Prevent an empty flex line is added when the first flex item's initial length

is large enough to be judged a line wrapping is required.

Change-Id: I2526d00fe53fccfbab5959a10f33d11dfa5f62fa

flexbox/src/androidTest/java/com/google/android/flexbox/test/FlexboxAndroidTest.java

@@ -3018,6 +3018,72 @@ public class FlexboxAndroidTest {
                 is(text1.getHeight() + text2.getHeight() + lp2.topMargin + lp2.bottomMargin));
     }
 
+    @Test
+    @FlakyTest(tolerance = TOLERANCE)
+    public void testFirstItemLarge_horizontal() throws Throwable {
+        // This test verifies a empty flex line is not added when the first flex item is large
+        // and judged wrapping is required with the first item.
+        final FlexboxTestActivity activity = mActivityRule.getActivity();
+        mActivityRule.runOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                activity.setContentView(R.layout.activity_first_item_large_horizontal_test);
+            }
+        });
+        FlexboxLayout flexboxLayout = (FlexboxLayout) activity.findViewById(R.id.flexbox_layout);
+
+        assertThat(flexboxLayout.getFlexWrap(), is(FlexboxLayout.FLEX_WRAP_WRAP));
+        assertThat(flexboxLayout.getFlexDirection(), is(FlexboxLayout.FLEX_DIRECTION_ROW));
+        assertThat(flexboxLayout.getAlignItems(), is(FlexboxLayout.ALIGN_ITEMS_STRETCH));
+        assertThat(flexboxLayout.getAlignContent(), is(FlexboxLayout.ALIGN_CONTENT_STRETCH));
+        // The sum of width of TextView1 and TextView2 is not enough for wrapping, but considering
+        // the margin for the TextView2, the second TextView should be wrapped
+        onView(withId(R.id.text1)).check(isTopAlignedWith(withId(R.id.flexbox_layout)));
+        onView(withId(R.id.text1)).check(isLeftAlignedWith(withId(R.id.flexbox_layout)));
+        onView(withId(R.id.text2)).check(isLeftAlignedWith(withId(R.id.flexbox_layout)));
+        onView(withId(R.id.text3)).check(isLeftAlignedWith(withId(R.id.flexbox_layout)));
+        onView(withId(R.id.text3)).check(isBottomAlignedWith(withId(R.id.flexbox_layout)));
+
+        TextView text1 = (TextView) activity.findViewById(R.id.text1);
+        TextView text2 = (TextView) activity.findViewById(R.id.text2);
+        TextView text3 = (TextView) activity.findViewById(R.id.text3);
+        assertThat(flexboxLayout.getHeight(),
+                is(text1.getHeight() + text2.getHeight() + text3.getHeight()));
+    }
+
+    @Test
+    @FlakyTest(tolerance = TOLERANCE)
+    public void testFirstItemLarge_vertical() throws Throwable {
+        // This test verifies a empty flex line is not added when the first flex item is large
+        // and judged wrapping is required with the first item.
+        final FlexboxTestActivity activity = mActivityRule.getActivity();
+        mActivityRule.runOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                activity.setContentView(R.layout.activity_first_item_large_vertical_test);
+            }
+        });
+        FlexboxLayout flexboxLayout = (FlexboxLayout) activity.findViewById(R.id.flexbox_layout);
+
+        assertThat(flexboxLayout.getFlexWrap(), is(FlexboxLayout.FLEX_WRAP_WRAP));
+        assertThat(flexboxLayout.getFlexDirection(), is(FlexboxLayout.FLEX_DIRECTION_COLUMN));
+        assertThat(flexboxLayout.getAlignItems(), is(FlexboxLayout.ALIGN_ITEMS_STRETCH));
+        assertThat(flexboxLayout.getAlignContent(), is(FlexboxLayout.ALIGN_CONTENT_STRETCH));
+        // The sum of width of TextView1 and TextView2 is not enough for wrapping, but considering
+        // the margin for the TextView2, the second TextView should be wrapped
+        onView(withId(R.id.text1)).check(isTopAlignedWith(withId(R.id.flexbox_layout)));
+        onView(withId(R.id.text1)).check(isLeftAlignedWith(withId(R.id.flexbox_layout)));
+        onView(withId(R.id.text2)).check(isTopAlignedWith(withId(R.id.flexbox_layout)));
+        onView(withId(R.id.text3)).check(isTopAlignedWith(withId(R.id.flexbox_layout)));
+        onView(withId(R.id.text3)).check(isRightAlignedWith(withId(R.id.flexbox_layout)));
+
+        TextView text1 = (TextView) activity.findViewById(R.id.text1);
+        TextView text2 = (TextView) activity.findViewById(R.id.text2);
+        TextView text3 = (TextView) activity.findViewById(R.id.text3);
+        assertThat(flexboxLayout.getWidth(),
+                is(text1.getWidth() + text2.getWidth() + text3.getWidth()));
+    }
+
     @Test
     @FlakyTest(tolerance = TOLERANCE)
     public void testWrap_childMargin_vertical() throws Throwable {

