Add undo/redo functionality and refactor signature settings UI

- Introduced HistoryAPIBridge for managing undo/redo actions.
- Updated SignSettings component to include undo/redo buttons.
- Refactored signature type selection to use Tabs for better UI.
- Enhanced SignatureAPIBridge to store image data for annotations.
- Integrated history management into SignatureContext for state handling.

frontend/src/components/tools/sign/SignSettings.tsx

@@ -1,6 +1,6 @@
 import React, { useRef, useState } from 'react';
 import { useTranslation } from "react-i18next";
-import { Stack, TextInput, FileInput, Paper, Group, Button, Text, Alert, Modal, ColorSwatch, Menu, ActionIcon, Slider, Select, Combobox, useCombobox, ColorPicker } from '@mantine/core';
+import { Stack, TextInput, FileInput, Paper, Group, Button, Text, Alert, Modal, ColorSwatch, Menu, ActionIcon, Slider, Select, Combobox, useCombobox, ColorPicker, Tabs } from '@mantine/core';
 import ButtonSelector from "../../shared/ButtonSelector";
 import { SignParameters } from "../../../hooks/tools/sign/useSignParameters";
 
@@ -12,9 +12,11 @@ interface SignSettingsProps {
   onActivateSignaturePlacement?: () => void;
   onDeactivateSignature?: () => void;
   onUpdateDrawSettings?: (color: string, size: number) => void;
+  onUndo?: () => void;
+  onRedo?: () => void;
 }
 
-const SignSettings = ({ parameters, onParameterChange, disabled = false, onActivateDrawMode, onActivateSignaturePlacement, onDeactivateSignature, onUpdateDrawSettings }: SignSettingsProps) => {
+const SignSettings = ({ parameters, onParameterChange, disabled = false, onActivateDrawMode, onActivateSignaturePlacement, onDeactivateSignature, onUpdateDrawSettings, onUndo, onRedo }: SignSettingsProps) => {
   const { t } = useTranslation();
   const canvasRef = useRef<HTMLCanvasElement>(null);
   const [isDrawing, setIsDrawing] = useState(false);
@@ -432,35 +434,43 @@ const SignSettings = ({ parameters, onParameterChange, disabled = false, onActiv
   return (
     <Stack gap="md">
       {/* Signature Type Selection */}
-      <div>
-        <Text size="sm" fw={500} mb="xs">
-          {t('sign.type.title', 'Signature Type')}
-        </Text>
-        <ButtonSelector
-          value={parameters.signatureType}
-          onChange={(value) => onParameterChange('signatureType', value as 'image' | 'text' | 'draw' | 'canvas')}
-          options={[
-            {
-              value: 'draw',
-              label: t('sign.type.draw', 'Draw'),
-            },
-            {
-              value: 'canvas',
-              label: t('sign.type.canvas', 'Canvas'),
-            },
-            {
-              value: 'image',
-              label: t('sign.type.image', 'Image'),
-            },
-            {
-              value: 'text',
-              label: t('sign.type.text', 'Text'),
-            },
-          ]}
-          disabled={disabled}
-        />
-      </div>
+      <Tabs
+        value={parameters.signatureType}
+        onChange={(value) => onParameterChange('signatureType', value as 'image' | 'text' | 'draw' | 'canvas')}
+      >
+        <Tabs.List grow>
+          <Tabs.Tab value="draw" style={{ fontSize: '0.8rem' }}>
+            {t('sign.type.draw', 'Draw')}
+          </Tabs.Tab>
+          <Tabs.Tab value="canvas" style={{ fontSize: '0.8rem' }}>
+            {t('sign.type.canvas', 'Canvas')}
+          </Tabs.Tab>
+          <Tabs.Tab value="image" style={{ fontSize: '0.8rem' }}>
+            {t('sign.type.image', 'Image')}
+          </Tabs.Tab>
+          <Tabs.Tab value="text" style={{ fontSize: '0.8rem' }}>
+            {t('sign.type.text', 'Text')}
+          </Tabs.Tab>
+        </Tabs.List>
+      </Tabs>
 
