LayoutAssertions.java
/*
* Copyright (C) 2014 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 androidx.test.espresso.assertion;
import static androidx.test.espresso.assertion.ViewAssertions.selectedDescendantsMatch;
import static androidx.test.espresso.matcher.LayoutMatchers.hasEllipsizedText;
import static androidx.test.espresso.matcher.LayoutMatchers.hasMultilineText;
import static androidx.test.espresso.matcher.ViewMatchers.isAssignableFrom;
import static androidx.test.espresso.matcher.ViewMatchers.withEffectiveVisibility;
import static androidx.test.espresso.util.HumanReadables.describe;
import static androidx.test.espresso.util.TreeIterables.breadthFirstViewTraversal;
import static com.google.common.base.Preconditions.checkNotNull;
import static org.hamcrest.Matchers.allOf;
import static org.hamcrest.Matchers.anyOf;
import static org.hamcrest.Matchers.not;
import android.graphics.Rect;
import android.support.annotation.VisibleForTesting;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import androidx.test.espresso.NoMatchingViewException;
import androidx.test.espresso.ViewAssertion;
import androidx.test.espresso.matcher.ViewMatchers.Visibility;
import androidx.test.espresso.remote.annotation.RemoteMsgConstructor;
import androidx.test.espresso.remote.annotation.RemoteMsgField;
import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import junit.framework.AssertionFailedError;
import org.hamcrest.Matcher;
/** A collection of layout {@link ViewAssertion}s. */
public final class LayoutAssertions {
private LayoutAssertions() {}
/**
* Returns a {@link ViewAssertion} that asserts that view hierarchy does not contain ellipsized or
* cut off text views.
*/
public static ViewAssertion noEllipsizedText() {
return selectedDescendantsMatch(isAssignableFrom(TextView.class), not(hasEllipsizedText()));
}
/**
* Returns a {@link ViewAssertion} that asserts that view hierarchy does not contain multiline
* buttons.
*/
public static ViewAssertion noMultilineButtons() {
return selectedDescendantsMatch(isAssignableFrom(Button.class), not(hasMultilineText()));
}
/**
* Returns a {@link ViewAssertion} that asserts that descendant views matching the selector do not
* overlap each other.
*
* <p>Example: {@code onView(rootView).check(noOverlaps(isAssignableFrom(TextView.class));}
*/
public static ViewAssertion noOverlaps(final Matcher<View> selector) {
return new NoOverlapsViewAssertion(checkNotNull(selector));
}
/**
* Returns a {@link ViewAssertion} that asserts that descendant objects assignable to TextView or
* ImageView do not overlap each other.
*
* <p>Example: {@code onView(rootView).check(noOverlaps());}
*/
public static ViewAssertion noOverlaps() {
return noOverlaps(
allOf(
withEffectiveVisibility(Visibility.VISIBLE),
anyOf(isAssignableFrom(TextView.class), isAssignableFrom(ImageView.class))));
}
private static Rect getRect(View view) {
int[] coords = {0, 0};
view.getLocationOnScreen(coords);
return new Rect(
coords[0], coords[1], coords[0] + view.getWidth() - 1, coords[1] + view.getHeight() - 1);
}
@VisibleForTesting
static class NoOverlapsViewAssertion implements ViewAssertion {
@RemoteMsgField(order = 0)
private final Matcher<View> selector;
@RemoteMsgConstructor
private NoOverlapsViewAssertion(Matcher<View> selector) {
this.selector = selector;
}
@SuppressWarnings("unchecked")
@Override
public void check(View view, NoMatchingViewException noViewException) {
final Predicate<View> viewPredicate =
new Predicate<View>() {
@Override
public boolean apply(View input) {
return selector.matches(input);
}
};
if (noViewException != null) {
throw noViewException;
}
Iterator<View> selectedViewIterator =
Iterables.filter(breadthFirstViewTraversal(view), viewPredicate).iterator();
List<View> prevViews = new LinkedList<>();
StringBuilder errorMessage = new StringBuilder();
while (selectedViewIterator.hasNext()) {
View selectedView = selectedViewIterator.next();
Rect viewRect = getRect(selectedView);
if (!viewRect.isEmpty()
&& !(selectedView instanceof TextView
&& ((TextView) selectedView).getText().length() == 0)) {
for (View prevView : prevViews) {
// Mutual intersection of ImageViews is acceptable in most cases.
if (selectedView instanceof ImageView && prevView instanceof ImageView) {
continue;
}
Rect prevRect = getRect(prevView);
if (Rect.intersects(viewRect, prevRect)) {
// Overlap detected, add to the error message
if (errorMessage.length() > 0) {
errorMessage.append(",\n\n");
}
errorMessage.append(
String.format(
Locale.ROOT, "%s overlaps\n%s", describe(selectedView), describe(prevView)));
break;
}
}
prevViews.add(selectedView);
}
}
if (errorMessage.length() > 0) {
throw new AssertionFailedError(errorMessage.toString());
}
}
@Override
public String toString() {
return String.format(Locale.ROOT, "NoOverlapsViewAssertion{selector=%s}", selector);
}
}
}