feat(编辑能力): 补齐分散对齐与段落即时调整

assets/webui/index.html

@@ -140,7 +140,7 @@
 					<option value="left">左齐</option>
 					<option value="center">居中</option>
 					<option value="right">右齐</option>
-					<option value="justify">两端</option>
+					<option value="justify">两端</option><option value="distributed">分散</option>
 				</select>
 				<label class="editor-field"><span>行距</span><span class="editor-number"><input id="textLineHeight" type="number" min="0" step="any" placeholder="自动" title="行距，0为自动" disabled><span>pt</span></span></label>
 				<button id="textWrap" class="button" type="button" data-pressed="false" disabled>折行</button>

assets/webui/ofdgo.js

@@ -1,4 +1,4 @@
-import { SVG_NAMESPACE, CanvasEditor, canEditObject, editTextValue, richTextModel, fontFaceStyle, missingGlyphMessage, objectEditReason, selectedText, lineShape, selectionBounds, pagePoint } from "./ofdgo_edit.js";
+import { SVG_NAMESPACE, CanvasEditor, canEditObject, editTextValue, richTextModel, richTextAlignment, fontFaceStyle, missingGlyphMessage, objectEditReason, selectedText, lineShape, selectionBounds, pagePoint } from "./ofdgo_edit.js";
 import { FontManager, FontPicker } from "./ofdgo_font.js";
 import { nativeHost, createEngineWorker, engineLimits, documentBytes, saveFilePicker, directoryPicker } from "./ofdgo_host.js";
 import { PrintDialog } from "./ofdgo_print.js";
@@ -704,7 +704,7 @@ const annotationFields = Object.fromEntries(["CreateForm", "CreateCancel", "Cont
 el.editorTools.addEventListener("scroll", () => fontPicker.position());
 
 const canvasEditor = new CanvasEditor(el.viewerPanel, {
-	textControls: [el.textFont, el.textFontToggle, el.textFontAdd, el.textFontList, el.textSize, el.textColor, textBackground, ...textFormatButtons, el.undoButton, el.redoButton, el.saveButton, el.saveAsButton, el.fontInput, document.querySelector("#textReflow")],
+	textControls: [el.textAlign, el.textFont, el.textFontToggle, el.textFontAdd, el.textFontList, el.textSize, el.textColor, textBackground, ...textFormatButtons, el.undoButton, el.redoButton, el.saveButton, el.saveAsButton, el.fontInput, document.querySelector("#textReflow")],
 	keepTextFocus: () => fontPicker.open || el.closePanel.open || canvasEditor.input?.fontDialog,
 	textClipboardScope: () => `${documentTab().id}:${documentContentKey(state)}:${state.editorInfo?.revision ?? ""}`,
 	getTextClipboard: () => workspace.textClipboard,
@@ -867,7 +867,7 @@ el.textColor.addEventListener("change", () => changeTextStyle(true));
 for (const button of textFormatButtons) button.addEventListener("click", () => changeRangeFormat(button.dataset.textFormat));
 textBackground.addEventListener("change", () => changeRangeFormat("background", textBackground.value));
 editorClick(el.textWrap, () => changeParagraph(!currentTextStyle().wrap));
-el.textAlign.addEventListener("change", () => changeParagraph());
+el.textAlign.addEventListener("change", () => changeTextAlignment());
 el.textLineHeight.addEventListener("change", () => changeParagraph());
 editorClick(el.paragraphButton, () => {
 	const item = currentTextStyle();
@@ -4253,9 +4253,11 @@ async function validateRichText(item, model, width, fonts = []) {
 }
 
 async function saveRichText(item, model, fonts = [], box = item) {
+	const tab = documentTab(), openSeq = state.openSeq, wasmSeq = state.wasmSeq;
 	const boundary = { x: box.x, y: box.y, width: box.width, height: box.height };
 	if (box.frameWidth !== undefined) Object.assign(boundary, { frameWidth: box.frameWidth, frameOffset: box.frameOffset || 0 });
 	fonts = await validateRichText(item, model, box.frameWidth ?? item.textFrame?.width ?? item.width, fonts);
+	if (tab.closed || !isForegroundDocument(tab) || tab.state.openSeq !== openSeq || tab.state.wasmSeq !== wasmSeq) return false;
 	return changeDocument("ofdgoSaveRichText", item.draft ? null : item,
 		...(item.draft ? [item.index, ""] : []), JSON.stringify(model), boundary, fonts);
 }
@@ -4552,6 +4554,25 @@ function inputMillimeters(input, original) {
 	return points === displayPoints(original) ? original : points * 25.4 / 72;
 }
 
