update(AligningGuidelines): Fix some bugs and add custom features.

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## [next]
 
+- fix(AligningGuidelines): Too many shapes will result in too many reference lines [#10120] (https://github.com/fabricjs/fabric.js/pull/10120)
+- fix(AligningGuidelines): Align guidless changes aspect ratio on snapping when scaling [#10114](https://github.com/fabricjs/fabric.js/issues/10114)
 ## [6.4.2]
 
 - Fix(): path parsing performance [#10123](https://github.com/fabricjs/fabric.js/pull/10123)

extensions/aligning_guidelines/README.MD

@@ -11,7 +11,11 @@ const config = {
   /** Aligning line dimensions */
   width: 1,
   /** Aligning line color */
-  color: 'rgb(255,0,0,0.9)',
+  color: 'rgba(255,0,0,0.9)',
+  /** Close Vertical line, default false. */
+  closeVLine: false,
+  /** Close horizontal line, default false. */
+  closeHLine: false,
 };
 
 const deactivate = initAligningGuidelines(myCanvas, options);
@@ -20,3 +24,72 @@ const deactivate = initAligningGuidelines(myCanvas, options);
 
 deactivate();
 ```
+
+### custom function
+
+```ts
+import { initAligningGuidelines } from 'fabric/extensions';
+import { FabricObject } from 'fabric';
+
+// You can customize the return graphic, and the example will only compare it with sibling elements
+initAligningGuidelines(myCanvas, {
+  getObjectsByTarget: function (target) {
+    const set = new Set<FabricObject>();
+    const p = target.parent ?? target.canvas;
+    p?.getObjects().forEach((o) => {
+      set.add(o);
+    });
+    return set;
+  },
+});
+```
+
+```ts
+import { initAligningGuidelines } from 'fabric/extensions';
+
+// You can customize the alignment point, the example only aligns the TL control point
+initAligningGuidelines(myCanvas, {
+  getPointMap: function (target) {
+    const tl = target.getCoords().tl;
+    return { tl };
+  },
+});
+```
+
+```ts
+import { initAligningGuidelines } from 'fabric/extensions';
+
+FabricObject.createControls = function () {
+  // custom controllers
+  return { controls: { abc: new Control({}) } };
+};
+
+// You can set control points for custom controllers
+initAligningGuidelines(myCanvas, {
+  getPointMap: function (target) {
+    const abc = target.getCoords().tl;
+    return { abc };
+  },
+  getContraryMap: function (target) {
+    const abc = target.aCoords.br;
+    return { abc };
+  },
+  contraryOriginMap: {
+    // If abc is the top-left point, then the reference point is the bottom-right.
+    abc: ['right', 'bottom'],
+  },
+});
+```
+
+```ts
+import { initAligningGuidelines } from 'fabric/extensions';
+
+// You can close all
+initAligningGuidelines(myCanvas, {
+  closeVLine: true,
+  closeHLine: true,
+  getPointMap: function (_) {
+    return {};
+  },
+});
+```

extensions/aligning_guidelines/constant.ts

@@ -6,5 +6,9 @@ export const aligningLineConfig: AligningLineConfig = {
   /** Aligning line dimensions */
   width: 1,
   /** Aligning line color */
-  color: 'rgb(255,0,0,0.9)',
+  color: 'rgba(255,0,0,0.9)',
+  /** Close Vertical line, default false. */
+  closeVLine: false,
+  /** Close horizontal line, default false. */
+  closeHLine: false,
 };

extensions/aligning_guidelines/index.ts

@@ -2,10 +2,9 @@ import type {
   BasicTransformEvent,
   Canvas,
   FabricObject,
-  TBBox,
   TPointerEvent,
 } from 'fabric';
-import { Point, util } from 'fabric';
+import { Point } from 'fabric';
 import {
   collectHorizontalPoint,
   collectVerticalPoint,
@@ -15,14 +14,11 @@ import {
   drawPointList,
   drawVerticalLine,
 } from './util/draw';
-import { getObjectsByTarget } from './util/get-objects-by-target';
 import { collectLine } from './util/collect-line';
-import type {
-  AligningLineConfig,
-  HorizontalLine,
-  VerticalLine,
-} from './typedefs';
+import type { AligningLineConfig, LineProps } from './typedefs';
 import { aligningLineConfig } from './constant';
+import { getObjectsByTarget } from './util/get-objects-by-target';
+import { getContraryMap, getPointMap } from './util/basic';
 
 type TransformEvent = BasicTransformEvent<TPointerEvent> & {
   target: FabricObject;
@@ -32,113 +28,153 @@ export type { AligningLineConfig } from './typedefs';
 
 export function initAligningGuidelines(
   canvas: Canvas,
