Adding app grid layout with fastscroller.

- Adding filtering and using alphabetic index for app grouping.

Change-Id: I745b644fa8f90f5ff24a8642ac377ef1c65d8aff

1 files changed, 131 insertions, 0 deletions

diff --git a/src/com/android/launcher3/compat/AlphabeticIndexCompat.java b/src/com/android/launcher3/compat/AlphabeticIndexCompat.java
new file mode 100644
index 000000000..602a84566
--- /dev/null
+++ b/src/com/android/launcher3/compat/AlphabeticIndexCompat.java
@@ -0,0 +1,131 @@
+package com.android.launcher3.compat;
+
+import android.content.Context;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Method;
+import java.util.Locale;
+
+/**
+ * Fallback class to support Alphabetic indexing if not supported by the framework.
+ * TODO(winsonc): disable for non-english locales
+ */
+class BaseAlphabeticIndex {
+
+    private static final String BUCKETS = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ-";
+    private static final int UNKNOWN_BUCKET_INDEX = BUCKETS.length() - 1;
+
+    public BaseAlphabeticIndex() {}
+
+    /**
+     * Sets the max number of the label buckets in this index.
+     */
+    public void setMaxLabelCount(int count) {
+        // Not currently supported
+    }
+
+    /**
+     * Returns the index of the bucket in which the given string should appear.
+     */
+    public int getBucketIndex(String s) {
+        if (s.isEmpty()) {
+            return UNKNOWN_BUCKET_INDEX;
+        }
+        int index = BUCKETS.indexOf(s.substring(0, 1).toUpperCase());
+        if (index != -1) {
+            return index;
+        }
+        return UNKNOWN_BUCKET_INDEX;
+    }
+
+    /**
+     * Returns the label for the bucket at the given index (as returned by getBucketIndex).
+     */
+    public String getBucketLabel(int index) {
+        return BUCKETS.substring(index, index + 1);
+    }
+}
+
+/**
+ * Reflected libcore.icu.AlphabeticIndex implementation, falls back to the base alphabetic index.
+ */
+public class AlphabeticIndexCompat extends BaseAlphabeticIndex {
+
+    private Object mAlphabeticIndex;
+    private Method mAddLabelsMethod;
+    private Method mSetMaxLabelCountMethod;
+    private Method mGetBucketIndexMethod;
+    private Method mGetBucketLabelMethod;
+    private boolean mHasValidAlphabeticIndex;
+
+    public AlphabeticIndexCompat(Context context) {
+        super();
+        try {
+            Locale curLocale = context.getResources().getConfiguration().locale;
+            Class clazz = Class.forName("libcore.icu.AlphabeticIndex");
+            Constructor ctor = clazz.getConstructor(Locale.class);
+            mAddLabelsMethod = clazz.getDeclaredMethod("addLabels", Locale.class);
+            mSetMaxLabelCountMethod = clazz.getDeclaredMethod("setMaxLabelCount", int.class);
+            mGetBucketIndexMethod = clazz.getDeclaredMethod("getBucketIndex", String.class);
+            mGetBucketLabelMethod = clazz.getDeclaredMethod("getBucketLabel", int.class);
+            mAlphabeticIndex = ctor.newInstance(curLocale);
+            try {
+                // Ensure we always have some base English locale buckets
+                if (!curLocale.getLanguage().equals(new Locale("en").getLanguage())) {
+                    mAddLabelsMethod.invoke(mAlphabeticIndex, Locale.ENGLISH);
+                }
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+            mHasValidAlphabeticIndex = true;
+        } catch (Exception e) {
+            mHasValidAlphabeticIndex = false;
+        }
+    }
+
+    /**
+     * Sets the max number of the label buckets in this index.
+     * (ICU 51 default is 99)
+     */
+    public void setMaxLabelCount(int count) {
+        if (mHasValidAlphabeticIndex) {
+            try {
+                mSetMaxLabelCountMethod.invoke(mAlphabeticIndex, count);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        } else {
+            super.setMaxLabelCount(count);
+        }
+    }
+
+    /**
+     * Returns the index of the bucket in which {@param s} should appear.
+     * Function is synchronized because underlying routine walks an iterator
+     * whose state is maintained inside the index object.
+     */
+    public int getBucketIndex(String s) {
+        if (mHasValidAlphabeticIndex) {
+            try {
+                return (Integer) mGetBucketIndexMethod.invoke(mAlphabeticIndex, s);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+        return super.getBucketIndex(s);
+    }
+
+    /**
+     * Returns the label for the bucket at the given index (as returned by getBucketIndex).
+     */
+    public String getBucketLabel(int index) {
+        if (mHasValidAlphabeticIndex) {
+            try {
+                return (String) mGetBucketLabelMethod.invoke(mAlphabeticIndex, index);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+        return super.getBucketLabel(index);
+    }
+}