+      {/* Undo/Redo Controls */}
+      <Group justify="space-between" grow>
+        <Button
+          variant="outline"
+          onClick={onUndo}
+          disabled={disabled}
+        >
+          {t('sign.undo', 'Undo')}
+        </Button>
+        <Button
+          variant="outline"
+          onClick={onRedo}
+          disabled={disabled}
+        >
+          {t('sign.redo', 'Redo')}
+        </Button>
+      </Group>
 
       {/* Signature Creation based on type */}
       {parameters.signatureType === 'canvas' && (
@@ -782,9 +792,9 @@ const SignSettings = ({ parameters, onParameterChange, disabled = false, onActiv
       {(parameters.signatureType === 'canvas' || parameters.signatureType === 'image' || parameters.signatureType === 'text') && (
         <Alert color="blue" title={t('sign.instructions.title', 'How to add signature')}>
           <Text size="sm">
-            {parameters.signatureType === 'canvas' && 'Draw your signature in the canvas above. Placement mode will activate automatically when you finish drawing.'}
-            {parameters.signatureType === 'image' && 'Upload your signature image above. Placement mode will activate automatically when the image is loaded.'}
-            {parameters.signatureType === 'text' && 'Enter your name above. Placement mode will activate automatically when you type your name.'}
+            {parameters.signatureType === 'canvas' && 'After drawing your signature in the canvas above, click anywhere on the PDF to place it.'}
+            {parameters.signatureType === 'image' && 'After uploading your signature image above, click anywhere on the PDF to place it.'}
+            {parameters.signatureType === 'text' && 'After entering your name above, click anywhere on the PDF to place your signature.'}
           </Text>
         </Alert>
       )}

frontend/src/components/viewer/EmbedPdfViewer.tsx

@@ -40,7 +40,7 @@ const EmbedPdfViewerContent = ({
   const isSignatureMode = selectedTool === 'sign';
 
   // Get signature context
-  const { signatureApiRef } = useSignature();
+  const { signatureApiRef, historyApiRef } = useSignature();
 
 
   // Get current file from FileContext
@@ -189,8 +189,17 @@ const EmbedPdfViewerContent = ({
               url={effectiveFile.url}
               enableSignature={isSignatureMode}
               signatureApiRef={signatureApiRef as React.RefObject<any>}
+              historyApiRef={historyApiRef as React.RefObject<any>}
               onSignatureAdded={(annotation) => {
                 console.log('Signature added:', annotation);
+                if (annotation.type === 13) {
+                  console.log('- imageSrc:', !!annotation.imageSrc, annotation.imageSrc?.length);
+                  console.log('- contents:', !!annotation.contents, annotation.contents?.length);
+                  console.log('- data:', !!annotation.data, annotation.data?.length);
+                  console.log('- imageData:', !!annotation.imageData, annotation.imageData?.length);
+                  console.log('- appearance:', !!annotation.appearance, typeof annotation.appearance);
+                  console.log('- All keys:', Object.keys(annotation));
+                }
                 // Future: Handle signature completion
               }}
             />

