Bug 1763570 - Wait for APZ state to set autofill information. r=geckoview-reviewers,owlish

When setting focus to input element, Gecko sets focused element to central via
`zoomToFocusedInput`. So when we receives `focusin` event, content may be
scrolled and zoomed. To pass correct element rectangle, we have to wait until
it is completed.

Fennec added `PanZoom:StateChange` event to listen APZ state. So GV should use
same way.

Differential Revision: https://phabricator.services.mozilla.com/D150453

dom/ipc/BrowserChild.cpp

@@ -1473,13 +1473,19 @@ bool BrowserChild::NotifyAPZStateChange(
     const layers::GeckoContentController::APZStateChange& aChange,
     const int& aArg) {
   mAPZEventState->ProcessAPZStateChange(aViewId, aChange, aArg);
+  nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
   if (aChange ==
       layers::GeckoContentController::APZStateChange::eTransformEnd) {
     // This is used by tests to determine when the APZ is done doing whatever
     // it's doing. XXX generify this as needed when writing additional tests.
-    nsCOMPtr<nsIObserverService> observerService =
-        mozilla::services::GetObserverService();
     observerService->NotifyObservers(nullptr, "APZ:TransformEnd", nullptr);
+    observerService->NotifyObservers(nullptr, "PanZoom:StateChange",
+                                     u"NOTHING");
+  } else if (aChange ==
+             layers::GeckoContentController::APZStateChange::eTransformBegin) {
+    observerService->NotifyObservers(nullptr, "PanZoom:StateChange",
+                                     u"PANNING");
   }
   return true;
 }

mobile/android/actors/GeckoViewAutoFillChild.jsm

@@ -47,11 +47,22 @@ class GeckoViewAutoFillChild extends GeckoViewActorChild {
         break;
       }
       case "focusin": {
-        if (
-          this.contentWindow.HTMLInputElement.isInstance(aEvent.composedTarget)
-        ) {
-          this.onFocus(aEvent.composedTarget);
+        const element = aEvent.composedTarget;
+        if (!this.contentWindow.HTMLInputElement.isInstance(element)) {
+          break;
         }
+        GeckoViewUtils.waitForPanZoomState(this.contentWindow).finally(() => {
+          if (Cu.isDeadWrapper(element)) {
+            // Focus element is removed or document is navigated to new page.
+            return;
+          }
+          const focusedElement =
+            Services.focus.focusedElement ||
+            element.ownerDocument?.activeElement;
+          if (element == focusedElement) {
+            this.onFocus(focusedElement);
+          }
+        });
         break;
       }
       case "focusout": {

mobile/android/geckoview/src/androidTest/java/org/mozilla/geckoview/test/AutofillDelegateTest.kt

@@ -6,6 +6,7 @@ package org.mozilla.geckoview.test
 
 import androidx.test.filters.MediumTest
 import android.util.SparseArray
+import android.view.KeyEvent
 import android.view.View
 import org.hamcrest.Matchers.*
 import org.junit.Test
@@ -13,6 +14,7 @@ import org.junit.runner.RunWith
 import org.junit.runners.Parameterized
 import org.mozilla.geckoview.Autofill
 import org.mozilla.geckoview.GeckoSession
+import org.mozilla.geckoview.GeckoSession.TextInputDelegate
 import org.mozilla.geckoview.test.rule.GeckoSessionTestRule.*
 
 @RunWith(Parameterized::class)
@@ -510,4 +512,26 @@ class AutofillDelegateTest : BaseSessionTest() {
         assertThat("autofill hint count",
                    checkAutofillChild(root), equalTo(6))
     }
+
+    @WithDisplay(width = 100, height = 100)
+    @Test fun autofillWaitForKeyboard() {
+        // Wait for the accessibility nodes to populate.
+        mainSession.loadUri(pageUrl)
+        mainSession.waitForPageStop()
+
+        mainSession.pressKey(KeyEvent.KEYCODE_CTRL_LEFT)
+        mainSession.evaluateJS("document.querySelector('#pass2').focus()")
+
+        sessionRule.waitUntilCalled(object : Autofill.Delegate, TextInputDelegate {
+            @AssertCalled(order = [2])
+            override fun onNodeFocus(session: GeckoSession,
+                                     node: Autofill.Node,
+                                     data: Autofill.NodeData) {
+                assertThat("ID should be valid", node, notNullValue())
+            }
+
+            @AssertCalled(order = [1])
+            override fun showSoftInput(session: GeckoSession) {}
+        })
+    }
 }

mobile/android/modules/geckoview/GeckoViewUtils.jsm

@@ -7,6 +7,9 @@ const { XPCOMUtils } = ChromeUtils.importESModule(
   "resource://gre/modules/XPCOMUtils.sys.mjs"
 );
 const { Log } = ChromeUtils.import("resource://gre/modules/Log.jsm");
+const { clearTimeout, setTimeout } = ChromeUtils.import(
+  "resource://gre/modules/Timer.jsm"
+);
 
 const lazy = {};
 
@@ -325,6 +328,54 @@ var GeckoViewUtils = {
     return null;
   },
 
+  /**
+   * Return promise for waiting for finishing PanZoomState.
+   *
+   * @param aWindow a DOM window.
+   * @return promise
+   */
+  waitForPanZoomState(aWindow) {
+    return new Promise((resolve, reject) => {
+      if (
+        !aWindow?.windowUtils.asyncPanZoomEnabled ||
+        !Services.prefs.getBoolPref("apz.zoom-to-focused-input.enabled")
+      ) {
+        // No zoomToFocusedInput.
+        resolve();
+        return;
+      }
+
+      let timerId = 0;
+
+      const panZoomState = (aSubject, aTopic, aData) => {
+        if (timerId != 0) {
+          // aWindow may be dead object now.
+          try {
+            clearTimeout(timerId);
+          } catch (e) {}
+          timerId = 0;
+        }
+
+        if (aData === "NOTHING") {
+          Services.obs.removeObserver(panZoomState, "PanZoom:StateChange");
+          resolve();
+        }
+      };
+
+      Services.obs.addObserver(panZoomState, "PanZoom:StateChange");
+
+      // "GeckoView:ZoomToInput" has the timeout as 500ms when window isn't
+      // resized (it means on-screen-keyboard is already shown).
+      // So after up to 500ms, APZ event is sent. So we need to wait for more
+      // 500ms.
+      timerId = setTimeout(() => {
+        // PanZoom state isn't changed. zoomToFocusedInput will return error.
+        Services.obs.removeObserver(panZoomState, "PanZoom:StateChange");
+        reject();
+      }, 600);
+    });
+  },
+
   /**
    * Add logging functions to the specified scope that forward to the given
    * Log.jsm logger. Currently "debug" and "warn" functions are supported. To