[ModalDialog] Touch filtering for obscured button

Add support for touch filtering for buttons obscured by another visible
window. This change is needed for migrating permission dialogs to
ModalDialogManager.

In this change:
- Add boolean property FILTER_TOUCH_FOR_SECURITY to ModalDialogProperties
- Add logic in ModalDialogView to filter touch events
- Propagate the property to ModalDialogView through ModalDialogViewBinder

BUG=940046

Change-Id: I6f363f3922c3ba2883f24b376347f305590478a7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1524909Reviewed-by: Theresa <twellington@chromium.org>
Reviewed-by: Becky Zhou <huayinz@chromium.org>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Commit-Queue: Pavel Yatsuk <pavely@chromium.org>
Cr-Commit-Position: refs/heads/master@{#642726}

chrome/android/java/src/org/chromium/chrome/browser/modaldialog/ModalDialogView.java

@@ -6,8 +6,10 @@ package org.chromium.chrome.browser.modaldialog;
 
 import android.content.Context;
 import android.graphics.drawable.Drawable;
+import android.os.Build;
 import android.text.TextUtils;
 import android.util.AttributeSet;
+import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.Button;
@@ -15,16 +17,21 @@ import android.widget.ImageView;
 import android.widget.TextView;
 
 import org.chromium.base.Callback;
+import org.chromium.base.Log;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.widget.BoundedLinearLayout;
 import org.chromium.chrome.browser.widget.FadingEdgeScrollView;
 import org.chromium.ui.UiUtils;
 import org.chromium.ui.modaldialog.ModalDialogProperties;
 
+import java.lang.reflect.Field;
+
 /**
  * Generic dialog view for app modal or tab modal alert dialogs.
  */
 public class ModalDialogView extends BoundedLinearLayout implements View.OnClickListener {
+    private static final String TAG = "ModalDialogView";
+
     private ModalDialogProperties.Controller mController;
 
     private FadingEdgeScrollView mScrollView;
@@ -38,6 +45,7 @@ public class ModalDialogView extends BoundedLinearLayout implements View.OnClick
     private Button mNegativeButton;
     private Callback<Integer> mOnButtonClickedCallback;
     private boolean mTitleScrollable;
+    private boolean mFilterTouchForSecurity;
 
     /**
      * Constructor for inflating from XML.
@@ -157,6 +165,45 @@ public class ModalDialogView extends BoundedLinearLayout implements View.OnClick
         mCustomViewContainer.setLayoutParams(layoutParams);
     }
 
+    /**
+     * @param filterTouchForSecurity Whether button touch events should be filtered when buttons are
+     *                               obscured by another visible window.
+     */
+    void setFilterTouchForSecurity(boolean filterTouchForSecurity) {
+        if (mFilterTouchForSecurity == filterTouchForSecurity) return;
+
+        mFilterTouchForSecurity = filterTouchForSecurity;
+        if (filterTouchForSecurity) {
+            setupFilterTouchForSecurity();
+        } else {
+            assert false : "Shouldn't remove touch filter after setting it up";
+        }
+    }
+
+    /** Setup touch filters to block events when buttons are obscured by another window. */
+    private void setupFilterTouchForSecurity() {
+        Button positiveButton = getButton(ModalDialogProperties.ButtonType.POSITIVE);
+        Button negativeButton = getButton(ModalDialogProperties.ButtonType.NEGATIVE);
+        View.OnTouchListener onTouchListener = (View v, MotionEvent ev) -> {
+            // Filter touch events based MotionEvent.FLAG_WINDOW_IS_PARTIALLY_OBSCURED which is
+            // introduced on M+.
+            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) return false;
+
+            try {
+                Field field = MotionEvent.class.getField("FLAG_WINDOW_IS_PARTIALLY_OBSCURED");
+                if ((ev.getFlags() & field.getInt(null)) != 0) return true;
+            } catch (NoSuchFieldException | IllegalAccessException e) {
+                Log.e(TAG, "Reflection failure: " + e);
+            }
+            return false;
+        };
+
+        positiveButton.setFilterTouchesWhenObscured(true);
+        positiveButton.setOnTouchListener(onTouchListener);
+        negativeButton.setFilterTouchesWhenObscured(true);
+        negativeButton.setOnTouchListener(onTouchListener);
+    }
+
     /** @param message The message in the dialog content. */
     void setMessage(String message) {
         mMessageView.setText(message);

chrome/android/java/src/org/chromium/chrome/browser/modaldialog/ModalDialogViewBinder.java

