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Commit 95459d3e authored by Riddle Hsu's avatar Riddle Hsu
Browse files

Ensure consistent attach/detach callback on transient view 

- Not allow to add as transient view if it still has a parent.
  (The normal usage of addTransientView should be after removeView)
- If a view container is not attached, its transient view should
  not be attached.
- If a transient view is already detached from parent, no need
  to detach again when removing the transient view.

Bug: 109814657
Test: atest FrameworksCoreTests:ViewGroupTransientViewTest
Change-Id: I243cc292e4aaba987d48eeb202559de866a8c208
parent acda839b

core/java/android/view/ViewGroup.java

+13 −4
Original line number Diff line number Diff line
@@ -4652,7 +4652,7 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager 
     * which is added in order to fade it out in its old location should be removed

     * once the animation is complete.</p>

     *

     * @param view The view to be added

     * @param view The view to be added. The view must not have a parent.

     * @param index The index at which this view should be drawn, must be >= 0.

     * This value is relative to the {@link #getChildAt(int) index} values in the normal

     * child list of this container, where any transient view at a particular index will
@@ -4661,9 +4661,14 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager 
     * @hide

     */

    public void addTransientView(View view, int index) {

        if (index < 0) {

        if (index < 0 || view == null) {

            return;

        }

        if (view.mParent != null) {

            throw new IllegalStateException("The specified view already has a parent "

                    + view.mParent);

        }



        if (mTransientIndices == null) {

            mTransientIndices = new ArrayList<Integer>();

            mTransientViews = new ArrayList<View>();
@@ -4683,7 +4688,9 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager 
            mTransientViews.add(view);

        }

        view.mParent = this;

        if (mAttachInfo != null) {

            view.dispatchAttachedToWindow(mAttachInfo, (mViewFlags & VISIBILITY_MASK));

        }

        invalidate(true);

    }
@@ -4705,7 +4712,9 @@ public abstract class ViewGroup extends View implements ViewParent, ViewManager 
                mTransientViews.remove(i);

                mTransientIndices.remove(i);

                view.mParent = null;

                if (view.mAttachInfo != null) {

                    view.dispatchDetachedFromWindow();

                }

                invalidate(true);

                return;

            }

core/tests/coretests/src/android/view/ViewGroupTransientViewTest.java

0 → 100644
+163 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2018 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */



package android.view;



import static junit.framework.Assert.assertEquals;

import static junit.framework.Assert.fail;



import android.app.Activity;

import android.content.Context;

import android.graphics.Canvas;

import android.support.test.annotation.UiThreadTest;

import android.support.test.filters.MediumTest;

import android.support.test.rule.ActivityTestRule;

import android.support.test.runner.AndroidJUnit4;

import android.widget.FrameLayout;



import org.junit.Before;

import org.junit.Rule;

import org.junit.Test;

import org.junit.runner.RunWith;



import java.util.concurrent.CountDownLatch;

import java.util.concurrent.TimeUnit;



@MediumTest

@RunWith(AndroidJUnit4.class)

public class ViewGroupTransientViewTest {



    @Rule

    public ActivityTestRule<Activity> mActivityRule = new ActivityTestRule<>(Activity.class);



    private FrameLayout mBasePanel;

    private ViewGroup mTestViewGroup;

    private TestView mTestView;



    @Before

    public void setUp() {

        final Activity activity = mActivityRule.getActivity();

        mBasePanel = new FrameLayout(activity);

        mTestViewGroup = new FrameLayout(activity);

        mTestView = new TestView(activity);

        activity.runOnUiThread(() -> activity.setContentView(mBasePanel));

    }



    @UiThreadTest

    @Test

    public void addAndRemove_inNonAttachedViewGroup_shouldNotAttachAndDetach() {

        mTestViewGroup.addTransientView(mTestView, 0);

        assertEquals(0, mTestView.mAttachedCount);



        mTestViewGroup.removeTransientView(mTestView);

        assertEquals(0, mTestView.mDetachedCount);

    }



    @UiThreadTest

    @Test

    public void addAndRemove_inAttachedViewGroup_shouldAttachAndDetachOnce() {

        mBasePanel.addView(mTestViewGroup);

        mTestViewGroup.addTransientView(mTestView, 0);

        assertEquals(mTestView, mTestViewGroup.getTransientView(0));

        assertEquals(1, mTestViewGroup.getTransientViewCount());

        assertEquals(1, mTestView.mAttachedCount);



        mBasePanel.removeView(mTestViewGroup);

        mTestViewGroup.removeTransientView(mTestView);

        assertEquals(null, mTestViewGroup.getTransientView(0));

        assertEquals(0, mTestViewGroup.getTransientViewCount());

        assertEquals(1, mTestView.mDetachedCount);

    }



    @UiThreadTest

    @Test

    public void addRemoveAdd_noException() {

        mBasePanel.addView(mTestViewGroup);

        mTestViewGroup.addTransientView(mTestView, 1);

        mTestViewGroup.removeTransientView(mTestView);

        mTestViewGroup.addTransientView(mTestView, 2);

    }



    @UiThreadTest

    @Test

    public void reAddBeforeRemove_shouldThrowException() {

        mTestViewGroup.addView(mTestView);



        try {

            mTestViewGroup.addTransientView(mTestView, 0);

            fail("Not allow to add as transient view before removing it");

        } catch (IllegalStateException e) {

            // Expected

        }



        mTestViewGroup.removeView(mTestView);

        mTestViewGroup.addTransientView(mTestView, 0);

        try {

            mTestViewGroup.addTransientView(mTestView, 1);

            fail("Not allow to add the same transient view again");

        } catch (IllegalStateException e) {

            // Expected

        }

    }



    @Test

    public void drawTransientView() throws Exception {

        // For view can be drawn if keyguard is active.

        mActivityRule.getActivity().setShowWhenLocked(true);



        final CountDownLatch latch = new CountDownLatch(1);

        mTestView.mOnDraw = () -> latch.countDown();



        mActivityRule.getActivity().runOnUiThread(() -> {

            mBasePanel.addView(mTestViewGroup);

            mTestViewGroup.addTransientView(mTestView, 0);

        });



        if (!latch.await(3, TimeUnit.SECONDS)) {

            fail("Transient view does not draw");

        }

    }



    private static class TestView extends View {

        int mAttachedCount;

        int mDetachedCount;

        Runnable mOnDraw;



        TestView(Context context) {

            super(context);

        }



        @Override

        protected void onAttachedToWindow() {

            super.onAttachedToWindow();

            mAttachedCount++;

        }



        @Override

        protected void onDetachedFromWindow() {

            super.onDetachedFromWindow();

            mDetachedCount++;

        }



        @Override

        protected void onDraw(Canvas canvas) {

            if (mOnDraw != null) {

                mOnDraw.run();

                mOnDraw = null;

            }

        }

    }

}