+async function changeTextAlignment() {
+	const align = el.textAlign.value, editing = canvasEditor.input, tab = documentTab();
+	if (!state.ready || state.exporting || document.body.hasAttribute("data-busy") || editing?.composing || editing?.saving || !align) return;
+	try {
+		if (editing) {
+			if (!editing.rich && !editing.item.draft && !confirmTextReflow(editing.item)) return;
+			if (!await ensureRichInput() || !isForegroundDocument(tab) || canvasEditor.input !== editing) return;
+			editing.rich.align(align);
+		} else if (canvasEditor.selected?.richText) {
+			const item = canvasEditor.selected;
+			await saveRichText(item, { ...item.richText, paragraphs: undefined, layout: { ...item.richText.layout, align } });
+		} else await changeParagraph();
+	} catch (error) {
+		if (isForegroundDocument(tab) && canvasEditor.input === editing) showError(error, false);
+	} finally {
+		if (isForegroundDocument(tab)) updateObjectControls(canvasEditor.selected, true);
+	}
+}
+
 async function changeParagraph(wrap) {
 	const item = currentTextStyle();
 	const explicitWrap = wrap !== undefined;
@@ -4577,7 +4598,7 @@ async function changeParagraph(wrap) {
 		updateObjectControls(item, true);
 		return;
 	}
-	if (item.richText) await saveRichText(item, { ...item.richText, layout: { ...item.richText.layout, wrap: Boolean(wrap), align: el.textAlign.value, lineHeight: height, letterSpacing: spacing } });
+	if (item.richText) await saveRichText(item, { ...item.richText, layout: { ...item.richText.layout, wrap: Boolean(wrap), lineHeight: height, letterSpacing: spacing } });
 	else await changeDocument("ofdgoLayoutText", item, null, null, Boolean(wrap), el.textAlign.value, height, spacing, ...textIndents(item));
 	updateObjectControls(canvasEditor.selected, true);
 }
@@ -12466,14 +12487,18 @@ function updateObjectControls(item, reset = false) {
 		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);
+	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 && (item?.selectionIDs || !canEditObject(item, "layoutKnown"));
 	reflow.hidden = !positioned;
 	el.textWrap.hidden = !!positioned;
 	reflow.disabled = textDisabled || !canEditObject(item, "reflow") || !!canvasEditor.input?.reflow;
-	el.paragraphButton.disabled = el.textAlign.disabled;
+	el.paragraphButton.disabled = el.textWrap.disabled;
+	el.textAlign.disabled = el.textSize.disabled || Boolean(item?.items || item?.selectionIDs);
 	const layoutKnown = text === state.textDefaults || Boolean(item?.draft) || canEditObject(item, "layoutKnown");
-	el.textAlign.value = layoutKnown ? text.align || "left" : "";
+	const rich = canvasEditor.input?.rich;
+	const alignment = rich ? richTextAlignment(rich.model, ...rich.selection()) : item?.richText ? richTextAlignment(item.richText) : layoutKnown ? text.align || "left" : "";
+	el.textAlign.options[0].textContent = rich || item?.richText ? "混合" : "原文";
+	el.textAlign.value = alignment;
 	el.textLineHeight.placeholder = layoutKnown ? "自动" : "原文";
 	el.textSpacing.placeholder = layoutKnown ? "0" : "原文";
 	el.textWrap.setAttribute("data-pressed", String(Boolean(text.wrap)));

assets/webui/ofdgo_edit.js

@@ -42,6 +42,76 @@ export function richTextModel(item) {
 			firstLineIndent: item.firstLineIndent || 0, autoBidi: true } };
 }
 
