From 9cced050491b8db80be19ed6c419d3cb6eb4ba08 Mon Sep 17 00:00:00 2001
From: Peter Keuter <github@peterkeuter.nl>
Date: Wed, 28 Feb 2024 15:25:12 +0100
Subject: [PATCH] Login-page a11y improvements

Closes #27190

Signed-off-by: Peter Keuter <github@peterkeuter.nl>
---
 .../main/resources/theme/base/login/login.ftl |  18 +-
 .../login/resources/js/menu-button-links.js   | 315 ++++++++++++++++++
 .../resources/theme/base/login/template.ftl   |  13 +-
 .../keycloak/login/resources/css/login.css    |  16 +-
 4 files changed, 347 insertions(+), 15 deletions(-)
 create mode 100644 themes/src/main/resources/theme/base/login/resources/js/menu-button-links.js

diff --git a/themes/src/main/resources/theme/base/login/login.ftl b/themes/src/main/resources/theme/base/login/login.ftl
index 81c9dbf144..d6008e0e4b 100755
--- a/themes/src/main/resources/theme/base/login/login.ftl
+++ b/themes/src/main/resources/theme/base/login/login.ftl
@@ -11,7 +11,7 @@
                         <div class="${properties.kcFormGroupClass!}">
                             <label for="username" class="${properties.kcLabelClass!}"><#if !realm.loginWithEmailAllowed>${msg("username")}<#elseif !realm.registrationEmailAsUsername>${msg("usernameOrEmail")}<#else>${msg("email")}</#if></label>
 
-                            <input tabindex="1" id="username" class="${properties.kcInputClass!}" name="username" value="${(login.username!'')}"  type="text" autofocus autocomplete="off"
+                            <input tabindex="2" id="username" class="${properties.kcInputClass!}" name="username" value="${(login.username!'')}"  type="text" autofocus autocomplete="username"
                                    aria-invalid="<#if messagesPerField.existsError('username','password')>true</#if>"
                             />
 
@@ -28,11 +28,11 @@
                         <label for="password" class="${properties.kcLabelClass!}">${msg("password")}</label>
 
                         <div class="${properties.kcInputGroup!}">
-                            <input tabindex="2" id="password" class="${properties.kcInputClass!}" name="password" type="password" autocomplete="off"
+                            <input tabindex="3" id="password" class="${properties.kcInputClass!}" name="password" type="password" autocomplete="current-password"
                                    aria-invalid="<#if messagesPerField.existsError('username','password')>true</#if>"
                             />
                             <button class="${properties.kcFormPasswordVisibilityButtonClass!}" type="button" aria-label="${msg("showPassword")}"
-                                    aria-controls="password"  data-password-toggle
+                                    aria-controls="password" data-password-toggle tabindex="4"
                                     data-icon-show="${properties.kcFormPasswordVisibilityIconShow!}" data-icon-hide="${properties.kcFormPasswordVisibilityIconHide!}"
                                     data-label-show="${msg('showPassword')}" data-label-hide="${msg('hidePassword')}">
                                 <i class="${properties.kcFormPasswordVisibilityIconShow!}" aria-hidden="true"></i>
@@ -53,9 +53,9 @@
                                 <div class="checkbox">
                                     <label>
                                         <#if login.rememberMe??>
-                                            <input tabindex="3" id="rememberMe" name="rememberMe" type="checkbox" checked> ${msg("rememberMe")}
+                                            <input tabindex="5" id="rememberMe" name="rememberMe" type="checkbox" checked> ${msg("rememberMe")}
                                         <#else>
-                                            <input tabindex="3" id="rememberMe" name="rememberMe" type="checkbox"> ${msg("rememberMe")}
+                                            <input tabindex="5" id="rememberMe" name="rememberMe" type="checkbox"> ${msg("rememberMe")}
                                         </#if>
                                     </label>
                                 </div>
@@ -63,7 +63,7 @@
                             </div>
                             <div class="${properties.kcFormOptionsWrapperClass!}">
                                 <#if realm.resetPasswordAllowed>
-                                    <span><a tabindex="5" href="${url.loginResetCredentialsUrl}">${msg("doForgotPassword")}</a></span>
+                                    <span><a tabindex="6" href="${url.loginResetCredentialsUrl}">${msg("doForgotPassword")}</a></span>
                                 </#if>
                             </div>
 
