feat(编辑能力): 支持多图元文字联合编辑

assets/webui/ofdgo.js

@@ -667,14 +667,18 @@ const canvasEditor = new CanvasEditor(el.viewerPanel, {
 	onDrawText: beginCanvasText,
 	onDrawAnnotation: placeAnnotation,
 	onDrawInk: (index, points, style, pressure) => changeDocument("ofdgoInsertInk", null, index, JSON.stringify(points), style.lineWidth, pressure, style.strokeColor),
-	onPreviewText: (item, value, font, size, reflow) => callWASM("ofdgoPreviewText", item.index, item.id, value, font || null, size, !!reflow),
+	onPreviewText: (item, value, font, size, reflow, color = null) => item.selectionIDs
+		? callWASM("ofdgoPreviewTextSelection", item.index, item.selectionIDs, value, font || null, size, color, !!reflow)
+		: callWASM("ofdgoPreviewText", item.index, item.id, value, font || null, size, !!reflow),
 	onCommitRichText: saveRichText,
 	onPreviewRichText: validateRichText,
 	onTextError: (message, previous) => {
 		if (message) setStatus(message);
 		else if (el.statusText.textContent === previous) setStatus(state.doc ? pageStatus(state.pageIndex, state.doc.pageCount) : STATUS.ready);
 	},
-	onCommitText: (item, value, fontData, color = null, reflow = false) => item.draft
+	onCommitText: (item, value, fontData, color = null, reflow = false) => item.selectionIDs
+		? changeDocument("ofdgoUpdateTextSelection", item, value, fontData || null, canvasEditor.input?.style?.size ?? null, color, reflow)
+		: item.draft
 		? changeDocument("ofdgoInsertText", null, item.index, value, fontData || item.fontData, item.x, item.y, item.size, item.color, item.width, item.wrap, item.align, item.paragraphHeight, item.letterSpacing, ...textIndents(item))
 		: changeDocument("ofdgoUpdateText", item, value, fontData || null, item.size, color, reflow),
 	onTextChange: () => {
@@ -2881,7 +2885,30 @@ function updateAnnotationFields() {
 }
 
 async function editCanvasObject(item) {
-	if (!state.editing || document.body.hasAttribute("aria-busy") || canvasEditor.input || item.items) return;
+	if (!state.editing || document.body.hasAttribute("aria-busy") || canvasEditor.input) return;
+	if (item.items) {
+		if (!item.items.every(member => member.type === "TextObject" && !member.richText)) return;
+		const openSeq = state.openSeq;
+		setBusy(true);
+		try {
+			const ids = item.items.map(member => member.id);
+			const data = await callWASM("ofdgoTextSelection", item.index, ids);
+			const faces = new Map();
+			for (const font of data.fonts) {
+				faces.set(font.id, await new FontFace(`ofdgo-selection-${crypto.randomUUID()}`, font.bytes, fontFaceStyle(font.bytes)).load());
+			}
+			if (openSeq !== state.openSeq || canvasEditor.selected !== item || !item.node.isConnected) return;
+			const face = faces.get(data.item.font);
+			if (!face) throw new Error("字体不可用");
+			Object.assign(item, data.item, { type: "TextObject", selectionIDs: ids, id: ids });
+			canvasEditor.editText(item, face, data.source, null, faces);
+		} catch (err) {
+			if (openSeq === state.openSeq) showError(err, false);
+		} finally {
+			if (openSeq === state.openSeq) setBusy(false);
+		}
+		return;
+	}
 	if (!item.richText && canEditObject(item, "enter")) return enterCompositeScope(item.index, item.id);
 	if (item.type === "Annotation") {
 		editAnnotationDetails(item);
@@ -3054,6 +3081,7 @@ async function ensureRichInput() {
 		editing = canvasEditor.input;
 	}
 	if (!editing) return false;
+	if (editing.item.selectionIDs) return false;
 	if (editing.rich) return true;
 	if (editing.composing || editing.saving) return false;
 	const rich = await loadRichText(editing.item, editing.face);
@@ -3603,8 +3631,11 @@ async function changeDocument(name, item, ...args) {
 		const editingAnnotation = name === "ofdgoWriteAnnotation" && Boolean(state.annotationCreate?.item);
 		if (scope && inserting && name === "ofdgoSaveRichText") throw new Error("组合内部暂不支持新增富文本");
 		if (scope && inserting) args.push(scope.key);
-		if (scoped && !operation) throw new Error("内部对象暂不支持此操作");
+		const textSelection = name === "ofdgoUpdateTextSelection";
-		const doc = scoped
+		if (scoped && !operation && !textSelection) throw new Error("内部对象暂不支持此操作");
+		const doc = textSelection
+			? await callWASM(name, item.index, item.selectionIDs, ...args)
+			: scoped
 			? await callWASM("ofdgoChangeCompositeObjects", item.index, scope.key, Array.isArray(item.id) ? item.id : members.map(member => member.id), operation, ...args)
 			: annotated && operation ? await callWASM("ofdgoChangeSelection", item.index, ids, operation, ...args)
 			: await callWASM(name, ...(item ? [item.index, item.id] : []), ...args);
@@ -3666,7 +3697,7 @@ async function changeDocument(name, item, ...args) {
 		}
 		const view = restoredView;
 		const reindex = !!scope && (scoped && ["ofdgoDeleteObject", "ofdgoDeleteObjects", "ofdgoCopyObjects", "ofdgoOrderObjects", "ofdgoEraseObjects", "ofdgoEraseObjectsPath", "ofdgoGroupObjects"].includes(name)
-			|| inserting || name === "ofdgoPasteObjects" && !!args[4]);
+			|| textSelection || inserting || name === "ofdgoPasteObjects" && !!args[4]);
 		const reindexed = restoring ? view?.reindex && view.before : reindex && before;
 		const clipboard = state.objectClipboard;
 		if (reindexed && clipboard?.scope?.startsWith(reindexed.scope + "/") && clipboard.page === reindexed.page) state.objectClipboard = null;
@@ -3709,6 +3740,7 @@ async function changeDocument(name, item, ...args) {
 			canvasEditor.pendingSelection = { index: item?.index ?? args[0], ids: name === "ofdgoInsertInk" ? [] : doc.selectedIDs };
 		}
 		if (scoped && name === "ofdgoOrderObjects") canvasEditor.pendingSelection = { index: item.index, ids: doc.selectedIDs };
+		if (textSelection) canvasEditor.pendingSelection = { index: item.index, ids: doc.selectedIDs || [] };
 		openSeq = ++state.openSeq;
 		if (changingFont) {
 			await refreshFontBinding(doc, openSeq);
@@ -11737,8 +11769,9 @@ function updateObjectControls(item, reset = false) {
 	el.resetCropButton.setAttribute("aria-label", cropping ? "取消裁剪" : "还原图片");
 	el.resetCropButton.disabled = canEditObject(item, "resetCrop") ? disabled : el.cropImageButton.disabled || !cropping && (item.scoped ? !item.cropped : !item.imageBounds || ["x", "y", "width", "height"].every(key => Math.abs(item[key] - item.imageBounds[key]) < 1e-9));
 	el.objectDistribute.disabled = el.objectAlign.disabled || !item.items || item.items.length < 3;
-	el.editObjectButton.disabled = disabled || Boolean(item.items) || !canEditObject(item, "enter") && (item.type === "PathObject"
+	el.editObjectButton.disabled = disabled || (item.items ? !item.items.every(member => member.type === "TextObject" && !member.richText)
-		|| !(item.type === "TextObject" && canEditObject(item, "rewriteText")) && !canEditObject(item, item.type === "TextObject" ? "textContent" : item.type === "ImageObject" ? "replaceImage" : "update"));
+		: !canEditObject(item, "enter") && (item.type === "PathObject"
+		|| !(item.type === "TextObject" && canEditObject(item, "rewriteText")) && !canEditObject(item, item.type === "TextObject" ? "textContent" : item.type === "ImageObject" ? "replaceImage" : "update")));
 	el.editObjectButton.textContent = canEditObject(item, "enter") ? "进入" : item?.type === "ImageObject" ? "替换" : "修改";
 	el.editObjectButton.title = canEditObject(item, "enter") ? item?.type === "Annotation" ? "进入注解" : "进入组合" : item?.type === "ImageObject" ? "替换图片" : item?.type === "Annotation" ? "修改注解" : "修改对象";
 	el.editObjectButton.setAttribute("aria-label", el.editObjectButton.title);
@@ -11747,7 +11780,7 @@ function updateObjectControls(item, reset = false) {
 	const text = selection ? currentTextStyle() : state.textDefaults;
 	const textDisabled = !state.editing || !state.ready || state.exporting || Boolean(item?.items && (!selection || item.items.some(member => member.richText))) || Boolean(canvasEditor.input?.composing || canvasEditor.input?.saving);
 	fontPicker.setDisabled(textDisabled || text !== state.textDefaults && !item.draft && !canEditObject(item, "replaceFont"));
-	el.textSize.disabled = textDisabled || text !== state.textDefaults && !item.draft && (!canEditObject(item, "reflow") || Boolean(item?.items) && !canEditObject(item, "layoutKnown"));
+	el.textSize.disabled = textDisabled || text !== state.textDefaults && !item.draft && (!canEditObject(item, "reflow") || Boolean(item?.items && !item.selectionIDs) && !canEditObject(item, "layoutKnown"));
 	el.textColor.disabled = textDisabled || text !== state.textDefaults && !item.draft && !item.richText && !canEditObject(item, "paint");
 	el.textFontAdd.disabled = !state.editing || !state.ready || state.exporting;
 	const formatsDisabled = textDisabled || Boolean(item?.items || item?.scoped) || Boolean(item && !item.draft && (!selection || !canEditObject(item, "textContent")));
@@ -11764,9 +11797,12 @@ function updateObjectControls(item, reset = false) {
 	if (richHistory) {
 		el.undoButton.disabled = textDisabled || richHistory.index === 0;
 		el.redoButton.disabled = textDisabled || richHistory.index === richHistory.entries.length - 1;
+	} else {
+		el.undoButton.disabled = !state.editorInfo?.canUndo || !state.ready || state.exporting;
+		el.redoButton.disabled = !state.editorInfo?.canRedo || !state.ready || state.exporting;
 	}
 	el.textAlign.disabled = el.textWrap.disabled = el.textLineHeight.disabled = el.textSpacing.disabled = el.textSize.disabled || Boolean(item?.items || item?.draft) || Boolean(canvasEditor.input);
-	const reflow = document.querySelector("#textReflow"), positioned = canvasEditor.input?.source && !canEditObject(item, "layoutKnown");
+	const reflow = document.querySelector("#textReflow"), positioned = canvasEditor.input?.source && (item?.selectionIDs || !canEditObject(item, "layoutKnown"));
 	reflow.hidden = !positioned;
 	el.textWrap.hidden = !!positioned;
 	reflow.disabled = textDisabled || !canEditObject(item, "reflow") || !!canvasEditor.input?.reflow;

