1 files changed, 82 insertions, 0 deletions
diff --git a/dom/html/test/file_fullscreen-utils.js b/dom/html/test/file_fullscreen-utils.js
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index 000000000..d1af72f8c
--- /dev/null
+++ b/dom/html/test/file_fullscreen-utils.js
@@ -0,0 +1,82 @@
+
+// Returns true if the window occupies the entire screen.
+// Note this only returns true once the transition from normal to
+// fullscreen mode is complete.
+function inFullscreenMode(win) {
+  return win.innerWidth == win.screen.width &&
+         win.innerHeight == win.screen.height;
+}
+
+// Returns true if the window is in normal mode, i.e. non fullscreen mode.
+// Note this only returns true once the transition from fullscreen back to
+// normal mode is complete.
+function inNormalMode(win) {
+  return win.innerWidth == win.normalSize.w &&
+         win.innerHeight == win.normalSize.h;
+}
+
+// Adds a listener that will be called once a fullscreen transition
+// is complete. When type==='enter', callback is called when we've
+// received a fullscreenchange event, and the fullscreen transition is
+// complete. When type==='exit', callback is called when we've
+// received a fullscreenchange event and the window dimensions match
+// the window dimensions when the window opened (so don't resize the
+// window while running your test!). inDoc is the document which
+// the listeners are added on, if absent, the listeners are added to
+// the current document.
+function addFullscreenChangeContinuation(type, callback, inDoc) {
+  var doc = inDoc || document;
+  var topWin = doc.defaultView.top;
+  // Remember the window size in non-fullscreen mode.
+  if (!topWin.normalSize) {
+    topWin.normalSize = {
+      w: window.innerWidth,
+      h: window.innerHeight
+    };
+  }
+  function checkCondition() {
+    if (type == "enter") {
+      return inFullscreenMode(topWin);
+    } else if (type == "exit") {
+      // If we just revert the state to a previous fullscreen state,
+      // the window won't back to the normal mode. Hence we check
+      // fullscreenElement first here. Note that we need to check
+      // the fullscreen element of the outmost document here instead
+      // of the current one.
+      return topWin.document.fullscreenElement || inNormalMode(topWin);
+    } else {
+      throw "'type' must be either 'enter', or 'exit'.";
+    }
+  }
+  function invokeCallback(event) {
+    // Use async call after a paint to workaround unfinished fullscreen
+    // change even when the window size has changed on Linux.
+    requestAnimationFrame(() => setTimeout(() => callback(event), 0), 0);
+  }
+  function onFullscreenChange(event) {
+    doc.removeEventListener("fullscreenchange", onFullscreenChange, false);
+    if (checkCondition()) {
+      invokeCallback(event);
+      return;
+    }
+    function onResize() {
+      if (checkCondition()) {
+        topWin.removeEventListener("resize", onResize, false);
+        invokeCallback(event);
+      }
+    }
+    topWin.addEventListener("resize", onResize, false);
+  }
+  doc.addEventListener("fullscreenchange", onFullscreenChange, false);
+}
+
+// Calls |callback| when the next fullscreenerror is dispatched to inDoc||document.
+function addFullscreenErrorContinuation(callback, inDoc) {
+  var doc = inDoc || document;
+  var listener = function(event) {
+    doc.removeEventListener("fullscreenerror", listener, false);
+    setTimeout(function(){callback(event);}, 0);
+  };
+  doc.addEventListener("fullscreenerror", listener, false);
+}
+