feat(创建编辑): 完善多选排版，优化工具栏与页外绘制

ofdgo_editor_batch.go

@@ -15,11 +15,179 @@
 package ofdgo
 
 import (
+	"cmp"
 	"fmt"
 	"reflect"
 	"slices"
+	"strconv"
+
+	"github.com/tdewolff/canvas"
 )
 
+// CopyObjects 按原绘制顺序复制同页对象并平移，复用资源，提交一次撤销记录。
+// 入参: page 页面索引, ids 对象标识, dx、dy 毫米位移
+// 返回: []string 按绘制顺序排列的新对象标识, error 错误信息
+func (e *Editor) CopyObjects(page int, ids []string, dx, dy float64) ([]string, error) {
+	if !finite(dx) || !finite(dy) {
+		return nil, fmt.Errorf("copy requires finite offsets")
+	}
+	_, indexes, err := e.selectedObjects(page, ids)
+	if err != nil {
+		return nil, err
+	}
+	slices.Sort(indexes)
+	before := e.pages[page].Content.Layer[0].Objects
+	objects := make([]GraphicObject, len(indexes))
+	result := make([]string, len(indexes))
+	for i, index := range indexes {
+		object, err := cloneEditorObject(before[index])
+		if err != nil {
+			return nil, err
+		}
+		object, err = transformEditorObject(object, dx, dy, 1)
+		if err != nil {
+			return nil, err
+		}
+		result[i] = strconv.Itoa(e.maxID + i + 1)
+		objects[i], err = e.prepareObject(result[i], object)
+		if err != nil {
+			return nil, err
+		}
+	}
+	e.maxID += len(objects)
+	e.replaceObjects(page, append(slices.Clone(before), objects...))
+	return result, nil
+}
+
+// OrderObjects 调整同页选区的绘制顺序，保留选中及未选中对象各自的相对顺序。
+// 入参: page 页面索引, ids 对象标识, order 为up、down、top或bottom
+// 返回: error 错误信息
+func (e *Editor) OrderObjects(page int, ids []string, order string) error {
+	if !slices.Contains([]string{"up", "down", "top", "bottom"}, order) {
+		return fmt.Errorf("invalid object order %q", order)
+	}
+	_, indexes, err := e.selectedObjects(page, ids)
+	if err != nil || len(indexes) == 0 {
+		return err
+	}
+	objects := slices.Clone(e.pages[page].Content.Layer[0].Objects)
+	selected := make([]bool, len(objects))
+	for _, index := range indexes {
+		selected[index] = true
+	}
+	switch order {
+	case "up":
+		for i := len(objects) - 2; i >= 0; i-- {
+			if selected[i] && !selected[i+1] {
+				objects[i], objects[i+1] = objects[i+1], objects[i]
+				selected[i], selected[i+1] = false, true
+			}
+		}
+	case "down":
+		for i := 1; i < len(objects); i++ {
+			if selected[i] && !selected[i-1] {
+				objects[i], objects[i-1] = objects[i-1], objects[i]
+				selected[i], selected[i-1] = false, true
+			}
+		}
+	default:
+		ordered := make([]GraphicObject, 0, len(objects))
+		for _, takeSelected := range []bool{order == "bottom", order != "bottom"} {
+			for i, object := range objects {
+				if selected[i] == takeSelected {
+					ordered = append(ordered, object)
+				}
+			}
+		}
+		objects = ordered
+	}
+	e.replaceObjects(page, objects)
+	return nil
+}
+
+// DistributeObjects 按可见范围等距分布同页对象，固定两端对象，保留绘制顺序。
+// 不足三个对象时不修改；允许负间距，无法保持位置顺序的重叠布局返回错误。
+// 入参: page 页面索引, ids 对象标识, axis 为horizontal或vertical
+// 返回: error 错误信息
+func (e *Editor) DistributeObjects(page int, ids []string, axis string) error {
+	if axis != "horizontal" && axis != "vertical" {
+		return fmt.Errorf("invalid distribution axis %q", axis)
