Fix Layout initialization in the skipCache path

C++ local var initialization always tricks me.  Previously, Layout
didn't have a constructor, which meant that defining it on the stack
left mAdvance uninitialized.  This was not an issue when we were doing
"new Layout()", since that invokes zero-initialization, but was an
issue for the skipCache path that was allocating layout on stack by
just "Layout l" instead of "Layout l = Layout()".  To avoid surprises,
add a constructors that clears everything.

Also adds reset() method to reset the layout for reuse.

Change-Id: I3e02f00da9dd7d360abe13f63c310f6882292d0a

1 files changed, 9 insertions, 2 deletions

diff --git a/include/minikin/Layout.h b/include/minikin/Layout.h
index c88d087..9f87597 100644
--- a/include/minikin/Layout.h
+++ b/include/minikin/Layout.h
@@ -64,6 +64,14 @@ class LayoutContext;
 // extend through the lifetime of the Layout object.
 class Layout {
 public:
+
+    Layout() : mGlyphs(), mAdvances(), mCollection(0), mFaces(), mAdvance(0), mBounds() {
+        mBounds.setEmpty();
+    }
+
+    // Clears layout, ready to be used again
+    void reset();
+
     void dump() const;
     void setFontCollection(const FontCollection* collection);
 
@@ -72,8 +80,7 @@ public:
 
     void draw(Bitmap*, int x0, int y0, float size) const;
 
-    // This must be called before any invocations.
-    // TODO: probably have a factory instead
+    // Deprecated. Nont needed. Remove when callers are removed.
     static void init();
 
     // public accessors