+function paragraphRange(text, start, end) {
+	const first = text.slice(0, start).split("\n").length - 1;
+	return [first, end > start ? text.slice(0, end - 1).split("\n").length - 1 : first];
+}
+
+export function richTextAlignment(model, start = 0, end = model.runs.reduce((n, run) => n + run.text.length, 0)) {
+	const text = model.runs.map(run => run.text).join("");
+	const [first, last] = paragraphRange(text, start, end);
+	const align = model.paragraphs?.[first]?.align || model.layout.align || "left";
+	for (let i = first + 1; i <= last; i++) if ((model.paragraphs?.[i]?.align || model.layout.align || "left") !== align) return "";
+	return align;
+}
+
+function replaceParagraphs(model, text, start, end, inserted, paragraphs) {
+	if (!model.paragraphs?.length && !paragraphs?.length) return;
+	const first = text.slice(0, start).split("\n").length - 1, last = text.slice(0, end).split("\n").length - 1;
+	const current = model.paragraphs?.length ? model.paragraphs : text.split("\n").map(() => ({ align: "" }));
+	model.paragraphs = [...current.slice(0, first),
+		...inserted.split("\n").map((_, i) => ({ ...(paragraphs?.[i] || current[first]) })), ...current.slice(last + 1)];
+}
+
+function distributeParagraph(input, paragraph) {
+	const probe = input.cloneNode(false), copy = paragraph.cloneNode(true);
+	Object.assign(probe.style, { position: "fixed", transform: "none", visibility: "hidden", pointerEvents: "none", width: `${input.offsetWidth}px` });
+	probe.contentEditable = "false";
+	probe.append(copy);
+	document.body.append(probe);
+	try {
+		const lines = [], range = document.createRange(), width = copy.clientWidth;
+		const spacing = parseFloat(getComputedStyle(probe).letterSpacing) || 0;
+		const indent = parseFloat(getComputedStyle(copy).textIndent) || 0;
+		for (const span of copy.children) {
+			const node = span.firstChild;
+			if (node?.nodeType !== 3) continue;
+			for (const part of graphemes.segment(node.textContent)) {
+				range.setStart(node, part.index); range.setEnd(node, part.index + part.segment.length);
+				const rect = range.getBoundingClientRect();
+				let line = lines.at(-1);
+				if (!line || rect.top >= line.bottom - 0.5 || rect.bottom <= line.top + 0.5) {
+					line = { top: rect.top, bottom: rect.bottom, parts: [] }; lines.push(line);
+				}
+				line.parts.push({ text: part.segment, width: rect.width, style: span.style.cssText });
+			}
+		}
+		if (!lines.length) return;
+		paragraph.replaceChildren();
+		for (const [index, line] of lines.entries()) {
+			if (index) { const wrap = document.createElement("br"); wrap.dataset.textWrap = "true"; paragraph.append(wrap); }
+			const row = document.createElement("span");
+			row.style.whiteSpace = "pre";
+			let end = line.parts.length;
+			while (end && line.parts[end - 1].text === " ") end--;
+			const length = line.parts.slice(0, end).reduce((sum, part) => sum + part.width, 0) - (end ? spacing : 0);
+			const extra = end > 1 ? Math.max(0, width - (index ? 0 : indent) - length) / (end - 1) : 0;
+			let previous;
+			for (const [i, part] of line.parts.entries()) {
+				const tracking = i < end - 1 ? spacing + extra : i === end - 1 ? 0 : spacing;
+				const key = `${part.style}:${tracking}`;
+				if (previous?.key === key) previous.node.firstChild.appendData(part.text);
+				else {
+					const span = document.createElement("span"); span.style.cssText = part.style;
+					span.style.letterSpacing = `${tracking}px`; span.textContent = part.text; row.append(span);
+					previous = {key, node:span};
+				}
+			}
+			paragraph.append(row);
+		}
+	} finally { probe.remove(); }
+}
+
 function normalizeRuns(runs) {
 	const result = [];
 	for (const run of runs) {
@@ -104,6 +174,7 @@ export class RichTextSession {
 		this.model = structuredClone(model);
 		this.model.runs = normalizeRuns(model.runs);
 		this.initial = JSON.stringify(this.model);
+		this.recordedParagraphs = this.model.paragraphs;
 		this.faces = faces;
 		for (const face of faces.values()) document.fonts.add(face);
 		this.imports = new Map(imports.map(font => [font.key, font.data]));
@@ -156,11 +227,19 @@ export class RichTextSession {
 	record(before) {
 		const change = textChange(before, this.model.runs);
 		const entry = { change, typing: { ...this.typing }, caret: [...this.caret] }, old = this.entries[this.index];
+		const beforeText = before.map(run => run.text).join("");
+		if (beforeText !== this.text && this.model.paragraphs === this.recordedParagraphs) {
+			const removed = change.before.map(run => run.text).join(""), inserted = change.after.map(run => run.text).join("");
+			replaceParagraphs(this.model, beforeText, change.start, change.start + removed.length, inserted);
+		}
+		const paragraphsChanged = JSON.stringify(this.recordedParagraphs) !== JSON.stringify(this.model.paragraphs);
+		if (paragraphsChanged) entry.paragraphs = { before: this.recordedParagraphs, after: this.model.paragraphs };
+		this.recordedParagraphs = this.model.paragraphs;
 		const changed = change.before.length || change.after.length;
-		if (!changed && JSON.stringify(entry.typing) === JSON.stringify(old.typing)) return;
