feat: Support labels for arrow 🔥 (#5723)

* feat: support arrow with text

* render arrow -> clear rect-> render text

* move bound text when linear elements move

* fix centering cursor when linear element rotated

* fix y coord when new line added and container has 3 points

* update text position when 2nd point moved

* support adding label on top of 2nd point when 3 points are present

* change linear element editor shortcut to cmd+enter and fix tests

* scale bound text points when resizing via bounding box

* ohh yeah rotation works :)

* fix coords when updating text properties

* calculate new position after rotation always from original position

* rotate the bound text by same angle as parent

* don't rotate text and make sure dimensions and coords are always calculated from original point

* hardcoding the text width for now

* Move the linear element when bound text hit

* Rotation working yaay

* consider text element angle when editing

* refactor

* update x2 coords if needed when text updated

* simplify

* consider bound text to be part of bounding box when hit

* show bounding box correctly when multiple element selected

* fix typo

* support rotating multiple elements

* support multiple element resizing

* shift bound text to mid point when odd points

* Always render linear element handles inside editor after element rendered so point is visible for bound text

* Delete bound text when point attached to it deleted

* move bound to mid segement mid point when points are even

* shift bound text when points nearby deleted and handle segment deletion

* Resize working :)

* more resize fixes

* don't update cache-its breaking delete points, look for better soln

* update mid point cache for bound elements when updated

* introduce wrapping when resizing

* wrap when resize for 2 pointer linear elements

* support adding text for linear elements with more than 3 points

* export to svg  working :)

* clip from nearest enclosing element with non transparent color if present when exporting and fill with correct color in canvas

* fix snap

* use visible elements

* Make export to svg work with Mask :)

* remove id

* mask canvas linear element area where label is added

* decide the position of bound text during render

* fix coords when editing

* fix multiple resize

* update cache when bound text version changes

* fix masking when rotated

* render text in correct position in preview

* remove unnecessary code

* fix masking when rotating linear element

* fix masking with zoom

* fix mask in preview for export

* fix offsets in export view

* fix coords on svg export

* fix mask when element rotated in svg

* enable double-click to enter text

* fix hint

* Position cursor correctly and text dimensiosn when height of element is negative

* don't allow 2 pointer linear element with bound text width to go beyond min width

* code cleanup

* fix freedraw

* Add padding

* don't show vertical align action for linear element containers

* Add specs for getBoundTextElementPosition

* more specs

* move some utils to linearElementEditor.ts

* remove only :p

* check absoulte coods in test

* Add test to hide vertical align for linear eleemnt with bound text

* improve export preview

* support labels only for arrows

* spec

* fix large texts

* fix tests

* fix zooming

* enter line editor with cmd+double click

* Allow points to move beyond min width/height for 2 pointer arrow with bound text

* fix hint for line editing

* attempt to fix arrow getting deselected

* fix hint and shortcut

* Add padding of 5px when creating bound text and add spec

* Wrap bound text when arrow binding containers moved

* Add spec

* remove

* set boundTextElementVersion to null if not present

* dont use cache when version mismatch

* Add a padding of 5px vertically when creating text

* Add box sizing content box

* Set bound elements when text element created to fix the padding

* fix zooming in editor

* fix zoom in export

* remove globalCompositeOperation and use clearRect instead of fillRect

src/element/collision.ts

@@ -36,6 +36,7 @@ import { hasBoundTextElement, isImageElement } from "./typeChecks";
 import { isTextElement } from ".";
 import { isTransparent } from "../utils";
 import { shouldShowBoundingBox } from "./transformHandles";
+import { getBoundTextElement } from "./textElement";
 
 const isElementDraggableFromInside = (
   element: NonDeletedExcalidrawElement,
@@ -72,6 +73,13 @@ export const hitTest = (
     return isPointHittingElementBoundingBox(element, point, threshold);
   }
 
+  const boundTextElement = getBoundTextElement(element);
+  if (boundTextElement) {
+    const isHittingBoundTextElement = hitTest(boundTextElement, appState, x, y);
+    if (isHittingBoundTextElement) {
+      return true;
+    }
+  }
   return isHittingElementNotConsideringBoundingBox(element, appState, point);
 };
 
@@ -83,6 +91,13 @@ export const isHittingElementBoundingBoxWithoutHittingElement = (
 ): boolean => {
   const threshold = 10 / appState.zoom.value;
 
+  // So that bound text element hit is considered within bounding box of container even if its outside actual bounding box of element
+  // eg for linear elements text can be outside the element bounding box
+  const boundTextElement = getBoundTextElement(element);
+  if (boundTextElement && hitTest(boundTextElement, appState, x, y)) {
+    return false;
+  }
+
   return (
     !isHittingElementNotConsideringBoundingBox(element, appState, [x, y]) &&
     isPointHittingElementBoundingBox(element, [x, y], threshold)
@@ -95,7 +110,6 @@ export const isHittingElementNotConsideringBoundingBox = (
   point: Point,
 ): boolean => {
   const threshold = 10 / appState.zoom.value;
-
   const check = isTextElement(element)
     ? isStrictlyInside
     : isElementDraggableFromInside(element)
@@ -382,6 +396,7 @@ const hitTestLinear = (args: HitTestArgs): boolean => {
   if (!getShapeForElement(element)) {
     return false;
   }
+
   const [point, pointAbs, hwidth, hheight] = pointRelativeToElement(
     args.element,
     args.point,
@@ -434,8 +449,9 @@ const pointRelativeToElement = (
   pointTuple: Point,
 ): [GA.Point, GA.Point, number, number] => {
   const point = GAPoint.from(pointTuple);
+  const [x1, y1, x2, y2] = getElementAbsoluteCoords(element);
   const elementCoords = getElementAbsoluteCoords(element);
-  const center = coordsCenter(elementCoords);
+  const center = coordsCenter([x1, y1, x2, y2]);
   // GA has angle orientation opposite to `rotate`
   const rotate = GATransform.rotation(center, element.angle);
   const pointRotated = GATransform.apply(rotate, point);
@@ -466,8 +482,8 @@ export const pointInAbsoluteCoords = (
 const relativizationToElementCenter = (
   element: ExcalidrawElement,
 ): GA.Transform => {
-  const elementCoords = getElementAbsoluteCoords(element);
-  const center = coordsCenter(elementCoords);
+  const [x1, y1, x2, y2] = getElementAbsoluteCoords(element);
+  const center = coordsCenter([x1, y1, x2, y2]);
   // GA has angle orientation opposite to `rotate`
   const rotate = GATransform.rotation(center, element.angle);
   const translate = GA.reverse(
@@ -524,8 +540,8 @@ export const determineFocusPoint = (
   adjecentPoint: Point,
 ): Point => {
   if (focus === 0) {
-    const elementCoords = getElementAbsoluteCoords(element);
-    const center = coordsCenter(elementCoords);
+    const [x1, y1, x2, y2] = getElementAbsoluteCoords(element);
+    const center = coordsCenter([x1, y1, x2, y2]);
     return GAPoint.toTuple(center);
   }
   const relateToCenter = relativizationToElementCenter(element);