assets/webui/ofdgo_edit.js

@@ -484,7 +484,7 @@ function paintShape(node, shape, box) {
 
 export function canEditObject(item, capability) {
 	if (!item) return false;
-	const objects = item.items || [item];
+	const objects = item.selectionIDs ? [item] : item.items || [item];
 	return objects.every(object => Boolean(object.capabilities?.[capability] || capability === "move" && object.capabilities?.transform));
 }
 
@@ -512,6 +512,7 @@ export function objectEditReason(item) {
 }
 
 export function selectedText(item) {
+	if (item?.selectionIDs) return item;
 	if (!item?.items) return item?.type === "TextObject" ? item : null;
 	if (!item.items.every(member => member.type === "TextObject")) return null;
 	const text = { ...item, type: "TextObject" };
@@ -654,7 +655,7 @@ export class CanvasEditor {
 			}
 		}
 		surface.append(layer);
-		if (selected.size) this.setSelection(selection);
+		if (pending || selected.size) this.setSelection(selection);
 		if (pending) this.pendingSelection = null;
 		if (crop && selection.length === 1 && selection[0].id === crop.item.id
 			&& ["x", "y", "width", "height"].every(key => selection[0][key] === crop.item[key])) {
@@ -1497,10 +1498,11 @@ export class CanvasEditor {
 		}
 	}
 
-	editText(item, face, source = null, rich = null) {
+	editText(item, face, source = null, rich = null, faces = null) {
 		this.cancel();
 		this.closeText();
-		this.select(item);
+		if (!item.selectionIDs) this.select(item);
+		for (const face of faces?.values() || []) document.fonts.add(face);
 		document.fonts.add(face);
 		const input = document.createElement("div");
 		input.className = "edit-text";
@@ -1532,13 +1534,17 @@ export class CanvasEditor {
 			letterSpacing: `${(item.letterSpacing || 0) * PX_PER_MM}px`,
 			textIndent: `${(item.firstLineIndent || 0) * PX_PER_MM}px`,
 		});
-		this.input = { input, item, face, frame, source: Boolean(source), fontChoice: item.fontChoice };
+		this.input = { input, item, face, faces, frame, source: Boolean(source), fontChoice: item.fontChoice };
 		const editing = this.input;
 		if (rich) editing.rich = new RichTextSession(this, rich.model, rich.faces, rich.fonts);
 		if (rich && !rich.model.layout.lineHeight) input.style.lineHeight = "normal";
 		if (source) editing.history = { entries: [{ value: item.text, face, fontChoice: item.fontChoice }], index: 0 };
 		item.artwork?.classList.add("edit-text-source");
 		item.node.classList.add("edit-text-source");
+		for (const member of item.selectionIDs ? item.items : []) {
+			member.artwork?.classList.add("edit-text-source");
+			member.node.classList.add("edit-text-source");
+		}
 		item.surface.append(input);
 		this.fitTextInput();
 		if (source) this.paintSourceText(source);
@@ -1731,7 +1737,7 @@ export class CanvasEditor {
 		history.index = index;
 		const entry = history.entries[index], fragment = document.createDocumentFragment(), positions = [];
 		if (entry.face) {
-			document.fonts.delete(editing.face);
+			if (![...editing.faces?.values() || []].includes(editing.face)) document.fonts.delete(editing.face);
 			document.fonts.add(entry.face);
 			Object.assign(editing, { face: entry.face, fontData: entry.fontData, fontChoice: entry.fontChoice, style: entry.style, reflow: entry.reflow });
 			editing.input.style.fontFamily = `"${entry.face.family}"`;
@@ -1759,15 +1765,17 @@ export class CanvasEditor {
 		if (!editing?.source || editing.saving) return;
 		this.paintSourceDraft();
 		if (editing.composing) return;
-		const value = editTextValue(editing.input), font = editing.fontData, size = editing.style?.size || editing.item.size, reflow = !!editing.reflow;
+		const value = editTextValue(editing.input), font = editing.fontData;
+		const size = editing.style?.size ?? (editing.item.selectionIDs ? null : editing.item.size), color = editing.style?.color ?? null, reflow = !!editing.reflow;
 		if (value === "") {
 			this.setTextError(null);
 			return;
 		}
 		const current = () => this.input === editing && !editing.rich && !editing.composing && !editing.saving && editing.fontData === font
-			&& (editing.style?.size || editing.item.size) === size && !!editing.reflow === reflow && editTextValue(editing.input) === value;
+			&& (editing.style?.size ?? (editing.item.selectionIDs ? null : editing.item.size)) === size
+			&& (editing.style?.color ?? null) === color && !!editing.reflow === reflow && editTextValue(editing.input) === value;
 		try {
-			const source = await this.options.onPreviewText(editing.item, value, font, size, reflow);
+			const source = await this.options.onPreviewText(editing.item, value, font, size, reflow, color);
 			if (!current()) return;
 			this.setTextError(null);
 			this.paintSourceText(source);
@@ -1803,16 +1811,23 @@ export class CanvasEditor {
 		const size = (editing.style?.size || item.size) * PX_PER_MM;
 		const context = document.createElement("canvas").getContext("2d");
 		context.font = `${source.italic ? "italic" : "normal"} ${source.weight || 400} ${size}px "${face.family}"`;
-		const metrics = context.measureText("Mg"), baseline = (size + metrics.fontBoundingBoxAscent - metrics.fontBoundingBoxDescent) / 2;
 		Object.assign(input.style, { lineHeight: `${size}px`, fontWeight: String(source.weight || 400), fontStyle: source.italic ? "italic" : "normal" });
 		const fragment = document.createDocumentFragment(), positions = [];
 		let line, lineIndex = -1, naturalX = 0, position = 0, glyphIndex = 0;
-		const angle = (source.rotation || 0) * Math.PI / 180, cos = Math.cos(angle), sin = Math.sin(angle);
 		let left = Infinity, top = Infinity, right = -Infinity, bottom = -Infinity;
 		for (const run of source.runs) {
+			const runFace = editing.fontData ? face : editing.faces?.get(run.font) || face;
+			const runSize = (editing.style?.size ?? run.size ?? editing.item.size) * PX_PER_MM;
+			const weight = (run.weight ?? source.weight) || 400, italic = run.italic ?? source.italic;
+			const scale = (run.scale ?? source.scale) || 1, vscale = (run.vscale ?? source.vscale) || 1;
+			const rotation = run.rotation ?? source.rotation ?? 0, angle = rotation * Math.PI / 180;
+			const cos = Math.cos(angle), sin = Math.sin(angle);
+			context.font = `${italic ? "italic" : "normal"} ${weight} ${runSize}px "${runFace.family}"`;
+			const metrics = context.measureText("Mg"), baseline = (runSize + metrics.fontBoundingBoxAscent - metrics.fontBoundingBoxDescent) / 2;
 			if (!line || run.line) {
 				if (line) position++;
 				line = document.createElement("div");
+				line.style.height = `${size}px`;
 				fragment.append(line);
 				lineIndex++;
 				naturalX = 0;
@@ -1822,7 +1837,7 @@ export class CanvasEditor {
 				left = Math.min(left, x);
 				top = Math.min(top, y - baseline);
 				right = Math.max(right, x);
-				bottom = Math.max(bottom, y + size - baseline);
+				bottom = Math.max(bottom, y + runSize - baseline);
 			}
 			for (const char of run.text) {
 				x = run.positions[index][0] * PX_PER_MM;
@@ -1831,14 +1846,17 @@ export class CanvasEditor {
 				span.append(node);
 				const glyph = source.glyphs?.[glyphIndex++];
 				if (glyph) span.dataset.glyph = glyph;
-				Object.assign(span.style, { display: "inline-block", opacity: String((item.alpha ?? 255) / 255), transformOrigin: `left ${baseline}px`, transform: `translate(${x - naturalX}px,${y - baseline - lineIndex * size}px) rotate(${source.rotation || 0}deg) scale(${source.scale},${source.vscale || 1})` });
+				Object.assign(span.style, { display: "inline-block", verticalAlign: "top", fontFamily: `"${runFace.family}"`, fontSize: `${runSize}px`, lineHeight: `${runSize}px`,
+					fontWeight: String(weight), fontStyle: italic ? "italic" : "normal", color: editing.style?.color ?? run.color ?? item.color,
+					opacity: String((run.alpha ?? item.alpha ?? 255) / 255), transformOrigin: `left ${baseline}px`,
+					transform: `translate(${x - naturalX}px,${y - baseline - lineIndex * size}px) rotate(${rotation}deg) scale(${scale},${vscale})` });
 				line.append(span);
 				positions.push({ node, start: position, end: position + char.length });
 				position += char.length;
 				const advance = context.measureText(glyph || char).width;
 				if (glyph) span.style.width = `${advance}px`;
-				for (const dx of [0, advance * source.scale]) {
+				for (const dx of [0, advance * scale]) {
-					for (const dy of [-baseline * (source.vscale || 1), (size - baseline) * (source.vscale || 1)]) {
+					for (const dy of [-baseline * vscale, (runSize - baseline) * vscale]) {
 						const px = x + dx * cos - dy * sin, py = y + dx * sin + dy * cos;
 						left = Math.min(left, px);
 						top = Math.min(top, py);
@@ -1855,6 +1873,7 @@ export class CanvasEditor {
 				positions.push({ node, start: position, end: position });
 			}
 		}
+		if (!Number.isFinite(left)) { left = top = 0; right = bottom = size; }
 		for (const line of fragment.children) line.style.transform = `translate(${-left}px,${-top}px)`;
 		input.replaceChildren(fragment);
 		const [a, b, c, d, e, f] = frame.matrix;
@@ -1870,7 +1889,7 @@ export class CanvasEditor {
 		const editing = this.input;
 		if (editing.rich) { editing.rich.setFont(face, data, key); return; }
 		document.fonts.add(face);
-		document.fonts.delete(editing.face);
+		if (![...editing.faces?.values() || []].includes(editing.face)) document.fonts.delete(editing.face);
 		editing.face = face;
 		editing.fontData = data;
 		editing.input.style.fontFamily = `"${face.family}"`;
@@ -1884,7 +1903,7 @@ export class CanvasEditor {
 		const editing = this.input;
 		if (editing.rich) { editing.rich.apply(values); return; }
 		const style = { ...editing.style, ...values };
-		for (const key of Object.keys(style)) if (style[key] === editing.item[key]) delete style[key];
+		for (const key of Object.keys(style)) if (!editing.item.selectionIDs && style[key] === editing.item[key]) delete style[key];
 		editing.style = Object.keys(style).length ? style : null;
 		const item = { ...editing.item, ...editing.style };
 		editing.input.style.fontSize = `${item.size * PX_PER_MM}px`;
@@ -1892,7 +1911,7 @@ export class CanvasEditor {
 		this.recordSourceText();
 		this.fitTextInput();
 		this.options.onTextChange();
-		if ("size" in values) this.previewSourceText();
+		if ("size" in values || editing.item.selectionIDs) this.previewSourceText();
 	}
 