+		if (!changed && !paragraphsChanged && JSON.stringify(entry.typing) === JSON.stringify(old.typing)) return;
 		if (!changed) entry.change = null;
 		this.entries.splice(++this.index, Infinity, entry);
-		if (changed) this.preview();
+		if (changed || paragraphsChanged) this.preview();
 	}
 	undo(direction) {
 		if (this.editing.composing || this.editing.saving) return;
@@ -172,6 +251,9 @@ export class RichTextSession {
 			const end = change.start + removed.reduce((length, run) => length + run.text.length, 0);
 			this.model.runs = normalizeRuns([...sliceRuns(this.model.runs, 0, change.start), ...added, ...sliceRuns(this.model.runs, end, this.text.length)]);
 		}
+		const paragraphs = (direction < 0 ? this.entries[this.index] : entry).paragraphs;
+		if (paragraphs) this.model.paragraphs = direction < 0 ? paragraphs.before : paragraphs.after;
+		this.recordedParagraphs = this.model.paragraphs;
 		this.index += direction;
 		this.typing = { ...entry.typing };
 		this.caret = [...entry.caret];
@@ -187,6 +269,7 @@ export class RichTextSession {
 			const editing = this.editing;
 			if (this.editor.input !== editing || editing.composing || editing.saving) return;
 			const current = () => this.editor.input === editing && this.previewSequence === sequence && !editing.composing && !editing.saving;
+			if (!this.model.runs.length) { this.editor.setTextError(null); return; }
 			try {
 				await this.editor.options.onPreviewRichText(editing.item, this.model, editing.frame.width, this.fonts);
 				if (!current()) return;
@@ -213,10 +296,20 @@ export class RichTextSession {
 		this.render();
 		this.editor.options.onTextChange();
 	}
-	replace(runs) {
+	align(value) {
+		if (this.editing.composing || this.editing.saving) return;
 		this.remember();
-		const [start, end] = this.selection();
+		const [start, end] = this.selection(), [first, last] = paragraphRange(this.text, start, end);
+		this.model.paragraphs = this.text.split("\n").map((_, i) => ({ align: i >= first && i <= last ? value : this.model.paragraphs?.[i]?.align || "" }));
+		this.record(this.model.runs);
+		this.render();
+		this.editor.options.onTextChange();
+	}
+	replace(runs, paragraphs, range) {
+		this.remember();
+		const [start, end] = range || this.selection();
 		const before = this.model.runs;
+		if (paragraphs) replaceParagraphs(this.model, this.text, start, end, runs.map(run => run.text).join(""), paragraphs);
 		this.model.runs = normalizeRuns([...sliceRuns(this.model.runs, 0, start), ...runs, ...sliceRuns(this.model.runs, end, this.text.length)]);
 		this.caret = [start + runs.reduce((length, run) => length + run.text.length, 0)];
 		this.caret.push(this.caret[0]);
@@ -256,7 +349,9 @@ export class RichTextSession {
 		const runs = sliceRuns(this.model.runs, start, end), text = runs.map(run => run.text).join("");
 		const keys = new Set(runs.map(run => run.format.font));
 		const fonts = new Map([...keys].map(key => [key, this.imports.get(key) || this.resources.get(key)]).filter(([, data]) => data));
-		const clipboard = { token: crypto.randomUUID(), runs, text, scope: this.editor.options.textClipboardScope?.(),
+		const first = this.text.slice(0, start).split("\n").length - 1;
+		const paragraphs = text.split("\n").map((_, i) => ({ align: this.model.paragraphs?.[first + i]?.align || this.model.layout.align || "left" }));
+		const clipboard = { token: crypto.randomUUID(), runs, text, paragraphs, scope: this.editor.options.textClipboardScope?.(),
 			fonts, faces: new Map([...this.faces].filter(([key]) => keys.has(key))), choices: new Map([...this.choices].filter(([key]) => keys.has(key))) };
 		if (this.editor.options.setTextClipboard) this.editor.options.setTextClipboard(clipboard);
 		else this.editor.richClipboard = clipboard;
@@ -278,17 +373,17 @@ export class RichTextSession {
 			const keys = new Map(copy.runs.map(run => [run.format.font, sameScope ? run.format.font : `temp-font-${crypto.randomUUID()}`]));
 			let faces = copy.faces;
 			if (!sameScope) {
-				const original = this.model.runs, caret = this.selection();
+				const original = this.model.runs, paragraphs = this.model.paragraphs, caret = this.selection();
 				faces = new Map(await Promise.all([...copy.fonts].map(async ([key, data]) =>
 					[key, await new FontFace(`ofdgo-paste-${keys.get(key)}`, data, fontFaceStyle(data)).load()])));
-				if (this.editor.input !== this.editing || this.editing.composing || this.editing.saving || this.model.runs !== original || this.selection().join() !== caret.join()) return;
+				if (this.editor.input !== this.editing || this.editing.composing || this.editing.saving || this.model.runs !== original || this.model.paragraphs !== paragraphs || this.selection().join() !== caret.join()) return;
 			}
 			for (const [key, data] of copy.fonts) this.imports.set(keys.get(key), data);
 			for (const [key, face] of faces) if (!this.faces.has(keys.get(key))) { this.faces.set(keys.get(key), face); document.fonts.add(face); }
 			for (const [key, choice] of copy.choices) this.choices.set(keys.get(key), choice);
