Merge pull request #15121 from Snuffleupagus/loadingBar-cleanup

[api-minor] Further modernize the `ProgressBar` class (PR 14918 follow-up)

examples/mobile-viewer/viewer.css

@@ -221,13 +221,13 @@ canvas {
   }
 }
 
-#loadingBar .progress.indeterminate {
+#loadingBar.indeterminate .progress {
   transform: none;
   background-color: rgba(153, 153, 153, 1);
   transition: none;
 }
 
-#loadingBar .indeterminate .glimmer {
+#loadingBar.indeterminate .progress .glimmer {
   position: absolute;
   top: 0;
   left: 0;

examples/mobile-viewer/viewer.js

@@ -161,7 +161,7 @@ const PDFViewerApplication = {
   },
 
   get loadingBar() {
-    const bar = new pdfjsViewer.ProgressBar("#loadingBar");
+    const bar = new pdfjsViewer.ProgressBar("loadingBar");
 
     return pdfjsLib.shadow(this, "loadingBar", bar);
   },

web/app.js

@@ -718,7 +718,7 @@ const PDFViewerApplication = {
   },
 
   get loadingBar() {
-    const bar = new ProgressBar("#loadingBar");
+    const bar = new ProgressBar("loadingBar");
     return shadow(this, "loadingBar", bar);
   },
 
@@ -1160,31 +1160,33 @@ const PDFViewerApplication = {
     // that we discard some of the loaded data. This can cause the loading
     // bar to move backwards. So prevent this by only updating the bar if it
     // increases.
-    if (percent > this.loadingBar.percent || isNaN(percent)) {
-      this.loadingBar.percent = percent;
-
-      // When disableAutoFetch is enabled, it's not uncommon for the entire file
-      // to never be fetched (depends on e.g. the file structure). In this case
-      // the loading bar will not be completely filled, nor will it be hidden.
-      // To prevent displaying a partially filled loading bar permanently, we
-      // hide it when no data has been loaded during a certain amount of time.
-      const disableAutoFetch = this.pdfDocument
-        ? this.pdfDocument.loadingParams.disableAutoFetch
-        : AppOptions.get("disableAutoFetch");
-
-      if (disableAutoFetch && percent) {
-        if (this.disableAutoFetchLoadingBarTimeout) {
-          clearTimeout(this.disableAutoFetchLoadingBarTimeout);
-          this.disableAutoFetchLoadingBarTimeout = null;
-        }
-        this.loadingBar.show();
+    if (percent <= this.loadingBar.percent) {
+      return;
+    }
+    this.loadingBar.percent = percent;
 
-        this.disableAutoFetchLoadingBarTimeout = setTimeout(() => {
-          this.loadingBar.hide();
-          this.disableAutoFetchLoadingBarTimeout = null;
-        }, DISABLE_AUTO_FETCH_LOADING_BAR_TIMEOUT);
-      }
+    // When disableAutoFetch is enabled, it's not uncommon for the entire file
+    // to never be fetched (depends on e.g. the file structure). In this case
+    // the loading bar will not be completely filled, nor will it be hidden.
+    // To prevent displaying a partially filled loading bar permanently, we
+    // hide it when no data has been loaded during a certain amount of time.
+    const disableAutoFetch =
+      this.pdfDocument?.loadingParams.disableAutoFetch ??
+      AppOptions.get("disableAutoFetch");
+
+    if (!disableAutoFetch || isNaN(percent)) {
+      return;
+    }
+    if (this.disableAutoFetchLoadingBarTimeout) {
+      clearTimeout(this.disableAutoFetchLoadingBarTimeout);
+      this.disableAutoFetchLoadingBarTimeout = null;
     }
+    this.loadingBar.show();
+
+    this.disableAutoFetchLoadingBarTimeout = setTimeout(() => {
+      this.loadingBar.hide();
+      this.disableAutoFetchLoadingBarTimeout = null;
+    }, DISABLE_AUTO_FETCH_LOADING_BAR_TIMEOUT);
   },
 
   load(pdfDocument) {

web/ui_utils.js

@@ -689,6 +689,12 @@ function clamp(v, min, max) {
 }
 
 class ProgressBar {
+  #classList = null;
+
+  #percent = 0;
+
+  #visible = true;
+
   constructor(id) {
     if (
       (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) &&
@@ -699,34 +705,24 @@ class ProgressBar {
           "please use CSS rules to modify its appearance instead."
       );
     }
-    this.visible = true;
-
-    // Fetch the sub-elements for later.
-    this.div = document.querySelector(id + " .progress");
-    // Get the loading bar element, so it can be resized to fit the viewer.
-    this.bar = this.div.parentNode;
-
-    this.percent = 0;
-  }
-
-  #updateBar() {
-    if (this._indeterminate) {
-      this.div.classList.add("indeterminate");
-      return;
-    }
-    this.div.classList.remove("indeterminate");
-
-    docStyle.setProperty("--progressBar-percent", `${this._percent}%`);
+    const bar = document.getElementById(id);
+    this.#classList = bar.classList;
   }
 
   get percent() {
-    return this._percent;
+    return this.#percent;
   }
 
   set percent(val) {
-    this._indeterminate = isNaN(val);
-    this._percent = clamp(val, 0, 100);
-    this.#updateBar();
+    this.#percent = clamp(val, 0, 100);
+
+    if (isNaN(val)) {
+      this.#classList.add("indeterminate");
+      return;
+    }
+    this.#classList.remove("indeterminate");
+
+    docStyle.setProperty("--progressBar-percent", `${this.#percent}%`);
   }
 
   setWidth(viewer) {
@@ -741,19 +737,19 @@ class ProgressBar {
   }
 
   hide() {
-    if (!this.visible) {
+    if (!this.#visible) {
       return;
     }
-    this.visible = false;
-    this.bar.classList.add("hidden");
+    this.#visible = false;
+    this.#classList.add("hidden");
   }
 
   show() {
-    if (this.visible) {
+    if (this.#visible) {
       return;
     }
-    this.visible = true;
-    this.bar.classList.remove("hidden");
+    this.#visible = true;
+    this.#classList.remove("hidden");
   }
 }
 

web/viewer.css

@@ -384,13 +384,13 @@ select {
   }
 }
 
-#loadingBar .progress.indeterminate {
+#loadingBar.indeterminate .progress {
   transform: none;
   background-color: var(--progressBar-indeterminate-bg-color);
   transition: none;
 }
 
-#loadingBar .progress.indeterminate .glimmer {
+#loadingBar.indeterminate .progress .glimmer {
   position: absolute;
   top: 0;
   left: 0;