 	textChanged() {
@@ -1922,7 +1941,7 @@ export class CanvasEditor {
 		editing.input.contentEditable = "false";
 		let saved = false;
 		try {
-			saved = value === "" && !editing.item.draft ? await this.options.onDelete(editing.item)
+			saved = value === "" && !editing.item.draft && !editing.item.selectionIDs ? await this.options.onDelete(editing.item)
 				: editing.rich ? await this.options.onCommitRichText(editing.item, editing.rich.model, editing.rich.fonts)
 				: await this.options.onCommitText(editing.style ? { ...editing.item, ...editing.style } : editing.item, value, editing.fontData, editing.style?.color ?? null, !!editing.reflow);
 		} catch (error) {
@@ -1950,7 +1969,13 @@ export class CanvasEditor {
 			editing.input.remove();
 			editing.item.artwork?.classList.remove("edit-text-source");
 			editing.item.node.classList.remove("edit-text-source");
+			for (const member of editing.item.selectionIDs ? editing.item.items : []) {
+				member.artwork?.classList.remove("edit-text-source");
+				member.node.classList.remove("edit-text-source");
+			}
+			for (const face of editing.faces?.values() || []) document.fonts.delete(face);
 			document.fonts.delete(editing.face);
+			if (editing.item.selectionIDs && this.selected === editing.item) this.setSelection(editing.item.items);
 			if (editing.item.draft && this.selected === editing.item) this.select(null);
 			this.options.onTextChange();
 		}

internal/webui/wasm.go

@@ -305,6 +305,9 @@ func RunWASM() {
 	registerCallback("ofdgoInsertText", insertText)
 	registerCallback("ofdgoUpdateText", updateText)
 	registerCallback("ofdgoPreviewText", previewText)
+	registerCallback("ofdgoTextSelection", textSelection)
+	registerCallback("ofdgoPreviewTextSelection", previewTextSelection)
+	registerCallback("ofdgoUpdateTextSelection", updateTextSelection)
 	registerCallback("ofdgoStyleText", styleText)
 	registerCallback("ofdgoGetRichText", getRichText)
 	registerCallback("ofdgoSaveRichText", saveRichText)
@@ -3198,6 +3201,303 @@ func previewText(args []js.Value) (any, error) {
 	return map[string]any{"runs": runs, "glyphs": glyphs, "scale": scale, "vscale": text.VScale, "rotation": text.CharDirection, "weight": text.Weight, "italic": text.Italic}, nil
 }
 