@@ -4,6 +4,8 @@
 
 package org.chromium.chrome.browser.modaldialog;
 
+import android.text.TextUtils;
+
 import org.chromium.ui.modaldialog.ModalDialogProperties;
 import org.chromium.ui.modelutil.PropertyKey;
 import org.chromium.ui.modelutil.PropertyModel;
@@ -27,12 +29,14 @@ public class ModalDialogViewBinder
         } else if (ModalDialogProperties.CUSTOM_VIEW == propertyKey) {
             view.setCustomView(model.get(ModalDialogProperties.CUSTOM_VIEW));
         } else if (ModalDialogProperties.POSITIVE_BUTTON_TEXT == propertyKey) {
+            assert checkFilterTouchConsistency(model);
             view.setButtonText(ModalDialogProperties.ButtonType.POSITIVE,
                     model.get(ModalDialogProperties.POSITIVE_BUTTON_TEXT));
         } else if (ModalDialogProperties.POSITIVE_BUTTON_DISABLED == propertyKey) {
             view.setButtonEnabled(ModalDialogProperties.ButtonType.POSITIVE,
                     !model.get(ModalDialogProperties.POSITIVE_BUTTON_DISABLED));
         } else if (ModalDialogProperties.NEGATIVE_BUTTON_TEXT == propertyKey) {
+            assert checkFilterTouchConsistency(model);
             view.setButtonText(ModalDialogProperties.ButtonType.NEGATIVE,
                     model.get(ModalDialogProperties.NEGATIVE_BUTTON_TEXT));
         } else if (ModalDialogProperties.NEGATIVE_BUTTON_DISABLED == propertyKey) {
@@ -46,10 +50,26 @@ public class ModalDialogViewBinder
             });
         } else if (ModalDialogProperties.CANCEL_ON_TOUCH_OUTSIDE == propertyKey) {
             // Intentionally left empty since this is a property for the dialog container.
+        } else if (ModalDialogProperties.FILTER_TOUCH_FOR_SECURITY == propertyKey) {
+            assert checkFilterTouchConsistency(model);
+            view.setFilterTouchForSecurity(
+                    model.get(ModalDialogProperties.FILTER_TOUCH_FOR_SECURITY));
         } else if (ModalDialogProperties.CONTENT_DESCRIPTION == propertyKey) {
             // Intentionally left empty since this is a property used for the dialog container.
         } else {
             assert false : "Unhandled property detected in ModalDialogViewBinder!";
         }
     }
+
+    /**
+     * Checks if FILTER_TOUCH_FOR_SECURITY flag is consistent with the set of enabled buttons.
+     * Touch event filtering in ModalDialogView is only applied to standard buttons. When buttons
+     * are hidden, filtering touch events doesn't have effect.
+     * @return false if security sensitive dialog doesn't have standard buttons.
+     */
+    static boolean checkFilterTouchConsistency(PropertyModel model) {
+        return !model.get(ModalDialogProperties.FILTER_TOUCH_FOR_SECURITY)
+                || !TextUtils.isEmpty(model.get(ModalDialogProperties.POSITIVE_BUTTON_TEXT))
+                || !TextUtils.isEmpty(model.get(ModalDialogProperties.NEGATIVE_BUTTON_TEXT));
+    }
 }

chrome/android/java/src/org/chromium/chrome/browser/permissions/PermissionAppModalDialogView.java

@@ -44,6 +44,7 @@ class PermissionAppModalDialogView {
                         .with(ModalDialogProperties.NEGATIVE_BUTTON_TEXT,
                                 delegate.getSecondaryButtonText())
                         .with(ModalDialogProperties.CONTENT_DESCRIPTION, delegate.getMessageText())
+                        .with(ModalDialogProperties.FILTER_TOUCH_FOR_SECURITY, true)
                         .build();
     }
 

chrome/android/javatests/src/org/chromium/chrome/browser/modaldialog/ModalDialogViewTest.java

@@ -23,10 +23,14 @@ import android.support.test.filters.MediumTest;
 import android.text.TextUtils;
 import android.view.ContextThemeWrapper;
 import android.view.LayoutInflater;
+import android.view.View;
 import android.widget.FrameLayout;
 import android.widget.ScrollView;
 import android.widget.TextView;
 
