1 files changed, 119 insertions, 0 deletions
diff --git a/java/com/android/contacts/common/list/ContactsSectionIndexer.java b/java/com/android/contacts/common/list/ContactsSectionIndexer.java
new file mode 100644
index 000000000..3f0f2b7ee
--- /dev/null
+++ b/java/com/android/contacts/common/list/ContactsSectionIndexer.java
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2010 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.contacts.common.list;
+
+import android.text.TextUtils;
+import android.widget.SectionIndexer;
+import java.util.Arrays;
+
+/**
+ * A section indexer that is configured with precomputed section titles and their respective counts.
+ */
+public class ContactsSectionIndexer implements SectionIndexer {
+
+  private static final String BLANK_HEADER_STRING = " ";
+  private String[] mSections;
+  private int[] mPositions;
+  private int mCount;
+
+  /**
+   * Constructor.
+   *
+   * @param sections a non-null array
+   * @param counts a non-null array of the same size as <code>sections</code>
+   */
+  public ContactsSectionIndexer(String[] sections, int[] counts) {
+    if (sections == null || counts == null) {
+      throw new NullPointerException();
+    }
+
+    if (sections.length != counts.length) {
+      throw new IllegalArgumentException(
+          "The sections and counts arrays must have the same length");
+    }
+
+    // TODO process sections/counts based on current locale and/or specific section titles
+
+    this.mSections = sections;
+    mPositions = new int[counts.length];
+    int position = 0;
+    for (int i = 0; i < counts.length; i++) {
+      if (TextUtils.isEmpty(mSections[i])) {
+        mSections[i] = BLANK_HEADER_STRING;
+      } else if (!mSections[i].equals(BLANK_HEADER_STRING)) {
+        mSections[i] = mSections[i].trim();
+      }
+
+      mPositions[i] = position;
+      position += counts[i];
+    }
+    mCount = position;
+  }
+
+  public Object[] getSections() {
+    return mSections;
+  }
+
+  public int getPositionForSection(int section) {
+    if (section < 0 || section >= mSections.length) {
+      return -1;
+    }
+
+    return mPositions[section];
+  }
+
+  public int getSectionForPosition(int position) {
+    if (position < 0 || position >= mCount) {
+      return -1;
+    }
+
+    int index = Arrays.binarySearch(mPositions, position);
+
+    /*
+     * Consider this example: section positions are 0, 3, 5; the supplied
+     * position is 4. The section corresponding to position 4 starts at
+     * position 3, so the expected return value is 1. Binary search will not
+     * find 4 in the array and thus will return -insertPosition-1, i.e. -3.
+     * To get from that number to the expected value of 1 we need to negate
+     * and subtract 2.
+     */
+    return index >= 0 ? index : -index - 2;
+  }
+
+  public void setProfileAndFavoritesHeader(String header, int numberOfItemsToAdd) {
+    if (mSections != null) {
+      // Don't do anything if the header is already set properly.
+      if (mSections.length > 0 && header.equals(mSections[0])) {
+        return;
+      }
+
+      // Since the section indexer isn't aware of the profile at the top, we need to add a
+      // special section at the top for it and shift everything else down.
+      String[] tempSections = new String[mSections.length + 1];
+      int[] tempPositions = new int[mPositions.length + 1];
+      tempSections[0] = header;
+      tempPositions[0] = 0;
+      for (int i = 1; i <= mPositions.length; i++) {
+        tempSections[i] = mSections[i - 1];
+        tempPositions[i] = mPositions[i - 1] + numberOfItemsToAdd;
+      }
+      mSections = tempSections;
+      mPositions = tempPositions;
+      mCount = mCount + numberOfItemsToAdd;
+    }
+  }
+}