 			runs = copy.runs.map(run => ({ text: run.text, format: { ...run.format, font: keys.get(run.format.font) } }));
 		}
-		this.replace(runs || [{ text, format: { ...this.typing } }]);
+		this.replace(runs || [{ text, format: { ...this.typing } }], internal ? copy.paragraphs : null);
 	}
 	setFont(face, data, key) {
 		key ||= `temp-font-${crypto.randomUUID()}`;
@@ -308,10 +403,13 @@ export class RichTextSession {
 			}
 		}
 		if (!lines[0].length) lines[0].push({ text: "", format: this.typing });
+		this.editor.fitTextInput();
 		const previous = this.renderedLines || [];
 		let offset = 0;
 		this.renderedLines = lines.map((parts, index) => {
-			const key = JSON.stringify(parts.map(part => [part.text, part.format, this.faces.get(part.format.font)?.family]));
+			const align = this.model.paragraphs?.[index]?.align || this.model.layout.align || "left";
+			const distribute = align === "distributed" && !CSS.supports("text-justify", "inter-character");
+			const key = JSON.stringify([parts.map(part => [part.text, part.format, this.faces.get(part.format.font)?.family]), align, distribute ? input.offsetWidth : null]);
 			let paragraph = previous[index]?.key === key && previous[index].node.parentNode === input ? previous[index].node : null;
 			if (!paragraph) {
 				paragraph = document.createElement("div");
@@ -328,12 +426,15 @@ export class RichTextSession {
 					paragraph.style.fontSize = paragraph.firstElementChild.style.fontSize;
 					paragraph.append(document.createElement("br"));
 				}
+				Object.assign(paragraph.style, { textAlign: distribute ? "left" : align === "distributed" ? "justify" : align,
+					textAlignLast: !distribute && align === "distributed" ? "justify" : "auto", textJustify: align === "distributed" ? "inter-character" : "auto" });
+				if (distribute) distributeParagraph(input, paragraph);
 			}
 			if (input.childNodes[index] !== paragraph) input.insertBefore(paragraph, input.childNodes[index] || null);
 			if (index) offset++;
-			for (const span of paragraph.children) {
+			const walker = document.createTreeWalker(paragraph, NodeFilter.SHOW_TEXT);
-				if (span.nodeName !== "SPAN") continue;
+			let node;
-				const node = span.firstChild;
+			while ((node = walker.nextNode())) {
 				positions.push({ node, start: offset, end: offset + node.textContent.length });
 				offset += node.textContent.length;
 			}
@@ -342,7 +443,6 @@ export class RichTextSession {
 		while (input.childNodes.length > lines.length) input.lastChild.remove();
 		input.style.fontSize = this.model.runs.length ? "0px" : `${this.typing.size * PX_PER_MM}px`;
 		input.style.caretColor = this.typing.color || "#000000";
-		this.editor.fitTextInput();
 		this.editing.range = null;
 		input.focus({ preventScroll: true });
 		restoreTextSelection(positions, this.caret);
@@ -358,6 +458,7 @@ export class RichTextSession {
 export function editTextValue(input) {
 	let text = "", previous;
 	for (const node of input.childNodes) {
+		if (node.nodeName === "BR" && node.dataset.textWrap) continue;
 		const block = node.nodeName === "DIV" || node.nodeName === "P";
 		if (previous && (block || previous.nodeName === "DIV" || previous.nodeName === "P") && previous.nodeName !== "BR") text += "\n";
 		text += node.nodeType === 3 ? node.textContent : node.nodeName === "BR" ? (node.nextSibling ? "\n" : "") : editTextValue(node);
@@ -1743,6 +1844,16 @@ export class CanvasEditor {
 				if (event.inputType === "historyUndo" || event.inputType === "historyRedo") {
 					event.preventDefault(); editing.rich.undo(event.inputType === "historyUndo" ? -1 : 1); return;
 				}
+				if (!editing.composing && ["deleteContentBackward", "deleteContentForward"].includes(event.inputType) && input.querySelector("br[data-text-wrap]")) {
+					event.preventDefault();
+					const rich = editing.rich, range = rich.selection();
+					if (range[0] === range[1]) {
+						const bounds = [0, ...Array.from(graphemes.segment(rich.text), part => part.index + part.segment.length)];
+						if (event.inputType === "deleteContentBackward") range[0] = bounds.findLast(at => at < range[0]) ?? 0;
+						else range[1] = bounds.find(at => at > range[1]) ?? rich.text.length;
+					}
+					rich.replace([], null, range); return;
+				}
 				if (!editing.composing) { editing.rich.remember(); editing.rich.beforeCaret = editing.rich.selection(); }
 			}
 			if (editing.source && (event.inputType === "historyUndo" || event.inputType === "historyRedo")) {
@@ -1816,7 +1927,7 @@ export class CanvasEditor {
 		const { input, frame, item, rich } = editing;
 		const layout = rich?.model.layout || item;
 		const width = Math.max(0, frame.width - (layout.leftIndent || 0) - (layout.rightIndent || 0)) * PX_PER_MM + 4;
-		const autoWidth = !layout.align || layout.align === "left";
+		const autoWidth = (!layout.align || layout.align === "left") && !rich?.model.paragraphs?.some(paragraph => paragraph.align && paragraph.align !== "left");
 		Object.assign(input.style, {
 			width: autoWidth ? "max-content" : `${width}px`,
 			maxWidth: layout.wrap ? `${width}px` : "none",

