Add the common methods for the FlexContainer.

Adds the methods that FlexboxLayout and FlexboxLayoutManager have in common
in calculating the flexbox layout.

Change-Id: Ib0e0159cf0ea2cdc4f9c38020f4b34ec5eb2e537

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

@@ -18,11 +18,13 @@ package com.google.android.flexbox;
 
 import android.view.View;
 
+import java.util.List;
+
 /**
  * An interface that has the common behavior as the flex container such as {@link FlexboxLayout}
  * and {@link FlexboxLayoutManager}.
  */
-interface FlexContainer {
+public interface FlexContainer {
 
     /**
      * @return the number of child count contained in the flex container.
@@ -36,4 +38,98 @@ interface FlexContainer {
      * @return the view at the index
      */
     View getChildAt(int i);
+
+
+    /**
+     * Returns a View, which is reordered by taking the order attribute into account.
+     *
+     * @param i the index of the view
+     * @return the reordered view, which order attribute is taken into account.
+     * If the index is negative or out of bounds of the number of contained views,
+     * returns {@code null}.
+     * @see FlexItem#getOrder()
+     */
+    View getReorderedChildAt(int i);
+
+    /**
+     * @return the flex direction attribute of the flex container.
+     * @see FlexDirection
+     */
+    @FlexDirection
+    int getFlexDirection();
+
+    /**
+     * Sets the given flex direction attribute to the flex container.
+     *
+     * @param flexDirection the flex direction value
+     * @see FlexDirection
+     */
+    void setFlexDirection(@FlexDirection int flexDirection);
+
+    /**
+     * @return the flex wrap attribute of the flex container.
+     * @see FlexWrap
+     */
+    @FlexWrap
+    int getFlexWrap();
+
+    /**
+     * Sets the given flex wrap attribute to the flex container.
+     *
+     * @param flexWrap the flex wrap value
+     * @see FlexWrap
+     */
+    void setFlexWrap(@FlexWrap int flexWrap);
+
+    /**
+     * @return the justify content attribute of the flex container.
+     * @see JustifyContent
+     */
+    @JustifyContent
+    int getJustifyContent();
+
+    /**
+     * Sets the given justify content attribute to the flex container.
+     *
+     * @param justifyContent the justify content value
+     * @see JustifyContent
+     */
+    void setJustifyContent(@JustifyContent int justifyContent);
+
+    /**
+     * @return the align content attribute of the flex container.
+     * @see AlignContent
+     */
+    @AlignContent
+    int getAlignContent();
+
+    /**
+     * Sets the given align content attribute to the flex container.
+     *
+     * @param alignContent the align content value
+     */
+    void setAlignContent(@AlignContent int alignContent);
+
+    /**
+     * @return the align items attribute of the flex container.
+     * @see AlignItems
+     */
+    @AlignItems
+    int getAlignItems();
+
+    /**
+     * Sets the given align items attribute to the flex container.
+     *
+     * @param alignItems the align items value
+     * @see AlignItems
+     */
+    void setAlignItems(@AlignItems int alignItems);
+
+    /**
+     * @return the flex lines composing this flex container. The overridden method should return a
+     * copy of the original list excluding a dummy flex line (flex line that doesn't have any flex
+     * items in it but used for the alignment along the cross axis) so that any changes of the
+     * returned list are not reflected to the original list.
+     */
+    List<FlexLine> getFlexLines();
 }

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

@@ -628,7 +628,8 @@ public class FlexboxLayout extends ViewGroup implements FlexContainer {
 
     /**
      * 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 mFlexGrow (or mFlexShrink if remaining
+     * an individual child in each flex line if any children's mFlexGrow (or mFlexShrink if
+     * remaining
      * space is negative) properties are set to non-zero.
      *
      * @param flexDirection     the value of the flex direction
@@ -774,7 +775,8 @@ public class FlexboxLayout extends ViewGroup implements FlexContainer {
             } else {
                 // The direction of the main axis is vertical
                 if (!mChildrenFrozen[childIndex]) {
-                    float rawCalculatedHeight = child.getMeasuredHeight() + unitSpace * lp.mFlexGrow;
+                    float rawCalculatedHeight = child.getMeasuredHeight()
+                            + unitSpace * lp.mFlexGrow;
                     if (i == flexLine.mItemCount - 1) {
                         rawCalculatedHeight += accumulatedRoundError;
                         accumulatedRoundError = 0;
@@ -2117,10 +2119,12 @@ public class FlexboxLayout extends ViewGroup implements FlexContainer {
     }
 
     @FlexDirection
+    @Override
     public int getFlexDirection() {
         return mFlexDirection;
     }
 
+    @Override
     public void setFlexDirection(@FlexDirection int flexDirection) {
         if (mFlexDirection != flexDirection) {
             mFlexDirection = flexDirection;
@@ -2129,10 +2133,12 @@ public class FlexboxLayout extends ViewGroup implements FlexContainer {
     }
 
     @FlexWrap
+    @Override
     public int getFlexWrap() {
         return mFlexWrap;
     }
 
+    @Override
     public void setFlexWrap(@FlexWrap int flexWrap) {
         if (mFlexWrap != flexWrap) {
             mFlexWrap = flexWrap;
@@ -2141,10 +2147,12 @@ public class FlexboxLayout extends ViewGroup implements FlexContainer {
     }
 
     @JustifyContent
+    @Override
     public int getJustifyContent() {
         return mJustifyContent;
     }
 
