diff --git a/packages/SettingsLib/res/values/strings.xml b/packages/SettingsLib/res/values/strings.xml
index a2a3fd39128b6..fe3ef1a9b76bd 100644
--- a/packages/SettingsLib/res/values/strings.xml
+++ b/packages/SettingsLib/res/values/strings.xml
@@ -812,4 +812,18 @@
     <!-- HTTP proxy settings. The hint text field for the hostname. -->
     <string name="proxy_hostname_hint" translatable="false">proxy.example.com</string>
 
+    <!-- Description for the screen zoom level that makes interface elements small. [CHAR LIMIT=24] -->
+    <string name="screen_zoom_summary_small">Small</string>
+    <!-- Description for the device's default screen zoom level. [CHAR LIMIT=24] -->
+    <string name="screen_zoom_summary_default">Default</string>
+    <!-- Description for the screen zoom level that makes interface elements large. [CHAR LIMIT=24] -->
+    <string name="screen_zoom_summary_large">Large</string>
+    <!-- Description for the screen zoom level that makes interface elements larger. [CHAR LIMIT=24] -->
+    <string name="screen_zoom_summary_very_large">Larger</string>
+    <!-- Description for the screen zoom level that makes interface elements largest. [CHAR LIMIT=24] -->
+    <string name="screen_zoom_summary_extremely_large">Largest</string>
+    <!-- Description for a custom screen zoom level. This shows the requested display
+         density in raw pixels per inch rather than using a relative description. [CHAR LIMIT=24] -->
+    <string name="screen_zoom_summary_custom">Custom (<xliff:g id="densityDpi" example="160">%d</xliff:g>)</string>
+
 </resources>
diff --git a/packages/SettingsLib/src/com/android/settingslib/display/DisplayDensityUtils.java b/packages/SettingsLib/src/com/android/settingslib/display/DisplayDensityUtils.java
new file mode 100644
index 0000000000000..78d7c569fccd3
--- /dev/null
+++ b/packages/SettingsLib/src/com/android/settingslib/display/DisplayDensityUtils.java
@@ -0,0 +1,243 @@
+/*
+ * Copyright (C) 2015 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.settingslib.display;
+
+import com.android.settingslib.R;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.os.AsyncTask;
+import android.os.RemoteException;
+import android.util.DisplayMetrics;
+import android.util.Log;
+import android.util.MathUtils;
+import android.view.Display;
+import android.view.IWindowManager;
+import android.view.WindowManagerGlobal;
+
+import java.util.Arrays;
+
+/**
+ * Utility methods for working with display density.
+ */
+public class DisplayDensityUtils {
+    private static final String LOG_TAG = "DisplayDensityUtils";
+
+    /** Minimum increment between density scales. */
+    private static final float MIN_SCALE_INTERVAL = 0.09f;
+
+    /** Minimum density scale. This is available on all devices. */
+    private static final float MIN_SCALE = 0.85f;
+
+    /** Maximum density scale. The actual scale used depends on the device. */
+    private static final float MAX_SCALE = 1.50f;
+
+    /** Summary used for "default" scale. */
+    public static final int SUMMARY_DEFAULT = R.string.screen_zoom_summary_default;
+
+    /** Summary used for "custom" scale. */
+    private static final int SUMMARY_CUSTOM = R.string.screen_zoom_summary_custom;
+
+    /**
+     * Summaries for scales smaller than "default" in order of smallest to
+     * largest.
+     */
+    private static final int[] SUMMARIES_SMALLER = new int[] {
+            R.string.screen_zoom_summary_small
+    };
+
+    /**
+     * Summaries for scales larger than "default" in order of smallest to
+     * largest.
+     */
+    private static final int[] SUMMARIES_LARGER = new int[] {
+            R.string.screen_zoom_summary_large,
+            R.string.screen_zoom_summary_very_large,
+            R.string.screen_zoom_summary_extremely_large,
+    };
+
+    /**
+     * Minimum allowed screen dimension, corresponds to resource qualifiers
+     * "small" or "sw320dp". This value must be at least the minimum screen
+     * size required by the CDD so that we meet developer expectations.
+     */
+    private static final int MIN_DIMENSION_DP = 320;
+
+    private final String[] mEntries;
+    private final int[] mValues;
+
+    private final int mDefaultDensity;
+    private final int mCurrentIndex;
+
+    public DisplayDensityUtils(Context context) {
+        final int defaultDensity = DisplayDensityUtils.getDefaultDisplayDensity(
+                Display.DEFAULT_DISPLAY);
+        if (defaultDensity <= 0) {
+            mEntries = null;
+            mValues = null;
+            mDefaultDensity = 0;
+            mCurrentIndex = -1;
+            return;
+        }
+
+        final Resources res = context.getResources();
+        final DisplayMetrics metrics = res.getDisplayMetrics();
+        final int currentDensity = metrics.densityDpi;
+        int currentDensityIndex = -1;
+
+        // Compute number of "larger" and "smaller" scales for this display.
