copy android.widget.Scroller from AOSP and implement missing scroll APIs

This is needed to make ViewPager functional

src/api-impl-jni/util.c

@@ -116,6 +116,9 @@ void set_up_handle_cache(JNIEnv *env)
 	handle_cache.view.getSuggestedMinimumHeight = _METHOD(handle_cache.view.class, "getSuggestedMinimumHeight", "()I");
 	handle_cache.view.setMeasuredDimension = _METHOD(handle_cache.view.class, "setMeasuredDimension", "(II)V");
 	handle_cache.view.onGenericMotionEvent = _METHOD(handle_cache.view.class, "onGenericMotionEvent", "(Landroid/view/MotionEvent;)Z");
+	handle_cache.view.computeScroll = _METHOD(handle_cache.view.class, "computeScroll", "()V");
+	handle_cache.view.getScrollX = _METHOD(handle_cache.view.class, "getScrollX", "()I");
+	handle_cache.view.getScrollY = _METHOD(handle_cache.view.class, "getScrollY", "()I");
 
 	handle_cache.asset_manager.class = _REF((*env)->FindClass(env, "android/content/res/AssetManager"));
 	handle_cache.asset_manager.extractFromAPK = _STATIC_METHOD(handle_cache.asset_manager.class, "extractFromAPK", "(Ljava/lang/String;Ljava/lang/String;)V");

src/api-impl-jni/util.h

@@ -77,6 +77,9 @@ struct handle_cache {
 		jmethodID getSuggestedMinimumHeight;
 		jmethodID setMeasuredDimension;
 		jmethodID onGenericMotionEvent;
+		jmethodID computeScroll;
+		jmethodID getScrollX;
+		jmethodID getScrollY;
 	} view;
 	struct {
 		jclass class;

src/api-impl-jni/views/android_view_ViewGroup.c

@@ -45,7 +45,13 @@ static void android_layout_allocate(GtkLayoutManager *layout_manager, GtkWidget
 	if((*env)->ExceptionCheck(env))
 		(*env)->ExceptionDescribe(env);
 
-	(*env)->CallVoidMethod(env, layout->view, handle_cache.view.onLayout, TRUE, 0, 0, width, height);
+	(*env)->CallVoidMethod(env, layout->view, handle_cache.view.computeScroll);
+	if((*env)->ExceptionCheck(env))
+		(*env)->ExceptionDescribe(env);
+	int scroll_x = (*env)->CallIntMethod(env, layout->view, handle_cache.view.getScrollX);
+	int scroll_y = (*env)->CallIntMethod(env, layout->view, handle_cache.view.getScrollY);
+
+	(*env)->CallVoidMethod(env, layout->view, handle_cache.view.onLayout, TRUE, scroll_x, scroll_y, width, height);
 	if((*env)->ExceptionCheck(env))
 		(*env)->ExceptionDescribe(env);
 }

src/api-impl/android/hardware/SensorManager.java

@@ -6,6 +6,9 @@ import android.location.LocationManager;
 import android.os.Handler;
 
 public class SensorManager {
+
+	public static float GRAVITY_EARTH = 9.81f;
+
 	public Sensor getDefaultSensor(int type) {
 		return new Sensor(type);
 	}

src/api-impl/android/view/View.java

@@ -788,6 +788,9 @@ public class View extends Object {
 	private int right;
 	private int bottom;
 
+	private int scrollX = 0;
+	private int scrollY = 0;
+
 	public long widget; // pointer
 
 	public static HashMap<Integer, View> view_by_id = new HashMap<Integer, View>();
@@ -935,10 +938,17 @@ public class View extends Object {
 	public void getHitRect(Rect outRect) {}
 	public final boolean getLocalVisibleRect(Rect r) { return false; }
 
-	public final int getScrollX() { return 0; }
+	public final int getScrollX() {
-	public final int getScrollY() { return 0; }
+		return scrollX;
+	}
+	public final int getScrollY() {
+		return scrollY;
+	}
 
-	public void scrollTo(int x, int y) {}
+	public void scrollTo(int x, int y) {
+		scrollX = x;
+		scrollY = y;
+	}
 
 	protected void onScrollChanged(int l, int t, int oldl, int oldt) {}
 
@@ -972,7 +982,14 @@ public class View extends Object {
 		return 0;
 	}
 
-	public void postInvalidate() {}
+	public void postInvalidate() {
+		new Handler(Looper.getMainLooper()).post(new Runnable() {
+			@Override
+			public void run() {
+				requestLayout();
+			}
+		});
+	}
 
 	public void postInvalidate(int left, int top, int right, int bottom) {
 		System.out.println("postInvalidate(" + left + "," + top + "," + right + "," + bottom + ") called");
@@ -1108,6 +1125,10 @@ public class View extends Object {
 		layout(left, top + offset, right, bottom + offset);
 	}
 
+	public void offsetLeftAndRight(int offset) {
+		layout(left + offset, top, right + offset, bottom);
+	}
+
 	public void setBackgroundDrawable(Drawable backgroundDrawable) {}
 
 	public int getOverScrollMode() {return 0;}
@@ -1228,4 +1249,6 @@ public class View extends Object {
 		}
 		return result;
 	}
+
+	public void computeScroll() {}
 }

src/api-impl/android/view/ViewConfiguration.java

@@ -43,4 +43,8 @@ public class ViewConfiguration {
 	public int getScaledDoubleTapSlop() {
 		return 0;
 	}
+
+	public static float getScrollFriction() {
+		return 0.f;
+	}
 }

src/api-impl/android/widget/OverScroller.java

@@ -1,16 +1,25 @@
 package android.widget;
 
 import android.content.Context;
-import android.view.ViewGroup;
 import android.view.animation.Interpolator;
 
-public class OverScroller extends ViewGroup {
+public class OverScroller {
 
 	public OverScroller(Context context, Interpolator interpolator) {
-		super(context);
+	}
+
+	public OverScroller(Context context) {
 	}
 
 	public void abortAnimation () {}
 
 	public void startScroll(int startX, int startY, int dx, int dy, int duration) {}
+
+	public boolean computeScrollOffset() {return false;}
+
+	public int getCurrX() {return 0;}
+	public int getCurrY() {return 0;}
+
+	public int getFinalX() {return 0;}
+	public int getFinalY() {return 0;}
 }