weblayer: forces top-view shown during load

Prior to this patch, if the top-view was configured to only expand
at top, then on page load the top-view would not be shown.

During a load if current_browser_controls_visibility_constraint_ is BOTH,
then cc is called with current and constraints of BOTH. cc doesn't do
anything in this case. As we need to ensure the top-view is shown in
this scenario this changes the code to supply SHOWN.

This code path is only hit if top-view is configured to
only-expand-at-top, as when only-expand-at-top is false,
current_browser_controls_visibility_constraint_ is set to SHOWN.

I experimented with fixing in cc, but cc has no notion of page
loading. So, this fix is better done in WebLayer.

BUG=1135964
TEST=BrowserControlsTest

Change-Id: I7834ade5cd80de6946af0c2f917fb0ea1996e1f0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2476725
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#817985}

weblayer/browser/android/javatests/src/org/chromium/weblayer/test/BrowserControlsHelper.java

@@ -32,7 +32,7 @@ public final class BrowserControlsHelper {
 
     // Blocks until browser controls are fully initialized. Should only be created in a test's
     // setUp() method; see BrowserControlsHelper#createInSetUp().
-    private BrowserControlsHelper(InstrumentationActivity activity) throws Throwable {
+    private BrowserControlsHelper(InstrumentationActivity activity) throws Exception {
         Assert.assertTrue(CommandLine.isInitialized());
         Assert.assertTrue(CommandLine.getInstance().hasSwitch("enable-features"));
         String enabledFeatures = CommandLine.getInstance().getSwitchValue("enable-features");
@@ -73,7 +73,7 @@ public final class BrowserControlsHelper {
     }
 
     // Ensures that browser controls are fully initialized and ready for scrolls to be processed.
-    private void waitForBrowserControlsInitialization() throws Throwable {
+    private void waitForBrowserControlsInitialization() throws Exception {
         // Poll until the top view becomes visible.
         waitForBrowserControlsViewToBeVisible(mActivity.getTopContentsContainer());
         TestThreadUtils.runOnUiThreadBlocking(() -> {
@@ -88,7 +88,7 @@ public final class BrowserControlsHelper {
     // Creates a BrowserControlsHelper instance and blocks until browser controls are fully
     // initialized. Should be called from a test's setUp() method.
     static BrowserControlsHelper createAndBlockUntilBrowserControlsInitializedInSetUp(
-            InstrumentationActivity activity) throws Throwable {
+            InstrumentationActivity activity) throws Exception {
         return new BrowserControlsHelper(activity);
     }
 

weblayer/browser/android/javatests/src/org/chromium/weblayer/test/BrowserControlsTest.java

@@ -10,6 +10,7 @@ import static androidx.test.espresso.matcher.ViewMatchers.isDisplayed;
 import static androidx.test.espresso.matcher.ViewMatchers.withText;
 
 import android.os.Build;
+import android.os.Bundle;
 import android.os.RemoteException;
 import android.view.View;
 import android.view.ViewGroup;
@@ -20,16 +21,17 @@ import androidx.test.filters.SmallTest;
 
 import org.hamcrest.Matchers;
 import org.junit.Assert;
-import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
+import org.chromium.base.test.util.CallbackHelper;
 import org.chromium.base.test.util.CommandLineFlags;
 import org.chromium.base.test.util.MinAndroidSdkLevel;
 import org.chromium.content_public.browser.test.util.Criteria;
 import org.chromium.content_public.browser.test.util.CriteriaHelper;
 import org.chromium.content_public.browser.test.util.TestThreadUtils;
+import org.chromium.weblayer.BrowserControlsOffsetCallback;
 import org.chromium.weblayer.Tab;
 import org.chromium.weblayer.TestWebLayer;
 import org.chromium.weblayer.shell.InstrumentationActivity;
@@ -88,8 +90,7 @@ public class BrowserControlsTest {
         });
     }
 
