ofdgo/ofdgo_editor_composite_text.go

// 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"
	"strconv"
)

// UpdateCompositeText 修改内部文字，原文保留定位，已知段落按会话选项重排
// 空样式保留原字体、字号和颜色，显式改变字号时重新排版并保留首行基线
// 方向和字形映射沿用RewriteText的定位校验，不改变原文中未修改的属性
// 入参: page 页面索引, path 父复合路径, index 成员序号, value 文字, style 文字样式增量
// 返回: error 错误信息
func (e *Editor) UpdateCompositeText(page int, path ObjectPath, index int, value string, style TextStyle) error {
	return e.changeCompositeText(page, path, []int{index}, &value, style, nil, nil)
}

// StyleCompositeText 批量修改内部文字字体、字号或颜色，换字体保留原文字定位
// 更换字体时同步字形索引，无法逐字映射时需显式重排，缺字使整批操作失败
// 入参: page 页面索引, path 父复合路径, indexes 成员序号, style 文字样式增量
// 返回: error 错误信息
func (e *Editor) StyleCompositeText(page int, path ObjectPath, indexes []int, style TextStyle) error {
	return e.changeCompositeText(page, path, indexes, nil, style, nil, nil)
}

// LayoutCompositeText 显式重排内部普通文字，保留原始基线、变换、裁剪和绘制属性
// 段落选项仅保留在编辑会话中，撤销重做随对象恢复，保存为标准TextCode定位
// 入参: page 页面索引, path 父路径, index 成员序号, value 原文, options 段落选项
// 返回: error 错误信息
func (e *Editor) LayoutCompositeText(page int, path ObjectPath, index int, value string, options TextLayout) error {
	return e.changeCompositeText(page, path, []int{index}, &value, TextStyle{}, &options, nil)
}

// ResizeCompositeTextFrame 调整内部文字框本地宽度并按指定段落选项重排
// 入参: page 页面索引, path 父路径, index 成员序号, offset 左侧偏移, width 宽度, options 段落选项
// 返回: error 错误信息
func (e *Editor) ResizeCompositeTextFrame(page int, path ObjectPath, index int, offset, width float64, options TextLayout) error {
	return e.changeCompositeText(page, path, []int{index}, nil, TextStyle{}, &options, &Box{X: offset, W: width})
}

// changeCompositeText 生成独立文字副本，全部校验通过后合并原文
// 入参: page 页面索引, path 父复合路径, indexes 成员序号, value 新内容，nil保留定位, style 样式增量, options 显式段落选项, frame 可选文字框调整
// 返回: error 错误信息
func (e *Editor) changeCompositeText(page int, path ObjectPath, indexes []int, value *string, style TextStyle, options *TextLayout, frame *Box) error {
	return e.editCompositeObjects(page, path, indexes, func(_ *Renderer, nodes []*editorCompositeNode, members []CompositeMember) error {
		for i, node := range nodes {
			if err := e.updateCompositeText(node, members[i], value, style, options, frame); err != nil {
				return err
			}
		}
		return nil
	})
}