internal/webui/webui.go

@@ -5061,8 +5061,12 @@ func (e *businessEngine) browserRichText(value ofdgo.RichText) map[string]any {
 			"strikeout": format.Strikeout, "shadow": format.Shadow, "background": background,
 		}}
 	}
+	paragraphs := make([]any, len(value.Paragraphs))
+	for i, paragraph := range value.Paragraphs {
+		paragraphs[i] = map[string]any{"align": paragraph.Align}
+	}
 	layout := value.Layout
-	return map[string]any{"runs": runs, "layout": map[string]any{
+	return map[string]any{"runs": runs, "paragraphs": paragraphs, "layout": map[string]any{
 		"autoBidi": layout.AutoBidi, "shape": layout.Shape,
 		"shaping": map[string]any{
 			"Bidi": layout.Shaping.Bidi, "Direction": layout.Shaping.Direction,

ofdgo_editor_text.go

@@ -35,7 +35,7 @@ type MissingGlyphError struct {
 // TextLayout 本地横向段落选项
 // Shape显式启用FontShaper，保存为标准TextCode和CGTransform，不改变阅读时的原文定位
 // Shaping提供可比较的塑形选项，非零值也会启用塑形，并随会话内文字编辑保留
-// Wrap按CTM变换前的边界宽度折行，Align为left、center、right或justify
+// Wrap按CTM变换前的边界宽度折行，Align为left、center、right、justify或distributed
 // LineHeight为毫米单位的基线间距，0使用字体度量；LetterSpacing为字素间的附加毫米间距，可为负
 // LeftIndent和RightIndent为左右缩进，FirstLineIndent为每段首行相对左缩进的偏移，单位为毫米
 // AutoBidi自动识别双向文字并启用塑形，零值保持显式换行和左对齐
@@ -633,9 +633,9 @@ func breakTextLines(runes []rune, advances []float64, width float64, wrap bool,
 }
 
 // alignTextLine 将段落对齐转换为标准X和DeltaX，两端对齐保留段落末行左对齐
-// 入参: runes 行内字符, advances 含字距的字符步进, width 本地排版宽度, alignment 对齐方式, justify 是否允许本行两端对齐, spacing 附加字距
+// 入参: runes 行内字符, advances 含字距的字符步进, width 本地排版宽度, alignment 对齐方式, justify 是否允许本行两端对齐, spacing 附加字距, clusters 可选塑形簇起点
 // 返回: float64 行首X坐标, string 字符间的DeltaX序列
-func alignTextLine(runes []rune, advances []float64, width float64, alignment string, justify bool, spacing float64) (float64, string) {
+func alignTextLine(runes []rune, advances []float64, width float64, alignment string, justify bool, spacing float64, clusters map[int]bool) (float64, string) {
 	end := len(runes)
 	for end > 0 && runes[end-1] == ' ' {
 		end--
@@ -665,6 +665,17 @@ func alignTextLine(runes []rune, advances []float64, width float64, alignment st
 			}
 		}
 	}
+	if alignment == "distributed" && extra > 0 {
+		var seg segmenter.Segmenter
+		seg.Init(runes[:end])
+		for it := seg.GraphemeIterator(); it.Next(); {
+			cluster := it.Grapheme()
+			at := cluster.Offset + len(cluster.Text)
+			if at < end && (clusters == nil || clusters[at]) {
+				gaps[at-1] = true
+			}
+		}
+	}
 	deltas := make([]string, max(0, len(runes)-1))
 	for i := range deltas {
 		advance := advances[i]

