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web/pdf_layer_viewer.js

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+/* Copyright 2020 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.
+ */
+
+/** @typedef {import("./event_utils.js").EventBus} EventBus */
+// eslint-disable-next-line max-len
+/** @typedef {import("../src/optional_content_config.js").OptionalContentConfig} OptionalContentConfig */
+// eslint-disable-next-line max-len
+/** @typedef {import("../src/display/api.js").PDFDocumentProxy} PDFDocumentProxy */
+
+import { BaseTreeViewer } from "./base_tree_viewer.js";
+
+/**
+ * @typedef {Object} PDFLayerViewerOptions
+ * @property {HTMLDivElement} container - The viewer element.
+ * @property {EventBus} eventBus - The application event bus.
+ */
+
+/**
+ * @typedef {Object} PDFLayerViewerRenderParameters
+ * @property {OptionalContentConfig|null} optionalContentConfig - An
+ *   {OptionalContentConfig} instance.
+ * @property {PDFDocumentProxy} pdfDocument - A {PDFDocument} instance.
+ */
+
+class PDFLayerViewer extends BaseTreeViewer {
+  constructor(options) {
+    super(options);
+
+    this.eventBus._on("optionalcontentconfigchanged", evt => {
+      this.#updateLayers(evt.promise);
+    });
+    this.eventBus._on("resetlayers", () => {
+      this.#updateLayers();
+    });
+    this.eventBus._on("togglelayerstree", this._toggleAllTreeItems.bind(this));
+  }
+
+  reset() {
+    super.reset();
+    this._optionalContentConfig = null;
+
+    this._optionalContentVisibility?.clear();
+    this._optionalContentVisibility = null;
+  }
+
+  /**
+   * @protected
+   */
+  _dispatchEvent(layersCount) {
+    this.eventBus.dispatch("layersloaded", {
+      source: this,
+      layersCount,
+    });
+  }
+
+  /**
+   * @protected
+   */
+  _bindLink(element, { groupId, input }) {
+    const setVisibility = () => {
+      const visible = input.checked;
+      this._optionalContentConfig.setVisibility(groupId, visible);
+
+      const cached = this._optionalContentVisibility.get(groupId);
+      if (cached) {
+        cached.visible = visible;
+      }
+
+      this.eventBus.dispatch("optionalcontentconfig", {
+        source: this,
+        promise: Promise.resolve(this._optionalContentConfig),
+      });
+    };
+
+    element.onclick = evt => {
+      if (evt.target === input) {
+        setVisibility();
+        return true;
+      } else if (evt.target !== element) {
+        return true; // The target is the "label", which is handled above.
+      }
+      input.checked = !input.checked;
+      setVisibility();
+      return false;
+    };
+  }
+
+  /**
+   * @private
+   */
+  _setNestedName(element, { name = null }) {
+    if (typeof name === "string") {
+      element.textContent = this._normalizeTextContent(name);
+      return;
+    }
+    element.setAttribute("data-l10n-id", "pdfjs-additional-layers");
+    element.style.fontStyle = "italic";
+    // Trigger translation manually, since translation is paused when
+    // the final layer-tree is appended to the DOM.
+    this._l10n.translateOnce(element);
+  }
+
+  /**
+   * @protected
+   */
+  _addToggleButton(div, { name = null }) {
+    super._addToggleButton(div, /* hidden = */ name === null);
+  }
+
+  /**
+   * @private
+   */
+  _toggleAllTreeItems() {
+    if (!this._optionalContentConfig) {
+      return;
+    }
+    super._toggleAllTreeItems();
+  }
+
+  /**
+   * @param {PDFLayerViewerRenderParameters} params
+   */
+  render({ optionalContentConfig, pdfDocument }) {
+    if (this._optionalContentConfig) {
+      this.reset();
+    }
+    this._optionalContentConfig = optionalContentConfig || null;
+    this._pdfDocument = pdfDocument || null;
+
+    const groups = optionalContentConfig?.getOrder();
+    if (!groups) {
+      this._dispatchEvent(/* layersCount = */ 0);
+      return;
+    }
+    this._optionalContentVisibility = new Map();
+
+    const fragment = document.createDocumentFragment(),
+      queue = [{ parent: fragment, groups }];
+    let layersCount = 0,
+      hasAnyNesting = false;
+    while (queue.length > 0) {
+      const levelData = queue.shift();
+      for (const groupId of levelData.groups) {
+        const div = document.createElement("div");
+        div.className = "treeItem";
+
+        const element = document.createElement("a");
+        div.append(element);
+
+        if (typeof groupId === "object") {
+          hasAnyNesting = true;
+          this._addToggleButton(div, groupId);
+          this._setNestedName(element, groupId);
+
+          const itemsDiv = document.createElement("div");
+          itemsDiv.className = "treeItems";
+          div.append(itemsDiv);
+
+          queue.push({ parent: itemsDiv, groups: groupId.order });
+        } else {
+          const group = optionalContentConfig.getGroup(groupId);
+
+          const input = document.createElement("input");
+          this._bindLink(element, { groupId, input });
+          input.type = "checkbox";
+          input.checked = group.visible;
+
+          this._optionalContentVisibility.set(groupId, {
+            input,
+            visible: input.checked,
+          });
+
+          const label = document.createElement("label");
+          label.textContent = this._normalizeTextContent(group.name);
+
+          label.append(input);
+          element.append(label);
+          layersCount++;
+        }
+
+        levelData.parent.append(div);
+      }
+    }
+
+    this._finishRendering(fragment, layersCount, hasAnyNesting);
+  }
+
+  async #updateLayers(promise = null) {
+    if (!this._optionalContentConfig) {
+      return;
+    }
+    const pdfDocument = this._pdfDocument;
+    const optionalContentConfig = await (promise ||
+      pdfDocument.getOptionalContentConfig({ intent: "display" }));
+
+    if (pdfDocument !== this._pdfDocument) {
+      return; // The document was closed while the optional content resolved.
+    }
+    if (promise) {
+      // Ensure that the UI displays the correct state (e.g. with RBGroups).
+      for (const [groupId, cached] of this._optionalContentVisibility) {
+        const group = optionalContentConfig.getGroup(groupId);
+
+        if (group && cached.visible !== group.visible) {
+          cached.input.checked = cached.visible = !cached.visible;
+        }
+      }
+      return;
+    }
+    this.eventBus.dispatch("optionalcontentconfig", {
+      source: this,
+      promise: Promise.resolve(optionalContentConfig),
+    });
+
+    // Reset the sidebarView to the new state.
+    this.render({
+      optionalContentConfig,
+      pdfDocument: this._pdfDocument,
+    });
+  }
+}
+
+export { PDFLayerViewer };