feat:support ItemDecorations

lsjwzh · Jan 24, 2016 · 3211f78 · 3211f78
1 parent c0caee8
commit 3211f78
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Showing 5 changed files with 92 additions and 8 deletions.
diff --git a/app/src/main/java/com/lsjwzh/widget/recyclerviewpagerdeomo/MaterialDemoActivity.java b/app/src/main/java/com/lsjwzh/widget/recyclerviewpagerdeomo/MaterialDemoActivity.java
@@ -44,7 +44,7 @@ protected void initViewPager() {
         mRecyclerView.setAdapter(mAdapter);
         mRecyclerView.setHasFixedSize(true);
         mRecyclerView.setLongClickable(true);
-
+        mRecyclerView.addItemDecoration(new SpacesItemDecoration(50, mRecyclerView.getAdapter().getItemCount()));
         mRecyclerView.addOnPageChangedListener(new RecyclerViewPager.OnPageChangedListener() {
             @Override
             public void OnPageChanged(int oldPosition, int newPosition) {

diff --git a/app/src/main/java/com/lsjwzh/widget/recyclerviewpagerdeomo/SpacesItemDecoration.java b/app/src/main/java/com/lsjwzh/widget/recyclerviewpagerdeomo/SpacesItemDecoration.java
@@ -0,0 +1,31 @@
+package com.lsjwzh.widget.recyclerviewpagerdeomo;
+
+import android.graphics.Rect;
+import android.support.v7.widget.RecyclerView;
+import android.view.View;
+
+public class SpacesItemDecoration extends RecyclerView.ItemDecoration {
+    private final int mColumnCount;
+    private final int mSpace;
+
+    public SpacesItemDecoration(int space, int columnCount) {
+        this.mSpace = space;
+        this.mColumnCount = columnCount;
+    }
+
+    @Override
+    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
+        outRect.bottom = mSpace;
+        // Add top margin only for the first item to avoid double mSpace between items
+        if (parent.getChildLayoutPosition(view) == mColumnCount - 1) {
+            outRect.right = 0;
+        } else {
+            outRect.right = mSpace / 2;
+        }
+        if (parent.getChildLayoutPosition(view) == 0) {
+            outRect.left = 0;
+        } else {
+            outRect.left = mSpace / 2;
+        }
+    }
+}
diff --git a/app/src/main/res/layout/fragment_cheese_list.xml b/app/src/main/res/layout/fragment_cheese_list.xml
@@ -17,4 +17,4 @@
 <android.support.v7.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
         android:id="@+id/recyclerview"
         android:layout_width="match_parent"
-        android:layout_height="match_parent" />
+        android:layout_height="match_parent" />
diff --git a/lib/src/main/java/com/lsjwzh/widget/recyclerviewpager/RecyclerViewPager.java b/lib/src/main/java/com/lsjwzh/widget/recyclerviewpager/RecyclerViewPager.java
@@ -6,10 +6,12 @@
 