-  options: Partial<AligningLineConfig> = {},
+  options: Partial<AligningLineConfig> = {}
 ) {
   Object.assign(aligningLineConfig, options);
 
   const horizontalLines = new Set<string>();
   const verticalLines = new Set<string>();
+  // When we drag to resize using center points like mt, ml, mb, and mr,
+  // we do not need to draw line segments; we only need to draw the target points.
   let onlyDrawPoint = false;
-  const cacheMap = new Map<string, [TBBox, Point[]]>();
+  const cacheMap = new Map<string, Point[]>();
 
   const getCaCheMapValue = (object: FabricObject) => {
+    // If there is an ID and the ID is unique, we can cache using the ID for acceleration.
+    // However, since Fabric does not have a built-in ID, we use the position information as the key for caching.
+    // const cacheKey = object.id;
     const cacheKey = [
       object.calcTransformMatrix().toString(),
       object.width,
       object.height,
     ].join();
     const cacheValue = cacheMap.get(cacheKey);
     if (cacheValue) return cacheValue;
-    const coords = object.getCoords();
-    const rect = util.makeBoundingBoxFromPoints(coords);
-    const value: [TBBox, Point[]] = [rect, coords];
+    const value = object.getCoords();
+    value.push(object.getCenterPoint());
     cacheMap.set(cacheKey, value);
     return value;
   };
 
   function moving(e: TransformEvent) {
-    const activeObject = e.target;
-    activeObject.setCoords();
+    const target = e.target;
+    // We need to obtain the real-time coordinates of the current object, so we need to update them in real-time
+    target.setCoords();
     onlyDrawPoint = false;
     verticalLines.clear();
     horizontalLines.clear();
 
-    const objects = getObjectsByTarget(activeObject);
-    const activeObjectRect = activeObject.getBoundingRect();
-
-    for (const object of objects) {
-      const objectRect = getCaCheMapValue(object)[0];
-      const { vLines, hLines } = collectLine({
-        activeObject,
-        activeObjectRect,
-        objectRect,
-      });
-      vLines.forEach((o) => {
-        verticalLines.add(JSON.stringify(o));
-      });
-      hLines.forEach((o) => {
-        horizontalLines.add(JSON.stringify(o));
-      });
-    }
+    // Find the shapes associated with the current graphic to draw reference lines for it.
+    const objects =
+      options.getObjectsByTarget?.(target) ?? getObjectsByTarget(target);
+    const points: Point[] = [];
+    // Collect all the points to draw reference lines.
+    for (const object of objects) points.push(...getCaCheMapValue(object));
+
+    // Obtain horizontal and vertical reference lines.
+    const { vLines, hLines } = collectLine(target, points);
+    vLines.forEach((o) => {
+      // Objects cannot be deduplicated; convert them to strings for deduplication.
+      verticalLines.add(JSON.stringify(o));
+    });
+    hLines.forEach((o) => {
+      // Objects cannot be deduplicated; convert them to strings for deduplication.
+      horizontalLines.add(JSON.stringify(o));
+    });
   }
 
   function scalingOrResizing(e: TransformEvent) {
-    // br bl tr tl mb ml mt mr
-    const activeObject = e.target;
-    activeObject.setCoords();
+    const target = e.target;
+    // We need to obtain the real-time coordinates of the current object, so we need to update them in real-time
+    target.setCoords();
+    // The value of action can be scaleX, scaleY, scale, resize, etc.
+    // If it does not start with "scale," it is considered a modification of size.
     const isScale = String(e.transform.action).startsWith('scale');
     verticalLines.clear();
     horizontalLines.clear();
 
-    const objects = getObjectsByTarget(activeObject);
+    const objects =
+      options.getObjectsByTarget?.(target) ?? getObjectsByTarget(target);
     let corner = e.transform.corner;
-    if (activeObject.flipX) corner = corner.replace('l', 'r').replace('r', 'l');
-    if (activeObject.flipY) corner = corner.replace('t', 'b').replace('b', 't');
-    let index = ['tl', 'tr', 'br', 'bl', 'mt', 'mr', 'mb', 'ml'].indexOf(
-      corner,
-    );
-    if (index == -1) return;
-    onlyDrawPoint = index > 3;
+    // When the shape is flipped, the tl obtained through getCoords is actually tr,
