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.

1 files changed, 8 insertions, 0 deletions

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 @@ void DisplayHardware::init(uint32_t dpy)
         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);