Allow the qemu.sf.lcd_density property to override the value of ro.sf.lcd_density
ro.sf.lcd_density is usually defined in the build.prop file which is parsed by init
before anything else. Since its name begins with "ro.", this property is write-once
and cannot later be modified, e.g. in /system/etc/init.goldfish.sh.
In other words, you cannot use "emulator -prop ro.sf.lcd_density=<value>", since
it is impossible to override the value defined in build.prop
This patch modifies the system to recognize "qemu.sf.lcd_density" as an override
value, which can be set with "emulator -prop qemu.sf.lcd_density=<value>", forcing
a specific density.
A later patch will allow the emulator to automatically set this property depending
on AVD hardware configuration settings.
diff --git a/core/java/android/util/DisplayMetrics.java b/core/java/android/util/DisplayMetrics.java
index 245148d..a095913 100644
--- a/core/java/android/util/DisplayMetrics.java
+++ b/core/java/android/util/DisplayMetrics.java
@@ -37,8 +37,7 @@
* The device's density.
* @hide
*/
- public static final int DEVICE_DENSITY = SystemProperties.getInt("ro.sf.lcd_density",
- DEFAULT_DENSITY);
+ public static final int DEVICE_DENSITY = getDeviceDensity();
/**
* The absolute width of the display in pixels.
@@ -161,4 +160,13 @@
", height=" + heightPixels + ", scaledDensity=" + scaledDensity +
", 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", DEFAULT_DENSITY));
+ }
}
diff --git a/libs/surfaceflinger/DisplayHardware/DisplayHardware.cpp b/libs/surfaceflinger/DisplayHardware/DisplayHardware.cpp
index f14d7e9..971189f 100644
--- a/libs/surfaceflinger/DisplayHardware/DisplayHardware.cpp
+++ b/libs/surfaceflinger/DisplayHardware/DisplayHardware.cpp
@@ -193,6 +193,14 @@
LOGW("ro.sf.lcd_density not defined, using 160 dpi by default.");
strcpy(property, "160");
}
+
+ /* Override the property value if qemu.sf.lcd_density is defined. */
+ {
+ char qemu_property[PROPERTY_VALUE_MAX];
+ if (property_get("qemu.sf.lcd_density", qemu_property, NULL) > 0) {
+ strlcpy(property, qemu_property, sizeof property);
+ }
+ }
mDensity = atoi(property) * (1.0f/160.0f);