From aa8b0d74f4f4e14c3591582bad7baead0d30e655 Mon Sep 17 00:00:00 2001
From: Svetoslav Ganov <svetoslavganov@google.com>
Date: Tue, 1 Mar 2016 14:12:43 -0800
Subject: [PATCH] API for safe label to present in the UI

bug:23531798

Change-Id: Ic3e0ed3db11445dbc5e562ca1a91b181ec5f2553
---
 api/system-current.txt                        |  1 +
 .../android/content/pm/PackageItemInfo.java   | 56 +++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/api/system-current.txt b/api/system-current.txt
index 61a8953516c8c..589bb5f859983 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -9955,6 +9955,7 @@ package android.content.pm {
     method public android.graphics.drawable.Drawable loadIcon(android.content.pm.PackageManager);
     method public java.lang.CharSequence loadLabel(android.content.pm.PackageManager);
     method public android.graphics.drawable.Drawable loadLogo(android.content.pm.PackageManager);
+    method public java.lang.CharSequence loadSafeLabel(android.content.pm.PackageManager);
     method public android.graphics.drawable.Drawable loadUnbadgedIcon(android.content.pm.PackageManager);
     method public android.content.res.XmlResourceParser loadXmlMetaData(android.content.pm.PackageManager, java.lang.String);
     method public void writeToParcel(android.os.Parcel, int);
diff --git a/core/java/android/content/pm/PackageItemInfo.java b/core/java/android/content/pm/PackageItemInfo.java
index 4df83036daaf5..edd888b33b1e6 100644
--- a/core/java/android/content/pm/PackageItemInfo.java
+++ b/core/java/android/content/pm/PackageItemInfo.java
@@ -16,12 +16,16 @@
 
 package android.content.pm;
 
+import android.annotation.NonNull;
+import android.annotation.SystemApi;
 import android.content.res.XmlResourceParser;
 
 import android.graphics.drawable.Drawable;
 import android.os.Bundle;
 import android.os.Parcel;
 import android.os.UserHandle;
+import android.text.BidiFormatter;
+import android.text.TextPaint;
 import android.text.TextUtils;
 import android.util.Printer;
 
@@ -38,6 +42,8 @@ import java.util.Comparator;
  * in the implementation of Parcelable in subclasses.
  */
 public class PackageItemInfo {
+    private static final float MAX_LABEL_SIZE_PX = 500f;
+
     /**
      * Public name of this item. From the "android:name" attribute.
      */
@@ -139,6 +145,56 @@ public class PackageItemInfo {
         return packageName;
     }
 
+    /**
+     * Same as {@link #loadLabel(PackageManager)} with the addition that
+     * the returned label is safe for being presented in the UI since it
+     * will not contain new lines and the length will be limited to a
+     * reasonable amount. This prevents a malicious party to influence UI
+     * layout via the app label misleading the user into performing a
+     * detrimental for them action. If the label is too long it will be
+     * truncated and ellipsized at the end.
+     *
+     * @param pm A PackageManager from which the label can be loaded; usually
+     * the PackageManager from which you originally retrieved this item
+     * @return Returns a CharSequence containing the item's label. If the
+     * item does not have a label, its name is returned.
+     *
+     * @hide
+     */
+    @SystemApi
+    public @NonNull CharSequence loadSafeLabel(@NonNull PackageManager pm) {
+        // loadLabel() always returns non-null
+        CharSequence label = loadLabel(pm);
+
+        // If the label contains new line characters it may push the UI
+        // down to hide a part of it. Labels shouldn't have new line
+        // characters, so just truncate at the first time one is seen.
+        String labelStr = label.toString();
+        final int labelLength = labelStr.length();
+        int offset = 0;
+        while (offset < labelLength) {
+            final int codePoint = labelStr.codePointAt(offset);
+            final int type = Character.getType(codePoint);
+            if (type == Character.LINE_SEPARATOR
+                    || type == Character.CONTROL
+                    || type == Character.PARAGRAPH_SEPARATOR) {
+                labelStr = labelStr.substring(0, offset);
+                break;
+            }
+            offset += Character.charCount(codePoint);
+        }
+
+        if (labelStr.isEmpty()) {
+            return labelStr;
+        }
+
+        TextPaint paint = new TextPaint();
+        paint.setTextSize(42);
+
+        return TextUtils.ellipsize(labelStr, paint, MAX_LABEL_SIZE_PX,
+                TextUtils.TruncateAt.END);
+    }
+
     /**
      * Retrieve the current graphical icon associated with this item.  This
      * will call back on the given PackageManager to load the icon from