+// readTextSelection 将画布路径转换为同一容器的库层文字选区
+// 入参: ids 图元路径列表
+// 返回: ofdgo.TextSelection 文字选区, error 路径错误
+func readTextSelection(ids []string) (ofdgo.TextSelection, error) {
+	selection := ofdgo.TextSelection{IDs: ids}
+	if currentEditor == nil {
+		return selection, fmt.Errorf("no document is being edited")
+	}
+	if len(ids) == 0 {
+		return selection, fmt.Errorf("text selection is empty")
+	}
+	if index := strings.LastIndex(ids[0], "/"); index >= 0 {
+		key := ids[0][:index]
+		path, err := compositePath(key)
+		if err != nil {
+			return selection, err
+		}
+		indexes, err := compositeIndexes(key, ids)
+		return ofdgo.TextSelection{Root: &path, Indexes: indexes}, err
+	}
+	for _, id := range ids {
+		if strings.Contains(id, "/") {
+			return selection, fmt.Errorf("text selection crosses containers")
+		}
+	}
+	return selection, nil
+}
+
+// textSelection 分析联合文字并加载预览所需字体，不改变文档资源
+// 入参: args 页码和图元路径列表
+// 返回: any 文字选区、定位预览和字体, error 分析错误
+func textSelection(args []js.Value) (any, error) {
+	selection, err := readTextSelection(stringsFromJS(args[1]))
+	if err != nil {
+		return nil, err
+	}
+	analysis, err := currentEditor.AnalyzeTextSelection(args[0].Int(), selection)
+	if err != nil {
+		return nil, err
+	}
+	source, err := textSelectionSource(analysis.Parts, analysis.Bounds, analysis.Text, true)
+	if err != nil {
+		return nil, err
+	}
+	first := analysis.Parts[0].TextObject
+	_, origin := analysis.Parts[0].Matrix.Transform(0, 0)
+	_, unit := analysis.Parts[0].Matrix.Transform(0, 1)
+	item := editorBox(analysis.Bounds)
+	item["text"], item["font"], item["size"] = analysis.Text, first.Font, first.Size*(unit-origin)
+	item["color"] = richTextColorHex(analysis.Parts[0].Color)
+	item["alpha"] = 255
+	if first.Alpha != nil {
+		item["alpha"] = *first.Alpha
+	}
+	item["capabilities"] = map[string]any{"textContent": true, "rewriteText": analysis.Replace, "replaceFont": true, "paint": true, "reflow": analysis.Reflow, "layoutKnown": false}
+	item["textFrame"] = map[string]any{"width": analysis.Bounds.W, "height": analysis.Bounds.H, "matrix": editorMatrix(ofdgo.TranslationMatrix(analysis.Bounds.X, analysis.Bounds.Y))}
+	available, err := currentSession.Reader.Fonts()
+	if err != nil {
+		return nil, err
+	}
+	for _, font := range available {
+		if font.ID == first.Font {
+			item["fontName"] = font.FontName
+			break
+		}
+	}
+	data, err := json.Marshal(map[string]any{"item": item, "source": source})
+	if err != nil {
+		return nil, err
+	}
+	result := js.Global().Get("JSON").Call("parse", string(data))
+	fonts := js.Global().Get("Array").New()
+	seen := make(map[string]bool)
+	for _, part := range analysis.Parts {
+		id := part.TextObject.Font
+		if seen[id] {
+			continue
+		}
+		seen[id] = true
+		data, err := currentEditor.FontData(id)
+		if err != nil {
+			return nil, err
+		}
+		_, data, _, _, err = ofdgo.FixFontDataAggressive(data, true, false)
+		if err != nil {
+			return nil, err
+		}
+		font := js.Global().Get("Object").New()
+		font.Set("id", id)
+		font.Set("bytes", bytesToJS(data))
+		fonts.Call("push", font)
+	}
+	result.Set("fonts", fonts)
+	return successResult(result), nil
+}
+
+// textSelectionSource 将库层逐字定位转换为选区局部坐标及分段字体样式
+// 入参: parts 预览文字图元, box 原始选区边界, value 完整原文, mapped 是否使用原字形映射
+// 返回: map[string]any 定位预览, error 字形映射错误
+func textSelectionSource(parts []ofdgo.TextSelectionPart, box ofdgo.Box, value string, mapped bool) (map[string]any, error) {
+	runs := make([]any, 0, len(parts))
+	glyphs := make(map[int]string)
+	offset := 0
+	logical, cursor := []rune(value), 0
+	for _, part := range parts {
+		if part.Deleted {
+			continue
+		}
+		text := part.TextObject
+		originX, originY := part.Matrix.Transform(0, 0)
+		xAxis, _ := part.Matrix.Transform(1, 0)
+		_, yAxis := part.Matrix.Transform(0, 1)
+		sx, sy := xAxis-originX, yAxis-originY
+		scale := text.HScale
+		if scale == 0 {
+			scale = 1
+		}
+		for _, transform := range text.CGTransform {
+			if !mapped {
+				break
+			}
+			if transform.CodeCount != transform.GlyphCount {
+				return nil, fmt.Errorf("text selection contains ambiguous glyph mapping")
+			}
+			for i, value := range strings.Fields(transform.Glyphs) {
+				glyph, err := strconv.ParseUint(value, 10, 16)
+				if err != nil {
+					return nil, err
+				}
+				glyphs[offset+transform.CodePosition+i] = string(rune(0xF0000 + glyph))
+			}
+		}
+		alpha := 255
+		if text.Alpha != nil {
+			alpha = int(*text.Alpha)
+		}
+		chars := []rune(strings.ReplaceAll(text.Text(), "\n", ""))
+		if len(chars) != len(part.Points) {
+			return nil, fmt.Errorf("text selection positions do not match characters")
+		}
+		for i, char := range chars {
+			x, y := part.Matrix.Transform(part.Points[i].X, part.Points[i].Y)
+			line := false
+			for cursor < len(logical) && logical[cursor] == '\n' {
+				if line || len(runs) == 0 {
+					runs = append(runs, map[string]any{"text": "", "x": x - box.X, "y": y - box.Y - text.Size*sy,
+						"positions": [][2]float64{}, "line": line, "font": text.Font, "size": text.Size * sy})
+				}
+				line = true
+				cursor++
+			}
+			if cursor >= len(logical) || logical[cursor] != char {
+				return nil, fmt.Errorf("text selection preview does not match content")
+			}
+			cursor++
+			runs = append(runs, map[string]any{"text": string(char), "x": x - box.X, "y": y - box.Y,
+				"positions": [][2]float64{{x - box.X, y - box.Y}}, "line": line, "font": text.Font,
+				"size": text.Size * sy, "scale": scale * sx / sy, "vscale": 1, "rotation": 0,
+				"weight": text.Weight, "italic": text.Italic, "alpha": alpha, "color": richTextColorHex(part.Color)})
+		}
+		offset += len(chars)
+	}
+	for cursor < len(logical) && logical[cursor] == '\n' && len(runs) > 0 {
+		last := runs[len(runs)-1].(map[string]any)
+		runs = append(runs, map[string]any{"text": "", "x": float64(0), "y": last["y"].(float64) + last["size"].(float64),
+			"positions": [][2]float64{}, "line": true, "font": last["font"], "size": last["size"]})
+		cursor++
+	}
+	if cursor != len(logical) {
+		return nil, fmt.Errorf("text selection preview is incomplete")
+	}
+	return map[string]any{"runs": runs, "glyphs": glyphs}, nil
+}
+
+// readTextSelectionEdit 将完整草稿转为码点范围修改或显式富文本重排
+// 入参: args 编辑参数, analysis 原始选区
+// 返回: ofdgo.TextSelectionEdit 修改内容, error 参数错误
+func readTextSelectionEdit(args []js.Value, analysis ofdgo.TextSelectionAnalysis) (ofdgo.TextSelectionEdit, error) {
+	old, next := []rune(analysis.Text), []rune(args[2].String())
+	start, end, tail := 0, len(old), len(next)
+	for start < end && start < tail && old[start] == next[start] {
+		start++
+	}
+	for end > start && tail > start && old[end-1] == next[tail-1] {
+		end--
+		tail--
+	}
+	edit := ofdgo.TextSelectionEdit{Start: start, End: end, Text: string(next[start:tail])}
+	if !args[3].IsNull() {
+		var err error
+		edit.FontData, err = bytesFromJS(args[3])
+		if err != nil {
+			return edit, err
+		}
+	}
+	if !args[4].IsNull() {
+		edit.Size = args[4].Float()
+	}
+	if !args[5].IsNull() {
+		value := args[5].String()
+		if len(value) != 7 || value[0] != '#' {
+			return edit, fmt.Errorf("invalid RGB color %q", value)
+		}
+		rgb, err := hex.DecodeString(value[1:])
+		if err != nil {
+			return edit, err
+		}
+		edit.Color = fmt.Sprintf("%d %d %d", rgb[0], rgb[1], rgb[2])
+	}
+	if args[6].Bool() && len(next) > 0 {
+		value := analysis.RichText
+		var replacement []ofdgo.RichTextRun
+		if tail > start {
+			part, err := value.Slice(start, start)
+			if tail-start == end-start {
+				part, err = value.Slice(start, end)
+			}
+			if err != nil {
+				return edit, err
+			}
+			if tail-start == end-start {
+				offset := start
+				for _, run := range part.Runs {
+					count := len([]rune(run.Text))
+					replacement = append(replacement, ofdgo.RichTextRun{Text: string(next[offset : offset+count]), Format: run.Format})
+					offset += count
+				}
+			} else {
+				replacement = []ofdgo.RichTextRun{{Text: edit.Text, Format: part.Runs[0].Format}}
+			}
+		}
+		if err := value.Replace(start, end, replacement); err != nil {
+			return edit, err
+		}
+		value.Layout.AutoBidi, value.Layout.Wrap = true, true
+		edit.Reflow = &value
+	}
+	return edit, nil
+}
+
+// previewTextSelection 预览联合修改，不改变文档资源及撤销记录
+// 入参: args 页码、图元路径、内容、字体数据、字号、颜色和重排标记
+// 返回: any 定位预览, error 编辑错误
+func previewTextSelection(args []js.Value) (any, error) {
+	selection, err := readTextSelection(stringsFromJS(args[1]))
+	if err != nil {
+		return nil, err
+	}
+	analysis, err := currentEditor.AnalyzeTextSelection(args[0].Int(), selection)
+	if err != nil {
+		return nil, err
+	}
+	edit, err := readTextSelectionEdit(args, analysis)
+	if err != nil {
+		return nil, err
+	}
+	preview, err := currentEditor.PreviewTextSelection(args[0].Int(), analysis.Selection, edit)
+	if err != nil {
+		return nil, err
+	}
+	return textSelectionSource(preview.Parts, analysis.Bounds, preview.Text, len(edit.FontData) == 0)
+}
+
+// updateTextSelection 原子提交联合修改并恢复删除或重排后的选区
+// 入参: args 页码、图元路径、内容、字体数据、字号、颜色和重排标记
+// 返回: any 文档及选区信息, error 编辑错误
+func updateTextSelection(args []js.Value) (any, error) {
+	ids := stringsFromJS(args[1])
+	selection, err := readTextSelection(ids)
+	if err != nil {
+		return nil, err
+	}
+	page := args[0].Int()
+	analysis, err := currentEditor.AnalyzeTextSelection(page, selection)
+	if err != nil {
+		return nil, err
+	}
+	edit, err := readTextSelectionEdit(args, analysis)
+	if err != nil {
+		return nil, err
+	}
+	preview, err := currentEditor.PreviewTextSelection(page, analysis.Selection, edit)
+	if err != nil {
+		return nil, err
+	}
+	result, err := changeObjects(func() error { return currentEditor.UpdateTextSelection(page, analysis.Selection, edit) })
+	if err != nil {
+		return nil, err
+	}
+	selected := append([]string{}, preview.Selection.IDs...)
+	for _, index := range preview.Selection.Indexes {
+		key := ids[0][:strings.LastIndex(ids[0], "/")]
+		selected = append(selected, fmt.Sprintf("%s/%d", key, index))
+	}
+	return editorSelectionInfo{editorInfo: result.(editorInfo), SelectedIDs: selected}, nil
+}
+
 // previewPositionedText 预览保留定位的文字替换，不修改编辑器或撤销记录
 // 入参: args 页面、对象路径和内容
 // 返回: any SVG预览, error 错误信息