ofdgo_rich_layout.go

@@ -127,13 +127,17 @@ func (e *Editor) layoutRichText(value RichText, width float64) (richLayout, erro
 	var underlays []GraphicObject
 	var shadows []GraphicObject
 	var y float64
-	for start := 0; start <= len(chars); {
+	for start, paragraphIndex := 0, 0; start <= len(chars); paragraphIndex++ {
 		end := start
 		for end < len(chars) && chars[end] != '\n' {
 			end++
 		}
 		paragraph := chars[start:end]
-		local := richParagraphOptions(paragraph, options)
+		local := options
+		if len(value.Paragraphs) > 0 && value.Paragraphs[paragraphIndex].Align != "" {
+			local.Align = value.Paragraphs[paragraphIndex].Align
+		}
+		local = richParagraphOptions(paragraph, local)
 		if local.Shaping.Bidi && face == nil && len(paragraph) > 0 {
 			face, err = typefont.ParseTTF(bytes.NewReader(metrics[owners[start]].font.Write()))
 			if err != nil {
@@ -194,7 +198,16 @@ func (e *Editor) layoutRichText(value RichText, width float64) (richLayout, erro
 				ascent, descent, height = max(ascent, m.ascent), max(descent, m.descent), max(height, m.height)
 			}
 			height = max(height, ascent+descent)
-			x, delta := alignTextLine(chars[from:to], steps, available-indent, local.Align, lineIndex+1 < len(lines), local.LetterSpacing)
+			var clusters map[int]bool
+			if local.Align == "distributed" {
+				clusters = make(map[int]bool)
+				for _, span := range spans {
+					for _, glyph := range span.glyphs {
+						clusters[span.start+glyph.Cluster] = true
+					}
+				}
+			}
+			x, delta := alignTextLine(chars[from:to], steps, available-indent, local.Align, lineIndex+1 < len(lines), local.LetterSpacing, clusters)
 			copy(steps, parseFloats(delta))
 			if local.Shaping.Direction == "rtl" {
 				for j := to - from - 1; j >= 0 && chars[from+j] == ' '; j-- {

ofdgo_rich_text.go

@@ -29,9 +29,16 @@ import (
 var ErrNotRichText = errors.New("object is not rich text")
 
 // RichText 保存有序文字片段及段落选项，长度和范围使用Unicode码点而非字节
+// Paragraphs为空时所有段落沿用Layout，否则数量必须与LF分隔的段落一致
 type RichText struct {
-	Runs   []RichTextRun `json:"runs"`
+	Runs       []RichTextRun       `json:"runs"`
-	Layout TextLayout    `json:"layout"`
+	Layout     TextLayout          `json:"layout"`
+	Paragraphs []RichTextParagraph `json:"paragraphs,omitempty"`
+}
+
+// RichTextParagraph 保存显式段落的对齐方式，空值沿用Layout，按LF分隔的段落顺序排列
+type RichTextParagraph struct {
+	Align string `json:"align"`
 }
 
