perf(性能提升): 优化编辑性能与字体缓存

ofdgo_editor_selection.go

@@ -0,0 +1,179 @@
+// 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"
+	"slices"
+)
+
+// SelectionBounds 获取正文与注解混合选区的实际范围，复用同一次度量的资源缓存
+// 入参: page 页面索引, objects 正文标识, annotations 注解标识，各列表不得重复
+// 返回: Box 页面毫米范围, error 标识或度量错误
+func (e *Editor) SelectionBounds(page int, objects, annotations []string) (Box, error) {
+	boxes, _, _, err := e.selectionGeometry(page, objects, annotations)
+	if err != nil {
+		return Box{}, err
+	}
+	var bounds Box
+	for _, box := range boxes {
+		bounds = unionTextBox(bounds, box)
+	}
+	if bounds.W <= 0 || bounds.H <= 0 {
+		return Box{}, fmt.Errorf("selection has no visible bounds")
+	}
+	return bounds, nil
+}
+
+// AlignSelection 将正文与注解统一对齐，单选对齐页面，多选对齐选区，一次撤销恢复全部
+// 入参: page 页面索引, objects 正文标识, annotations 注解标识, alignment 为left、center、right、top、middle或bottom
+// 返回: error 标识、度量或编辑错误
+func (e *Editor) AlignSelection(page int, objects, annotations []string, alignment string) error {
+	if !slices.Contains([]string{"left", "center", "right", "top", "middle", "bottom"}, alignment) {
+		return fmt.Errorf("invalid alignment %q", alignment)
+	}
+	boxes, _, target, err := e.selectionGeometry(page, objects, annotations)
+	if err != nil || len(boxes) == 0 {
+		return err
+	}
+	if len(boxes) > 1 {
+		target = Box{}
+		for _, box := range boxes {
+			target = unionTextBox(target, box)
+		}
+	}
+	matrices := make([]Matrix, len(boxes))
+	for i, box := range boxes {
+		matrices[i] = editorAlignment(box, target, alignment)
+	}
+	return e.transformSelection(page, objects, annotations, matrices)
+}
+
+// DistributeSelection 按正文与注解实际范围等距分布，固定两端并校验位置顺序，一次撤销恢复全部
+// 入参: page 页面索引, objects 正文标识, annotations 注解标识, axis 为horizontal或vertical
+// 返回: error 标识、度量、重叠或编辑错误
+func (e *Editor) DistributeSelection(page int, objects, annotations []string, axis string) error {
+	if axis != "horizontal" && axis != "vertical" {
+		return fmt.Errorf("invalid distribution axis %q", axis)
+	}
+	boxes, positions, _, err := e.selectionGeometry(page, objects, annotations)
+	if err != nil || len(boxes) < 3 {
+		return err
+	}
+	matrices, err := editorDistribution(boxes, positions, axis)
+	if err != nil {
+		return err
+	}
+	return e.transformSelection(page, objects, annotations, matrices)
+}
+
+// selectionGeometry 一次读取页面与资源，按正文、注解标识顺序度量并保留绘制位置
+// 入参: page 页面索引, objects 正文标识, annotations 注解标识
+// 返回: []Box 成员范围, []editorObjectPosition 绘制位置, Box 页面范围, error 标识或度量错误
+func (e *Editor) selectionGeometry(page int, objects, annotations []string) ([]Box, []editorObjectPosition, Box, error) {
+	items, positions, err := e.selectedObjects(page, objects)
+	if err != nil {
+		return nil, nil, Box{}, err
+	}
+	reader, err := e.Reader()
+	if err != nil {
+		return nil, nil, Box{}, err
+	}
+	defer reader.Close()
+	content, err := reader.PageContentByIndex(page)
+	if err != nil {
+		return nil, nil, Box{}, err
+	}
+	renderer := e.newRenderer(reader)
+	paper, err := renderer.GetPageBox(content)
+	if err != nil {
+		return nil, nil, Box{}, err
+	}
+	boxes := make([]Box, 0, len(items)+len(annotations))
+	for i, item := range items {
+		box, err := renderer.ObjectBounds(item, e.pages[page].Content.Layer[positions[i].layer].DrawParam)
+		if err != nil {
+			return nil, nil, Box{}, err
+		}
+		boxes = append(boxes, box)
+	}
+	list := reader.Annots[content.ID]
+	lookup := make(map[string]int, len(list))
+	for i, annotation := range list {
+		lookup[annotation.ID] = i
+	}
+	seen := make(map[string]bool, len(annotations))
+	for _, id := range annotations {
+		index, found := lookup[id]
+		if seen[id] || !found {
+			return nil, nil, Box{}, fmt.Errorf("duplicate or missing annotation %q", id)
+		}
+		seen[id] = true
+		box, _, err := renderer.AnnotationGeometry(list[index])
+		if err != nil {
+			return nil, nil, Box{}, err
+		}
+		if box.W <= 0 || box.H <= 0 {
+			box, err = ParseBox(list[index].Appearance.Boundary)
+			if err != nil {
+				return nil, nil, Box{}, err
+			}
+		}
+		boxes = append(boxes, box)
+		positions = append(positions, editorObjectPosition{layer: len(content.Content.Layer), index: index})
+	}
+	for _, box := range boxes {
+		if !finite(box.X) || !finite(box.Y) || !finite(box.W) || !finite(box.H) || box.W <= 0 || box.H <= 0 {
+			return nil, nil, Box{}, fmt.Errorf("selection member has no visible bounds")
+		}
+	}
+	return boxes, positions, paper, nil
+}
+
+// transformSelection 原子应用成员平移，跳过未改变的成员及历史记录
+// 入参: page 页面索引, objects 正文标识, annotations 注解标识, matrices 按正文、注解排列的平移
+// 返回: error 编辑错误
+func (e *Editor) transformSelection(page int, objects, annotations []string, matrices []Matrix) error {
+	return e.Transaction(func(edit *Editor) error {
+		items, _, err := edit.selectedObjects(page, objects)
+		if err != nil {
+			return err
+		}
+		changes := make(map[string]Matrix, len(objects))
+		var updates []GraphicObject
+		for i, id := range objects {
+			if matrices[i] != IdentityMatrix {
+				changes[id] = matrices[i]
+				updates = append(updates, items[i])
+			}
+		}
+		if len(updates) != 0 {
+			if err := edit.transformObjects(page, updates, func(object GraphicObject) (GraphicObject, error) {
+				return edit.transformMatrix(object, changes[editorObjectID(object)])
+			}); err != nil {
+				return err
+			}
+		}
+		for i, id := range annotations {
+			matrix := matrices[len(objects)+i]
+			if matrix != IdentityMatrix {
+				if err := edit.MoveAnnotations(page, []string{id}, matrix.e, matrix.f); err != nil {
+					return err
+				}
+			}
+		}
+		return nil
+	})
+}