ofdgo_editor_text_selection.go

@@ -0,0 +1,841 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"fmt"
+	"image/color"
+	"math"
+	"reflect"
+	"slices"
+	"strings"
+	"unicode/utf8"
+)
+
+// TextSelection 指定同页同一直接容器的文字，Root为空使用IDs，否则使用Indexes
+// 分析返回的选区绑定文档和修订，结构或内容改变后需重新分析
+type TextSelection struct {
+	Root     *ObjectPath
+	IDs      []string
+	Indexes  []int
+	editor   *Editor
+	document editorDocumentIdentity
+	revision uint64
+	page     int
+}
+
+// TextSelectionEdit 指定码点范围替换，空Text表示删除，Font覆盖所有剩余文字
+// Reflow非空时使用完整富文本显式重排并忽略范围和Text，Width为可选页面段落宽度，单位为毫米
+// Size为页面毫米字号，零值保持原字号，Color为空保持原颜色，FontData优先于Font
+type TextSelectionEdit struct {
+	Start, End int
+	Text       string
+	Font       string
+	FontData   []byte
+	Size       float64
+	Color      string
+	Reflow     *RichText
+	Width      float64
+}
+
+// TextSelectionPart 保存源图元及合并文本码点范围，Matrix将TextObject局部坐标映射至页面
+// Deleted表示提交时删除源图元，重排生成项以Sources标识全部来源
+// Points为不含换行的局部码点原点，Color为解析后的RGB分量，Start和End使用原合并文本范围
+type TextSelectionPart struct {
+	ID         string
+	Index      int
+	Start, End int
+	TextObject TextObject
+	Matrix     Matrix
+	Deleted    bool
+	Sources    []int
+	Points     []Point
+	Color      string
+	points     []Point
+	position   ObjectPosition
+	raw        TextObject
+	container  *editorXML
+}
+
+// TextSelectionAnalysis 保存阅读顺序、格式和可执行能力，不插入推测空格
+type TextSelectionAnalysis struct {
+	Selection               TextSelection
+	Text                    string
+	RichText                RichText
+	Parts                   []TextSelectionPart
+	Bounds                  Box
+	Replace, Delete, Reflow bool
+}
+
+// TextSelectionPreview 保存实际更新后的文字和源映射，删除项保留原范围
+type TextSelectionPreview struct {
+	Selection TextSelection
+	Font      string
+	Text      string
+	Parts     []TextSelectionPart
+	Bounds    Box
+	analysis  TextSelectionAnalysis
+}
+
+// AnalyzeTextSelection 分析同一容器内的横排文字，拒绝重叠及无法可靠映射的布局
+// 入参: page 页面索引, selection 文字选区
+// 返回: TextSelectionAnalysis 阅读顺序与能力, error 选择或布局错误
+func (e *Editor) AnalyzeTextSelection(page int, selection TextSelection) (TextSelectionAnalysis, error) {
+	if selection.editor != nil && (selection.editor != e || selection.page != page || !e.documentIdentity().matches(selection.document) || selection.revision != e.revision) {
+		return TextSelectionAnalysis{}, fmt.Errorf("stale text selection")
+	}
+	copy := e.transactionSnapshot()
+	result, err := copy.analyzeTextSelection(page, selection)
+	if err == nil {
+		result.Selection.editor, result.Selection.document, result.Selection.revision = e, e.documentIdentity(), e.revision
+		result.Selection.page = page
+	}
+	return cloneEditorData(result), err
+}
+
+// analyzeTextSelection 在隔离资源视图中计算选区和逐字坐标
+// 入参: page 页面索引, selection 文字选区
+// 返回: TextSelectionAnalysis 分析快照, error 选择或布局错误
+func (e *Editor) analyzeTextSelection(page int, selection TextSelection) (TextSelectionAnalysis, error) {
+	result := TextSelectionAnalysis{Selection: selection, Replace: true, Delete: true, Reflow: true}
+	result.Selection.IDs = slices.Clone(selection.IDs)
+	result.Selection.Indexes = slices.Clone(selection.Indexes)
+	if selection.Root != nil {
+		root := cloneEditorData(*selection.Root)
+		result.Selection.Root = &root
+		if len(selection.IDs) != 0 || len(selection.Indexes) == 0 {
+			return result, fmt.Errorf("composite selection requires indexes only")
+		}
+		members, err := e.CompositeObjectsAt(page, root, selection.Indexes)
+		if err != nil {
+			return result, err
+		}
+		reader, _, _, nodes, err := e.compositeScope(page, root)
+		if err != nil {
+			return result, err
+		}
+		defer reader.Close()
+		for i, member := range members {
+			if member.Object.Type != "TextObject" || !member.Capabilities.RewriteText {
+				return result, fmt.Errorf("selection member is not editable text")
+			}
+			node := nodes[selection.Indexes[i]]
+			result.Parts = append(result.Parts, TextSelectionPart{ID: member.Object.TextObject.ID, Index: selection.Indexes[i], TextObject: member.Object.TextObject, raw: node.object.TextObject, Matrix: member.Matrix, position: member.Position, container: node.span.parent})
+		}
+	} else {
+		if len(selection.Indexes) != 0 || len(selection.IDs) == 0 {
+			return result, fmt.Errorf("page selection requires IDs only")
+		}
+		objects, _, err := e.selectedObjects(page, selection.IDs)
+		if err != nil {
+			return result, err
+		}
+		for _, object := range objects {
+			if object.Type != "TextObject" {
+				return result, fmt.Errorf("selection member is not text")
+			}
+			t := object.TextObject
+			capability, err := e.ObjectCapabilities(page, t.ID)
+			if err != nil {
+				return result, err
+			}
+			if !capability.RewriteText {
+				return result, capability.editError()
+			}
+			position, err := e.ObjectPosition(page, t.ID)
+			if err != nil {
+				return result, err
+			}
+			layer, _, err := e.findObject(page, t.ID)
+			if err != nil {
+				return result, err
+			}
+			resolved, err := e.resolveEditorStyle(object, layer.DrawParam)
+			if err != nil {
+				return result, err
+			}
+			box, err := ParseBox(t.Boundary)
+			if err != nil {
+				return result, err
+			}
+			container, _ := e.objectOrderIndexes(page, layer, t.ID)
+			result.Parts = append(result.Parts, TextSelectionPart{ID: t.ID, Index: position.Index, TextObject: resolved.TextObject, raw: t, Matrix: TranslationMatrix(box.X, box.Y).Multiply(NewMatrix(t.CTM)), position: position, container: container})
+		}
+	}
+	positions := make([]int, len(result.Parts))
+	for i, part := range result.Parts {
+		positions[i] = part.position.Index
+	}
+	slices.Sort(positions)
+	for i := 1; i < len(positions); i++ {
+		if positions[i] != positions[i-1]+1 {
+			return result, fmt.Errorf("text selection skips unselected container members")
+		}
+	}
+	for i := range result.Parts {
+		p := &result.Parts[i]
+		if p.container != result.Parts[0].container || p.position.Container != result.Parts[0].position.Container || p.position.Layer != result.Parts[0].position.Layer {
+			return result, fmt.Errorf("text selection crosses containers")
+		}
+		t := p.TextObject
+		m := p.Matrix
+		if math.Abs(m.a-m.d) > 1e-9*math.Max(m.a, m.d) {
+			result.Reflow = false
+		}
+		if t.ReadDirection != 0 || t.CharDirection != 0 || t.VScale != 0 || t.Decoration != "" || math.Abs(m.b) > 1e-9 || math.Abs(m.c) > 1e-9 || m.a <= 0 || m.d <= 0 {
+			return result, fmt.Errorf("text selection requires unambiguous horizontal character mapping")
+		}
+		if err := validateTextGlyphs(t, 1<<16); err != nil {
+			return result, err
+		}
+		for _, transform := range t.CGTransform {
+			if transform.CodeCount != transform.GlyphCount {
+				return result, fmt.Errorf("combined glyphs require independent explicit layout")
+			}
+		}
+		points, err := e.selectionTextPoints(t)
+		if err != nil {
+			return result, err
+		}
+		p.points = points
+		chars := []rune(t.Text())
+		var previous Point
+		hasPrevious := false
+		for j, point := range points {
