[Editor] Add a color picker with predefined colors for highlighting t…

…ext (bug 1866434)

The doorhanger for highlighting has a basic color picker composed of 5 predefined colors
to set the default color to use.
These colors can be changed thanks to a preference for now but it's something which could
be changed in the Firefox settings in the future.
Each highlight has in its own toolbar a color picker to just change its color.
The different color pickers are so similar (modulo few differences in their styles) that
this patch introduces a new class ColorPicker which provides a color picker component
which could be reused in future editors.
All in all, a large part of this patch is dedicated to color picker itself and its style
and the rest is almost a matter of wiring the component.

extensions/chromium/preferences_schema.json

@@ -85,6 +85,10 @@
       "type": "boolean",
       "default": false
     },
+    "highlightColors": {
+      "type": "string",
+      "default": "yellow=#FFFF98,green=#53FFBC,blue=#80EBFF,pink=#FFCBE6,red=#FF4F5F"
+    },
     "disableRange": {
       "title": "Disable range requests",
       "description": "Whether to disable range requests (not recommended).",

l10n/en-US/viewer.ftl

@@ -332,6 +332,8 @@ pdfjs-editor-remove-freetext-button =
     .title = Remove text
 pdfjs-editor-remove-stamp-button =
     .title = Remove image
+pdfjs-editor-remove-highlight-button =
+    .title = Remove highlight
 
 ##
 
@@ -384,3 +386,23 @@ pdfjs-editor-resizer-label-bottom-right = Bottom right corner — resize
 pdfjs-editor-resizer-label-bottom-middle = Bottom middle — resize
 pdfjs-editor-resizer-label-bottom-left = Bottom left corner — resize
 pdfjs-editor-resizer-label-middle-left = Middle left — resize
+
+## Color picker
+
+# This means "Color used to highlight text"
+pdfjs-editor-highlight-colorpicker-label = Highlight color
+
+pdfjs-editor-colorpicker-button =
+    .title = Change color
+pdfjs-editor-colorpicker-dropdown =
+    .aria-label = Color choices
+pdfjs-editor-colorpicker-yellow =
+    .title = Yellow
+pdfjs-editor-colorpicker-green =
+    .title = Green
+pdfjs-editor-colorpicker-blue =
+    .title = Blue
+pdfjs-editor-colorpicker-pink =
+    .title = Pink
+pdfjs-editor-colorpicker-red =
+    .title = Red