// updateCompositeText 按有效样式更新单个内部文字节点并保留段落基线
// 入参: node 原文节点, member 有效快照, value 新内容, style 样式增量, options 段落选项, frame 文字框调整
// 返回: error 错误信息
func (e *Editor) updateCompositeText(node *editorCompositeNode, member CompositeMember, value *string, style TextStyle, options *TextLayout, frame *Box) error {
	if style.Reflow {
		options = &TextLayout{AutoBidi: true}
	}
	rewriteOnly := value != nil && options == nil && frame == nil && style.Color == "" && (style.Font == "" || style.Font == member.Object.TextObject.Font) && (style.Size == 0 || style.Size == member.Object.TextObject.Size)
	if node.object.Type != "TextObject" || !member.Capabilities.ReplaceFont && !(rewriteOnly && member.Capabilities.RewriteText) {
		return fmt.Errorf("composite text style is not supported")
	}
	object := cloneEditorData(node.object)
	text := cloneEditorData(member.Object.TextObject)
	state := node.states[editorObjectID(node.object)]
	content, layout := text.TextLayout()
	original := content
	if style.Font != "" {
		if state.layout == nil && options == nil && (style.Size == 0 || style.Size == text.Size) {
			replacement := content
			if value != nil {
				replacement = *value
			}
			if err := e.RewriteTextWithFont(&text, replacement, style.Font); err != nil {
				return err
			}
		} else {
			text.Font = style.Font
		}
	}
	if value != nil {
		content = *value
	}
	if options != nil {
		layout = *options
	}
	if frame != nil {
		var err error
		if !node.boundaryInCTM {
			text = compositeBoundary(GraphicObject{Type: "TextObject", TextObject: text}, node.parent, true).TextObject
		}
		text, err = text.ResizeTextFrame(frame.X, frame.W)
		if err != nil {
			return err
		}
		if !node.boundaryInCTM {
			text = compositeBoundary(GraphicObject{Type: "TextObject", TextObject: text}, node.parent, false).TextObject
		}
		object.TextObject.Boundary, object.TextObject.CTM = text.Boundary, text.CTM
	}
	if options == nil && frame == nil && state.layout == nil && (style.Size == 0 || style.Size == text.Size) && content != original {
		if err := e.RewriteText(&text, content); err != nil {
			return err
		}
		object.TextObject.TextCode = text.TextCode
		object.TextObject.CGTransform = text.CGTransform
	} else if options != nil || content != original || style.Size != 0 && style.Size != text.Size || state.layout != nil && state.layout.options.Shape && style.Font != "" && style.Font != object.TextObject.Font {
		if style.Size != 0 {
			text.Size = style.Size
		}
		if state.layout == nil {
			if len(text.TextCode) == 0 {
				return fmt.Errorf("text codes are empty")
			}
			origin, err := creationNumbers(text.TextCode[0].X+" "+text.TextCode[0].Y, 2)
			if err != nil {
				return err
			}
			copy(state.origin[:], origin)
		}
		if err := e.layoutCompositeText(&text, content, layout, state.origin); err != nil {
			return err
		}
		object.TextObject.Size, object.TextObject.TextCode = text.Size, text.TextCode
		object.TextObject.CGTransform = text.CGTransform
		state.layout = &textLayout{value: content, options: layout}
	}
	if style.Font != "" && style.Font != object.TextObject.Font {
		if err := e.prepareText(&text); err != nil {
			return err
		}
		object.TextObject.Font = style.Font
		object.TextObject.CGTransform = text.CGTransform
	}
	if style.Color != "" {
		if err := creationColor(&FillColor{Value: style.Color}); err != nil {
			return err
		}
		var r, g, b float64
		fmt.Sscan(style.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 err
		}
		object.TextObject.FillColor = editorStyleColor(fill, member.Object.TextObject.FillColor)
	}
	if err := node.update(object); err != nil {
		return err
	}
	node.setState(state)
	return nil
}

// layoutCompositeText 重排普通文字并保持原首行基线起点
// 入参: text 有效文字样式, value 新内容, options 段落选项, origin 原始基线起点
// 返回: error 错误信息
func (e *Editor) layoutCompositeText(text *TextObject, value string, options TextLayout, origin [2]float64) error {
	if err := e.LayoutText(text, value, options); err != nil {
		return err
	}
	baseline, _ := strconv.ParseFloat(text.TextCode[0].Y, 64)
	for i := range text.TextCode {
		code := &text.TextCode[i]
		cx, _ := strconv.ParseFloat(code.X, 64)
		cy, _ := strconv.ParseFloat(code.Y, 64)
		code.X, code.Y = ofdNumber(cx+origin[0]), ofdNumber(cy+origin[1]-baseline)
	}
	return e.prepareText(text)
}