-    @Before
-    public void setUp() throws Throwable {
+    private void createActivityWithTopView() throws Exception {
         final String url = mActivityTestRule.getTestDataURL("tall_page.html");
         InstrumentationActivity activity = mActivityTestRule.launchShellWithUrl(url);
 
@@ -106,6 +107,7 @@ public class BrowserControlsTest {
     @Test
     @SmallTest
     public void testTopAndBottom() throws Exception {
+        createActivityWithTopView();
         InstrumentationActivity activity = mActivityTestRule.getActivity();
         View bottomView = TestThreadUtils.runOnUiThreadBlocking(() -> {
             TextView view = new TextView(activity);
@@ -164,6 +166,7 @@ public class BrowserControlsTest {
     @Test
     @SmallTest
     public void testBottomOnly() throws Exception {
+        createActivityWithTopView();
         InstrumentationActivity activity = mActivityTestRule.getActivity();
         // Remove the top-view.
         TestThreadUtils.runOnUiThreadBlocking(() -> { activity.getBrowser().setTopView(null); });
@@ -219,6 +222,7 @@ public class BrowserControlsTest {
     @Test
     @SmallTest
     public void testTopOnly() throws Exception {
+        createActivityWithTopView();
         InstrumentationActivity activity = mActivityTestRule.getActivity();
         View topView = activity.getTopContentsContainer();
 
@@ -249,6 +253,7 @@ public class BrowserControlsTest {
     @Test
     @SmallTest
     public void testTopMinHeight() throws Exception {
+        createActivityWithTopView();
         final int minHeight = 20;
         InstrumentationActivity activity = mActivityTestRule.getActivity();
         View topContents = activity.getTopContentsContainer();
@@ -288,6 +293,7 @@ public class BrowserControlsTest {
     @Test
     @SmallTest
     public void testOnlyExpandTopControlsAtPageTop() throws Exception {
+        createActivityWithTopView();
         InstrumentationActivity activity = mActivityTestRule.getActivity();
         View topContents = activity.getTopContentsContainer();
         TestThreadUtils.runOnUiThreadBlocking(
@@ -333,6 +339,7 @@ public class BrowserControlsTest {
     @Test
     @SmallTest
     public void testAlertDoesntShowTopControlsIfOnlyExpandTopControlsAtPageTop() throws Exception {
+        createActivityWithTopView();
         InstrumentationActivity activity = mActivityTestRule.getActivity();
         View topContents = activity.getTopContentsContainer();
         TestThreadUtils.runOnUiThreadBlocking(
@@ -371,6 +378,7 @@ public class BrowserControlsTest {
     @Test
     @SmallTest
     public void testAlertShowsTopControls() throws Exception {
+        createActivityWithTopView();
         InstrumentationActivity activity = mActivityTestRule.getActivity();
 
         // Move by the size of the top-controls.
@@ -400,6 +408,7 @@ public class BrowserControlsTest {
     @Test
     @SmallTest
     public void testAccessibility() throws Exception {
+        createActivityWithTopView();
         InstrumentationActivity activity = mActivityTestRule.getActivity();
 
         // Scroll such that top-controls are hidden.
@@ -434,6 +443,7 @@ public class BrowserControlsTest {
     @Test
     @SmallTest
     public void testRemoveAllFromTopView() throws Exception {
+        createActivityWithTopView();
         InstrumentationActivity activity = mActivityTestRule.getActivity();
 