+	}
+	objects, indexes, err := e.selectedObjects(page, ids)
+	if err != nil || len(objects) < 3 {
+		return err
+	}
+	boxes, err := e.objectBounds(page, objects)
+	if err != nil {
+		return err
+	}
+	positions, sizes := make([]float64, len(boxes)), make([]float64, len(boxes))
+	order := make([]int, len(boxes))
+	total := 0.0
+	for i, box := range boxes {
+		positions[i], sizes[i] = box.X, box.W
+		if axis == "vertical" {
+			positions[i], sizes[i] = box.Y, box.H
+		}
+		order[i] = i
+		total += sizes[i]
+	}
+	slices.SortFunc(order, func(i, j int) int {
+		if c := cmp.Compare(positions[i], positions[j]); c != 0 {
+			return c
+		}
+		return cmp.Compare(indexes[i], indexes[j])
+	})
+	first, last := order[0], order[len(order)-1]
+	gap := (positions[last] + sizes[last] - positions[first] - total) / float64(len(order)-1)
+	for i, index := range order[:len(order)-1] {
+		step := sizes[index] + gap
+		if canvas.Equal(step, 0) {
+			step = 0
+		}
+		if step < 0 || step == 0 && indexes[index] > indexes[order[i+1]] {
+			return fmt.Errorf("overlap prevents ordered equal-gap distribution")
+		}
+	}
+	next := positions[first] + sizes[first] + gap
+	updates := make([]GraphicObject, 0, len(order)-2)
+	for _, index := range order[1 : len(order)-1] {
+		position := next
+		next += sizes[index] + gap
+		if canvas.Equal(position, positions[index]) {
+			continue
+		}
+		dx, dy := position-positions[index], 0.0
+		if axis == "vertical" {
+			dx, dy = 0, dx
+		}
+		object, err := cloneEditorObject(objects[index])
+		if err != nil {
+			return err
+		}
+		object, err = transformEditorObject(object, dx, dy, 1)
+		if err != nil {
+			return err
+		}
+		updates = append(updates, object)
+	}
+	return e.UpdateObjects(page, updates)
+}
+
+// replaceObjects 替换正文对象列表，隔离历史快照与后续的增删、排序操作。
+func (e *Editor) replaceObjects(page int, objects []GraphicObject) {
+	before := e.pages[page].Content.Layer[0].Objects
+	if reflect.DeepEqual(before, objects) {
+		return
+	}
+	before, after := slices.Clone(before), slices.Clone(objects)
+	e.pages[page].Content.Layer[0].Objects = slices.Clone(after)
+	if change := e.recordChange(); change != nil {
+		change.undo = func(e *Editor) { e.pages[page].Content.Layer[0].Objects = slices.Clone(before) }
+		change.redo = func(e *Editor) { e.pages[page].Content.Layer[0].Objects = slices.Clone(after) }
+	}
+}
+
 // UpdateObjects 原子替换同页对象，按各对象ID定位，全部校验通过后提交一次历史记录。
 // 入参: page 页面索引, objects 新对象内容，ID不得重复
 // 返回: error 错误信息
@@ -146,11 +314,7 @@ func (e *Editor) DeleteObjects(page int, ids []string) error {
 	for _, index := range slices.Backward(indexes) {
 		after = slices.Delete(after, index, index+1)
 	}
-	e.pages[page].Content.Layer[0].Objects = slices.Clone(after)
-	if change := e.recordChange(); change != nil {
-		change.undo = func(e *Editor) { e.pages[page].Content.Layer[0].Objects = slices.Clone(before) }
-		change.redo = func(e *Editor) { e.pages[page].Content.Layer[0].Objects = slices.Clone(after) }
-	}
+	e.replaceObjects(page, after)
 	return nil
 }