Allow custom density setting

Use system property persist.sys.lcd_density to set custom density.  The
custom setting affects the entire UI.  It is independent of
ro.sf.lcd_density and has no effect on play store compatibility.

Code distilled from PA project via PAC project.

Change-Id: I8d26405d5d33bdf2890a0e9f67f113a4dc3e763b

3 files changed, 29 insertions, 9 deletions

diff --git a/core/java/android/content/res/Resources.java b/core/java/android/content/res/Resources.java
index f6a966b..77d3295 100644
--- a/core/java/android/content/res/Resources.java
+++ b/core/java/android/content/res/Resources.java
@@ -286,6 +286,7 @@ public class Resources {
             CompatibilityInfo compatInfo) {
         mAssets = assets;
         mMetrics.setToDefaults();
+        mMetrics.updateDensity();
         if (compatInfo != null) {
             mCompatibilityInfo = compatInfo;
         }
@@ -2123,6 +2124,7 @@ public class Resources {
             if (mConfiguration.densityDpi != Configuration.DENSITY_DPI_UNDEFINED) {
                 mMetrics.densityDpi = mConfiguration.densityDpi;
                 mMetrics.density = mConfiguration.densityDpi * DisplayMetrics.DENSITY_DEFAULT_SCALE;
+                mMetrics.updateDensity();
             }
             mMetrics.scaledDensity = mMetrics.density * mConfiguration.fontScale;
 
@@ -2552,7 +2554,7 @@ public class Resources {
             }
             sPreloaded = true;
             mPreloading = true;
-            sPreloadedDensity = DisplayMetrics.DENSITY_DEVICE;
+            sPreloadedDensity = DisplayMetrics.getDeviceDensity();
             mConfiguration.densityDpi = sPreloadedDensity;
             updateConfiguration(null, null);
         }
diff --git a/core/java/android/util/DisplayMetrics.java b/core/java/android/util/DisplayMetrics.java
index 9a69600..142c135 100644
--- a/core/java/android/util/DisplayMetrics.java
+++ b/core/java/android/util/DisplayMetrics.java
@@ -138,7 +138,15 @@ public class DisplayMetrics {
      * density for a display in {@link #densityDpi}.
      */
     @Deprecated
-    public static int DENSITY_DEVICE = getDeviceDensity();
+    public static int DENSITY_DEVICE;
+
+    public static int DENSITY_CURRENT;
+
+    static {
+        DENSITY_DEVICE = SystemProperties.getInt("qemu.sf.lcd_density", SystemProperties
+            .getInt("ro.sf.lcd_density", DENSITY_DEFAULT));
+        DENSITY_CURRENT = SystemProperties.getInt("persist.sys.lcd_density", DENSITY_DEVICE);
+    }
 
     /**
      * The absolute width of the display in pixels.
@@ -229,6 +237,19 @@ public class DisplayMetrics {
      */
     public float noncompatYdpi;
 
+    public void updateDensity() {
+        density = DENSITY_CURRENT / (float) DENSITY_DEFAULT;
+        densityDpi = DENSITY_CURRENT;
+        scaledDensity = density;
+        xdpi = DENSITY_CURRENT;
+        ydpi = DENSITY_CURRENT;
+        noncompatDensity = density;
+        noncompatDensityDpi = densityDpi;
+        noncompatScaledDensity = scaledDensity;
+        noncompatXdpi = xdpi;
+        noncompatYdpi = ydpi;
+    }
+
     public DisplayMetrics() {
     }
     
@@ -247,6 +268,7 @@ public class DisplayMetrics {
         noncompatScaledDensity = o.noncompatScaledDensity;
         noncompatXdpi = o.noncompatXdpi;
         noncompatYdpi = o.noncompatYdpi;
+        updateDensity();
     }
     
     public void setToDefaults() {
@@ -320,12 +342,7 @@ public class DisplayMetrics {
             ", xdpi=" + xdpi + ", ydpi=" + ydpi + "}";
     }
 
-    private static int getDeviceDensity() {
-        // qemu.sf.lcd_density can be used to override ro.sf.lcd_density
-        // when running in the emulator, allowing for dynamic configurations.
-        // The reason for this is that ro.sf.lcd_density is write-once and is
-        // set by the init process when it parses build.prop before anything else.
-        return SystemProperties.getInt("qemu.sf.lcd_density",
-                SystemProperties.getInt("ro.sf.lcd_density", DENSITY_DEFAULT));
+    public static int getDeviceDensity() {
+        return DENSITY_CURRENT;
     }
 }
diff --git a/core/java/android/view/DisplayInfo.java b/core/java/android/view/DisplayInfo.java
index cf17990..b07b9ec 100644
--- a/core/java/android/view/DisplayInfo.java
+++ b/core/java/android/view/DisplayInfo.java
@@ -505,6 +505,7 @@ public final class DisplayInfo implements Parcelable {
         outMetrics.scaledDensity = outMetrics.noncompatScaledDensity = outMetrics.density;
         outMetrics.xdpi = outMetrics.noncompatXdpi = physicalXDpi;
         outMetrics.ydpi = outMetrics.noncompatYdpi = physicalYDpi;
+        outMetrics.updateDensity();
 
         width = (configuration != null
                 && configuration.screenWidthDp != Configuration.SCREEN_WIDTH_DP_UNDEFINED)