LayoutLib: Hold onto delegate references.

When an object is given a delegate to hold onto, keep
the reference to the delegate instead of its native integer.

Also change the way the finalizer works by not explicitely deleting
the delegate. Instead we want the delegate to be deleted when
nothing holds a reference to it. To do this, instead of using
a regular SparseArray, we use a SparseArray of WeakReferences.
Because the main Java object that "owns" the delegate does not
actually holds a reference to the delegate, we fake this by
having the delegate manager hold a reference to delegates for
the main object. This is added/removed as the object is created
and the native finalized is called.

This makes layoutlib behave more like the JNI code where the native
objects are reference counted, and where the Java object can be
deleted but the delegate it owns is kept around (usually because
another type of delegates hold a reference on it.)

To properly handle the WeakReferences, we need to be able to
regularly clear the SparseArray of WeakReference that were
referencing objects that have been GC'ed.
Since the SparseArray is regularly being compacted (actually only
when items are removed), we use a custom SparseWeakArray (started
as a straight copy of SparseArray) that handles the WeakReference
and takes care of compacting the array by removing deleted indices
and WeakReference that returns null. Since our specific use case
doesn't call actually delete() or remove(), the compacting
only happens when the array needs to be resized.

Change-Id: Iacc5c1ff5b21732b8816fda87eb090da12d034e0

1 files changed, 48 insertions, 46 deletions

diff --git a/tools/layoutlib/bridge/src/android/graphics/Paint_Delegate.java b/tools/layoutlib/bridge/src/android/graphics/Paint_Delegate.java
index f5d2547..74a9124 100644
--- a/tools/layoutlib/bridge/src/android/graphics/Paint_Delegate.java
+++ b/tools/layoutlib/bridge/src/android/graphics/Paint_Delegate.java
@@ -75,19 +75,19 @@ public class Paint_Delegate {
     private int mCap;
     private int mJoin;
     private int mTextAlign;
-    private int mTypeface;
+    private Typeface_Delegate mTypeface;
     private float mStrokeWidth;
     private float mStrokeMiter;
     private float mTextSize;
     private float mTextScaleX;
     private float mTextSkewX;
 
-    private int mXfermode;
-    private int mColorFilter;
-    private int mShader;
-    private int mPathEffect;
-    private int mMaskFilter;
-    private int mRasterizer;
+    private Xfermode_Delegate mXfermode;
+    private ColorFilter_Delegate mColorFilter;
+    private Shader_Delegate mShader;
+    private PathEffect_Delegate mPathEffect;
+    private MaskFilter_Delegate mMaskFilter;
+    private Rasterizer_Delegate mRasterizer;
 
 
     // ---- Public Helper methods ----
@@ -172,17 +172,16 @@ public class Paint_Delegate {
     }
 
     public Stroke getJavaStroke() {
-        PathEffect_Delegate effectDelegate = PathEffect_Delegate.getDelegate(mPathEffect);
-        if (effectDelegate != null) {
-            if (effectDelegate.isSupported()) {
-                Stroke stroke = effectDelegate.getStroke(this);
+        if (mPathEffect != null) {
+            if (mPathEffect.isSupported()) {
+                Stroke stroke = mPathEffect.getStroke(this);
                 assert stroke != null;
                 if (stroke != null) {
                     return stroke;
                 }
             } else {
                 Bridge.getLog().fidelityWarning(LayoutLog.TAG_PATHEFFECT,
-                        effectDelegate.getSupportMessage(),
+                        mPathEffect.getSupportMessage(),
                         null, null /*data*/);
             }
         }
@@ -201,7 +200,7 @@ public class Paint_Delegate {
      * @return the delegate or null.
      */
     public Xfermode_Delegate getXfermode() {
-        return  Xfermode_Delegate.getDelegate(mXfermode);
+        return mXfermode;
     }
 
     /**
@@ -210,7 +209,7 @@ public class Paint_Delegate {
      * @return the delegate or null.
      */
     public ColorFilter_Delegate getColorFilter() {
-        return ColorFilter_Delegate.getDelegate(mColorFilter);
+        return mColorFilter;
     }
 
     /**
@@ -219,7 +218,7 @@ public class Paint_Delegate {
      * @return the delegate or null.
      */
     public Shader_Delegate getShader() {
-        return Shader_Delegate.getDelegate(mShader);
+        return mShader;
     }
 
     /**
@@ -228,7 +227,7 @@ public class Paint_Delegate {
      * @return the delegate or null.
      */
     public MaskFilter_Delegate getMaskFilter() {
-        return MaskFilter_Delegate.getDelegate(mMaskFilter);
+        return mMaskFilter;
     }
 
     /**
@@ -237,7 +236,7 @@ public class Paint_Delegate {
      * @return the delegate or null.
      */
     public Rasterizer_Delegate getRasterizer() {
-        return Rasterizer_Delegate.getDelegate(mRasterizer);
+        return mRasterizer;
     }
 
     // ---- native methods ----
@@ -585,7 +584,7 @@ public class Paint_Delegate {
     @LayoutlibDelegate
     /*package*/ static int native_init() {
         Paint_Delegate newDelegate = new Paint_Delegate();
-        return sManager.addDelegate(newDelegate);
+        return sManager.addNewDelegate(newDelegate);
     }
 
     @LayoutlibDelegate
@@ -597,7 +596,7 @@ public class Paint_Delegate {
         }
 
         Paint_Delegate newDelegate = new Paint_Delegate(delegate);
-        return sManager.addDelegate(newDelegate);
+        return sManager.addNewDelegate(newDelegate);
     }
 