+			if chars[j] == '\n' {
+				continue
+			}
+			p.Points = append(p.Points, point)
+			x, y := m.Transform(point.X, point.Y)
+			if !finite(x) || !finite(y) || hasPrevious && (point.Y < previous.Y-1e-7 || point.Y > previous.Y+1e-7 && chars[j-1] != '\n' || math.Abs(point.Y-previous.Y) < 1e-7 && point.X <= previous.X) {
+				return result, fmt.Errorf("ambiguous text reading order")
+			}
+			previous, hasPrevious = point, true
+			result.Bounds = unionTextBox(result.Bounds, m.TransformBox(Box{X: point.X, Y: point.Y - t.Size, W: t.Size, H: t.Size}))
+		}
+		if t.Clips != nil || len(t.Actions) != 0 || t.DrawParam != "" || t.Alpha != nil && *t.Alpha != 255 || t.Visible != nil && !*t.Visible || t.Stroke != nil && *t.Stroke || t.Fill != nil && !*t.Fill || t.HScale != 0 && t.HScale != 1 || t.Weight != 0 && t.Weight != 400 && t.Weight != 700 {
+			result.Reflow = false
+		}
+	}
+	slices.SortFunc(result.Parts, func(a, b TextSelectionPart) int {
+		ax, ay := a.Matrix.Transform(a.points[0].X, a.points[0].Y)
+		bx, by := b.Matrix.Transform(b.points[0].X, b.points[0].Y)
+		if ay < by {
+			return -1
+		}
+		if ay > by {
+			return 1
+		}
+		if ax < bx {
+			return -1
+		}
+		if ax > bx {
+			return 1
+		}
+		return 0
+	})
+	for start := 0; start < len(result.Parts); {
+		first := result.Parts[start]
+		_, anchor := first.Matrix.Transform(first.points[0].X, first.points[0].Y)
+		end := start + 1
+		for end < len(result.Parts) {
+			part := result.Parts[end]
+			_, y := part.Matrix.Transform(part.points[0].X, part.points[0].Y)
+			if y-anchor > 1e-6 {
+				break
+			}
+			end++
+		}
+		slices.SortStableFunc(result.Parts[start:end], func(a, b TextSelectionPart) int {
+			ax, _ := a.Matrix.Transform(a.points[0].X, a.points[0].Y)
+			bx, _ := b.Matrix.Transform(b.points[0].X, b.points[0].Y)
+			if ax < bx {
+				return -1
+			}
+			if ax > bx {
+				return 1
+			}
+			return 0
+		})
+		start = end
+	}
+	var baseline, lastEnd, lastOrigin, previousSize, rowStart float64
+	var text strings.Builder
+	offset := 0
+	for i := range result.Parts {
+		p := &result.Parts[i]
+		x, y := p.Matrix.Transform(p.points[0].X, p.points[0].Y)
+		if i > 0 && (y < baseline-1e-6 || math.Abs(y-baseline) < 1e-6 && (x <= lastOrigin+1e-7 || x < lastEnd-1e-7)) {
+			return result, fmt.Errorf("text objects overlap or interleave")
+		}
+		size := p.TextObject.Size * p.Matrix.d
+		if i > 0 {
+			limit := math.Max(size, previousSize)
+			if math.Abs(y-baseline) < 1e-6 && x-lastEnd > limit*8 || y > baseline+1e-6 && (y-baseline > limit*3 || math.Abs(x-rowStart) > limit*2) {
+				return result, fmt.Errorf("text selection has ambiguous column or paragraph gaps")
+			}
+		}
+		if i == 0 || y > baseline+1e-6 {
+			rowStart = x
+		}
+		if i > 0 && y > baseline+1e-6 {
+			text.WriteByte('\n')
+			offset++
+			result.RichText.Runs[len(result.RichText.Runs)-1].Text += "\n"
+		}
+		lastOrigin, baseline = p.Matrix.Transform(p.points[len(p.points)-1].X, p.points[len(p.points)-1].Y)
+		font, err := e.editorFont(p.TextObject.Font)
+		if err != nil {
+			return result, err
+		}
+		chars := []rune(strings.ReplaceAll(p.TextObject.Text(), "\n", ""))
+		glyph := font.GlyphIndex(chars[len(chars)-1])
+		for _, mapping := range p.TextObject.CGTransform {
+			if len(chars)-1 >= mapping.CodePosition && len(chars)-1 < mapping.CodePosition+mapping.CodeCount {
+				glyph = uint16(parseInts(mapping.Glyphs)[len(chars)-1-mapping.CodePosition])
+			}
+		}
+		scale := p.TextObject.HScale
+		if scale == 0 {
+			scale = 1
+		}
+		lastEnd = lastOrigin + float64(font.GlyphAdvance(glyph))*p.TextObject.Size/float64(font.UnitsPerEm())*scale*p.Matrix.a
+		previousSize = size
+		value := p.TextObject.Text()
+		p.Start = offset
+		text.WriteString(value)
+		offset += utf8.RuneCountInString(value)
+		p.End = offset
+		format := TextFormat{Font: p.TextObject.Font, Size: p.TextObject.Size * p.Matrix.d, Color: "0 0 0", Bold: p.TextObject.Weight == 700, Italic: p.TextObject.Italic}
+		if p.TextObject.FillColor != nil {
+			c := p.TextObject.FillColor
+			if c.Pattern != nil || c.AxialShd != nil || c.RadialShd != nil || c.GouraudShd != nil || c.LaGouraudShd != nil || c.unsupported {
+				result.Reflow = false
+			}
+			color, err := e.Color(p.TextObject.FillColor)
+			if err != nil {
+				return result, err
+			}
+			r, g, b, a := color.RGBA()
+			if a > 0 && a < 65535 {
+				r = r * 65535 / a
+				g = g * 65535 / a
+				b = b * 65535 / a
+			}
+			format.Color = fmt.Sprintf("%d %d %d", r>>8, g>>8, b>>8)
+			if a != 65535 {
+				result.Reflow = false
+			}
+		}
+		result.RichText.Runs = append(result.RichText.Runs, RichTextRun{Text: value, Format: format})
+		p.Color = format.Color
+	}
+	result.Text = text.String()
+	if result.Reflow && e.source != nil && (e.source.document.CustomTags.Path != "" || len(e.source.document.CustomTags.CustomTag) != 0) {
+		structures, err := e.Structure()
+		if err != nil {
+			result.Reflow = false
+		} else {
+			ids := make(map[string]bool, len(result.Parts)+1)
+			for _, part := range result.Parts {
+				ids[editorResourceID(part.ID)] = true
+			}
+			if selection.Root != nil {
+				ids[editorResourceID(selection.Root.ID)] = true
+				for i, index := range selection.Root.Children {
+					parent := *selection.Root
+					parent.Children = parent.Children[:i]
+					member, err := e.CompositeObject(page, parent, index)
+					if err != nil {
+						result.Reflow = false
+						break
+					}
+					ids[editorResourceID(editorObjectID(member.Object))] = true
+				}
+			}
+			pageID := editorResourceID(e.pages[page].ID)
+			for _, structure := range structures {
+				if structure.Error != "" || structure.Root == nil || !structure.CanBind {
+					result.Reflow = false
+					break
+				}
+				pending := []*StructureNode{structure.Root}
+				for len(pending) != 0 && result.Reflow {
+					node := pending[len(pending)-1]
+					pending = pending[:len(pending)-1]
+					for _, ref := range node.References {
+						if editorResourceID(ref.PageID) != pageID {
+							continue
+						}
+						for _, id := range ref.ObjectIDs {
+							if ids[editorResourceID(id)] {
+								result.Reflow = false
+							}
+						}
+					}
+					for i := range node.Children {
+						pending = append(pending, &node.Children[i])
+					}
+				}
+			}
+		}
+	}
+	return result, nil
+}
+
+// selectionTextPoints 读取标准逐字原点，不推断缺失的字符映射
+// 入参: t 文字对象
+// 返回: []Point 含换行占位的码点原点, error 字体或映射错误
+func (e *Editor) selectionTextPoints(t TextObject) ([]Point, error) {
+	font, err := e.editorFont(t.Font)
+	if err != nil {
+		return nil, err
+	}
+	ascent, _, _ := font.VerticalMetrics()
+	var points []Point
+	lines := newTextLineScanner(t)
+	mappings := make(map[int]CGTransform, len(t.CGTransform))
+	for _, mapping := range t.CGTransform {
+		mappings[mapping.CodePosition] = mapping
+	}
+	offset := 0
+	for _, code := range textCodeOrigins(t.TextCode, float64(ascent)*t.Size/float64(font.UnitsPerEm())) {
+		if lines.next(code) {