src/display/editor/color_picker.js

@@ -0,0 +1,228 @@
+/* Copyright 2023 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { AnnotationEditorParamsType, shadow } from "../../shared/util.js";
+import { KeyboardManager } from "./tools.js";
+import { noContextMenu } from "../display_utils.js";
+
+class ColorPicker {
+  #boundKeyDown = this.#keyDown.bind(this);
+
+  #button = null;
+
+  #buttonSwatch = null;
+
+  #defaultColor;
+
+  #dropdown = null;
+
+  #dropdownWasFromKeyboard = false;
+
+  #isMainColorPicker = false;
+
+  #eventBus;
+
+  #uiManager = null;
+
+  static get _keyboardManager() {
+    return shadow(
+      this,
+      "_keyboardManager",
+      new KeyboardManager([
+        [
+          ["Escape", "mac+Escape"],
+          ColorPicker.prototype._hideDropdownFromKeyboard,
+        ],
+        [[" ", "mac+ "], ColorPicker.prototype._colorSelectFromKeyboard],
+        [
+          ["ArrowDown", "ArrowRight", "mac+ArrowDown", "mac+ArrowRight"],
+          ColorPicker.prototype._moveToNext,
+        ],
+        [
+          ["ArrowUp", "ArrowLeft", "mac+ArrowUp", "mac+ArrowLeft"],
+          ColorPicker.prototype._moveToPrevious,
+        ],
+        [["Home", "mac+Home"], ColorPicker.prototype._moveToBeginning],
+        [["End", "mac+End"], ColorPicker.prototype._moveToEnd],
+      ])
+    );
+  }
+
+  constructor({ editor = null, uiManager = null }) {
+    this.#isMainColorPicker = !editor;
+    this.#uiManager = editor?._uiManager || uiManager;
+    this.#eventBus = this.#uiManager._eventBus;
+    this.#defaultColor =
+      editor?.color || this.#uiManager?.highlightColors.values().next().value;
+  }
+
+  renderButton() {
+    const button = (this.#button = document.createElement("button"));
+    button.className = "colorPicker";
+    button.tabIndex = "0";
+    button.setAttribute("data-l10n-id", "pdfjs-editor-colorpicker-button");
+    button.setAttribute("aria-haspopup", true);
+    button.addEventListener("click", this.#openDropdown.bind(this));
+    const swatch = (this.#buttonSwatch = document.createElement("span"));
+    swatch.className = "swatch";
+    swatch.style.backgroundColor = this.#defaultColor;
+    button.append(swatch);
+    return button;
+  }
+
+  renderMainDropdown() {
+    const dropdown = (this.#dropdown = this.#getDropdownRoot(
+      AnnotationEditorParamsType.DEFAULT_HIGHLIGHT_COLOR
+    ));
+    dropdown.setAttribute("aria-orientation", "horizontal");
+    dropdown.setAttribute("aria-labelledby", "highlightColorPickerLabel");
+
+    return dropdown;
+  }
+
+  #getDropdownRoot(paramType) {
+    const div = document.createElement("div");
+    div.addEventListener("contextmenu", noContextMenu);
+    div.className = "dropdown";
+    div.role = "listbox";
+    div.setAttribute("aria-multiselectable", false);
+    div.setAttribute("aria-orientation", "vertical");
+    div.setAttribute("data-l10n-id", "pdfjs-editor-colorpicker-dropdown");
+    for (const [name, color] of this.#uiManager.highlightColors) {
+      const button = document.createElement("button");
+      button.tabIndex = "0";
+      button.role = "option";
+      button.setAttribute("data-color", color);
+      button.title = name;
+      button.setAttribute("data-l10n-id", `pdfjs-editor-colorpicker-${name}`);
+      const swatch = document.createElement("span");
+      button.append(swatch);
+      swatch.className = "swatch";
+      swatch.style.backgroundColor = color;
+      button.setAttribute("aria-selected", color === this.#defaultColor);
+      button.addEventListener(
+        "click",
+        this.#colorSelect.bind(this, paramType, color)
+      );
+      div.append(button);
+    }
+
+    div.addEventListener("keydown", this.#boundKeyDown);
+
+    return div;
+  }
+
+  #colorSelect(type, color, event) {
+    event.stopPropagation();
+    this.#eventBus.dispatch("switchannotationeditorparams", {
+      source: this,
+      type,
+      value: color,
+    });
+  }
+
+  _colorSelectFromKeyboard(event) {
+    const color = event.target.getAttribute("data-color");
+    if (!color) {
+      return;
+    }
+    this.#colorSelect(color, event);
+  }
+
+  _moveToNext(event) {
+    if (event.target === this.#button) {
+      this.#dropdown.firstChild?.focus();
+      return;
+    }
+    event.target.nextSibling?.focus();
+  }
+
+  _moveToPrevious(event) {
+    event.target.previousSibling?.focus();
+  }
+
+  _moveToBeginning() {
+    this.#dropdown.firstChild?.focus();
+  }
+
+  _moveToEnd() {
+    this.#dropdown.lastChild?.focus();
+  }
+
+  #keyDown(event) {
+    ColorPicker._keyboardManager.exec(this, event);
+  }
+
+  #openDropdown(event) {
+    if (this.#dropdown && !this.#dropdown.classList.contains("hidden")) {
+      this.hideDropdown();
+      return;
+    }
+    this.#button.addEventListener("keydown", this.#boundKeyDown);
+    this.#dropdownWasFromKeyboard = event.detail === 0;
+    if (this.#dropdown) {
+      this.#dropdown.classList.toggle("hidden", false);
+      return;
+    }
+    const root = (this.#dropdown = this.#getDropdownRoot(
+      AnnotationEditorParamsType.HIGHLIGHT_COLOR
+    ));
+    this.#button.append(root);
+  }
+
+  hideDropdown() {
+    this.#dropdown?.classList.add("hidden");
+  }
+
+  _hideDropdownFromKeyboard() {
+    if (
+      this.#isMainColorPicker ||
+      !this.#dropdown ||
+      this.#dropdown.classList.contains("hidden")
+    ) {
+      return;
+    }
+    this.hideDropdown();
+    this.#button.removeEventListener("keydown", this.#boundKeyDown);
+    this.#button.focus({
+      preventScroll: true,
+      focusVisible: this.#dropdownWasFromKeyboard,
+    });
+  }
+
+  updateColor(color) {
+    if (this.#buttonSwatch) {
+      this.#buttonSwatch.style.backgroundColor = color;
+    }
+    if (!this.#dropdown) {
+      return;
+    }
+
+    const i = this.#uiManager.highlightColors.values();
+    for (const child of this.#dropdown.children) {
+      child.setAttribute("aria-selected", i.next().value === color);
+    }
+  }
+
+  destroy() {
+    this.#button?.remove();
+    this.#button = null;
+    this.#buttonSwatch = null;
+    this.#dropdown?.remove();
+    this.#dropdown = null;
+  }
+}
+
+export { ColorPicker };

src/display/editor/editor.js

@@ -903,15 +903,21 @@ class AnnotationEditor {
     this.#altText?.finish();
   }
 
+  /**
+   * Add a toolbar for this editor.
+   * @returns {Promise<EditorToolbar|null>}
+   */
   async addEditToolbar() {
     if (this.#editToolbar || this.#isInEditMode) {
-      return;
+      return this.#editToolbar;
     }
     this.#editToolbar = new EditorToolbar(this);
     this.div.append(this.#editToolbar.render());
     if (this.#altText) {
       this.#editToolbar.addAltTextButton(await this.#altText.render());
     }
+
+    return this.#editToolbar;
   }
 
   removeEditToolbar() {