flexbox/src/androidTest/res/layout/activity_first_item_large_horizontal_test.xml

+<?xml version="1.0" encoding="utf-8"?><!--
+  Copyright 2016 Google Inc. All rights reserved.
+
+  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.
+  -->
+<com.google.android.flexbox.FlexboxLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:id="@+id/flexbox_layout"
+    android:layout_width="320dp"
+    android:layout_height="320dp"
+    app:flexDirection="row"
+    app:flexWrap="wrap"
+    app:alignItems="stretch"
+    app:alignContent="stretch">
+
+    <TextView
+        android:id="@+id/text1"
+        android:layout_width="500dp"
+        android:layout_height="60dp"
+        android:text="1" />
+
+    <TextView
+        android:id="@+id/text2"
+        android:layout_width="120dp"
+        android:layout_height="60dp"
+        android:text="2" />
+
+    <TextView
+        android:id="@+id/text3"
+        android:layout_width="300dp"
+        android:layout_height="60dp"
+        android:text="3" />
+</com.google.android.flexbox.FlexboxLayout>
\ No newline at end of file

flexbox/src/androidTest/res/layout/activity_first_item_large_vertical_test.xml

+<?xml version="1.0" encoding="utf-8"?><!--
+  Copyright 2016 Google Inc. All rights reserved.
+
+  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.
+  -->
+<com.google.android.flexbox.FlexboxLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:id="@+id/flexbox_layout"
+    android:layout_width="320dp"
+    android:layout_height="320dp"
+    app:flexDirection="column"
+    app:flexWrap="wrap"
+    app:alignItems="stretch"
+    app:alignContent="stretch">
+
+    <TextView
+        android:id="@+id/text1"
+        android:layout_width="60dp"
+        android:layout_height="500dp"
+        android:text="1" />
+
+    <TextView
+        android:id="@+id/text2"
+        android:layout_width="60dp"
+        android:layout_height="120dp"
+        android:text="2" />
+
+    <TextView
+        android:id="@+id/text3"
+        android:layout_width="6dp"
+        android:layout_height="300dp"
+        android:text="3" />
+</com.google.android.flexbox.FlexboxLayout>
\ No newline at end of file

flexbox/src/main/java/com/google/android/flexbox/FlexboxLayout.java

@@ -499,7 +499,9 @@ public class FlexboxLayout extends ViewGroup {
 
                 if (isWrapRequired(mFlexWrap, widthMode, widthSize, flexLine.mainSize,
                         child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin, lp)) {
-                    mFlexLines.add(flexLine);
+                    if (flexLine.itemCount > 0) {
+                        mFlexLines.add(flexLine);
+                    }
 
                     flexLine = new FlexLine();
                     flexLine.itemCount = 1;
@@ -650,7 +652,9 @@ public class FlexboxLayout extends ViewGroup {
 
             if (isWrapRequired(mFlexWrap, heightMode, heightSize, flexLine.mainSize,
                     child.getMeasuredHeight() + lp.topMargin + lp.bottomMargin, lp)) {
-                mFlexLines.add(flexLine);
+                if (flexLine.itemCount > 0) {
+                    mFlexLines.add(flexLine);
+                }
 
                 flexLine = new FlexLine();
                 flexLine.itemCount = 1;