+import org.hamcrest.Description;
+import org.hamcrest.Matcher;
+import org.hamcrest.TypeSafeMatcher;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -335,6 +339,46 @@ public class ModalDialogViewTest {
         onView(withId(R.id.negative_button)).check(matches(not(isDisplayed())));
     }
 
+    @Test
+    @MediumTest
+    @Feature({"ModalDialog"})
+    public void testTouchFilter() {
+        PropertyModel model = createModel(
+                mModelBuilder
+                        .with(ModalDialogProperties.POSITIVE_BUTTON_TEXT, mResources, R.string.ok)
+                        .with(ModalDialogProperties.NEGATIVE_BUTTON_TEXT, mResources,
+                                R.string.cancel)
+                        .with(ModalDialogProperties.FILTER_TOUCH_FOR_SECURITY, true));
+        onView(withId(R.id.positive_button)).check(matches(touchFilterEnabled()));
+        onView(withId(R.id.negative_button)).check(matches(touchFilterEnabled()));
+    }
+
+    @Test
+    @MediumTest
+    @Feature({"ModalDialog"})
+    public void testTouchFilterDisabled() {
+        PropertyModel model = createModel(
+                mModelBuilder
+                        .with(ModalDialogProperties.POSITIVE_BUTTON_TEXT, mResources, R.string.ok)
+                        .with(ModalDialogProperties.NEGATIVE_BUTTON_TEXT, mResources,
+                                R.string.cancel));
+        onView(withId(R.id.positive_button)).check(matches(not(touchFilterEnabled())));
+        onView(withId(R.id.negative_button)).check(matches(not(touchFilterEnabled())));
+    }
+
+    private static Matcher<View> touchFilterEnabled() {
+        return new TypeSafeMatcher<View>() {
+            @Override
+            public void describeTo(Description description) {
+                description.appendText("Touch filtering enabled");
+            }
+            @Override
+            public boolean matchesSafely(View view) {
+                return view.getFilterTouchesWhenObscured();
+            }
+        };
+    }
+
     private PropertyModel createModel(PropertyModel.Builder modelBuilder) {
         return ThreadUtils.runOnUiThreadBlockingNoException(() -> {
             PropertyModel model = modelBuilder.build();

ui/android/java/src/org/chromium/ui/modaldialog/ModalDialogProperties.java

@@ -10,6 +10,7 @@ import android.view.View;
 
 import org.chromium.ui.modelutil.PropertyKey;
 import org.chromium.ui.modelutil.PropertyModel;
+import org.chromium.ui.modelutil.PropertyModel.ReadableBooleanPropertyKey;
 import org.chromium.ui.modelutil.PropertyModel.ReadableObjectPropertyKey;
 import org.chromium.ui.modelutil.PropertyModel.WritableBooleanPropertyKey;
 import org.chromium.ui.modelutil.PropertyModel.WritableObjectPropertyKey;
@@ -96,6 +97,13 @@ public class ModalDialogProperties {
     public static final WritableBooleanPropertyKey CANCEL_ON_TOUCH_OUTSIDE =
             new WritableBooleanPropertyKey();
 
+    /**
+     * Whether button touch events should be filtered when buttons are obscured by another visible
+     * window.
+     */
+    public static final ReadableBooleanPropertyKey FILTER_TOUCH_FOR_SECURITY =
+            new ReadableBooleanPropertyKey();
+
     /** Whether the title is scrollable with the message. */
     public static final WritableBooleanPropertyKey TITLE_SCROLLABLE =
             new WritableBooleanPropertyKey();
@@ -103,5 +111,5 @@ public class ModalDialogProperties {
     public static final PropertyKey[] ALL_KEYS = new PropertyKey[] {CONTROLLER, CONTENT_DESCRIPTION,
             TITLE, TITLE_ICON, MESSAGE, CUSTOM_VIEW, POSITIVE_BUTTON_TEXT, POSITIVE_BUTTON_DISABLED,
             NEGATIVE_BUTTON_TEXT, NEGATIVE_BUTTON_DISABLED, CANCEL_ON_TOUCH_OUTSIDE,
-            TITLE_SCROLLABLE};
+            FILTER_TOUCH_FOR_SECURITY, TITLE_SCROLLABLE};
 }