Add dev options to set swXdp

Change-Id: Ibe88e2b1a2e818838baf452b6da204fc9e004a42
Fixes: 27734698

res/values/strings.xml

@@ -7364,4 +7364,10 @@
     <!-- Summary of notification suggestion during optional steps of setup. [CHAR_LIMIT=80] -->
     <string name="notification_suggestion_summary">Show or hide notification content</string>
 
+    <!-- Summary of developer options to set the smallest width of the screen [CHAR LIMIT=60]-->
+    <string name="developer_density_summary"><xliff:g name="count" example="320">%d</xliff:g> dp</string>
+
+    <!-- Title of developer options to set the smallest width of the screen [CHAR LIMIT=60]-->
+    <string name="developer_smallest_width">Smallest width</string>
+
 </resources>

res/xml/development_prefs.xml

@@ -239,6 +239,10 @@
             android:entries="@array/overlay_display_devices_entries"
             android:entryValues="@array/overlay_display_devices_values" />
 
+        <com.android.settings.display.DensityPreference
+            android:key="density"
+            android:title="@string/developer_smallest_width" />
+
     </PreferenceCategory>
 
     <PreferenceCategory android:key="debug_hw_drawing_category"

src/com/android/settings/CustomEditTextPreference.java

@@ -105,6 +105,7 @@ public class CustomEditTextPreference extends EditTextPreference {
 
         @Override
         public void onDialogClosed(boolean positiveResult) {
+            super.onDialogClosed(positiveResult);
             getCustomizablePreference().onDialogClosed(positiveResult);
         }
 

src/com/android/settings/display/DensityPreference.java

@@ -0,0 +1,74 @@
+/*
+ * 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.settings.display;
+
+import android.content.Context;
+import android.content.res.Resources;
+import android.text.InputType;
+import android.util.AttributeSet;
+import android.util.DisplayMetrics;
+import android.view.Display;
+import android.view.View;
+import android.widget.EditText;
+import com.android.settings.CustomEditTextPreference;
+import com.android.settings.R;
+import com.android.settingslib.display.DisplayDensityUtils;
+
+public class DensityPreference extends CustomEditTextPreference {
+
+    public DensityPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    @Override
+    public void onAttached() {
+        super.onAttached();
+
+        setSummary(getContext().getString(R.string.developer_density_summary, getCurrentSwDp()));
+    }
+
+    private int getCurrentSwDp() {
+        final Resources res = getContext().getResources();
+        final DisplayMetrics metrics = res.getDisplayMetrics();
+        final float density = metrics.density;
+        final int minDimensionPx = Math.min(metrics.widthPixels, metrics.heightPixels);
+        return (int) (minDimensionPx / density);
+    }
+
+    @Override
+    protected void onBindDialogView(View view) {
+        super.onBindDialogView(view);
+
+        final EditText editText = (EditText) view.findViewById(android.R.id.edit);
+
+        if (editText != null) {
+            editText.setInputType(InputType.TYPE_CLASS_NUMBER);
+            editText.setText(getCurrentSwDp() + "");
+        }
+    }
+
+    @Override
+    protected void onDialogClosed(boolean positiveResult) {
+        if (positiveResult) {
+            final Resources res = getContext().getResources();
+            final DisplayMetrics metrics = res.getDisplayMetrics();
+            final int newSwDp = Math.max(Integer.parseInt(getText()), 320);
+            final int minDimensionPx = Math.min(metrics.widthPixels, metrics.heightPixels);
+            final int newDensity = DisplayMetrics.DENSITY_MEDIUM * minDimensionPx / newSwDp;
+            final int densityDpi = Math.max(newDensity, 120);
+            DisplayDensityUtils.setForcedDisplayDensity(Display.DEFAULT_DISPLAY, densityDpi);
+        }
+    }
+}