+    @Override
     public void setJustifyContent(@JustifyContent int justifyContent) {
         if (mJustifyContent != justifyContent) {
             mJustifyContent = justifyContent;
@@ -2153,10 +2161,12 @@ public class FlexboxLayout extends ViewGroup implements FlexContainer {
     }
 
     @AlignItems
+    @Override
     public int getAlignItems() {
         return mAlignItems;
     }
 
+    @Override
     public void setAlignItems(@AlignItems int alignItems) {
         if (mAlignItems != alignItems) {
             mAlignItems = alignItems;
@@ -2165,10 +2175,12 @@ public class FlexboxLayout extends ViewGroup implements FlexContainer {
     }
 
     @AlignContent
+    @Override
     public int getAlignContent() {
         return mAlignContent;
     }
 
+    @Override
     public void setAlignContent(@AlignContent int alignContent) {
         if (mAlignContent != alignContent) {
             mAlignContent = alignContent;
@@ -2182,6 +2194,7 @@ public class FlexboxLayout extends ViewGroup implements FlexContainer {
      * but used for the alignment along the cross axis).
      * Thus any changes of the returned list are not reflected to the original list.
      */
+    @Override
     public List<FlexLine> getFlexLines() {
         List<FlexLine> result = new ArrayList<>(mFlexLines.size());
         for (FlexLine flexLine : mFlexLines) {
@@ -2498,7 +2511,8 @@ public class FlexboxLayout extends ViewGroup implements FlexContainer {
             mFlexBasisPercent = a
                     .getFraction(R.styleable.FlexboxLayout_Layout_layout_flexBasisPercent, 1, 1,
                             FLEX_BASIS_PERCENT_DEFAULT);
-            mMinWidth = a.getDimensionPixelSize(R.styleable.FlexboxLayout_Layout_layout_minWidth, 0);
+            mMinWidth = a
+                    .getDimensionPixelSize(R.styleable.FlexboxLayout_Layout_layout_minWidth, 0);
             mMinHeight = a
                     .getDimensionPixelSize(R.styleable.FlexboxLayout_Layout_layout_minHeight, 0);
             mMaxWidth = a.getDimensionPixelSize(R.styleable.FlexboxLayout_Layout_layout_maxWidth,

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

@@ -25,6 +25,9 @@ import android.util.AttributeSet;
 import android.view.View;
 import android.view.ViewGroup;
 
+import java.util.ArrayList;
+import java.util.List;
+
 /**
  * LayoutManager for the {@link RecyclerView}. This class is intended to be used within a
  * {@link RecyclerView} and offers the same capabilities of measure/layout its children
@@ -61,6 +64,8 @@ public class FlexboxLayoutManager extends RecyclerView.LayoutManager implements
      */
     private int mAlignContent;
 
+    private List<FlexLine> mFlexLines = new ArrayList<>();
+
     private final FlexboxHelper mFlexboxHelper = new FlexboxHelper(this);
 
     /**
@@ -138,10 +143,12 @@ public class FlexboxLayoutManager extends RecyclerView.LayoutManager implements
     }
 
     @FlexDirection
+    @Override
     public int getFlexDirection() {
         return mFlexDirection;
     }
 
+    @Override
     public void setFlexDirection(@FlexDirection int flexDirection) {
         if (mFlexDirection != flexDirection) {
             mFlexDirection = flexDirection;
@@ -149,11 +156,13 @@ public class FlexboxLayoutManager extends RecyclerView.LayoutManager implements
         }
     }
 
+    @Override
     @FlexWrap
     public int getFlexWrap() {
         return mFlexWrap;
     }
 
+    @Override
     public void setFlexWrap(@FlexWrap int flexWrap) {
         if (mFlexWrap != flexWrap) {
             mFlexWrap = flexWrap;
@@ -162,10 +171,12 @@ public class FlexboxLayoutManager extends RecyclerView.LayoutManager implements
     }
 
     @JustifyContent
+    @Override
     public int getJustifyContent() {
         return mJustifyContent;
     }
 
+    @Override
     public void setJustifyContent(@JustifyContent int justifyContent) {
         if (mJustifyContent != justifyContent) {
             mJustifyContent = justifyContent;
@@ -174,10 +185,12 @@ public class FlexboxLayoutManager extends RecyclerView.LayoutManager implements
     }
 
     @AlignItems
+    @Override
     public int getAlignItems() {
         return mAlignItems;
     }
 
+    @Override
     public void setAlignItems(@AlignItems int alignItems) {
         if (mAlignItems != alignItems) {
             mAlignItems = alignItems;
@@ -186,10 +199,12 @@ public class FlexboxLayoutManager extends RecyclerView.LayoutManager implements
     }
 
     @AlignContent
+    @Override
     public int getAlignContent() {
         return mAlignContent;
     }
 
+    @Override
     public void setAlignContent(@AlignContent int alignContent) {
         if (mAlignContent != alignContent) {
             mAlignContent = alignContent;
@@ -197,6 +212,18 @@ public class FlexboxLayoutManager extends RecyclerView.LayoutManager implements
         }
     }
 
+    @Override
+    public List<FlexLine> getFlexLines() {
+        List<FlexLine> result = new ArrayList<>(mFlexLines.size());
+        for (FlexLine flexLine : mFlexLines) {
+            if (flexLine.getItemCount() == 0) {
+                continue;
+            }
+            result.add(flexLine);
+        }
+        return result;
+    }
+
     @Override
     public RecyclerView.LayoutParams generateDefaultLayoutParams() {
         return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);