+			points = append(points, Point{})
+		}
+		if code.Index != "" {
+			return nil, fmt.Errorf("glyph-index text has no character mapping")
+		}
+		position := NewTextPositioner(code)
+		chars := textCodeRunes(code.Value)
+		for i := 0; i < len(chars); {
+			mapping, ok := mappings[offset+i]
+			if !ok {
+				points = append(points, position.Next())
+				i++
+				continue
+			}
+			if mapping.CodeCount <= 0 || mapping.GlyphCount <= 0 || i+mapping.CodeCount > len(chars) {
+				return nil, fmt.Errorf("invalid text character mapping")
+			}
+			glyphPoints := make([]Point, mapping.GlyphCount)
+			for j := range glyphPoints {
+				glyphPoints[j] = position.Next()
+			}
+			for j := 0; j < mapping.CodeCount; j++ {
+				points = append(points, glyphPoints[min(j, len(glyphPoints)-1)])
+			}
+			i += mapping.CodeCount
+		}
+		offset += len(chars)
+	}
+	if len(points) == 0 || len(points) != utf8.RuneCountInString(t.Text()) {
+		return nil, fmt.Errorf("text selection requires a nonempty character mapping")
+	}
+	return points, nil
+}
+
+// PreviewTextSelection 在隔离快照生成与提交相同的结果，不分配文档资源或修改历史
+// 入参: page 页面索引, selection 文字选区, edit 编辑范围与样式
+// 返回: TextSelectionPreview 更新文字与来源映射, error 校验错误
+func (e *Editor) PreviewTextSelection(page int, selection TextSelection, edit TextSelectionEdit) (TextSelectionPreview, error) {
+	analysis, err := e.AnalyzeTextSelection(page, selection)
+	if err != nil {
+		return TextSelectionPreview{}, err
+	}
+	copy := e.transactionSnapshot()
+	if err := copy.prepareTextSelectionEdit(&edit); err != nil {
+		return TextSelectionPreview{}, err
+	}
+	result, err := copy.previewTextSelection(analysis, edit)
+	return cloneEditorData(result), err
+}
+
+// previewTextSelection 统一生成定位更新或显式富文本布局
+// 入参: analysis 选区快照, edit 编辑参数
+// 返回: TextSelectionPreview 更新预览, error 编辑错误
+func (e *Editor) previewTextSelection(analysis TextSelectionAnalysis, edit TextSelectionEdit) (TextSelectionPreview, error) {
+	result := TextSelectionPreview{analysis: analysis, Bounds: analysis.Bounds, Font: edit.Font}
+	if edit.Reflow != nil {
+		if !analysis.Reflow {
+			return result, fmt.Errorf("selection appearance cannot be safely reflowed")
+		}
+		value := cloneEditorData(*edit.Reflow)
+		for i := range value.Runs {
+			if edit.Font != "" {
+				value.Runs[i].Format.Font = edit.Font
+			}
+			if edit.Size != 0 {
+				value.Runs[i].Format.Size = edit.Size
+			}
+			if edit.Color != "" {
+				value.Runs[i].Format.Color = edit.Color
+			}
+		}
+		width := edit.Width
+		if width == 0 {
+			width = analysis.Bounds.W
+		}
+		layout, err := e.layoutRichText(value, width)
+		if err != nil {
+			return result, err
+		}
+		result.Text = value.Text()
+		for _, object := range layout.objects {
+			if object.Type != "TextObject" {
+				continue
+			}
+			box, err := ParseBox(object.TextObject.Boundary)
+			if err != nil {
+				return result, err
+			}
+			part := TextSelectionPart{Index: -1, TextObject: object.TextObject, Matrix: TranslationMatrix(analysis.Bounds.X+box.X, analysis.Bounds.Y+box.Y).Multiply(NewMatrix(object.TextObject.CTM))}
+			part.Color = "0 0 0"
+			if object.TextObject.FillColor != nil {
+				part.Color = object.TextObject.FillColor.Value
+			}
+			points, err := e.selectionTextPoints(object.TextObject)
+			if err != nil {
+				return result, err
+			}
+			for i, char := range []rune(object.TextObject.Text()) {
+				if char != '\n' {
+					part.Points = append(part.Points, points[i])
+				}
+			}
+			for i := range analysis.Parts {
+				part.Sources = append(part.Sources, i)
+			}
+			result.Parts = append(result.Parts, part)
+		}
+		result.Selection = selectionAfterTextEdit(analysis, nil, true)
+		return result, nil
+	}
+	if !utf8.ValidString(edit.Text) || strings.ContainsAny(edit.Text, "\r\t") || edit.Start < 0 || edit.End < edit.Start || edit.End > utf8.RuneCountInString(analysis.Text) {
+		return result, fmt.Errorf("invalid text selection range")
+	}
+	boundaries := richTextBoundaries(analysis.Text)
+	if !boundaries[edit.Start] || !boundaries[edit.End] {
+		return result, fmt.Errorf("text range splits a grapheme")
+	}
+	replacement := []rune(edit.Text)
+	originalText := []rune(analysis.Text)
+	wantedText := string(originalText[:edit.Start]) + edit.Text + string(originalText[edit.End:])
+	if len(replacement) != 0 && len(replacement) != edit.End-edit.Start {
+		return result, &EditError{Code: EditLayoutRequired, Err: fmt.Errorf("positioned replacement must have equal length or be a deletion")}
+	}
+	for _, source := range analysis.Parts {
+		p := source
+		t := cloneEditorData(source.TextObject)
+		old := []rune(t.Text())
+		var next []rune
+		var codes []TextCode
+		var transforms []CGTransform
+		glyphs := make(map[int]string)
+		for _, mapping := range t.CGTransform {
+			for j, glyph := range strings.Fields(mapping.Glyphs) {
+				glyphs[mapping.CodePosition+j] = glyph
+			}
+		}
+		glyphPosition, retained := 0, 0
+		p.Points = nil
+		for j, char := range old {
+			at := source.Start + j
+			original := char
+			if char != '\n' {
+				glyphPosition++
+			}
+			if at >= edit.Start && at < edit.End {
+				if len(replacement) == 0 {
+					continue
+				}
+				char = replacement[at-edit.Start]
+			}
+			if (original == '\n') != (char == '\n') {
+				return result, &EditError{Code: EditLayoutRequired, Err: fmt.Errorf("changing line breaks requires reflow")}
+			}
+			next = append(next, char)
+			if char == '\n' {
+				continue
+			}
+			point := source.points[j]
+			p.Points = append(p.Points, point)
+			codes = append(codes, TextCode{X: ofdNumber(point.X), Y: ofdNumber(point.Y), Value: escapeOFDText(string(char))})
+			if glyph, ok := glyphs[glyphPosition-1]; ok {
+				transforms = append(transforms, CGTransform{CodePosition: retained, CodeCount: 1, GlyphCount: 1, Glyphs: glyph})
+			}
+			retained++
+		}
+		p.Deleted = len(codes) == 0
+		if !p.Deleted {
+			if len(next) == len(old) && (string(next) != string(old) || edit.Font != "" && edit.Font != t.Font) {
+				if err := e.RewriteTextWithFont(&t, string(next), edit.Font); err != nil {
+					return result, err
+				}
+			} else if len(next) != len(old) {
+				t.TextCode, t.CGTransform, t.layout = codes, transforms, nil
+				if err := e.RewriteTextWithFont(&t, t.Text(), edit.Font); err != nil {
+					return result, err
+				}
+			}
+			if edit.Size != 0 {
+				t.Size = edit.Size / source.Matrix.d
+			}
+			if edit.Color != "" {
+				p.Color = edit.Color
+				var r, g, b float64
+				fmt.Sscan(edit.Color, &r, &g, &b)
+				fill, err := e.RGBColor(color.NRGBA{R: uint8(r), G: uint8(g), B: uint8(b), A: 255})
+				if err != nil {
+					return result, err
+				}
+				t.FillColor = editorStyleColor(fill, t.FillColor)
+			}
+			if err := validateEditorGeometry(GraphicObject{Type: "TextObject", TextObject: t}); err != nil {
+				return result, err
+			}
+			if result.Text != "" && source.Start > 0 && []rune(analysis.Text)[source.Start-1] == '\n' {
+				result.Text += "\n"
