Library setup

.gitignore

@@ -1,6 +1,7 @@
 .gradle
 .idea
 build/
+*.iml
 
 # Ignore Gradle GUI config
 gradle-app.setting

build.gradle

@@ -0,0 +1,18 @@
+buildscript {
+    repositories {
+        mavenCentral()
+    }
+    dependencies {
+        classpath 'com.android.tools.build:gradle:0.12.+'
+    }
+}
+def isReleaseBuild() {
+    return version.contains("SNAPSHOT") == false
+}
+allprojects {
+    version = VERSION_NAME
+    group = GROUP
+    repositories {
+        mavenCentral()
+    }
+}

gradle.properties

@@ -0,0 +1,3 @@
+
+VERSION_NAME=0.1.0
+GROUP=com.eowise

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Mon Sep 22 01:04:39 CEST 2014
+#Mon Sep 22 01:26:00 CEST 2014
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.0-bin.zip
+distributionUrl=http\://services.gradle.org/distributions/gradle-1.12-all.zip

library/.gitignore

@@ -0,0 +1,2 @@
+build/
+*.iml

library/build.gradle

@@ -0,0 +1,10 @@
+apply plugin: 'com.android.library'
+
+dependencies {
+    compile 'com.android.support:recyclerview-v7:+'
+}
+
+android {
+    compileSdkVersion 'android-L'
+    buildToolsVersion '20.0.0'
+}

library/src/main/AndroidManifest.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.eowise.recyclerview.stickyheaders">
+
+</manifest>

library/src/main/java/com/eowise/recyclerview/stickyheaders/StickyHeadersAdapter.java

@@ -0,0 +1,12 @@
+package com.eowise.recyclerview.stickyheaders;
+
+import android.view.ViewGroup;
+
+public interface StickyHeadersAdapter<ItemViewHolder extends android.support.v7.widget.RecyclerView.ViewHolder, HeaderViewHolder extends android.support.v7.widget.RecyclerView.ViewHolder> {
+
+    HeaderViewHolder onCreateViewHolder(ViewGroup parent);
+
+    void onBindViewHolder(HeaderViewHolder headerViewHolder, ItemViewHolder itemViewHolder, int position);
+
+    long getHeaderId(ItemViewHolder viewHolder, int position);
+}

library/src/main/java/com/eowise/recyclerview/stickyheaders/StickyHeadersItemDecoration.java

@@ -0,0 +1,62 @@
+package com.eowise.recyclerview.stickyheaders;
+
+import android.graphics.Canvas;
+import android.graphics.Rect;
+import android.support.v7.widget.RecyclerView;
+import android.view.View;
+import android.view.ViewGroup;
+
+/**
+ * Created by aurel on 22/09/14.
+ */
+public class StickyHeadersItemDecoration extends RecyclerView.ItemDecoration {
+
+    private final StickyHeadersAdapter adapter;
+    private final RecyclerView.ViewHolder headerViewHolder;
+
+    private final int itemHeight;
+
+    public StickyHeadersItemDecoration(StickyHeadersAdapter adapter, RecyclerView parent) {
+        this.adapter = adapter;
+        this.headerViewHolder = adapter.onCreateViewHolder(parent);
+
+        int widthSpec = View.MeasureSpec.makeMeasureSpec(ViewGroup.LayoutParams.MATCH_PARENT, View.MeasureSpec.AT_MOST);
+        int heightSpec = View.MeasureSpec.makeMeasureSpec(ViewGroup.LayoutParams.WRAP_CONTENT, View.MeasureSpec.UNSPECIFIED);
+        headerViewHolder.itemView.measure(widthSpec, heightSpec);
+        itemHeight = headerViewHolder.itemView.getMeasuredHeight();
+    }
+
+    @Override
+    public void onDrawOver(Canvas c, RecyclerView parent) {
+        final int childCount = parent.getChildCount();
+        View header = headerViewHolder.itemView;
+
+        if (!header.isLaidOut()) {
+            int widthSpec = View.MeasureSpec.makeMeasureSpec(parent.getWidth(), View.MeasureSpec.EXACTLY);
+            int heightSpec = View.MeasureSpec.makeMeasureSpec(ViewGroup.LayoutParams.WRAP_CONTENT, View.MeasureSpec.UNSPECIFIED);
+            header.measure(widthSpec, heightSpec);
+            header.layout(0, 0, header.getMeasuredWidth(), header.getMeasuredHeight());
+        }
+
+        for (int i = 0; i < childCount; i++) {
+            final View child = parent.getChildAt(i);
+            float y = child.getY() < itemHeight ? 0 : child.getY() - itemHeight;
+            y = child.getY() + child.getHeight() < itemHeight ? y - (itemHeight - (child.getY() + child.getHeight())) : y;
+            final RecyclerView.ViewHolder itemViewHolder = parent.getChildViewHolder(child);
+
+            adapter.onBindViewHolder(headerViewHolder, itemViewHolder, itemViewHolder.getPosition());
+
+            c.save();
+            c.translate(0, y);
+            header.draw(c);
+            c.restore();
+        }
+    }
+
+    @Override
+    public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) {
+
+        outRect.set(0, itemHeight, 0, 0);
+    }
+
+}

settings.gradle

@@ -0,0 +1 @@
+include 'library'