From 2bca0eebc9059e8170fc49b1935a23e6fc8bc268 Mon Sep 17 00:00:00 2001
From: Daniel Freedman <dfreedm@google.com>
Date: Thu, 10 May 2018 15:10:03 -0700
Subject: [PATCH] Only disable tabs for "disablable" elements

Fixes #5190
---
 lib/utils/gestures.html          |  15 +++-
 test/unit/gestures-elements.html |  76 ++++++++++++++++++--
 test/unit/gestures.html          | 116 +++++++++++++++++++++----------
 3 files changed, 164 insertions(+), 43 deletions(-)

diff --git a/lib/utils/gestures.html b/lib/utils/gestures.html
index 2a05daa462..a948ac3a7e 100644
--- a/lib/utils/gestures.html
+++ b/lib/utils/gestures.html
@@ -113,6 +113,19 @@
     'select': true
   };
 
+  /** @type {!Object<boolean>} */
+  const canBeDisabled = {
+    'button': true,
+    'command': true,
+    'fieldset': true,
+    'input': true,
+    'keygen': true,
+    'optgroup': true,
+    'option': true,
+    'select': true,
+    'textarea': true
+  };
+
   /**
    * @param {HTMLElement} el Element to check labelling status
    * @return {boolean} element can have labels
@@ -1058,7 +1071,7 @@
       let dy = Math.abs(e.clientY - this.info.y);
       // find original target from `preventer` for TouchEvents, or `e` for MouseEvents
       let t = Gestures._findOriginalTarget(/** @type {Event} */(preventer || e));
-      if (!t || t.disabled) {
+      if (!t || (canBeDisabled[t.localName] && t.disabled)) {
         return;
       }
       // dx,dy can be NaN if `click` has been simulated and there was no `down` for `start`
diff --git a/test/unit/gestures-elements.html b/test/unit/gestures-elements.html
index 15b7abeb1a..a6ea460c3f 100644
--- a/test/unit/gestures-elements.html
+++ b/test/unit/gestures-elements.html
@@ -244,24 +244,92 @@
   </script>
 </dom-module>
 
+<script>
+  class XDisabled extends Polymer.Element {
+    static get is() {
+      return 'x-disabled';
+    }
+    static get properties() {
+      return {
+        disabled: Boolean
+      };
+    }
+    constructor() {
+      super();
+      this.disabled = true;
+    }
+  }
+  customElements.define(XDisabled.is, XDisabled);
+</script>
+
 <dom-module id="x-disabled-tap">
   <template>
     <button id="disabled" on-tap="tap" disabled></button>
     <div disabled>
       <button id="nested" on-tap="tap"></button>
     </div>
+    <x-disabled id="disabledEl" on-tap="tap"></x-disabled>
+  </template>
+  <script>
+    class XDisabledTap extends Polymer.GestureEventListeners(Polymer.Element) {
+      constructor() {
+        super();
+        this.taps = [];
+      }
+      static get is() {
+        return 'x-disabled-tap';
+      }
+      tap(e) {
+        const target = e.target;
+        this.taps.push(`${target.localName}${target.id ? '#' + target.id : ''}`);
+      }
+    }
+    customElements.define(XDisabledTap.is, XDisabledTap);
+  </script>
+</dom-module>
+
+<dom-module id="all-disabled">
+  <template>
+    <button></button>
+    <!-- MDN lists as obsolete -->
+    <!-- <command></command> -->
+    <fieldset></fieldset>
+    <input>
+    <!-- MDN lists as obsolete -->
+    <!-- <keygen> -->
+    <select>
+      <optgroup>
+        <option></option>
+      </optgroup>
+    </select>
+    <textarea></textarea>
+    <div></div>
   </template>
   <script>
-    class XDisabled extends Polymer.GestureEventListeners(Polymer.Element) {
+    class AllDisabled extends Polymer.GestureEventListeners(Polymer.Element) {
+      static get is() {
+        return 'all-disabled';
+      }
       constructor() {
         super();
         this.taps = [];
       }
-      static get is() {return 'x-disabled-tap';}
       tap(e) {
-        this.taps.push(e.id);
+        this.taps.push(e.target.localName);
+      }
+      ready() {
+        super.ready();
+        this.shadowRoot.querySelectorAll('*').forEach((el) => {
+          el.setAttribute('disabled', '');
+          Polymer.Gestures.addListener(el, 'tap', (e) => this.tap(e));
+        });
+      }
+      tapAll() {
+        this.shadowRoot.querySelectorAll('*').forEach((el) => {
+          el.click();
+        });
       }
     }
-    customElements.define(XDisabled.is, XDisabled);
+    customElements.define(AllDisabled.is, AllDisabled);
   </script>
 </dom-module>
\ No newline at end of file
diff --git a/test/unit/gestures.html b/test/unit/gestures.html
index b1a001bdd4..a691526bea 100644
--- a/test/unit/gestures.html
+++ b/test/unit/gestures.html
@@ -615,44 +615,84 @@
         });
       });
 