 // RichTextRun 保存文字及完整格式，换行使用LF，长度单位为毫米
@@ -142,6 +149,14 @@ func (v RichText) Validate() error {
 	if err := validateRichLayout(v.Layout); err != nil {
 		return err
 	}
+	if len(v.Paragraphs) != 0 && len(v.Paragraphs) != strings.Count(v.Text(), "\n")+1 {
+		return fmt.Errorf("rich text paragraph count does not match text")
+	}
+	for _, paragraph := range v.Paragraphs {
+		if err := validateRichLayout(TextLayout{Align: paragraph.Align}); err != nil {
+			return err
+		}
+	}
 	bounds := richTextBoundaries(v.Text())
 	position := 0
 	for _, run := range v.Runs {
@@ -189,7 +204,7 @@ func validateRichLayout(v TextLayout) error {
 		return fmt.Errorf("invalid rich text layout dimensions")
 	}
 	switch v.Align {
-	case "", "left", "center", "right", "justify":
+	case "", "left", "center", "right", "justify", "distributed":
 	default:
 		return fmt.Errorf("invalid rich text alignment")
 	}
@@ -233,6 +248,12 @@ func (v RichText) Slice(start, end int) (RichText, error) {
 		return RichText{}, err
 	}
 	result := RichText{Layout: v.Layout, Runs: v.sliceRuns(start, end)}
+	if len(v.Paragraphs) > 0 {
+		chars := []rune(v.Text())
+		first := strings.Count(string(chars[:start]), "\n")
+		count := strings.Count(string(chars[start:end]), "\n") + 1
+		result.Paragraphs = slices.Clone(v.Paragraphs[first : first+count])
+	}
 	if len(result.Runs) == 0 {
 		position := 0
 		format := v.Runs[len(v.Runs)-1].Format
@@ -282,6 +303,20 @@ func (v *RichText) Replace(start, end int, runs []RichTextRun) error {
 		caret, _ := v.Slice(start, start)
 		next.Runs = caret.Runs
 	}
+	if len(v.Paragraphs) > 0 {
+		chars := []rune(v.Text())
+		first := strings.Count(string(chars[:start]), "\n")
+		last := first + strings.Count(string(chars[start:end]), "\n")
+		next.Paragraphs = slices.Clone(v.Paragraphs[:first])
+		count := 1
+		for _, run := range runs {
+			count += strings.Count(run.Text, "\n")
+		}
+		for range count {
+			next.Paragraphs = append(next.Paragraphs, v.Paragraphs[first])
+		}
+		next.Paragraphs = append(next.Paragraphs, v.Paragraphs[last+1:]...)
+	}
 	next = normalizeRichText(next)
 	if err := next.Validate(); err != nil {
 		return err
@@ -310,7 +345,42 @@ func (v *RichText) ApplyFormat(start, end int, patch TextFormatPatch) error {
 	if start == end {
 		return nil
 	}
-	return v.Replace(start, end, part.Runs)
+	paragraphs := v.Paragraphs
+	if err := v.Replace(start, end, part.Runs); err != nil {
+		return err
+	}
+	v.Paragraphs = paragraphs
+	return nil
+}
+
+// AlignParagraphs 修改光标所在或半开选区涉及的段落，选区末端不包含下一段首
+// 入参: start 起点, end 终点, align 对齐方式
+// 返回: error 无效范围或对齐方式
+func (v *RichText) AlignParagraphs(start, end int, align string) error {
+	if v == nil {
+		return fmt.Errorf("nil rich text")
+	}
+	if err := v.checkRange(start, end); err != nil {
+		return err
+	}
+	if err := validateRichLayout(TextLayout{Align: align}); err != nil {
+		return err
+	}
+	chars := []rune(v.Text())
+	first := strings.Count(string(chars[:start]), "\n")
+	last := first
+	if end > start {
+		last = strings.Count(string(chars[:end-1]), "\n")
+	}
+	paragraphs := slices.Clone(v.Paragraphs)
+	if len(paragraphs) == 0 {
+		paragraphs = make([]RichTextParagraph, strings.Count(v.Text(), "\n")+1)
+	}
+	for i := first; i <= last; i++ {
+		paragraphs[i].Align = align
+	}
+	v.Paragraphs = paragraphs
+	return nil
 }
 
 // apply 应用显式给出的格式字段

ofdgo_text_layout.go

@@ -63,7 +63,7 @@ func LayoutText(obj *TextObject, value string, options TextLayout, metrics FontM
 	if !finite(options.LeftIndent) || !finite(options.RightIndent) || !finite(options.FirstLineIndent) {
 		return fmt.Errorf("paragraph indents must be finite")
 	}
-	if !slices.Contains([]string{"", "left", "center", "right", "justify"}, options.Align) {
+	if !slices.Contains([]string{"", "left", "center", "right", "justify", "distributed"}, options.Align) {
 		return fmt.Errorf("invalid text alignment %q", options.Align)
 	}
 	var width float64
@@ -129,7 +129,7 @@ func LayoutText(obj *TextObject, value string, options TextLayout, metrics FontM
 			if i == 0 {
 				indent = options.FirstLineIndent
 			}
-			x, deltas := alignTextLine(runes[line[0]:line[1]], advances[line[0]:line[1]], width-indent, options.Align, i+1 < len(lines), options.LetterSpacing)
+			x, deltas := alignTextLine(runes[line[0]:line[1]], advances[line[0]:line[1]], width-indent, options.Align, i+1 < len(lines), options.LetterSpacing, nil)
 			x += options.LeftIndent + indent
 			y := float64(ascender)*unit + float64(len(codes))*lineHeight
 			if !finite(x) || !finite(y) {
@@ -220,7 +220,14 @@ func layoutShapedText(obj *TextObject, value string, options TextLayout, metrics
 				}
 			}
 			chars := runes[line[0]:line[1]]
-			x, delta := alignTextLine(chars, lineAdvances, available, options.Align, i+1 < len(lines), options.LetterSpacing)
+			var clusters map[int]bool
+			if options.Align == "distributed" {
+				clusters = make(map[int]bool)
+				for _, glyph := range glyphs {
+					clusters[glyph.Cluster] = true
+				}
+			}
+			x, delta := alignTextLine(chars, lineAdvances, available, options.Align, i+1 < len(lines), options.LetterSpacing, clusters)
 			if options.Shaping.Direction == "rtl" {
 				for j := len(chars) - 1; j >= 0 && chars[j] == ' '; j-- {
 					x -= lineAdvances[j]