Demo hack!

To make a 800 tall screen run like a 720:

adb shell setprop persist.demo.screensizehack 800=720

Note this is a persistent property, so it will (intentionally) remain across boots.

Change-Id: I8a8a9f937399327444e8fb154b91f0e642db116e

3 files changed, 37 insertions, 4 deletions

diff --git a/core/java/android/view/Display.java b/core/java/android/view/Display.java
index 34d7935..b748064 100644
--- a/core/java/android/view/Display.java
+++ b/core/java/android/view/Display.java
@@ -136,6 +136,11 @@ public class Display
         outMetrics.ydpi         = mDpiY;
     }
 
+    /**
+     * @hide Helper for our fake display size hack.
+     */
+    native public static int unmapDisplaySize(int newSize);
+    
     /*
      * We use a class initializer to allow the native code to cache some
      * field offsets.
diff --git a/core/jni/android_view_Display.cpp b/core/jni/android_view_Display.cpp
index 2e160ae..ac8835a 100644
--- a/core/jni/android_view_Display.cpp
+++ b/core/jni/android_view_Display.cpp
@@ -17,6 +17,8 @@
 #include <stdio.h>
 #include <assert.h>
 
+#include <cutils/properties.h>
+
 #include <surfaceflinger/SurfaceComposerClient.h>
 #include <ui/PixelFormat.h>
 #include <ui/DisplayInfo.h>
@@ -24,6 +26,7 @@
 #include "jni.h"
 #include <android_runtime/AndroidRuntime.h>
 #include <utils/misc.h>
+#include <utils/Log.h>
 
 // ----------------------------------------------------------------------------
 
@@ -41,6 +44,9 @@ struct offsets_t {
 };
 static offsets_t offsets;
 
+static int gOldSize = -1;
+static int gNewSize = -1;
+
 static void doThrow(JNIEnv* env, const char* exc, const char* msg = NULL)
 {
     jclass npeClazz = env->FindClass(exc);
@@ -69,14 +75,16 @@ static jint android_view_Display_getWidth(
         JNIEnv* env, jobject clazz)
 {
     DisplayID dpy = env->GetIntField(clazz, offsets.display);
-    return SurfaceComposerClient::getDisplayWidth(dpy);
+    jint w = SurfaceComposerClient::getDisplayWidth(dpy);
+    return w == gOldSize ? gNewSize : w;
 }
 
 static jint android_view_Display_getHeight(
         JNIEnv* env, jobject clazz)
 {
     DisplayID dpy = env->GetIntField(clazz, offsets.display);
-    return SurfaceComposerClient::getDisplayHeight(dpy);
+    int h = SurfaceComposerClient::getDisplayHeight(dpy);
+    return h == gOldSize ? gNewSize : h;
 }
 
 static jint android_view_Display_getOrientation(
@@ -92,6 +100,13 @@ static jint android_view_Display_getDisplayCount(
     return SurfaceComposerClient::getNumberOfDisplays();
 }
 
+static jint android_view_Display_unmapDisplaySize(
+        JNIEnv* env, jclass clazz, jint newSize)
+{
+    if (newSize == gNewSize) return gOldSize;
+    return newSize;
+}
+
 // ----------------------------------------------------------------------------
 
 const char* const kClassPathName = "android/view/Display";
@@ -110,7 +125,9 @@ static JNINativeMethod gMethods[] = {
     {   "getHeight", "()I",
             (void*)android_view_Display_getHeight },
     {   "getOrientation", "()I",
-            (void*)android_view_Display_getOrientation }
+            (void*)android_view_Display_getOrientation },
+    {   "unmapDisplaySize", "(I)I",
+            (void*)android_view_Display_unmapDisplaySize }
 };
 
 void nativeClassInit(JNIEnv* env, jclass clazz)
@@ -125,6 +142,16 @@ void nativeClassInit(JNIEnv* env, jclass clazz)
 
 int register_android_view_Display(JNIEnv* env)
 {
+    char buf[PROPERTY_VALUE_MAX];
+    int len = property_get("persist.demo.screensizehack", buf, "");
+    if (len > 0) {
+        int temp1, temp2;
+        if (sscanf(buf, "%d=%d", &temp1, &temp2) == 2) {
+            gOldSize = temp1;
+            gNewSize = temp2;
+        }
+    }
+
     return AndroidRuntime::registerNativeMethods(env,
             kClassPathName, gMethods, NELEM(gMethods));
 }
diff --git a/services/java/com/android/server/WindowManagerService.java b/services/java/com/android/server/WindowManagerService.java
index 26dd692..748f2e9 100644
--- a/services/java/com/android/server/WindowManagerService.java
+++ b/services/java/com/android/server/WindowManagerService.java
@@ -6239,7 +6239,8 @@ public class WindowManagerService extends IWindowManager.Stub
             mDisplay = wm.getDefaultDisplay();
             mInitialDisplayWidth = mDisplay.getWidth();
             mInitialDisplayHeight = mDisplay.getHeight();
-            mInputManager.setDisplaySize(0, mInitialDisplayWidth, mInitialDisplayHeight);
+            mInputManager.setDisplaySize(0, Display.unmapDisplaySize(mInitialDisplayWidth),
+                    Display.unmapDisplaySize(mInitialDisplayHeight));
         }
 
         try {