feat: Open links in split view via shift+click

src/zen/common/sys/ZenActorsManager.sys.mjs

@@ -57,6 +57,22 @@ let JSWINDOWACTORS = {
     remoteTypes: ["web", "file"],
     enablePreference: "zen.glance.enabled",
   },
+  ZenSplitView: {
+    parent: {
+      esModuleURI: "resource:///actors/ZenSplitViewParent.sys.mjs",
+    },
+    child: {
+      esModuleURI: "resource:///actors/ZenSplitViewChild.sys.mjs",
+      events: {
+        DOMContentLoaded: {},
+        click: {
+          capture: true,
+        },
+      },
+    },
+    allFrames: true,
+    remoteTypes: ["web", "file"],
+  },
 };
 
 if (!Services.appinfo.inSafeMode) {

src/zen/moz.build

@@ -19,4 +19,5 @@ DIRS += [
     "sessionstore",
     "share",
     "spaces",
+    "split-view",
 ]

src/zen/split-view/ZenViewSplitter.mjs

@@ -1228,6 +1228,15 @@ class nsZenViewSplitter extends nsZenDOMOperatedFeature {
       window.gContextMenu.mediaURL ||
       window.gContextMenu.contentData.docLocation ||
       window.gContextMenu.target.ownerDocument.location.href;
+    this.splitLinkFromURL(url);
+  }
+
+  /**
+   * Opens a URL in a new tab and splits it with the current tab.
+   *
+   * @param {string} url - The URL to open in split view.
+   */
+  splitLinkFromURL(url) {
     const currentTab = gZenGlanceManager.getTabOrGlanceParent(
       window.gBrowser.selectedTab
     );

src/zen/split-view/actors/ZenSplitViewChild.sys.mjs

@@ -0,0 +1,39 @@
+// 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/.
+
+export class ZenSplitViewChild extends JSWindowActorChild {
+  #glanceActivationMethod;
+
+  async handleEvent(event) {
+    const handler = this[`on_${event.type}`];
+    if (typeof handler === "function") {
+      await handler.call(this, event);
+    }
+  }
+
+  async on_DOMContentLoaded() {
+    this.#glanceActivationMethod = await this.sendQuery(
+      "ZenSplitView:GetGlanceActivationMethod"
+    );
+  }
+
+  on_click(event) {
+    if (event.button !== 0 || event.defaultPrevented) {
+      return;
+    }
+    if (!event.shiftKey || event.ctrlKey || event.altKey || event.metaKey) {
+      return;
+    }
+    if (this.#glanceActivationMethod === "shift") {
+      return;
+    }
+    const anchor = event.target.closest("a[href]");
+    if (!anchor) {
+      return;
+    }
+    event.preventDefault();
+    event.stopPropagation();
+    this.sendAsyncMessage("ZenSplitView:OpenInSplit", { url: anchor.href });
+  }
+}

src/zen/split-view/actors/ZenSplitViewParent.sys.mjs

@@ -0,0 +1,23 @@
+// 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/.
+
+export class ZenSplitViewParent extends JSWindowActorParent {
+  async receiveMessage(message) {
+    switch (message.name) {
+      case "ZenSplitView:GetGlanceActivationMethod":
+        return Services.prefs.getStringPref(
+          "zen.glance.activation-method",
+          "ctrl"
+        );
+      case "ZenSplitView:OpenInSplit":
+        this.browsingContext.topChromeWindow.gZenViewSplitter?.splitLinkFromURL(
+          message.data.url
+        );
+        return null;
+      default:
+        console.warn(`[split-view]: Unknown message: ${message.name}`);
+        return null;
+    }
+  }
+}

src/zen/split-view/moz.build

@@ -0,0 +1,9 @@
+#
+# 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/.
+
+FINAL_TARGET_FILES.actors += [
+    "actors/ZenSplitViewChild.sys.mjs",
+    "actors/ZenSplitViewParent.sys.mjs",
+]