+    // and tl is actually tr. We need to make correction adjustments.
+    // tr <-> tl、 bl <-> br、  mb <-> mt、 ml <-> mr
+    if (target.flipX) corner = corner.replace('l', 'r').replace('r', 'l');
+    if (target.flipY) corner = corner.replace('t', 'b').replace('b', 't');
+    const coords = target.getCoords();
+    // Obtain the coordinates of the current operation point through the value of corner.
+    // users can be allowed to customize and pass in custom corners.
+    const pointMap = options.getPointMap?.(target) ?? getPointMap(target);
+    if (!(corner in pointMap)) return;
+    onlyDrawPoint = corner.includes('m');
     if (onlyDrawPoint) {
-      const angle = activeObject.getTotalAngle();
+      const angle = target.getTotalAngle();
+      // When the shape is rotated, it is meaningless to draw points using the center point.
       if (angle % 90 != 0) return;
-      index -= 4;
-    }
-    let point = activeObject.getCoords()[index];
-    for (const object of objects) {
-      const [rect, coords] = getCaCheMapValue(object);
-      const center = new Point(
-        rect.left + rect.width / 2,
-        rect.top + rect.height / 2,
-      );
-      const list = [...coords, center];
-      const props = { activeObject, point, list, isScale, index };
-      const vLines = collectVerticalPoint(props);
-      const hLines = collectHorizontalPoint(props);
-      vLines.forEach((o) => {
-        verticalLines.add(JSON.stringify(o));
-      });
-      hLines.forEach((o) => {
-        horizontalLines.add(JSON.stringify(o));
-      });
-      if (vLines.length || hLines.length)
-        point = activeObject.getCoords()[index];
     }
+    // If manipulating tl, then when the shape changes size, it should be positioned by br,
+    // and the same applies to others.
+    // users can be allowed to customize and pass in custom corners.
+    const contraryMap =
+      options.getContraryMap?.(target) ?? getContraryMap(target);
+
+    const point = pointMap[corner];
+    const diagonalPoint = contraryMap[corner];
+    const uniformIsToggled = e.e[canvas.uniScaleKey!];
+    let isUniform =
+      (canvas.uniformScaling && !uniformIsToggled) ||
+      (!canvas.uniformScaling && uniformIsToggled);
+    // When controlling through the center point,
+    // if isUniform is true, it actually changes the skew, so it is meaningless.
+    if (onlyDrawPoint) isUniform = false;
+
+    const list: Point[] = [];
+    for (const object of objects) list.push(...getCaCheMapValue(object));
+
+    const props = {
+      target,
+      point,
+      diagonalPoint,
+      corner,
+      list,
+      isScale,
+      isUniform,
+    };
+    // Obtain horizontal and vertical reference lines.
+    const vLines = collectVerticalPoint(props);
+    const hLines = collectHorizontalPoint(props);
+    vLines.forEach((o) => {
+      // Objects cannot be deduplicated; convert them to strings for deduplication.
+      verticalLines.add(JSON.stringify(o));
+    });
+    hLines.forEach((o) => {
+      // Objects cannot be deduplicated; convert them to strings for deduplication.
+      horizontalLines.add(JSON.stringify(o));
+    });
   }
 
   function beforeRender() {
     canvas.clearContext(canvas.contextTop);
   }
   function afterRender() {
     if (onlyDrawPoint) {
-      const list: Array<VerticalLine | HorizontalLine> = [];
-      for (const v of verticalLines) list.push(JSON.parse(v));
-      for (const h of horizontalLines) list.push(JSON.parse(h));
+      const list: LineProps[] = [];
+      if (!options.closeVLine) {
+        for (const v of verticalLines) list.push(JSON.parse(v));
+      }
+      if (!options.closeHLine) {
+        for (const h of horizontalLines) list.push(JSON.parse(h));
+      }
       drawPointList(canvas, list);
     } else {
-      for (const v of verticalLines) drawVerticalLine(canvas, JSON.parse(v));
-      for (const h of horizontalLines)
-        drawHorizontalLine(canvas, JSON.parse(h));
+      if (!options.closeVLine) {
+        for (const v of verticalLines) drawVerticalLine(canvas, JSON.parse(v));
+      }
+      if (!options.closeHLine) {
+        for (const h of horizontalLines) {
+          drawHorizontalLine(canvas, JSON.parse(h));
+        }
+      }
     }
   }
   function mouseUp() {