feat: implement backend and frontend support for PDF text overlays and annotations

engine/src/parser/pdfium_edit_annotations.cpp

@@ -129,6 +129,7 @@ std::expected<void, EngineError> PdfiumDocument::applyOp_decoration(const nlohma
                 int subtype = FPDF_ANNOT_UNDERLINE;
                 if (type == "strikeout") subtype = FPDF_ANNOT_STRIKEOUT;
                 else if (type == "squiggly") subtype = FPDF_ANNOT_SQUIGGLY;
+                else if (type == "highlight") subtype = FPDF_ANNOT_HIGHLIGHT;
 
                 FPDF_ANNOTATION annot = FPDFPage_CreateAnnot(page, subtype);
                 if (!annot) {

frontend/src/App.tsx

@@ -270,7 +270,7 @@ function App() {
     if (!can('canAnnotate')) { denyToast('Text decorations'); return; }
     const quadPointsBackend = lines.map((line) => {
       const lx = line.x / zoom, ly = line.y / zoom, lw = line.width / zoom, lh = line.height / zoom;
-      return { x1: lx, y1: ly + lh, x2: lx + lw, y2: ly + lh, x3: lx + lw, y3: ly, x4: lx, y4: ly };
+      return { x1: lx, y1: ly, x2: lx + lw, y2: ly, x3: lx, y3: ly + lh, x4: lx + lw, y4: ly + lh };
     });
 
     let minX = Infinity, minY = Infinity, maxX = -Infinity, maxY = -Infinity;
@@ -280,7 +280,7 @@ function App() {
       if (ly < minY) minY = ly;
       if (lx + lw > maxX) maxX = lx + lw;
       if (ly + lh > maxY) maxY = ly + lh;
-      return [{ x: lx, y: ly + lh }, { x: lx + lw, y: ly + lh }, { x: lx + lw, y: ly }, { x: lx, y: ly }];
+      return [{ x: lx, y: ly }, { x: lx + lw, y: ly }, { x: lx, y: ly + lh }, { x: lx + lw, y: ly + lh }];
     });
 
     const newAnno = {

frontend/src/lib/textSelection.ts

@@ -194,8 +194,10 @@ export class TextSelectionModel {
     }
     const rects: SelRect[] = [];
     for (const arr of byLine.values()) {
-      const x = Math.min(...arr.map((g) => g.x));
-      const right = Math.max(...arr.map((g) => g.right));
+      const nonSpace = arr.filter(g => !/^\s+$/.test(g.text));
+      const measureArr = nonSpace.length > 0 ? nonSpace : arr;
+      const x = Math.min(...measureArr.map((g) => g.x));
+      const right = Math.max(...measureArr.map((g) => g.right));
       const band = this.lines[arr[0].line];
       rects.push({ x, y: band.top, w: right - x, h: band.bottom - band.top });
     }

frontend/src/viewer/AnnotationLayer.tsx

@@ -115,7 +115,7 @@ export const AnnotationLayer: React.FC<AnnotationLayerProps> = ({
               onPointerDown={(e) => handlePointerDown(e, anno)}
               onPointerMove={(e) => handlePointerMove(e, anno.id)}
               onPointerUp={(e) => handlePointerUp(e, anno)}
-              className={`absolute ${isDraggable(anno.type) ? 'cursor-move' : 'cursor-pointer'} rounded-[2px] transition-[opacity,box-shadow] duration-150 hover:shadow-[0_2px_8px_rgba(16,24,40,0.18)] type-${anno.type} ${isDragging ? 'shadow-lg z-50' : ''}`}
+              className={`absolute ${isDraggable(anno.type) ? 'cursor-move' : 'cursor-pointer'} rounded-[2px] transition-[opacity,box-shadow] duration-150 ${['highlight', 'strikeout', 'underline', 'squiggly'].includes(anno.type) ? '' : 'hover:shadow-[0_2px_8px_rgba(16,24,40,0.18)]'} type-${anno.type} ${isDragging ? 'shadow-lg z-50' : ''}`}
               style={{
                 left: `${scaledBbox.x + currentOffset.x * zoom}px`,
                 top: `${scaledBbox.y + currentOffset.y * zoom}px`,

gateway/app/routers/edits.py

@@ -283,6 +283,20 @@ class SquigglyOperation(BaseModel):
     pageIndex: int = Field(..., ge=0)
     data: DecorationData
 
+class SignatureData(BaseModel):
+    x: float
+    y: float
+    width: float
+    height: float
+    image_data: str | None = None
+    author: str = "Signer"
+
+class SignatureOperation(BaseModel):
+    id: str
+    type: Literal["signature"]
+    pageIndex: int = Field(..., ge=0)
+    data: SignatureData
+
 EditOperation = Annotated[
     TextOverlayOperation
     | RedactionOperation
@@ -301,7 +315,9 @@ EditOperation = Annotated[
     | ReflowParagraphOperation
     | UnderlineOperation
     | StrikeoutOperation
-    | SquigglyOperation,
+    | SquigglyOperation
+    | SignatureOperation
+    ,
     Field(discriminator="type"),
 ]