diff --git a/lib/checks/mobile/target-size-evaluate.js b/lib/checks/mobile/target-size-evaluate.js index 4f18351adf..a0224c8ad2 100644 --- a/lib/checks/mobile/target-size-evaluate.js +++ b/lib/checks/mobile/target-size-evaluate.js @@ -1,8 +1,10 @@ import { findNearbyElms, isFocusable, isInTabOrder } from '../../commons/dom'; import { getRoleType } from '../../commons/aria'; -import { splitRects, hasVisualOverlap } from '../../commons/math'; - -const roundingMargin = 0.05; +import { + splitRects, + rectHasMinimumSize, + hasVisualOverlap +} from '../../commons/math'; /** * Determine if an element has a minimum size, taking into account @@ -165,12 +167,6 @@ function isDescendantNotInTabOrder(vAncestor, vNode) { ); } -function rectHasMinimumSize(minSize, { width, height }) { - return ( - width + roundingMargin >= minSize && height + roundingMargin >= minSize - ); -} - function mapActualNodes(vNodes) { return vNodes.map(({ actualNode }) => actualNode); } diff --git a/lib/commons/dom/get-target-rects.js b/lib/commons/dom/get-target-rects.js new file mode 100644 index 0000000000..fc5b2aabe7 --- /dev/null +++ b/lib/commons/dom/get-target-rects.js @@ -0,0 +1,38 @@ +import findNearbyElms from './find-nearby-elms'; +import isInTabOrder from './is-in-tab-order'; +import { splitRects, hasVisualOverlap } from '../math'; +import memoize from '../../core/utils/memoize'; + +export default memoize(getTargetRects); + +/** + * Return all unobscured rects of a target. + * @see https://www.w3.org/TR/WCAG22/#dfn-bounding-boxes + * @param {VitualNode} vNode + * @return {DOMRect[]} + */ +function getTargetRects(vNode) { + const nodeRect = vNode.boundingClientRect; + const overlappingVNodes = findNearbyElms(vNode).filter(vNeighbor => { + return ( + hasVisualOverlap(vNode, vNeighbor) && + vNeighbor.getComputedStylePropertyValue('pointer-events') !== 'none' && + !isDescendantNotInTabOrder(vNode, vNeighbor) + ); + }); + + if (!overlappingVNodes.length) { + return [nodeRect]; + } + + const obscuringRects = overlappingVNodes.map( + ({ boundingClientRect: rect }) => rect + ); + return splitRects(nodeRect, obscuringRects); +} + +function isDescendantNotInTabOrder(vAncestor, vNode) { + return ( + vAncestor.actualNode.contains(vNode.actualNode) && !isInTabOrder(vNode) + ); +} diff --git a/lib/commons/dom/get-target-size.js b/lib/commons/dom/get-target-size.js index f16c245227..926bbc0d0d 100644 --- a/lib/commons/dom/get-target-size.js +++ b/lib/commons/dom/get-target-size.js @@ -1,9 +1,7 @@ -import findNearbyElms from './find-nearby-elms'; -import { splitRects, hasVisualOverlap } from '../math'; +import getTargetRects from './get-target-rects'; +import { rectHasMinimumSize } from '../math'; import memoize from '../../core/utils/memoize'; -const roundingMargin = 0.05; - export default memoize(getTargetSize); /** @@ -11,37 +9,8 @@ export default memoize(getTargetSize); * @see https://www.w3.org/TR/WCAG22/#dfn-targets */ function getTargetSize(vNode, minSize) { - const nodeRect = vNode.boundingClientRect; - const overlappingVNodes = findNearbyElms(vNode).filter(vNeighbor => { - return ( - vNeighbor.getComputedStylePropertyValue('pointer-events') !