         // Install a different top-view.
@@ -465,4 +475,64 @@ public class BrowserControlsTest {
             Criteria.checkThat(getVisiblePageHeight(), Matchers.not(mPageHeightWithTopView));
         });
     }
+
+    private void registerBrowserControlsOffsetCallbackForOffset(
+            CallbackHelper helper, int targetOffset) {
+        InstrumentationActivity activity = mActivityTestRule.getActivity();
+        TestThreadUtils.runOnUiThreadBlocking(() -> {
+            activity.getBrowser().registerBrowserControlsOffsetCallback(
+                    new BrowserControlsOffsetCallback() {
+                        @Override
+                        public void onTopViewOffsetChanged(int offset) {
+                            if (offset == targetOffset) {
+                                activity.getBrowser().unregisterBrowserControlsOffsetCallback(this);
+                                helper.notifyCalled();
+                            }
+                        }
+                    });
+        });
+    }
+
+    @MinAndroidSdkLevel(Build.VERSION_CODES.M)
+    @Test
+    @SmallTest
+    public void testTopExpandedWhenOnlyExpandAtTop() throws Exception {
+        Bundle extras = new Bundle();
+        extras.putBoolean(InstrumentationActivity.EXTRA_ONLY_EXPAND_CONTROLS_AT_TOP, true);
+        final String url = mActivityTestRule.getTestDataURL("tall_page.html");
+        InstrumentationActivity activity = mActivityTestRule.launchShell(extras);
+        CallbackHelper helper = new CallbackHelper();
+        registerBrowserControlsOffsetCallbackForOffset(helper, 0);
+        mActivityTestRule.navigateAndWait(url);
+        helper.waitForFirst();
+    }
+
+    @MinAndroidSdkLevel(Build.VERSION_CODES.M)
+    @Test
+    @SmallTest
+    public void testTopExpandedOnLoadWhenOnlyExpandAtTop() throws Exception {
+        Bundle extras = new Bundle();
+        extras.putBoolean(InstrumentationActivity.EXTRA_ONLY_EXPAND_CONTROLS_AT_TOP, true);
+        InstrumentationActivity activity = mActivityTestRule.launchShell(extras);
+        CallbackHelper helper = new CallbackHelper();
+        registerBrowserControlsOffsetCallbackForOffset(helper, 0);
+        mActivityTestRule.navigateAndWait(mActivityTestRule.getTestDataURL("tall_page.html"));
+        int callCount = 0;
+        helper.waitForCallback(callCount++);
+
+        mTopViewHeight = TestThreadUtils.runOnUiThreadBlocking(
+                () -> { return activity.getTopContentsContainer().getHeight(); });
+        Assert.assertNotEquals(mTopViewHeight, 0);
+
+        // Scroll such that top-controls are hidden.
+        registerBrowserControlsOffsetCallbackForOffset(helper, -mTopViewHeight);
+        EventUtils.simulateDragFromCenterOfView(
+                activity.getWindow().getDecorView(), 0, -mTopViewHeight);
+        helper.waitForCallback(callCount++);
+
+        // Load a new page. The top-controls should be shown again.
+        registerBrowserControlsOffsetCallbackForOffset(helper, 0);
+        mActivityTestRule.navigateAndWait(mActivityTestRule.getTestDataURL("simple_page.html"));
+        helper.waitForCallback(callCount++);
+    }
 }

weblayer/browser/controls_visibility_reason.h

@@ -10,6 +10,10 @@ namespace weblayer {
 // This enum represents actions or UI conditions that affect the visibility of
 // top UI, and is used to track concurrent concerns and to allow native and Java
 // code to coordinate.
+//
+// WARNING: only a subset of these are used if OnlyExpandTopControlsAtPageTop
+// is true.
+//
 // GENERATED_JAVA_ENUM_PACKAGE: org.chromium.weblayer_private
 // GENERATED_JAVA_CLASS_NAME_OVERRIDE: ImplControlsVisibilityReason
 enum class ControlsVisibilityReason {