@@ -71,7 +71,7 @@
 
                       <div id="kc-form-buttons" class="${properties.kcFormGroupClass!}">
                           <input type="hidden" id="id-hidden-input" name="credentialId" <#if auth.selectedCredential?has_content>value="${auth.selectedCredential}"</#if>/>
-                          <input tabindex="4" class="${properties.kcButtonClass!} ${properties.kcButtonPrimaryClass!} ${properties.kcButtonBlockClass!} ${properties.kcButtonLargeClass!}" name="login" id="kc-login" type="submit" value="${msg("doLogIn")}"/>
+                          <input tabindex="7" class="${properties.kcButtonClass!} ${properties.kcButtonPrimaryClass!} ${properties.kcButtonBlockClass!} ${properties.kcButtonLargeClass!}" name="login" id="kc-login" type="submit" value="${msg("doLogIn")}"/>
                       </div>
                 </form>
             </#if>
@@ -82,7 +82,7 @@
         <#if realm.password && realm.registrationAllowed && !registrationDisabled??>
             <div id="kc-registration-container">
                 <div id="kc-registration">
-                    <span>${msg("noAccount")} <a tabindex="6"
+                    <span>${msg("noAccount")} <a tabindex="8"
                                                  href="${url.registrationUrl}">${msg("doRegister")}</a></span>
                 </div>
             </div>
@@ -91,7 +91,7 @@
         <#if realm.password && social.providers??>
             <div id="kc-social-providers" class="${properties.kcFormSocialAccountSectionClass!}">
                 <hr/>
-                <h4>${msg("identity-provider-login-label")}</h4>
+                <h2>${msg("identity-provider-login-label")}</h2>
 