     @LayoutlibDelegate
@@ -728,7 +727,9 @@ public class Paint_Delegate {
             return shader;
         }
 
-        return delegate.mShader = shader;
+        delegate.mShader = Shader_Delegate.getDelegate(shader);
+
+        return shader;
     }
 
     @LayoutlibDelegate
@@ -739,13 +740,12 @@ public class Paint_Delegate {
             return filter;
         }
 
-        delegate.mColorFilter = filter;
+        delegate.mColorFilter = ColorFilter_Delegate.getDelegate(filter);;
 
         // since none of those are supported, display a fidelity warning right away
-        ColorFilter_Delegate filterDelegate = delegate.getColorFilter();
-        if (filterDelegate != null && filterDelegate.isSupported() == false) {
+        if (delegate.mColorFilter != null && delegate.mColorFilter.isSupported() == false) {
             Bridge.getLog().fidelityWarning(LayoutLog.TAG_COLORFILTER,
-                    filterDelegate.getSupportMessage(), null, null /*data*/);
+                    delegate.mColorFilter.getSupportMessage(), null, null /*data*/);
         }
 
         return filter;
@@ -759,7 +759,9 @@ public class Paint_Delegate {
             return xfermode;
         }
 
-        return delegate.mXfermode = xfermode;
+        delegate.mXfermode = Xfermode_Delegate.getDelegate(xfermode);
+
+        return xfermode;
     }
 
     @LayoutlibDelegate
@@ -770,7 +772,9 @@ public class Paint_Delegate {
             return effect;
         }
 
-        return delegate.mPathEffect = effect;
+        delegate.mPathEffect = PathEffect_Delegate.getDelegate(effect);
+
+        return effect;
     }
 
     @LayoutlibDelegate
@@ -781,13 +785,12 @@ public class Paint_Delegate {
             return maskfilter;
         }
 
-        delegate.mMaskFilter = maskfilter;
+        delegate.mMaskFilter = MaskFilter_Delegate.getDelegate(maskfilter);
 
         // since none of those are supported, display a fidelity warning right away
-        MaskFilter_Delegate filterDelegate = delegate.getMaskFilter();
-        if (filterDelegate != null && filterDelegate.isSupported() == false) {
+        if (delegate.mMaskFilter != null && delegate.mMaskFilter.isSupported() == false) {
             Bridge.getLog().fidelityWarning(LayoutLog.TAG_MASKFILTER,
-                    filterDelegate.getSupportMessage(), null, null /*data*/);
+                    delegate.mMaskFilter.getSupportMessage(), null, null /*data*/);
         }
 
         return maskfilter;
@@ -801,9 +804,9 @@ public class Paint_Delegate {
             return 0;
         }
 
-        delegate.mTypeface = typeface;
+        delegate.mTypeface = Typeface_Delegate.getDelegate(typeface);
         delegate.updateFontObject();
-        return delegate.mTypeface;
+        return typeface;
     }
 
     @LayoutlibDelegate
@@ -814,13 +817,12 @@ public class Paint_Delegate {
             return rasterizer;
         }
 
-        delegate.mRasterizer = rasterizer;
+        delegate.mRasterizer = Rasterizer_Delegate.getDelegate(rasterizer);
 
         // since none of those are supported, display a fidelity warning right away
-        Rasterizer_Delegate rasterizerDelegate = delegate.getRasterizer();
-        if (rasterizerDelegate != null && rasterizerDelegate.isSupported() == false) {
+        if (delegate.mRasterizer != null && delegate.mRasterizer.isSupported() == false) {
             Bridge.getLog().fidelityWarning(LayoutLog.TAG_RASTERIZER,
-                    rasterizerDelegate.getSupportMessage(), null, null /*data*/);
+                    delegate.mRasterizer.getSupportMessage(), null, null /*data*/);
         }
 
         return rasterizer;
@@ -986,7 +988,7 @@ public class Paint_Delegate {
 
     @LayoutlibDelegate
     /*package*/ static void finalizer(int nativePaint) {
-        sManager.removeDelegate(nativePaint);
+        sManager.removeJavaReferenceFor(nativePaint);
     }
 
     // ---- Private delegate/helper methods ----
@@ -1028,18 +1030,18 @@ public class Paint_Delegate {
         mCap = Paint.Cap.BUTT.nativeInt;
         mJoin = Paint.Join.MITER.nativeInt;
         mTextAlign = 0;
-        mTypeface = Typeface.sDefaults[0].native_instance;
+        mTypeface = Typeface_Delegate.getDelegate(Typeface.sDefaults[0].native_instance);
         mStrokeWidth = 1.f;
         mStrokeMiter = 4.f;
         mTextSize = 20.f;
         mTextScaleX = 1.f;
         mTextSkewX = 0.f;
-        mXfermode = 0;
-        mColorFilter = 0;
-        mShader = 0;
-        mPathEffect = 0;
-        mMaskFilter = 0;
-        mRasterizer = 0;
+        mXfermode = null;
+        mColorFilter = null;
+        mShader = null;
+        mPathEffect = null;
+        mMaskFilter = null;
+        mRasterizer = null;
         updateFontObject();
     }
 
@@ -1048,9 +1050,9 @@ public class Paint_Delegate {
      */
     @SuppressWarnings("deprecation")
     private void updateFontObject() {
-        if (mTypeface != 0) {
+        if (mTypeface != null) {
             // Get the fonts from the TypeFace object.
-            List<Font> fonts = Typeface_Delegate.getFonts(mTypeface);
+            List<Font> fonts = mTypeface.getFonts();
 
             // create new font objects as well as FontMetrics, based on the current text size
             // and skew info.