== 'none' && - hasVisualOverlap(vNode, vNeighbor) - ); - }); - - if (!overlappingVNodes.length) { - return nodeRect; - } - - return getLargestUnobscuredArea(vNode, overlappingVNodes, minSize); -} - -// Find areas of the target that are not obscured -function getLargestUnobscuredArea(vNode, obscuredNodes, minSize) { - const nodeRect = vNode.boundingClientRect; - if (obscuredNodes.length === 0) { - return null; - } - const obscuringRects = obscuredNodes.map( - ({ boundingClientRect: rect }) => rect - ); - const unobscuredRects = splitRects(nodeRect, obscuringRects); - if (!unobscuredRects.length) { - return null; - } - - // Of the unobscured inner rects, work out the largest - return getLargestRect(unobscuredRects, minSize); + const rects = getTargetRects(vNode); + return getLargestRect(rects, minSize); } // Find the largest rectangle in the array, prioritize ones that meet a minimum size @@ -58,9 +27,3 @@ function getLargestRect(rects, minSize) { return areaA > areaB ? rectA : rectB; }); } - -function rectHasMinimumSize(minSize, { width, height }) { - return ( - width + roundingMargin >= minSize && height + roundingMargin >= minSize - ); -} diff --git a/lib/commons/dom/index.js b/lib/commons/dom/index.js index fbac8213f0..57ae0756c9 100644 --- a/lib/commons/dom/index.js +++ b/lib/commons/dom/index.js @@ -17,6 +17,7 @@ export { default as getOverflowHiddenAncestors } from './get-overflow-hidden-anc export { default as getRootNode } from './get-root-node'; export { default as getScrollOffset } from './get-scroll-offset'; export { default as getTabbableElements } from './get-tabbable-elements'; +export { default as getTargetRects } from './get-target-rects'; export { default as getTargetSize } from './get-target-size'; export { default as getTextElementStack } from './get-text-element-stack'; export { default as getViewportSize } from './get-viewport-size'; diff --git a/lib/commons/math/get-offset.js b/lib/commons/math/get-offset.js index 65cba9b0e3..664871fda0 100644 --- a/lib/commons/math/get-offset.js +++ b/lib/commons/math/get-offset.js @@ -1,38 +1,53 @@ -import { getTargetSize } from '../dom'; +import { getTargetRects, getTargetSize } from '../dom'; +import { getBoundingRect } from './get-bounding-rect'; +import { isPointInRect } from './is-point-in-rect'; +import { getRectCenter } from './get-rect-center'; +import rectHasMinimumSize from './rect-has-minimum-size'; /** - * Get the offset between node A and node B + * Get the offset between target A and neighbor B. This assumes that the target is undersized and needs to check the spacing exception. * @method getOffset * @memberof axe.commons.math - * @param {VirtualNode} vNodeA - * @param {VirtualNode} vNodeB + * @param {VirtualNode} vTarget + * @param {VirtualNode} vNeighbor * @param {Number} radius * @returns {number} */ -export default function getOffset(vNodeA, vNodeB, minRadiusNeighbour = 12) { - const rectA = getTargetSize(vNodeA); - const rectB = getTargetSize(vNodeB); +export default function getOffset(vTarget, vNeighbor, minRadiusNeighbour = 12) { + const targetRects = getTargetRects(vTarget); + const neighborRects = getTargetRects(vNeighbor); - // one of the rects is fully obscured - if (rectA === null || rectB === null) { + if (!targetRects.length || !neighborRects.length) { return 0; } - const centerA = { - x: rectA.x + rectA.width / 2, - y: rectA.y + rectA.height / 2 - }; - const centerB = { - x: rectB.x + rectB.width / 2, - y: rectB.y + rectB.height / 2 - }; - const sideB = getClosestPoint(centerA, rectB); + const targetBoundingBox = targetRects.reduce(getBoundingRect); + const targetCenter = getRectCenter(targetBoundingBox); - return Math.min( - // subtract the radius of the circle from the distance - pointDistance(centerA, centerB) - minRadiusNeighbour, - pointDistance(centerA, sideB) - ); + // calculate distance to the closest edge of each neighbor rect + let minDistance = Infinity; + for (const rect of neighborRects) { + if (isPointInRect(targetCenter, rect)) { + return 0; + } + + const closestPoint = getClosestPoint(targetCenter, rect); + const distance = pointDistance(targetCenter, closestPoint); + minDistance = Math.min(minDistance, distance); + } + + const neighborTargetSize = getTargetSize(vNeighbor); + if (rectHasMinimumSize(minRadiusNeighbour * 2, neighborTargetSize)) { + return minDistance; + } + + const neighborBoundingBox = neighborRects.reduce(getBoundingRect); + const neighborCenter = getRectCenter(neighborBoundingBox); + // subtract the radius of the circle from the distance to center to get distance to edge of the neighbor circle + const centerDistance = + pointDistance(targetCenter, neighborCenter) - minRadiusNeighbour; + + return Math.max(0, Math.min(minDistance, centerDistance)); } function getClosestPoint(point, rect) { diff --git a/lib/commons/math/index.js b/lib/commons/math/index.js index b6edc3d4aa..88ac3a9cdc 100644 --- a/lib/commons/math/index.js +++ b/lib/commons/math/index.js @@ -4,5 +4,6 @@ export { default as getOffset } from './get-offset'; export { getRectCenter } from './get-rect-center'; export { default as hasVisualOverlap } from './has-visual-overlap'; export { isPointInRect } from './is-point-in-rect'; +export { default as rectHasMinimumSize } from './rect-has-minimum-size'; export { default as rectsOverlap } from './rects-overlap'; export { default as splitRects } from './split-rects'; diff --git a/lib/commons/math/rect-has-minimum-size.js b/lib/commons/math/rect-has-minimum-size.js new file mode 100644 index 0000000000..014a888e35 --- /dev/null +++ b/lib/commons/math/rect-has-minimum-size.js @@ -0,0 +1,7 @@ +const roundingMargin = 0.05; + +export default function rectHasMinimumSize(minSize, { width, height }) { + return ( + width + roundingMargin >= minSize && height + roundingMargin >= minSize + ); +} diff --git a/test/commons/dom/get-target-rects.js b/test/commons/dom/get-target-rects.js new file mode 100644 index 0000000000..f25abe2918 --- /dev/null +++ b/test/commons/dom/get-target-rects.js @@ -0,0 +1,83 @@ +describe('get-target-rects', () => { + const getTargetRects = axe.commons.dom.getTargetRects; + const { queryFixture } = axe.testUtils; + + it('returns the bounding rect when unobscured', () => { + const vNode = queryFixture(''); + const rects = getTargetRects(vNode); + assert.deepEqual(rects, [vNode.actualNode.getBoundingClientRect()]); + }); + + it('returns subset rect when obscured', () => { + const vNode = queryFixture(` + +
+ `); + const rects = getTargetRects(vNode); + assert.deepEqual(rects, [new DOMRect(10, 5, 20, 40)]); + }); + + it('ignores elements with "pointer-events: none"', () => { + const vNode = queryFixture(` + +
+ `); + const rects = getTargetRects(vNode); + assert.deepEqual(rects, [vNode.actualNode.getBoundingClientRect()]); + }); + + it("ignores elements that don't overlap the target", () => { + const vNode = queryFixture(` + +
+ `); + const rects = getTargetRects(vNode); + assert.deepEqual(rects, [vNode.actualNode.getBoundingClientRect()]); + }); + + it('ignores non-tabbable descendants of the target', () => { + const vNode = queryFixture(` + + `); + const rects = getTargetRects(vNode); + assert.deepEqual(rects, [vNode.actualNode.getBoundingClientRect()]); + }); + + it('returns each unobscured area', () => { + const vNode = queryFixture(` + +
+
+ `); + const rects = getTargetRects(vNode); + assert.deepEqual(rects, [ + new DOMRect(10, 5, 20, 15), + new DOMRect(10, 30, 20, 15) + ]); + }); + + it('returns empty if target is fully obscured', () => { + const vNode = queryFixture(` + +