                 <ul class="${properties.kcFormSocialAccountListClass!} <#if social.providers?size gt 3>${properties.kcFormSocialAccountListGridClass!}</#if>">
                     <#list social.providers as p>
diff --git a/themes/src/main/resources/theme/base/login/resources/js/menu-button-links.js b/themes/src/main/resources/theme/base/login/resources/js/menu-button-links.js
new file mode 100644
index 0000000000..0fd79f0f68
--- /dev/null
+++ b/themes/src/main/resources/theme/base/login/resources/js/menu-button-links.js
@@ -0,0 +1,315 @@
+// @ts-check
+/*
+ *   This content is licensed according to the W3C Software License at
+ *   https://www.w3.org/Consortium/Legal/2015/copyright-software-and-document
+ *
+ *   File:   menu-button-links.js
+ *
+ *   Desc:   Creates a menu button that opens a menu of links
+ *
+ *   Modified by Peter Keuter to adhere to the coding standards of Keycloak
+ *   Original file: https://www.w3.org/WAI/content-assets/wai-aria-practices/patterns/menu-button/examples/js/menu-button-links.js
+ *   Source: https://www.w3.org/TR/wai-aria-practices/examples/menu-button/menu-button-links.html
+ */
+
+class MenuButtonLinks {
+  constructor(domNode) {
+    this.domNode = domNode;
+    this.buttonNode = domNode.querySelector("button");
+    this.menuNode = domNode.querySelector('[role="menu"]');
+    this.menuitemNodes = [];
+    this.firstMenuitem = false;
+    this.lastMenuitem = false;
+    this.firstChars = [];
+
+    this.buttonNode.addEventListener("keydown", (e) => this.onButtonKeydown(e));
+    this.buttonNode.addEventListener("click", (e) => this.onButtonClick(e));
+
+    const nodes = domNode.querySelectorAll('[role="menuitem"]');
+
+    for (const menuitem of nodes) {
+      this.menuitemNodes.push(menuitem);
+      menuitem.tabIndex = -1;
+      this.firstChars.push(menuitem.textContent.trim()[0].toLowerCase());
+
+      menuitem.addEventListener("keydown", (e) => this.onMenuitemKeydown(e));
+
+      menuitem.addEventListener("mouseover", (e) =>
+        this.onMenuitemMouseover(e)
+      );
+
+      if (!this.firstMenuitem) {
+        this.firstMenuitem = menuitem;
+      }
+      this.lastMenuitem = menuitem;
+    }
+
+    domNode.addEventListener("focusin", () => this.onFocusin());
+    domNode.addEventListener("focusout", () => this.onFocusout());
+
+    window.addEventListener(
+      "mousedown",
+      (e) => this.onBackgroundMousedown(e),
+      true
+    );
+  }
+
+  setFocusToMenuitem = (newMenuitem) =>
+    this.menuitemNodes.forEach((item) => {
+      if (item === newMenuitem) {
+        item.tabIndex = 0;
+        newMenuitem.focus();
+      } else {
+        item.tabIndex = -1;
+      }
+    });
+
+  setFocusToFirstMenuitem = () => this.setFocusToMenuitem(this.firstMenuitem);
+
+  setFocusToLastMenuitem = () => this.setFocusToMenuitem(this.lastMenuitem);
+
+  setFocusToPreviousMenuitem = (currentMenuitem) => {
+    let newMenuitem, index;
+
+    if (currentMenuitem === this.firstMenuitem) {
+      newMenuitem = this.lastMenuitem;
+    } else {
+      index = this.menuitemNodes.indexOf(currentMenuitem);
+      newMenuitem = this.menuitemNodes[index - 1];
+    }
+
+    this.setFocusToMenuitem(newMenuitem);
+
+    return newMenuitem;
+  };
+
+  setFocusToNextMenuitem = (currentMenuitem) => {
+    let newMenuitem, index;
+
+    if (currentMenuitem === this.lastMenuitem) {
+      newMenuitem = this.firstMenuitem;
+    } else {
+      index = this.menuitemNodes.indexOf(currentMenuitem);
+      newMenuitem = this.menuitemNodes[index + 1];
+    }
+    this.setFocusToMenuitem(newMenuitem);
+
+    return newMenuitem;
+  };
+
+  setFocusByFirstCharacter = (currentMenuitem, char) => {
+    let start, index;
+
+    if (char.length > 1) {
+      return;
+    }
+
+    char = char.toLowerCase();
+
+    // Get start index for search based on position of currentItem
+    start = this.menuitemNodes.indexOf(currentMenuitem) + 1;
+    if (start >= this.menuitemNodes.length) {
+      start = 0;
+    }
+
+    // Check remaining slots in the menu
+    index = this.firstChars.indexOf(char, start);
+
+    // If not found in remaining slots, check from beginning
+    if (index === -1) {
+      index = this.firstChars.indexOf(char, 0);
+    }
+
+    // If match was found...
+    if (index > -1) {
+      this.setFocusToMenuitem(this.menuitemNodes[index]);
+    }
+  };
+
+  // Utilities
+
+  getIndexFirstChars = (startIndex, char) => {
+    for (let i = startIndex; i < this.firstChars.length; i++) {
+      if (char === this.firstChars[i]) {
+        return i;
+      }
+    }
+    return -1;
+  };
+
+  // Popup menu methods
+
+  openPopup = () => {
+    this.menuNode.style.display = "block";
+    this.buttonNode.setAttribute("aria-expanded", "true");
+  };
+
+  closePopup = () => {
+    if (this.isOpen()) {
+      this.buttonNode.setAttribute("aria-expanded", "false");
+      this.menuNode.style.removeProperty("display");
+    }
+  };
+
+  isOpen = () => {
+    return this.buttonNode.getAttribute("aria-expanded") === "true";
+  };
+
+  // Menu event handlers
+
+  onFocusin = () => {
+    this.domNode.classList.add("focus");
+  };
+
+  onFocusout = () => {
+    this.domNode.classList.remove("focus");
+  };
+
+  onButtonKeydown = (event) => {
+    const key = event.key;
+    let flag = false;
+
+    switch (key) {
+      case " ":
+      case "Enter":
+      case "ArrowDown":
+      case "Down":
+        this.openPopup();
+        this.setFocusToFirstMenuitem();
+        flag = true;
+        break;
+
+      case "Esc":
+      case "Escape":
+        this.closePopup();
+        this.buttonNode.focus();
+        flag = true;
+        break;
+
+      case "Up":
+      case "ArrowUp":
+        this.openPopup();
+        this.setFocusToLastMenuitem();
+        flag = true;
+        break;
+
+      default:
+        break;
+    }
+
+    if (flag) {
+      event.stopPropagation();
+      event.preventDefault();
+    }
+  };
+
