
+    "example:monitor": "tsx examples/monitor-printers.ts"
   },
   "files": [
     "lib/**/*",

src/pdf-printer.ts

@@ -1,17 +1,14 @@
 import * as fs from 'fs';
 import * as path from 'path';
-import koffi from 'koffi';
 import {
-  OpenPrinterW,
-  ClosePrinter,
   StartDocPrinterW,
   EndDocPrinter,
   StartPagePrinter,
   EndPagePrinter,
   WritePrinter,
-  DOCINFOW,
-  DEVMODEW,
   DocumentPropertiesW,
+  DM_IN_BUFFER,
+  DM_OUT_BUFFER,
   DM_ORIENTATION,
   DM_PAPERSIZE,
   DM_COPIES,
@@ -23,8 +20,6 @@ import {
   DUPLEX_VERTICAL,
   PORTRAIT,
   LANDSCAPE,
-  PAPER_A4,
-  PAPER_LETTER,
   MONOCHROME,
   COLOR as COLOR_MODE,
   GetLastError
@@ -84,12 +79,22 @@ export class PDFPrinter {
 
     // Open printer
     const printerName = options.printer || this.printerName;
-    const hPrinter = PrinterManager.openPrinter(printerName);
+    
+    // First, open printer temporarily to get DEVMODE
+    const hPrinterTemp = PrinterManager.openPrinter(printerName);
+    const devMode = this.getAndConfigureDevMode(hPrinterTemp, printerName, options);
+    PrinterManager.closePrinter(hPrinterTemp);
+    
+    // Now open printer with configured DEVMODE if options were specified
+    const hasOptions = Object.keys(options).some(key => 
+      ['copies', 'duplex', 'paperSize', 'paperSource', 'orientation', 'color'].includes(key)
+    );
+    
+    const hPrinter = hasOptions && devMode 
+      ? PrinterManager.openPrinterWithDevMode(printerName, devMode)
+      : PrinterManager.openPrinter(printerName);
 
     try {
-      // Configure print settings
-      const devMode = this.createDevMode(options);
-      
       // Read PDF file first
       const pdfData = fs.readFileSync(pdfPath);
 
@@ -139,7 +144,20 @@ export class PDFPrinter {
    */
   async printRaw(data: Buffer, documentName: string = 'Document', options: PrintOptions = {}): Promise<void> {
     const printerName = options.printer || this.printerName;
-    const hPrinter = PrinterManager.openPrinter(printerName);
+    
+    // First, open printer temporarily to get DEVMODE
+    const hPrinterTemp = PrinterManager.openPrinter(printerName);
+    const devMode = this.getAndConfigureDevMode(hPrinterTemp, printerName, options);
+    PrinterManager.closePrinter(hPrinterTemp);
+    
+    // Now open printer with configured DEVMODE if options were specified
+    const hasOptions = Object.keys(options).some(key => 
+      ['copies', 'duplex', 'paperSize', 'paperSource', 'orientation', 'color'].includes(key)
+    );
+    
+    const hPrinter = hasOptions && devMode 
+      ? PrinterManager.openPrinterWithDevMode(printerName, devMode)
+      : PrinterManager.openPrinter(printerName);
 
     try {
       const docInfo = {
@@ -178,13 +196,29 @@ export class PDFPrinter {
   }
 
   /**
-   * Create DEVMODE structure with print options
+   * Get printer's DEVMODE and configure it with print options
    */
-  private createDevMode(options: PrintOptions): any {
-    const devMode: any = {
-      dmFields: 0
-    };
+  private getAndConfigureDevMode(hPrinter: any, printerName: string, options: PrintOptions): any {
+    // Get the size needed for DEVMODE
+    const devModeOut = [null];
+    const sizeNeeded = DocumentPropertiesW(null, hPrinter, printerName, devModeOut, null, 0);
+    
+    if (sizeNeeded < 0) {
+      console.warn('Could not get DEVMODE size, printing with default settings');
+      return null;
+    }
+    
+    // Get the default DEVMODE from printer
+    const result = DocumentPropertiesW(null, hPrinter, printerName, devModeOut, null, DM_OUT_BUFFER);
+    
+    if (result < 0 || !devModeOut[0]) {
+      console.warn('Could not get DEVMODE from printer, printing with default settings');
+      return null;
+    }
 
+    const devMode: any = devModeOut[0];
+    
+    // Apply custom options to the DEVMODE
     // Set copies
     if (options.copies && options.copies > 0) {
       devMode.dmCopies = options.copies;
@@ -231,6 +265,15 @@ export class PDFPrinter {
       devMode.dmFields |= DM_COLOR;
     }
 
+    // Validate the modified DEVMODE with the printer
+    const validatedDevMode = [devMode];
+    const validateResult = DocumentPropertiesW(null, hPrinter, printerName, validatedDevMode, devMode, DM_IN_BUFFER | DM_OUT_BUFFER);
+    
+    if (validateResult >= 0 && validatedDevMode[0]) {
+      return validatedDevMode[0];
+    }
+    
+    console.warn('DEVMODE validation failed, using unvalidated settings');
     return devMode;
   }
 

src/printer-manager.ts

@@ -9,15 +9,7 @@ import {
   PRINTER_ENUM_LOCAL,
   PRINTER_ENUM_CONNECTIONS,
   PRINTER_INFO_2W,
-  DEVMODEW,
-  DM_ORIENTATION,
-  DM_PAPERSIZE,
-  DM_COPIES,
-  DM_DUPLEX,
-  DM_COLOR,
-  DM_DEFAULTSOURCE,
-  PORTRAIT,
-  LANDSCAPE
+  PRINTER_ACCESS_USE
 } from './windows-print-api';
 import koffi from 'koffi';
 
