1 files changed, 103 insertions, 0 deletions
diff --git a/comm/mail/modules/SummaryFrameManager.jsm b/comm/mail/modules/SummaryFrameManager.jsm
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+++ b/comm/mail/modules/SummaryFrameManager.jsm
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+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const EXPORTED_SYMBOLS = ["SummaryFrameManager"];
+
+/**
+ * The SummaryFrameManager manages the source attribute of iframes which can
+ * be multi-purposed.  For example, the thread/multimessage summary and the
+ * folder summary both use it.  The SummaryFrameManager takes care of
+ * causing the content file to be reloaded as necessary, and manages event
+ * handlers, so that the right callback is called when the specified
+ * document is loaded.
+ *
+ * @param aFrame the iframe that we're managing
+ */
+function SummaryFrameManager(aFrame) {
+  this.iframe = aFrame;
+  this.iframe.addEventListener(
+    "DOMContentLoaded",
+    this._onLoad.bind(this),
+    true
+  );
+  this.pendingCallback = null;
+  this.pendingOrLoadedUrl = this.iframe.docShell
+    ? this.iframe.contentDocument.location.href
+    : "about:blank";
+  this.callback = null;
+  this.url = "";
+}
+
+SummaryFrameManager.prototype = {
+  /**
+   * Clear the summary frame.
+   */
+  clear() {
+    this.loadAndCallback("about:blank");
+  },
+
+  /**
+   * Load the specified URL if necessary, and cause the specified callback to be
+   * called either when the document is loaded, or immediately if the document
+   * is already loaded.
+   *
+   * @param aUrl the URL to load
+   * @param aCallback the callback to run when the URL has loaded; this function
+   *        is passed a single boolean indicating if the URL was changed
+   */
+  loadAndCallback(aUrl, aCallback) {
+    this.url = aUrl;
+    if (this.pendingOrLoadedUrl != aUrl) {
+      // We're changing the document. Stash the callback that we want to call
+      // when it's done loading
+      this.pendingCallback = aCallback;
+      this.callback = null; // clear it
+      this.iframe.contentDocument.location.href = aUrl;
+      this.pendingOrLoadedUrl = aUrl;
+    } else if (!this.pendingCallback) {
+      // We're being called, but the document has been set already -- either
+      // we've already received the DOMContentLoaded event, in which case we can
+      // just call the callback directly, or we're still loading in which case
+      // we should just wait for the dom event handler, but update the callback.
+
+      this.callback = aCallback;
+      if (this.callback) {
+        this.callback(false);
+      }
+    } else {
+      this.pendingCallback = aCallback;
+    }
+  },
+
+  _onLoad(event) {
+    try {
+      // Make sure we're responding to the summary frame being loaded, and not
+      // some subnode.
+      if (
+        event.target != this.iframe.contentDocument ||
+        this.pendingOrLoadedUrl == "about:blank"
+      ) {
+        return;
+      }
+      if (event.target.ownerGlobal.location.href == "about:blank") {
+        return;
+      }
+
+      this.callback = this.pendingCallback;
+      this.pendingCallback = null;
+      if (
+        this.pendingOrLoadedUrl != this.iframe.contentDocument.location.href
+      ) {
+        console.error(
+          "Please do not load stuff in the multimessage browser directly, " +
+            "use the SummaryFrameManager instead."
+        );
+      } else if (this.callback) {
+        this.callback(true);
+      }
+    } catch (e) {
+      console.error(e);
+    }
+  },
+};