-      test('disabled elements don\'t fire taps', function() {
-        let el = document.createElement('x-disabled-tap');
-        document.body.appendChild(el);
-        // tap an element with disabled attribute
-        let target = el.$.disabled;
-        // simulate the event sequence of a touch on the screen
-        let touches = [{
-          clientX: 0,
-          clientY: 0,
-          identifier: 1,
-          // target is set to the element with `addEventListener`, which is `target`
-          target
-        }];
-        let touchstart = new CustomEvent('touchstart', {bubbles: true, composed: true});
-        touchstart.changedTouches = touchstart.touches = touches;
-        target.dispatchEvent(touchstart);
-        let touchend = new CustomEvent('touchend', {bubbles: true, composed: true});
-        touchend.touches = touchend.changedTouches = touches;
-        target.dispatchEvent(touchend);
-        assert.equal(el.taps.length, 0);
-        // tap an element with a disabled ancestor
-        target = el.$.nested;
-        // simulate the event sequence of a touch on the screen
-        touches = [{
-          clientX: 0,
-          clientY: 0,
-          identifier: 1,
-          // target is set to the element with `addEventListener`, which is `target`
-          target
-        }];
-        touchstart = new CustomEvent('touchstart', {bubbles: true, composed: true});
-        touchstart.changedTouches = touchstart.touches = touches;
-        target.dispatchEvent(touchstart);
-        touchend = new CustomEvent('touchend', {bubbles: true, composed: true});
-        touchend.touches = touchend.changedTouches = touches;
-        target.dispatchEvent(touchend);
-        assert.equal(el.taps.length, 1);
-        document.body.removeChild(el);
+      suite('disabled', function() {
+        test('click() function works as expected on disabled elements', function() {
+          Polymer.Gestures.resetMouseCanceller();
+          let el = document.createElement('x-disabled-tap');
+          document.body.appendChild(el);
+          el.$.disabled.click();
+          el.$.nested.click();
+          el.$.disabledEl.click();
+          assert.deepEqual(el.taps, ['button#nested', 'x-disabled#disabledEl']);
+          document.body.removeChild(el);
+        });
+
+        test('disabled elements don\'t fire taps', function() {
+          let el = document.createElement('x-disabled-tap');
+          document.body.appendChild(el);
+          // tap an element with disabled attribute
+          let target = el.$.disabled;
+          // simulate the event sequence of a touch on the screen
+          let touches = [{
+            clientX: 0,
+            clientY: 0,
+            identifier: 1,
+            // target is set to the element with `addEventListener`, which is `target`
+            target
+          }];
+          let touchstart = new CustomEvent('touchstart', {bubbles: true, composed: true});
+          touchstart.changedTouches = touchstart.touches = touches;
+          target.dispatchEvent(touchstart);
+          let touchend = new CustomEvent('touchend', {bubbles: true, composed: true});
+          touchend.touches = touchend.changedTouches = touches;
+          target.dispatchEvent(touchend);
+          assert.deepEqual(el.taps, []);
+
+          // tap an element with a disabled ancestor
+          target = el.$.nested;
+          // simulate the event sequence of a touch on the screen
+          touches = [{
+            clientX: 0,
+            clientY: 0,
+            identifier: 1,
+            // target is set to the element with `addEventListener`, which is `target`
+            target
+          }];
+          touchstart = new CustomEvent('touchstart', {bubbles: true, composed: true});
+          touchstart.changedTouches = touchstart.touches = touches;
+          target.dispatchEvent(touchstart);
+          touchend = new CustomEvent('touchend', {bubbles: true, composed: true});
+          touchend.touches = touchend.changedTouches = touches;
+          target.dispatchEvent(touchend);
+          assert.deepEqual(el.taps, ['button#nested']);
+
+          // tap a custom element with a `disabled` property
+          target = el.$.disabledEl;
+          // simulate the event sequence of a touch on the screen
+          touches = [{
+            clientX: 0,
+            clientY: 0,
+            identifier: 1,
+            // target is set to the element with `addEventListener`, which is `target`
+            target
+          }];
+          touchstart = new CustomEvent('touchstart', {bubbles: true, composed: true});
+          touchstart.changedTouches = touchstart.touches = touches;
+          target.dispatchEvent(touchstart);
+          touchend = new CustomEvent('touchend', {bubbles: true, composed: true});
+          touchend.touches = touchend.changedTouches = touches;
+          target.dispatchEvent(touchend);
+          assert.deepEqual(el.taps, ['button#nested', 'x-disabled#disabledEl']);
+          document.body.removeChild(el);
+        });
+
+        test('test all "disablable" elements', function() {
+          const el = document.createElement('all-disabled');
+          document.body.appendChild(el);
+          el.tapAll();
+          assert.deepEqual(el.taps, ['div']);
+          document.body.removeChild(el);
+        })
       });
     });
   </script>