Fixes the #47

Change-Id: I6951cb986e096276255374e5962084353471a2ee

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

@@ -2583,6 +2583,64 @@ public class FlexboxAndroidTest {
         assertThat(textView5.getTop(), is(textView3.getBottom()));
     }
 
+    @Test
+    @FlakyTest(tolerance = TOLERANCE)
+    public void testView_visibility_gone_first_item_in_flex_line_horizontal() throws Throwable {
+        // This test verifies if the FlexboxLayout is visible when the visibility of the first
+        // flex item in the second flex line (or arbitrary flex lines other than the first flex line)
+        // is set to "gone"
+        // There was an issue reported for that
+        // https://github.com/google/flexbox-layout/issues/47
+        final FlexboxTestActivity activity = mActivityRule.getActivity();
+        mActivityRule.runOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                activity.setContentView(
+                        R.layout.activity_visibility_gone_first_item_in_flex_line_row);
+            }
+        });
+        InstrumentationRegistry.getInstrumentation().waitForIdleSync();
+
+        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));
+        TextView textView1 = (TextView) activity.findViewById(R.id.text1);
+        TextView textView3 = (TextView) activity.findViewById(R.id.text3);
+
+        assertTrue(flexboxLayout.getHeight() > 0);
+        assertThat(flexboxLayout.getHeight(), is(textView1.getHeight() + textView3.getHeight()));
+    }
+
+    @Test
+    @FlakyTest(tolerance = TOLERANCE)
+    public void testView_visibility_gone_first_item_in_flex_line_vertical() throws Throwable {
+        // This test verifies if the FlexboxLayout is visible when the visibility of the first
+        // flex item in the second flex line (or arbitrary flex lines other than the first flex line)
+        // is set to "gone"
+        // There was an issue reported for that
+        // https://github.com/google/flexbox-layout/issues/47
+        final FlexboxTestActivity activity = mActivityRule.getActivity();
+        mActivityRule.runOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                activity.setContentView(
+                        R.layout.activity_visibility_gone_first_item_in_flex_line_column);
+            }
+        });
+        InstrumentationRegistry.getInstrumentation().waitForIdleSync();
+
+        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));
+        TextView textView1 = (TextView) activity.findViewById(R.id.text1);
+        TextView textView3 = (TextView) activity.findViewById(R.id.text3);
+
+        assertTrue(flexboxLayout.getWidth() > 0);
+        assertThat(flexboxLayout.getWidth(), is(textView1.getWidth() + textView3.getWidth()));
+    }
+
     @Test
     @FlakyTest(tolerance = TOLERANCE)
     public void testView_visibility_invisible() throws Throwable {

flexbox/src/androidTest/res/layout/activity_visibility_gone_first_item_in_flex_line_column.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="wrap_content"
+    android:layout_height="360dp"
+    app:flexDirection="column"
+    app:flexWrap="wrap">
+
+    <TextView
+        android:id="@+id/text1"
+        android:layout_width="wrap_content"
+        android:layout_height="160dp"
+        android:text="1" />
+
+    <TextView
+        android:id="@+id/text2"
+        android:layout_width="wrap_content"
+        android:layout_height="160dp"
+        android:text="2" />
+
+    <TextView
+        android:id="@+id/text3"
+        android:layout_width="wrap_content"
+        android:layout_height="160dp"
+        android:visibility="gone"
+        android:text="3" />
+
+</com.google.android.flexbox.FlexboxLayout>

flexbox/src/androidTest/res/layout/activity_visibility_gone_first_item_in_flex_line_row.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="360dp"
+    android:layout_height="wrap_content"
+    app:flexDirection="row"
+    app:flexWrap="wrap">
+
+    <TextView
+        android:id="@+id/text1"
+        android:layout_width="160dp"
+        android:layout_height="wrap_content"
+        android:text="1" />
+
+    <TextView
+        android:id="@+id/text2"
+        android:layout_width="160dp"
+        android:layout_height="wrap_content"
+        android:text="2" />
+
+    <TextView
+        android:id="@+id/text3"
+        android:layout_width="160dp"
+        android:layout_height="wrap_content"
+        android:visibility="gone"
+        android:text="3" />
+
+</com.google.android.flexbox.FlexboxLayout>

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

@@ -442,9 +442,11 @@ public class FlexboxLayout extends ViewGroup {
             for (int i = 0; i < childCount; i++) {
                 View child = getReorderedChildAt(i);
                 if (child == null) {
+                    addFlexLineIfLastFlexItem(i, childCount, paddingEnd, flexLine);
                     continue;
                 } else if (child.getVisibility() == View.GONE) {
                     flexLine.itemCount++;
+                    addFlexLineIfLastFlexItem(i, childCount, paddingEnd, flexLine);
                     continue;
                 }
 
@@ -519,11 +521,7 @@ public class FlexboxLayout extends ViewGroup {
                                     child.getMeasuredHeight() - child.getBaseline()
                                             + lp.bottomMargin);
                 }
-                if (i == childCount - 1 && flexLine.itemCount != 0) {
-                    // Add the flex line if this item is the last item
-                    flexLine.mainSize += paddingEnd;
-                    mFlexLines.add(flexLine);
-                }
+                addFlexLineIfLastFlexItem(i, childCount, paddingEnd, flexLine);
             }
         }
 
@@ -595,9 +593,11 @@ public class FlexboxLayout extends ViewGroup {
         for (int i = 0; i < childCount; i++) {
             View child = getReorderedChildAt(i);
             if (child == null) {
+                addFlexLineIfLastFlexItem(i, childCount, paddingBottom, flexLine);
                 continue;
             } else if (child.getVisibility() == View.GONE) {
                 flexLine.itemCount++;
+                addFlexLineIfLastFlexItem(i, childCount, paddingBottom, flexLine);
                 continue;
             }
 
@@ -660,11 +660,7 @@ public class FlexboxLayout extends ViewGroup {
             // later
             flexLine.crossSize = Math.max(flexLine.crossSize, largestWidthInColumn);
 
-            if (i == childCount - 1 && flexLine.itemCount != 0) {
-                // Add the flex line if this item is the last item
-                flexLine.mainSize += paddingBottom;
-                mFlexLines.add(flexLine);
-            }
+            addFlexLineIfLastFlexItem(i, childCount, paddingBottom, flexLine);
         }
 
         determineMainSize(mFlexDirection, widthMeasureSpec, heightMeasureSpec);
@@ -676,6 +672,15 @@ public class FlexboxLayout extends ViewGroup {
                 childState);
     }
 
+    private void addFlexLineIfLastFlexItem(int childIndex, int childCount, int paddingToAdd,
+            FlexLine flexLine) {
+        if (childIndex == childCount - 1 && flexLine.itemCount != 0) {
+            // Add the flex line if this item is the last item
+            flexLine.mainSize += paddingToAdd;
+            mFlexLines.add(flexLine);
+        }
+    }
+
     /**
      * Determine the main size by expanding (shrinking if negative remaining free space is given)
      * an individual child in each flex line if any children's flexGrow (or flexShrink if remaining