frontend/src/components/viewer/HistoryAPIBridge.tsx

@@ -0,0 +1,86 @@
+import React, { useImperativeHandle, forwardRef, useEffect } from 'react';
+import { useHistoryCapability } from '@embedpdf/plugin-history/react';
+import { useAnnotationCapability } from '@embedpdf/plugin-annotation/react';
+import { useSignature } from '../../contexts/SignatureContext';
+
+export interface HistoryAPI {
+  undo: () => void;
+  redo: () => void;
+  canUndo: () => boolean;
+  canRedo: () => boolean;
+}
+
+export interface HistoryAPIBridgeProps {}
+
+export const HistoryAPIBridge = forwardRef<HistoryAPI, HistoryAPIBridgeProps>((props, ref) => {
+  const { provides: historyApi } = useHistoryCapability();
+  const { provides: annotationApi } = useAnnotationCapability();
+  const { getImageData } = useSignature();
+
+
+  useImperativeHandle(ref, () => ({
+    undo: () => {
+      if (historyApi) {
+        historyApi.undo();
+
+        // Restore image data for STAMP annotations after undo
+        setTimeout(() => {
+          if (!annotationApi) return;
+
+          for (let pageIndex = 0; pageIndex < 10; pageIndex++) {
+            const pageAnnotationsTask = annotationApi.getPageAnnotations?.({ pageIndex });
+            if (pageAnnotationsTask) {
+              pageAnnotationsTask.toPromise().then((pageAnnotations: any) => {
+                if (pageAnnotations) {
+                  pageAnnotations.forEach((ann: any) => {
+                    if (ann.type === 13) {
+                      const storedImageData = getImageData(ann.id);
+
+                      if (storedImageData && (!ann.imageSrc || ann.imageSrc !== storedImageData)) {
+                        const originalData = {
+                          type: ann.type,
+                          rect: ann.rect,
+                          author: ann.author || 'Digital Signature',
+                          subject: ann.subject || 'Digital Signature',
+                          pageIndex: pageIndex,
+                          id: ann.id,
+                          created: ann.created || new Date(),
+                          imageSrc: storedImageData
+                        };
+
+                        annotationApi.deleteAnnotation(pageIndex, ann.id);
+                        setTimeout(() => {
+                          annotationApi.createAnnotation(pageIndex, originalData);
+                        }, 50);
+                      }
+                    }
+                  });
+                }
+              }).catch((error: any) => {
+                console.error(`Failed to get annotations for page ${pageIndex}:`, error);
+              });
+            }
+          }
+        }, 200);
+      }
+    },
+
+    redo: () => {
+      if (historyApi) {
+        historyApi.redo();
+      }
+    },
+
+    canUndo: () => {
+      return historyApi ? historyApi.canUndo() : false;
+    },
+
+    canRedo: () => {
+      return historyApi ? historyApi.canRedo() : false;
+    },
+  }), [historyApi]);
+
+  return null; // This is a bridge component with no UI
+});
+
+HistoryAPIBridge.displayName = 'HistoryAPIBridge';

frontend/src/components/viewer/LocalEmbedPDF.tsx

@@ -35,6 +35,7 @@ import { SearchAPIBridge } from './SearchAPIBridge';
 import { ThumbnailAPIBridge } from './ThumbnailAPIBridge';
 import { RotateAPIBridge } from './RotateAPIBridge';
 import { SignatureAPIBridge, SignatureAPI } from './SignatureAPIBridge';
+import { HistoryAPIBridge, HistoryAPI } from './HistoryAPIBridge';
 
 interface LocalEmbedPDFProps {
   file?: File | Blob;
@@ -42,9 +43,10 @@ interface LocalEmbedPDFProps {
   enableSignature?: boolean;
   onSignatureAdded?: (annotation: any) => void;
   signatureApiRef?: React.RefObject<SignatureAPI>;
+  historyApiRef?: React.RefObject<HistoryAPI>;
 }
 
-export function LocalEmbedPDF({ file, url, enableSignature = false, onSignatureAdded, signatureApiRef }: LocalEmbedPDFProps) {
+export function LocalEmbedPDF({ file, url, enableSignature = false, onSignatureAdded, signatureApiRef, historyApiRef }: LocalEmbedPDFProps) {
   const [pdfUrl, setPdfUrl] = useState<string | null>(null);
   const [annotations, setAnnotations] = useState<Array<{id: string, pageIndex: number, rect: any}>>([]);
 
@@ -257,6 +259,7 @@ export function LocalEmbedPDF({ file, url, enableSignature = false, onSignatureA
         <ThumbnailAPIBridge />
         <RotateAPIBridge />
         {enableSignature && <SignatureAPIBridge ref={signatureApiRef} />}
+        {enableSignature && <HistoryAPIBridge ref={historyApiRef} />}
         <GlobalPointerProvider>
           <Viewport
             style={{

frontend/src/components/viewer/SignatureAPIBridge.tsx

@@ -20,7 +20,8 @@ export interface SignatureAPIBridgeProps {}
 
 export const SignatureAPIBridge = forwardRef<SignatureAPI, SignatureAPIBridgeProps>((props, ref) => {
   const { provides: annotationApi } = useAnnotationCapability();
-  const { signatureConfig } = useSignature();
+  const { signatureConfig, storeImageData } = useSignature();
+
 