 import android.content.Context;
 import android.content.res.TypedArray;
+import android.graphics.PointF;
 import android.os.Build;
 import android.os.Parcelable;
 import android.support.annotation.NonNull;
 import android.support.v7.widget.LinearLayoutManager;
+import android.support.v7.widget.LinearSmoothScroller;
 import android.support.v7.widget.RecyclerView;
 import android.util.AttributeSet;
 import android.util.Log;
@@ -173,7 +175,54 @@ public void smoothScrollToPosition(int position) {
             Log.d("@", "smoothScrollToPosition:" + position);
         }
         mSmoothScrollTargetPosition = position;
-        super.smoothScrollToPosition(position);
+        if (getLayoutManager() != null && getLayoutManager() instanceof LinearLayoutManager) {
+            // exclude item decoration
+            LinearSmoothScroller linearSmoothScroller =
+                    new LinearSmoothScroller(getContext()) {
+                        @Override
+                        public PointF computeScrollVectorForPosition(int targetPosition) {
+                            if (getLayoutManager() == null) {
+                                return null;
+                            }
+                            return ((LinearLayoutManager) getLayoutManager())
+                                    .computeScrollVectorForPosition(targetPosition);
+                        }
+
+                        @Override
+                        protected void onTargetFound(View targetView, RecyclerView.State state, Action action) {
+                            if (getLayoutManager() == null) {
+                                return;
+                            }
+                            int dx = calculateDxToMakeVisible(targetView,
+                                    getHorizontalSnapPreference());
+                            int dy = calculateDyToMakeVisible(targetView,
+                                    getVerticalSnapPreference());
+                            if (dx > 0) {
+                                dx = dx - getLayoutManager()
+                                        .getLeftDecorationWidth(targetView);
+                            } else {
+                                dx = dx + getLayoutManager()
+                                        .getRightDecorationWidth(targetView);
+                            }
+                            if (dy > 0) {
+                                dy = dy - getLayoutManager()
+                                        .getTopDecorationHeight(targetView);
+                            } else {
+                                dy = dy + getLayoutManager()
+                                        .getBottomDecorationHeight(targetView);
+                            }
+                            final int distance = (int) Math.sqrt(dx * dx + dy * dy);
+                            final int time = calculateTimeForDeceleration(distance);
+                            if (time > 0) {
+                                action.update(-dx, -dy, time, mDecelerateInterpolator);
+                            }
+                        }
+                    };
+            linearSmoothScroller.setTargetPosition(position);
+            getLayoutManager().startSmoothScroll(linearSmoothScroller);
+        } else {
+            super.smoothScrollToPosition(position);
+        }
     }
 
     @Override
@@ -256,7 +305,7 @@ protected void adjustPositionX(int velocityX) {
                         else targetPosition++;
                     } else if (mTouchSpan < centerXChild.getWidth() * -mTriggerOffset && targetPosition != mViewPagerAdapter.getItemCount() - 1) {
                         if (!reverseLayout) targetPosition++;
-                        else targetPosition --;
+                        else targetPosition--;
                     }
                 }
             }
@@ -401,7 +450,7 @@ public void onScrollStateChanged(int state) {
                         // if user is tending to cancel paging action, don't perform position changing
                         if (spanX > mCurView.getWidth() * mTriggerOffset && mCurView.getLeft() >= mMaxLeftWhenDragging) {
                             if (!reverseLayout) targetPosition--;
-                            else targetPosition ++;
+                            else targetPosition++;
                         } else if (spanX < mCurView.getWidth() * -mTriggerOffset && mCurView.getLeft() <= mMinLeftWhenDragging) {
                             if (!reverseLayout) targetPosition++;
                             else targetPosition--;

diff --git a/tablayoutsupport/src/main/java/com/lsjwzh/widget/recyclerviewpager/TabLayoutSupport.java b/tablayoutsupport/src/main/java/com/lsjwzh/widget/recyclerviewpager/TabLayoutSupport.java
@@ -6,6 +6,7 @@
 import android.support.design.widget.TabLayout;
 import android.support.v7.widget.RecyclerView;
 import android.util.Log;
+import android.view.View;
 
 public class TabLayoutSupport {
 
@@ -76,9 +77,12 @@ public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
             final int pagerWidth = recyclerView.getWidth()
                     - recyclerView.getPaddingLeft()
                     - recyclerView.getPaddingRight();
-            int centerChildPosition = viewPager.getChildAdapterPosition(ViewUtils.getCenterXChild
-                    (viewPager));
-            float offset = mPagerLeftBeforeScroll - ViewUtils.getCenterXChild(viewPager).getLeft()
+            final View centerXChild = ViewUtils.getCenterXChild(viewPager);
+            if (centerXChild == null) {
+                return;
+            }
+            int centerChildPosition = viewPager.getChildAdapterPosition(centerXChild);
+            float offset = mPagerLeftBeforeScroll - centerXChild.getLeft()
                     + pagerWidth * (centerChildPosition - mPositionBeforeScroll);
             final float positionOffset = offset * 1f / pagerWidth;
             if (tabLayout != null) {