+ `); + const rects = getTargetRects(vNode); + assert.lengthOf(rects, 0); + }); + + it('returns subset rect of the target with tabbable descendant', () => { + const vNode = queryFixture(` + + `); + const rects = getTargetRects(vNode); + console.log(JSON.stringify(rects)); + assert.deepEqual(rects, [ + new DOMRect(10, 5, 30, 7), + new DOMRect(10, 5, 7, 40) + ]); + }); +}); diff --git a/test/commons/dom/get-target-size.js b/test/commons/dom/get-target-size.js index ddb876f7aa..10bda51300 100644 --- a/test/commons/dom/get-target-size.js +++ b/test/commons/dom/get-target-size.js @@ -23,7 +23,7 @@ describe('get-target-size', () => {
`); const rect = getTargetSize(vNode); - assert.deepEqual(rect, new DOMRect(10, 5, 30, 40)); + assert.deepEqual(rect, vNode.actualNode.getBoundingClientRect()); }); it("ignores elements that don't overlap the target", () => { @@ -32,7 +32,7 @@ describe('get-target-size', () => {
`); const rect = getTargetSize(vNode); - assert.deepEqual(rect, new DOMRect(10, 5, 30, 40)); + assert.deepEqual(rect, vNode.actualNode.getBoundingClientRect()); }); it('returns the largest unobscured area', () => { diff --git a/test/commons/math/get-offset.js b/test/commons/math/get-offset.js index cdbd1a5682..073c8d0649 100644 --- a/test/commons/math/get-offset.js +++ b/test/commons/math/get-offset.js @@ -62,4 +62,14 @@ describe('getOffset', () => { const nodeB = fixture.children[3]; assert.closeTo(getOffset(nodeA, nodeB, 30), 20, round); }); + + it('returns 0 if center of nodeA is enclosed by nodeB', () => { + const fixture = fixtureSetup(` + + + `); + const nodeA = fixture.children[1]; + const nodeB = fixture.children[3]; + assert.equal(getOffset(nodeA, nodeB, 30), 0); + }); }); diff --git a/test/commons/math/rect-has-minimum-size.js b/test/commons/math/rect-has-minimum-size.js new file mode 100644 index 0000000000..7d93b5c83a --- /dev/null +++ b/test/commons/math/rect-has-minimum-size.js @@ -0,0 +1,28 @@ +describe('rectHasMinimumSize', () => { + const rectHasMinimumSize = axe.commons.math.rectHasMinimumSize; + + it('returns true if rect is large enough', () => { + const rect = new DOMRect(10, 20, 10, 20); + assert.isTrue(rectHasMinimumSize(10, rect)); + }); + + it('returns true for rounding margin', () => { + const rect = new DOMRect(10, 20, 9.95, 20); + assert.isTrue(rectHasMinimumSize(10, rect)); + }); + + it('returns false if width is too small', () => { + const rect = new DOMRect(10, 20, 5, 20); + assert.isFalse(rectHasMinimumSize(10, rect)); + }); + + it('returns false if height is too small', () => { + const rect = new DOMRect(10, 20, 10, 5); + assert.isFalse(rectHasMinimumSize(10, rect)); + }); + + it('returns false when below rounding margin', () => { + const rect = new DOMRect(10, 20, 9.94, 20); + assert.isFalse(rectHasMinimumSize(10, rect)); + }); +}); diff --git a/test/integration/full/target-size/target-size.html b/test/integration/full/target-size/target-size.html index d6a1b2f873..9358f9ab81 100644 --- a/test/integration/full/target-size/target-size.html +++ b/test/integration/full/target-size/target-size.html @@ -177,6 +177,9 @@ .ml-n6 { margin-left: -36px; } + .ml-n5 { + margin-left: -30px; + } .ml-n4 { margin-left: -24px; } @@ -456,13 +459,12 @@
- +
- - +
@@ -481,7 +483,7 @@
- +
@@ -496,26 +498,26 @@
-

Example K1 - K3 pass, the middle element of K4 fails.

+

Example K1 and K2 pass, K3 and K4 fail.

- +
- +
- +
- +
@@ -588,6 +590,7 @@
+ @@ -640,6 +643,7 @@
+