   // Enable keyboard deletion of selected annotations
   useEffect(() => {
@@ -31,13 +32,30 @@ export const SignatureAPIBridge = forwardRef<SignatureAPI, SignatureAPIBridgePro
         const selectedAnnotation = annotationApi.getSelectedAnnotation?.();
 
         if (selectedAnnotation) {
-          const annotation = selectedAnnotation as any;
-          const pageIndex = annotation.object?.pageIndex || 0;
-          const id = annotation.object?.id;
+          // First, let EmbedPDF try to handle this natively
+          // Only intervene if needed
+          setTimeout(() => {
+            // Check if the annotation is still selected after a brief delay
+            // If EmbedPDF handled it natively, it should be gone
+            const stillSelected = annotationApi.getSelectedAnnotation?.();
 
-          if (id) {
-            annotationApi.deleteAnnotation(pageIndex, id);
-          }
+            if (stillSelected) {
+              // EmbedPDF didn't handle it, so we need to delete manually
+              const annotation = stillSelected as any;
+              const pageIndex = annotation.object?.pageIndex || 0;
+              const id = annotation.object?.id;
+
+              if (id) {
+                // Try deleteSelected method first (should integrate with history)
+                if ((annotationApi as any).deleteSelected) {
+                  (annotationApi as any).deleteSelected();
+                } else {
+                  // Fallback to direct deletion
+                  annotationApi.deleteAnnotation(pageIndex, id);
+                }
+              }
+            }
+          }, 10);
         }
       }
     };
@@ -50,7 +68,14 @@ export const SignatureAPIBridge = forwardRef<SignatureAPI, SignatureAPIBridgePro
     addImageSignature: (signatureData: string, x: number, y: number, width: number, height: number, pageIndex: number) => {
       if (!annotationApi) return;
 
-      // Create image stamp annotation
+      // Create image stamp annotation with proper image data
+      console.log('Creating image annotation with data length:', signatureData?.length);
+
+      const annotationId = uuidV4();
+
+      // Store image data in our persistent store
+      storeImageData(annotationId, signatureData);
+
       annotationApi.createAnnotation(pageIndex, {
         type: PdfAnnotationSubtype.STAMP,
         rect: {
@@ -60,8 +85,14 @@ export const SignatureAPIBridge = forwardRef<SignatureAPI, SignatureAPIBridgePro
         author: 'Digital Signature',
         subject: 'Digital Signature',
         pageIndex: pageIndex,
-        id: uuidV4(),
+        id: annotationId,
         created: new Date(),
+        // Store image data in multiple places to ensure history captures it
+        imageSrc: signatureData,
+        contents: signatureData, // Some annotation systems use contents
+        data: signatureData, // Try data field
+        imageData: signatureData, // Try imageData field
+        appearance: signatureData // Try appearance field
       });
     },
 
@@ -86,6 +117,10 @@ export const SignatureAPIBridge = forwardRef<SignatureAPI, SignatureAPIBridgePro
         pageIndex: pageIndex,
         id: uuidV4(),
         created: new Date(),
+        customData: {
+          signatureText: text,
+          signatureType: 'text'
+        }
       });
     },
 
@@ -235,6 +270,11 @@ export const SignatureAPIBridge = forwardRef<SignatureAPI, SignatureAPIBridgePro
       switch (params.signatureType) {
         case 'image':
           if (params.signatureData) {
+            const annotationId = uuidV4();
+
+            // Store image data in our persistent store
+            storeImageData(annotationId, params.signatureData);
+
             annotationApi.createAnnotation(page, {
               type: PdfAnnotationSubtype.STAMP,
               rect: {
@@ -244,8 +284,14 @@ export const SignatureAPIBridge = forwardRef<SignatureAPI, SignatureAPIBridgePro
               author: 'Digital Signature',
               subject: `Digital Signature - ${params.reason || 'Document signing'}`,
               pageIndex: page,
-              id: uuidV4(),
+              id: annotationId,
               created: new Date(),
+              // Store image data in multiple places to ensure history captures it
+              imageSrc: params.signatureData,
+              contents: params.signatureData, // Some annotation systems use contents
+              data: params.signatureData, // Try data field
+              imageData: params.signatureData, // Try imageData field
+              appearance: params.signatureData // Try appearance field
             });
 
             // Switch to select mode after placing signature so it can be easily deleted
@@ -274,6 +320,10 @@ export const SignatureAPIBridge = forwardRef<SignatureAPI, SignatureAPIBridgePro
               pageIndex: page,
               id: uuidV4(),
               created: new Date(),
+              customData: {
+                signatureText: params.signerName,
+                signatureType: 'text'
+              }
             });
 