+        final int minDimensionPx = Math.min(metrics.widthPixels, metrics.heightPixels);
+        final int maxDensity = DisplayMetrics.DENSITY_MEDIUM * minDimensionPx / MIN_DIMENSION_DP;
+        final float maxScale = Math.min(MAX_SCALE, maxDensity / (float) defaultDensity);
+        final float minScale = MIN_SCALE;
+        final int numLarger = (int) MathUtils.constrain((maxScale - 1) / MIN_SCALE_INTERVAL,
+                0, SUMMARIES_LARGER.length);
+        final int numSmaller = (int) MathUtils.constrain((1 - minScale) / MIN_SCALE_INTERVAL,
+                0, SUMMARIES_SMALLER.length);
+
+        String[] entries = new String[1 + numSmaller + numLarger];
+        int[] values = new int[entries.length];
+        int curIndex = 0;
+
+        if (numSmaller > 0) {
+            final float interval = (1 - minScale) / numSmaller;
+            for (int i = numSmaller - 1; i >= 0; i--) {
+                // Round down to a multiple of 2 by truncating the low bit.
+                final int density = ((int) (defaultDensity * (1 - (i + 1) * interval))) & ~1;
+                if (currentDensity == density) {
+                    currentDensityIndex = curIndex;
+                }
+                entries[curIndex] = res.getString(SUMMARIES_SMALLER[i]);
+                values[curIndex] = density;
+                curIndex++;
+            }
+        }
+
+        if (currentDensity == defaultDensity) {
+            currentDensityIndex = curIndex;
+        }
+        values[curIndex] = defaultDensity;
+        entries[curIndex] = res.getString(SUMMARY_DEFAULT);
+        curIndex++;
+
+        if (numLarger > 0) {
+            final float interval = (maxScale - 1) / numLarger;
+            for (int i = 0; i < numLarger; i++) {
+                // Round down to a multiple of 2 by truncating the low bit.
+                final int density = ((int) (defaultDensity * (1 + (i + 1) * interval))) & ~1;
+                if (currentDensity == density) {
+                    currentDensityIndex = curIndex;
+                }
+                values[curIndex] = density;
+                entries[curIndex] = res.getString(SUMMARIES_LARGER[i]);
+                curIndex++;
+            }
+        }
+
+        final int displayIndex;
+        if (currentDensityIndex >= 0) {
+            displayIndex = currentDensityIndex;
+        } else {
+            // We don't understand the current density. Must have been set by
+            // someone else. Make room for another entry...
+            int newLength = values.length + 1;
+            values = Arrays.copyOf(values, newLength);
+            values[curIndex] = currentDensity;
+
+            entries = Arrays.copyOf(entries, newLength);
+            entries[curIndex] = res.getString(SUMMARY_CUSTOM, currentDensity);
+
+            displayIndex = curIndex;
+        }
+
+        mDefaultDensity = defaultDensity;
+        mCurrentIndex = displayIndex;
+        mEntries = entries;
+        mValues = values;
+    }
+
+    public String[] getEntries() {
+        return mEntries;
+    }
+
+    public int[] getValues() {
+        return mValues;
+    }
+
+    public int getCurrentIndex() {
+        return mCurrentIndex;
+    }
+
+    public int getDefaultDensity() {
+        return mDefaultDensity;
+    }
+
+    /**
+     * Returns the default density for the specified display.
+     *
+     * @param displayId the identifier of the display
+     * @return the default density of the specified display, or {@code -1} if
+     *         the display does not exist or the density could not be obtained
+     */
+    private static int getDefaultDisplayDensity(int displayId) {
+       try {
+           final IWindowManager wm = WindowManagerGlobal.getWindowManagerService();
+           return wm.getInitialDisplayDensity(displayId);
+       } catch (RemoteException exc) {
+           return -1;
+       }
+    }
+
+    /**
+     * Asynchronously applies display density changes to the specified display.
+     *
+     * @param displayId the identifier of the display to modify
+     */
+    public static void clearForcedDisplayDensity(final int displayId) {
+        AsyncTask.execute(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    final IWindowManager wm = WindowManagerGlobal.getWindowManagerService();
+                    wm.clearForcedDisplayDensity(displayId);
+                } catch (RemoteException exc) {
+                    Log.w(LOG_TAG, "Unable to clear forced display density setting");
+                }
+            }
+        });
+    }
+
+    /**
+     * Asynchronously applies display density changes to the specified display.
+     *
+     * @param displayId the identifier of the display to modify
+     * @param density the density to force for the specified display
+     */
+    public static void setForcedDisplayDensity(final int displayId, final int density) {
+        AsyncTask.execute(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    final IWindowManager wm = WindowManagerGlobal.getWindowManagerService();
+                    wm.setForcedDisplayDensity(displayId, density);
+                } catch (RemoteException exc) {
+                    Log.w(LOG_TAG, "Unable to save forced display density setting");
+                }
+            }
+        });
+    }
+}