1 files changed, 81 insertions, 0 deletions
diff --git a/setupwizardlib/src/main/java/com/android/setupwizardlib/util/ListViewRequireScrollHelper.java b/setupwizardlib/src/main/java/com/android/setupwizardlib/util/ListViewRequireScrollHelper.java
new file mode 100644
index 0000000..7877569
--- /dev/null
+++ b/setupwizardlib/src/main/java/com/android/setupwizardlib/util/ListViewRequireScrollHelper.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * 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.
+ */
+
+package com.android.setupwizardlib.util;
+
+import android.os.Build;
+import android.widget.AbsListView;
+import android.widget.ListAdapter;
+import android.widget.ListView;
+
+import com.android.setupwizardlib.view.NavigationBar;
+
+/**
+ * Add this helper to require the list view to be scrolled to the bottom, making sure that the
+ * user sees all content on the screen. This will change the navigation bar to show the more button
+ * instead of the next button when there is more content to be seen. When the more button is
+ * clicked, the list view will be scrolled one page down.
+ */
+public class ListViewRequireScrollHelper extends AbstractRequireScrollHelper
+        implements AbsListView.OnScrollListener {
+
+    public static void requireScroll(NavigationBar navigationBar, ListView listView) {
+        new ListViewRequireScrollHelper(navigationBar, listView).requireScroll();
+    }
+
+    private final ListView mListView;
+
+    private ListViewRequireScrollHelper(NavigationBar navigationBar, ListView listView) {
+        super(navigationBar);
+        mListView = listView;
+    }
+
+    @Override
+    protected void requireScroll() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.FROYO) {
+            // APIs to scroll a list only exists on Froyo or above.
+            super.requireScroll();
+            mListView.setOnScrollListener(this);
+
+            final ListAdapter adapter = mListView.getAdapter();
+            if (mListView.getLastVisiblePosition() < adapter.getCount()) {
+                notifyRequiresScroll();
+            }
+        }
+    }
+
+    @Override
+    protected void pageScrollDown() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.FROYO) {
+            final int height = mListView.getHeight();
+            mListView.smoothScrollBy(height, 500);
+        }
+    }
+
+    @Override
+    public void onScrollStateChanged(AbsListView view, int scrollState) {
+    }
+
+    @Override
+    public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount,
+            int totalItemCount) {
+        if (firstVisibleItem + visibleItemCount >= totalItemCount) {
+            notifyScrolledToBottom();
+        } else {
+            notifyRequiresScroll();
+        }
+    }
+}