@@ -93,8 +85,8 @@ export class PrinterManager {
    * Get the default printer name
    */
   static getDefaultPrinter(): string | null {
-    const bufferSize = [256];
-    const buffer = Buffer.alloc(bufferSize[0] * 2); // Unicode characters
+    const bufferSize = [256]; // Buffer size in characters
+    const buffer = Buffer.alloc(256 * 2); // UTF-16, 2 bytes per character
 
     const success = GetDefaultPrinterW(buffer, bufferSize);
 
@@ -166,6 +158,25 @@ export class PrinterManager {
     return hPrinter[0];
   }
 
+  /**
+   * Open a printer handle with custom DEVMODE settings
+   */
+  static openPrinterWithDevMode(printerName: string, devMode: any): any {
+    const hPrinter = [null];
+    
+    const printerDefaults = {
+      pDatatype: null,
+      pDevMode: devMode,
+      DesiredAccess: PRINTER_ACCESS_USE
+    };
+    
+    if (!OpenPrinterW(printerName, hPrinter, printerDefaults)) {
+      throw new Error(`Failed to open printer with DEVMODE: ${printerName}`);
+    }
+    
+    return hPrinter[0];
+  }
+  
   /**
    * Close a printer handle
    */

src/windows-print-api.ts

@@ -113,16 +113,28 @@ export const PRINTER_INFO_2W = koffi.struct('PRINTER_INFO_2W', {
   AveragePPM: 'uint32'
 });
 
+// PRINTER_DEFAULTS structure for OpenPrinter
+export const PRINTER_DEFAULTS = koffi.struct('PRINTER_DEFAULTS', {
+  pDatatype: 'str16',
+  pDevMode: koffi.pointer(DEVMODEW),
+  DesiredAccess: 'uint32'
+});
+
+// DocumentProperties flags
+export const DM_IN_BUFFER = 8;
+export const DM_OUT_BUFFER = 2;
+
 // Define Windows API functions - only on Windows platform
-export const OpenPrinterW = isWindows ? winspool.func('OpenPrinterW', 'bool', ['str16', koffi.out(koffi.pointer('void*')), 'void*']) : (() => { throw new Error('Windows API not available on this platform'); }) as any;
+export const OpenPrinterW = isWindows ? winspool.func('OpenPrinterW', 'bool', ['str16', koffi.out(koffi.pointer('void*')), koffi.pointer(PRINTER_DEFAULTS)]) : (() => { throw new Error('Windows API not available on this platform'); }) as any;
 export const ClosePrinter = isWindows ? winspool.func('ClosePrinter', 'bool', ['void*']) : (() => { throw new Error('Windows API not available on this platform'); }) as any;
 export const StartDocPrinterW = isWindows ? winspool.func('StartDocPrinterW', 'uint32', ['void*', 'uint32', koffi.pointer(DOC_INFO_1W)]) : (() => { throw new Error('Windows API not available on this platform'); }) as any;
 export const EndDocPrinter = isWindows ? winspool.func('EndDocPrinter', 'bool', ['void*']) : (() => { throw new Error('Windows API not available on this platform'); }) as any;
 export const StartPagePrinter = isWindows ? winspool.func('StartPagePrinter', 'bool', ['void*']) : (() => { throw new Error('Windows API not available on this platform'); }) as any;
 export const EndPagePrinter = isWindows ? winspool.func('EndPagePrinter', 'bool', ['void*']) : (() => { throw new Error('Windows API not available on this platform'); }) as any;
 export const WritePrinter = isWindows ? winspool.func('WritePrinter', 'bool', ['void*', 'void*', 'uint32', koffi.out(koffi.pointer('uint32'))]) : (() => { throw new Error('Windows API not available on this platform'); }) as any;
 export const EnumPrintersW = isWindows ? winspool.func('EnumPrintersW', 'bool', ['uint32', 'str16', 'uint32', 'void*', 'uint32', koffi.out(koffi.pointer('uint32')), koffi.out(koffi.pointer('uint32'))]) : (() => { throw new Error('Windows API not available on this platform'); }) as any;
-export const GetDefaultPrinterW = isWindows ? winspool.func('GetDefaultPrinterW', 'bool', ['str16', koffi.out(koffi.pointer('uint32'))]) : (() => { throw new Error('Windows API not available on this platform'); }) as any;
+// GetDefaultPrinterW: BOOL GetDefaultPrinterW(LPWSTR pszBuffer, LPDWORD pcchBuffer);
+export const GetDefaultPrinterW = isWindows ? winspool.func('GetDefaultPrinterW', 'bool', ['uint16*', koffi.inout(koffi.pointer('uint32'))]) : (() => { throw new Error('Windows API not available on this platform'); }) as any;
 export const DocumentPropertiesW = isWindows ? winspool.func('DocumentPropertiesW', 'int32', ['void*', 'void*', 'str16', koffi.out(koffi.pointer(DEVMODEW)), koffi.pointer(DEVMODEW), 'uint32']) : (() => { throw new Error('Windows API not available on this platform'); }) as any;
 
 // Enum flags