weblayer/browser/tab_impl.cc

@@ -1194,6 +1194,30 @@ void TabImpl::OnUpdateBrowserControlsStateBecauseOfProcessSwitch(
     // bounce around.
     UpdateBrowserControlsState(content::BROWSER_CONTROLS_STATE_SHOWN, false);
   } else {
+    if (did_commit && current_browser_controls_visibility_constraint_ ==
+                          content::BROWSER_CONTROLS_STATE_BOTH) {
+      // If the current state is BROWSER_CONTROLS_STATE_BOTH, then
+      // TabImpl::UpdateBrowserControlsState() is going to call
+      // WebContents::UpdateBrowserControlsState() with both current and
+      // constraints set to BROWSER_CONTROLS_STATE_BOTH. cc does
+      // nothing in this case. During a navigation the top-view needs to be
+      // shown. To force the top-view to show, supply
+      // BROWSER_CONTROLS_STATE_SHOWN. This path is only hit if top-view
+      // is configured to only-expand-at-top, as in this case the top-view isn't
+      // forced shown during a page load.
+      //
+      // It's entirely possible the scroll offset is changed as part of the
+      // loading process (such as happens with back/forward navigation or
+      // links part way down a page). Trying to detect this and compensate
+      // here is likely to be racy, so the top-view is always shown.
+      const bool animate =
+          !base::FeatureList::IsEnabled(kImmediatelyHideBrowserControlsForTest);
+      web_contents_->GetMainFrame()->UpdateBrowserControlsState(
+          content::BROWSER_CONTROLS_STATE_BOTH,
+          content::BROWSER_CONTROLS_STATE_SHOWN, animate);
+      // This falls through to call UpdateBrowserControlsState() again to
+      // ensure the constraint is set back to BOTH.
+    }
     UpdateBrowserControlsState(
         content::BROWSER_CONTROLS_STATE_BOTH,
         current_browser_controls_visibility_constraint_ !=

weblayer/shell/android/shell_apk/src/org/chromium/weblayer/shell/InstrumentationActivity.java

@@ -43,6 +43,8 @@ import java.util.List;
 /**
  * Activity for running instrumentation tests.
  */
+// This isn't part of Chrome, so using explicit colors/sizes is ok.
+@SuppressWarnings("checkstyle:SetTextColorAndSetTextSizeCheck")
 public class InstrumentationActivity extends FragmentActivity {
     private static final String TAG = "WLInstrumentation";
     private static final String KEY_MAIN_VIEW_ID = "mainViewId";
@@ -55,6 +57,10 @@ public class InstrumentationActivity extends FragmentActivity {
     // True by default. If set to false, the test should call loadWebLayerSync.
     public static final String EXTRA_CREATE_WEBLAYER = "EXTRA_CREATE_WEBLAYER";
 
+    public static final String EXTRA_TOP_VIEW_MIN_HEIGHT = "EXTRA_TOP_VIEW_MIN_HEIGHT";
+    public static final String EXTRA_ONLY_EXPAND_CONTROLS_AT_TOP =
+            "EXTRA_ONLY_EXPAND_CONTROLS_AT_TOP";
+
     // Used in tests to specify whether WebLayer URL bar should set default click listeners
     // that show Page Info UI on its TextView.
     public static final String EXTRA_URLBAR_TEXT_CLICKABLE = "EXTRA_URLBAR_TEXT_CLICKABLE";
@@ -266,7 +272,18 @@ public class InstrumentationActivity extends FragmentActivity {
         mBrowser = Browser.fromFragment(mFragment);
         mProfile = mBrowser.getProfile();
 
+        final boolean onlyExpandControlsAtTop =
+                getIntent().getBooleanExtra(EXTRA_ONLY_EXPAND_CONTROLS_AT_TOP, false);
+        final int minTopViewHeight = getIntent().getIntExtra(EXTRA_TOP_VIEW_MIN_HEIGHT, -1);
+
+        if (onlyExpandControlsAtTop || minTopViewHeight != -1) {
+            // This was added in 86.
+            mBrowser.setTopView(mTopContentsContainer, Math.max(0, minTopViewHeight),
+                    onlyExpandControlsAtTop,
+                    /* animate */ false);
+        } else {
             mBrowser.setTopView(mTopContentsContainer);
+        }
 
         mRendererCrashListener = new TabCallback() {
             @Override