Update RecyclerView sample to show use of ItemDecoration
Add dividers between list items. These modify the space allocated for
each item.
Change-Id: I995a172ed0b6acef6b84faaa50c02f0ae8db1002
diff --git a/samples/Support7Demos/src/com/example/android/supportv7/widget/RecyclerViewActivity.java b/samples/Support7Demos/src/com/example/android/supportv7/widget/RecyclerViewActivity.java
index 6eba43d..5692cb8 100644
--- a/samples/Support7Demos/src/com/example/android/supportv7/widget/RecyclerViewActivity.java
+++ b/samples/Support7Demos/src/com/example/android/supportv7/widget/RecyclerViewActivity.java
@@ -20,16 +20,20 @@
import android.R;
import android.app.Activity;
import android.content.Context;
+import android.content.res.TypedArray;
+import android.graphics.Canvas;
+import android.graphics.Rect;
+import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.support.v4.view.MenuItemCompat;
import android.support.v7.widget.RecyclerView;
import android.util.DisplayMetrics;
+import android.util.Log;
import android.util.TypedValue;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
-import android.view.View.MeasureSpec;
import android.widget.TextView;
import com.example.android.supportv7.Cheeses;
@@ -37,6 +41,8 @@
import java.util.Collections;
public class RecyclerViewActivity extends Activity {
+ private static final String TAG = "RecyclerViewActivity";
+
private RecyclerView mRecyclerView;
@Override
@@ -49,6 +55,9 @@
rv.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT));
rv.setAdapter(new MyAdapter(Cheeses.sCheeseStrings));
+
+ rv.addItemDecoration(new DividerItemDecoration(this));
+
setContentView(rv);
mRecyclerView = rv;
@@ -105,8 +114,8 @@
View v = recycler.getViewForPosition(adapter, mFirstPosition + i);
addView(v, i);
measureChildWithMargins(v, 0, 0);
- bottom = top + v.getMeasuredHeight();
- v.layout(left, top, right, bottom);
+ bottom = top + getDecoratedMeasuredHeight(v);
+ layoutDecorated(v, left, top, right, bottom);
}
removeAndRecycleScrap(recycler);
@@ -136,7 +145,7 @@
if (dy < 0) {
while (scrolled > dy) {
final View topView = getChildAt(0);
- final int hangingTop = Math.max(-topView.getTop(), 0);
+ final int hangingTop = Math.max(-getDecoratedTop(topView), 0);
final int scrollBy = Math.min(scrolled - dy, hangingTop);
scrolled -= scrollBy;
offsetChildrenVertical(scrollBy);
@@ -145,9 +154,9 @@
View v = recycler.getViewForPosition(adapter, mFirstPosition);
addView(v, 0);
measureChildWithMargins(v, 0, 0);
- final int bottom = topView.getTop(); // TODO decorated top?
- final int top = bottom - v.getMeasuredHeight();
- v.layout(left, top, right, bottom);
+ final int bottom = getDecoratedTop(topView);
+ final int top = bottom - getDecoratedMeasuredHeight(v);
+ layoutDecorated(v, left, top, right, bottom);
} else {
break;
}
@@ -156,18 +165,19 @@
final int parentHeight = getHeight();
while (scrolled < dy) {
final View bottomView = getChildAt(getChildCount() - 1);
- final int hangingBottom = Math.max(bottomView.getBottom() - parentHeight, 0);
+ final int hangingBottom =
+ Math.max(getDecoratedBottom(bottomView) - parentHeight, 0);
final int scrollBy = -Math.min(dy - scrolled, hangingBottom);
scrolled -= scrollBy;
offsetChildrenVertical(scrollBy);
if (scrolled < dy && getItemCount() > mFirstPosition + getChildCount()) {
View v = recycler.getViewForPosition(adapter,
mFirstPosition + getChildCount());
- final int top = getChildAt(getChildCount() - 1).getBottom();
+ final int top = getDecoratedBottom(getChildAt(getChildCount() - 1));
addView(v);
measureChildWithMargins(v, 0, 0);
- final int bottom = top + v.getMeasuredHeight();
- v.layout(left, top, right, bottom);
+ final int bottom = top + getDecoratedMeasuredHeight(v);
+ layoutDecorated(v, left, top, right, bottom);
} else {
break;
}
@@ -195,11 +205,11 @@
while (mFirstPosition > 0 && newViewsHeight < mScrollDistance) {
mFirstPosition--;
View v = recycler.getViewForPosition(adapter, mFirstPosition);
- final int bottom = getChildAt(0).getTop(); // TODO decorated top?
+ final int bottom = getDecoratedTop(getChildAt(0));
addView(v, 0);
measureChildWithMargins(v, 0, 0);
- final int top = bottom - v.getMeasuredHeight();
- v.layout(left, top, right, bottom);
+ final int top = bottom - getDecoratedMeasuredHeight(v);
+ layoutDecorated(v, left, top, right, bottom);
if (v.isFocusable()) {
toFocus = v;
break;
@@ -210,11 +220,11 @@
while (mFirstPosition + getChildCount() < getItemCount() &&
newViewsHeight < mScrollDistance) {
View v = recycler.getViewForPosition(adapter, mFirstPosition + getChildCount());
- final int top = getChildAt(getChildCount() - 1).getBottom();
+ final int top = getDecoratedBottom(getChildAt(getChildCount() - 1));
addView(v);
measureChildWithMargins(v, 0, 0);
- final int bottom = top + v.getMeasuredHeight();
- v.layout(left, top, right, bottom);
+ final int bottom = top + getDecoratedMeasuredHeight(v);
+ layoutDecorated(v, left, top, right, bottom);
if (v.isFocusable()) {
toFocus = v;
break;
@@ -234,8 +244,10 @@
int last = 0;
for (int i = 0; i < childCount; i++) {
final View v = getChildAt(i);
- if (v.hasFocus() || (v.getRight() >= 0 && v.getLeft() <= parentWidth &&
- v.getBottom() >= 0 && v.getTop() <= parentHeight)) {
+ if (v.hasFocus() || (getDecoratedRight(v) >= 0 &&
+ getDecoratedLeft(v) <= parentWidth &&
+ getDecoratedBottom(v) >= 0 &&
+ getDecoratedTop(v) <= parentHeight)) {
if (!foundFirst) {
first = i;
foundFirst = true;
@@ -316,4 +328,42 @@
return super.toString() + " '" + textView.getText();
}
}
+
+ static class DividerItemDecoration extends RecyclerView.ItemDecoration {
+ private static final int[] ATTRS = new int[] {
+ R.attr.listDivider
+ };
+
+ private Drawable mDivider;
+
+ public DividerItemDecoration(Context context) {
+ final TypedArray a = context.obtainStyledAttributes(ATTRS);
+ mDivider = a.getDrawable(0);
+ a.recycle();
+ }
+
+ public DividerItemDecoration(Drawable divider) {
+ mDivider = divider;
+ }
+
+ @Override
+ public void onDraw(Canvas c, RecyclerView parent) {
+ final int left = parent.getPaddingLeft();
+ final int right = parent.getWidth() - parent.getPaddingRight();
+
+ final int childCount = parent.getChildCount();
+ for (int i = 0; i < childCount; i++) {
+ final View child = parent.getChildAt(i);
+ final int top = child.getBottom();
+ final int bottom = top + mDivider.getIntrinsicHeight();
+ mDivider.setBounds(left, top, right, bottom);
+ mDivider.draw(c);
+ }
+ }
+
+ @Override
+ public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
+ outRect.set(0, 0, 0, mDivider.getIntrinsicHeight());
+ }
+ }
}