+			}
+			result.Text += t.Text()
+		}
+		p.TextObject = t
+		result.Parts = append(result.Parts, p)
+	}
+	result.Selection = selectionAfterTextEdit(analysis, result.Parts, false)
+	if result.Text != wantedText {
+		return result, &EditError{Code: EditLayoutRequired, Err: fmt.Errorf("changing positioned line breaks requires explicit reflow")}
+	}
+	return result, nil
+}
+
+// prepareTextSelectionEdit 在当前隔离视图校验覆盖样式并注册替换字体
+// 入参: edit 编辑参数
+// 返回: error 字体或样式错误
+func (e *Editor) prepareTextSelectionEdit(edit *TextSelectionEdit) error {
+	if !finite(edit.Size) || edit.Size < 0 || !finite(edit.Width) || edit.Width < 0 {
+		return fmt.Errorf("invalid text selection dimensions")
+	}
+	if edit.Color != "" {
+		if err := creationColor(&FillColor{Value: edit.Color}); err != nil {
+			return err
+		}
+	}
+	if len(edit.FontData) > 0 {
+		id, err := e.AddFont(FontFile{Data: edit.FontData}, 0)
+		if err != nil {
+			return err
+		}
+		edit.Font = id
+	}
+	return nil
+}
+
+// selectionAfterTextEdit 计算删除及重排后的选中位置，不保留旧修订绑定
+// 入参: analysis 原选区, parts 更新项, reflow 是否合并为富文本
+// 返回: TextSelection 提交后可用于重新枚举的选择
+func selectionAfterTextEdit(analysis TextSelectionAnalysis, parts []TextSelectionPart, reflow bool) TextSelection {
+	result := TextSelection{Root: analysis.Selection.Root}
+	deleted := make(map[int]bool)
+	if reflow {
+		for _, part := range analysis.Parts[1:] {
+			deleted[part.Index] = true
+		}
+		parts = analysis.Parts[:1]
+	} else {
+		for _, part := range parts {
+			if part.Deleted {
+				deleted[part.Index] = true
+			}
+		}
+	}
+	for _, part := range parts {
+		if part.Deleted {
+			continue
+		}
+		if result.Root == nil {
+			result.IDs = append(result.IDs, part.ID)
+			continue
+		}
+		index := part.Index
+		for removed := range deleted {
+			if removed < part.Index {
+				index--
+			}
+		}
+		result.Indexes = append(result.Indexes, index)
+	}
+	return result
+}
+
+// UpdateTextSelection 原子提交联合文字修改，失败不改变资源、ID或撤销重做
+// 入参: page 页面索引, selection 文字选区, edit 编辑范围与样式
+// 返回: error 校验或提交错误
+func (e *Editor) UpdateTextSelection(page int, selection TextSelection, edit TextSelectionEdit) error {
+	analysis, err := e.AnalyzeTextSelection(page, selection)
+	if err != nil {
+		return err
+	}
+	return e.Transaction(func(e *Editor) error {
+		if err := e.prepareTextSelectionEdit(&edit); err != nil {
+			return err
+		}
+		preview, err := e.previewTextSelection(analysis, edit)
+		if err != nil {
+			return err
+		}
+		if edit.Reflow != nil {
+			return e.reflowTextSelection(page, selection, edit, preview)
+		}
+		if selection.Root != nil {
+			return e.editCompositeObjects(page, *selection.Root, selection.Indexes, func(_ *Renderer, nodes []*editorCompositeNode, _ []CompositeMember) error {
+				for i, node := range nodes {
+					for _, part := range preview.Parts {
+						if part.Index != selection.Indexes[i] {
+							continue
+						}
+						if part.Deleted {
+							node.owner.patches = append(node.owner.patches, editorXMLPatch{node.span.start, node.span.end, nil})
+							continue
+						}
+						object := cloneEditorData(node.object)
+						object.TextObject.TextCode, object.TextObject.CGTransform = part.TextObject.TextCode, part.TextObject.CGTransform
+						if edit.Font != "" {
+							object.TextObject.Font = part.TextObject.Font
+						}
+						if edit.Size != 0 {
+							object.TextObject.Size = part.TextObject.Size
+						}
+						if edit.Color != "" {
+							object.TextObject.FillColor = part.TextObject.FillColor
+						}
+						if reflect.DeepEqual(object, node.object) {
+							continue
+						}
+						if err := node.update(object); err != nil {
+							return err
+						}
+						node.setState(editorCompositeState{})
+					}
+				}
+				return nil
+			})
+		}
+		var updates []GraphicObject
+		var deleted []string
+		for _, part := range preview.Parts {
+			if part.Deleted {
+				deleted = append(deleted, part.ID)
+				continue
+			}
+			next := selectionUpdatedText(part, edit)
+			if !reflect.DeepEqual(next, part.raw) {
+				updates = append(updates, GraphicObject{Type: "TextObject", TextObject: next})
+			}
+		}
+		if len(updates) > 0 {
+			if err := e.updateObjects(page, updates, true); err != nil {
+				return err
+			}
+		}
+		if len(deleted) > 0 {
+			return e.DeleteObjects(page, deleted)
+		}
+		return nil
+	})
+}
+
+// selectionUpdatedText 仅更新请求字段，保留源对象继承样式与排版状态
+// 入参: part 预览项, edit 编辑参数
+// 返回: TextObject 可提交的原始对象
+func selectionUpdatedText(part TextSelectionPart, edit TextSelectionEdit) TextObject {
+	next := cloneEditorData(part.raw)
+	next.TextCode, next.CGTransform, next.layout = part.TextObject.TextCode, part.TextObject.CGTransform, part.TextObject.layout
+	if edit.Font != "" {
+		next.Font = part.TextObject.Font
+	}
+	if edit.Size != 0 {
+		next.Size = part.TextObject.Size
+	}
+	if edit.Color != "" {
+		next.FillColor = part.TextObject.FillColor
+	}
+	return next
+}
+
+// reflowTextSelection 将富文本排版结果替换至首个源位置，其他源成员一并删除
+// 入参: page 页面索引, selection 原选择, edit 编辑参数, preview 布局预览
+// 返回: error 排版或提交错误
+func (e *Editor) reflowTextSelection(page int, selection TextSelection, edit TextSelectionEdit, preview TextSelectionPreview) error {
+	value := cloneEditorData(*edit.Reflow)
+	for i := range value.Runs {
+		if edit.Font != "" {
+			value.Runs[i].Format.Font = edit.Font
+		}
+		if edit.Size != 0 {
+			value.Runs[i].Format.Size = edit.Size
+		}
+		if edit.Color != "" {
+			value.Runs[i].Format.Color = edit.Color
+		}
+	}
+	box := preview.Bounds
+	if edit.Width != 0 {
+		box.W = edit.Width
+	}
+	object, meta, err := e.prepareRichText(box, value)
+	if err != nil {
+		return err
+	}
+	first := preview.analysis.Parts[0]
+	if selection.Root == nil {
+		object.CompositeGraphicUnit.ID = first.ID
+		if err := e.updateObjects(page, []GraphicObject{object}, true); err != nil {
+			return err
+		}
+		var deleted []string
+		for _, part := range preview.analysis.Parts[1:] {
+			deleted = append(deleted, part.ID)
+		}
+		if len(deleted) > 0 {
+			if err := e.DeleteObjects(page, deleted); err != nil {
+				return err
+			}
+		}
+		return e.putRichTextMetadata(page, first.ID, meta, -1)
+	}
+	return e.editCompositeObjects(page, *selection.Root, selection.Indexes, func(_ *Renderer, nodes []*editorCompositeNode, _ []CompositeMember) error {
+		for i, node := range nodes {
+			if selection.Indexes[i] != first.Index {
+				node.owner.patches = append(node.owner.patches, editorXMLPatch{node.span.start, node.span.end, nil})
+				continue
+			}
+			inverse, ok := node.parent.Invert()
+			if !ok {
+				return fmt.Errorf("invalid composite parent transform")
+			}
+			local := transformEditorMatrix(object, inverse)
+			local.CompositeGraphicUnit.ID = node.object.TextObject.ID
+			if !node.boundaryInCTM {
+				local = compositeBoundary(local, node.parent, false)
+			}
+			if err := node.update(local); err != nil {
+				return err
+			}
+			node.setState(editorCompositeState{})
+		}
+		return nil
+	})
+}