+  onButtonClick(event) {
+    if (this.isOpen()) {
+      this.closePopup();
+      this.buttonNode.focus();
+    } else {
+      this.openPopup();
+      this.setFocusToFirstMenuitem();
+    }
+
+    event.stopPropagation();
+    event.preventDefault();
+  }
+
+  onMenuitemKeydown(event) {
+    const tgt = event.currentTarget;
+    const key = event.key;
+    let flag = false;
+
+    const isPrintableCharacter = (str) => str.length === 1 && str.match(/\S/);
+
+    if (event.ctrlKey || event.altKey || event.metaKey) {
+      return;
+    }
+
+    if (event.shiftKey) {
+      if (isPrintableCharacter(key)) {
+        this.setFocusByFirstCharacter(tgt, key);
+        flag = true;
+      }
+
+      if (event.key === "Tab") {
+        this.buttonNode.focus();
+        this.closePopup();
+        flag = true;
+      }
+    } else {
+      switch (key) {
+        case " ":
+          window.location.href = tgt.href;
+          break;
+
+        case "Esc":
+        case "Escape":
+          this.closePopup();
+          this.buttonNode.focus();
+          flag = true;
+          break;
+
+        case "Up":
+        case "ArrowUp":
+          this.setFocusToPreviousMenuitem(tgt);
+          flag = true;
+          break;
+
+        case "ArrowDown":
+        case "Down":
+          this.setFocusToNextMenuitem(tgt);
+          flag = true;
+          break;
+
+        case "Home":
+        case "PageUp":
+          this.setFocusToFirstMenuitem();
+          flag = true;
+          break;
+
+        case "End":
+        case "PageDown":
+          this.setFocusToLastMenuitem();
+          flag = true;
+          break;
+
+        case "Tab":
+          this.closePopup();
+          break;
+
+        default:
+          if (isPrintableCharacter(key)) {
+            this.setFocusByFirstCharacter(tgt, key);
+            flag = true;
+          }
+          break;
+      }
+    }
+
+    if (flag) {
+      event.stopPropagation();
+      event.preventDefault();
+    }
+  }
+
+  onMenuitemMouseover(event) {
+    const tgt = event.currentTarget;
+    tgt.focus();
+  }
+
+  onBackgroundMousedown(event) {
+    if (!this.domNode.contains(event.target)) {
+      if (this.isOpen()) {
+        this.closePopup();
+        this.buttonNode.focus();
+      }
+    }
+  }
+}
+
+const menuButtons = document.querySelectorAll(".menu-button-links");
+for (const button of menuButtons) {
+  new MenuButtonLinks(button);
+}
diff --git a/themes/src/main/resources/theme/base/login/template.ftl b/themes/src/main/resources/theme/base/login/template.ftl
index d28cf40eb4..a70b230b8f 100644
--- a/themes/src/main/resources/theme/base/login/template.ftl
+++ b/themes/src/main/resources/theme/base/login/template.ftl
@@ -29,6 +29,7 @@
             <script src="${url.resourcesPath}/${script}" type="text/javascript"></script>
         </#list>
     </#if>
+    <script src="${url.resourcesPath}/js/menu-button-links.js" type="module"></script>
     <#if scripts??>
         <#list scripts as script>
             <script src="${script}" type="text/javascript"></script>
@@ -58,13 +59,15 @@
             <#if realm.internationalizationEnabled  && locale.supported?size gt 1>
                 <div class="${properties.kcLocaleMainClass!}" id="kc-locale">
                     <div id="kc-locale-wrapper" class="${properties.kcLocaleWrapperClass!}">
-                        <div id="kc-locale-dropdown" class="${properties.kcLocaleDropDownClass!}">
-                            <a href="#" id="kc-current-locale-link">${locale.current}</a>
-                            <ul class="${properties.kcLocaleListClass!}">
+                        <div id="kc-locale-dropdown" class="menu-button-links ${properties.kcLocaleDropDownClass!}">
+                            <button tabindex="1" id="kc-current-locale-link" aria-label="${msg("languages")}" aria-haspopup="true" aria-expanded="false" aria-controls="language-switch1">${locale.current}</button>
+                            <ul role="menu" tabindex="-1" aria-labelledby="kc-current-locale-link" aria-activedescendant="" id="language-switch1" class="${properties.kcLocaleListClass!}">
+                                <#assign i = 1>
                                 <#list locale.supported as l>
-                                    <li class="${properties.kcLocaleListItemClass!}">
-                                        <a class="${properties.kcLocaleItemClass!}" href="${l.url}">${l.label}</a>
+                                    <li class="${properties.kcLocaleListItemClass!}" role="none">
+                                        <a role="menuitem" id="language-${i}" class="${properties.kcLocaleItemClass!}" href="${l.url}">${l.label}</a>
                                     </li>
+                                    <#assign i++>
                                 </#list>
                             </ul>
                         </div>
diff --git a/themes/src/main/resources/theme/keycloak/login/resources/css/login.css b/themes/src/main/resources/theme/keycloak/login/resources/css/login.css
index 90b4d8dfc3..b9ce1e573c 100644
--- a/themes/src/main/resources/theme/keycloak/login/resources/css/login.css
+++ b/themes/src/main/resources/theme/keycloak/login/resources/css/login.css
@@ -53,7 +53,17 @@ h1#kc-page-title {
     font-size: var(--pf-global--FontSize--sm);
 }
 
-a#kc-current-locale-link::after {
+#kc-locale-dropdown button {
+    background: none;
+    border: none;
+    padding: 0;
+    cursor: pointer;
+    color: var(--pf-global--Color--200);
+    text-align: right;
+    font-size: var(--pf-global--FontSize--sm);
+}
+
+button#kc-current-locale-link::after {
     content: "\2c5";
     margin-left: var(--pf-global--spacer--xs)
 }
@@ -274,6 +284,10 @@ ul#kc-totp-supported-apps {
     color: var(--pf-global--Color--200);
 }
 
+.kc-social-gray h2 {
+    font-size: 1em;
+}
+
 .kc-social-item {
     margin-bottom: var(--pf-global--spacer--sm);
     font-size: 15px;