             // Switch to select mode after placing signature so it can be easily deleted

frontend/src/contexts/SignatureContext.tsx

@@ -1,6 +1,7 @@
 import React, { createContext, useContext, useState, ReactNode, useCallback, useRef, useEffect } from 'react';
 import { SignParameters } from '../hooks/tools/sign/useSignParameters';
 import { SignatureAPI } from '../components/viewer/SignatureAPIBridge';
+import { HistoryAPI } from '../components/viewer/HistoryAPIBridge';
 
 // Signature state interface
 interface SignatureState {
@@ -19,11 +20,16 @@ interface SignatureActions {
   activateSignaturePlacementMode: () => void;
   activateDeleteMode: () => void;
   updateDrawSettings: (color: string, size: number) => void;
+  undo: () => void;
+  redo: () => void;
+  storeImageData: (id: string, data: string) => void;
+  getImageData: (id: string) => string | undefined;
 }
 
 // Combined context interface
 interface SignatureContextValue extends SignatureState, SignatureActions {
   signatureApiRef: React.RefObject<SignatureAPI | null>;
+  historyApiRef: React.RefObject<HistoryAPI | null>;
 }
 
 // Create context
@@ -39,6 +45,8 @@ const initialState: SignatureState = {
 export const SignatureProvider: React.FC<{ children: ReactNode }> = ({ children }) => {
   const [state, setState] = useState<SignatureState>(initialState);
   const signatureApiRef = useRef<SignatureAPI>(null);
+  const historyApiRef = useRef<HistoryAPI>(null);
+  const imageDataStore = useRef<Map<string, string>>(new Map());
 
   // Actions
   const setSignatureConfig = useCallback((config: SignParameters | null) => {
@@ -100,12 +108,36 @@ export const SignatureProvider: React.FC<{ children: ReactNode }> = ({ children
     }
   }, []);
 
+  const undo = useCallback(() => {
+    if (historyApiRef.current) {
+      historyApiRef.current.undo();
+    }
+  }, []);
+
+  const redo = useCallback(() => {
+    if (historyApiRef.current) {
+      historyApiRef.current.redo();
+    }
+  }, []);
+
+  const storeImageData = useCallback((id: string, data: string) => {
+    console.log('Storing image data for annotation:', id, data.length, 'chars');
+    imageDataStore.current.set(id, data);
+  }, []);
+
+  const getImageData = useCallback((id: string) => {
+    const data = imageDataStore.current.get(id);
+    console.log('Retrieving image data for annotation:', id, data?.length, 'chars');
+    return data;
+  }, []);
+
 
   // No auto-activation - all modes use manual buttons
 
   const contextValue: SignatureContextValue = {
     ...state,
     signatureApiRef,
+    historyApiRef,
     setSignatureConfig,
     setPlacementMode,
     activateDrawMode,
@@ -113,6 +145,10 @@ export const SignatureProvider: React.FC<{ children: ReactNode }> = ({ children
     activateSignaturePlacementMode,
     activateDeleteMode,
     updateDrawSettings,
+    undo,
+    redo,
+    storeImageData,
+    getImageData,
   };
 
   return (

frontend/src/tools/Sign.tsx

@@ -12,7 +12,7 @@ import { useSignature } from "../contexts/SignatureContext";
 const Sign = (props: BaseToolProps) => {
   const { t } = useTranslation();
   const { setWorkbench } = useNavigation();
-  const { setSignatureConfig, activateDrawMode, activateSignaturePlacementMode, deactivateDrawMode, updateDrawSettings } = useSignature();
+  const { setSignatureConfig, activateDrawMode, activateSignaturePlacementMode, deactivateDrawMode, updateDrawSettings, undo, redo } = useSignature();
 
   // Manual sync function
   const syncSignatureConfig = () => {
@@ -65,6 +65,8 @@ const Sign = (props: BaseToolProps) => {
             onActivateSignaturePlacement={handleSignaturePlacement}
             onDeactivateSignature={deactivateDrawMode}
             onUpdateDrawSettings={updateDrawSettings}
+            onUndo={undo}
+            onRedo={redo}
           />
         ),
       });