Bug 662038, part 0: Add gfxContext::CurrentDash(). r=jrmuizel

gfx/thebes/gfxContext.cpp

@@ -545,7 +545,28 @@ gfxContext::SetDash(gfxFloat *dashes, int ndash, gfxFloat offset)
 {
     cairo_set_dash(mCairo, dashes, ndash, offset);
 }
-//void getDash() const;
+
+bool
+gfxContext::CurrentDash(FallibleTArray<gfxFloat>& dashes, gfxFloat* offset) const
+{
+    int count = cairo_get_dash_count(mCairo);
+    if (count <= 0 || !dashes.SetLength(count)) {
+        return false;
+    }
+    cairo_get_dash(mCairo, dashes.Elements(), offset);
+    return true;
+}
+
+gfxFloat
+gfxContext::CurrentDashOffset() const
+{
+    if (cairo_get_dash_count(mCairo) <= 0) {
+        return 0.0;
+    }
+    gfxFloat offset;
+    cairo_get_dash(mCairo, NULL, &offset);
+    return offset;
+}
 
 void
 gfxContext::SetLineWidth(gfxFloat width)

gfx/thebes/gfxContext.h

@@ -51,6 +51,7 @@
 #include "nsISupportsImpl.h"
 
 typedef struct _cairo cairo_t;
+template <typename T> class FallibleTArray;
 
 /**
  * This is the main class for doing actual drawing. It is initialized using
@@ -465,7 +466,12 @@ public:
 
     void SetDash(gfxLineType ltype);
     void SetDash(gfxFloat *dashes, int ndash, gfxFloat offset);
-    //void getDash() const;
+    // Return true if dashing is set, false if it's not enabled or the
+    // context is in an error state.  |offset| can be NULL to mean
+    // "don't care".
+    bool CurrentDash(FallibleTArray<gfxFloat>& dashes, gfxFloat* offset) const;
+    // Returns 0.0 if dashing isn't enabled.
+    gfxFloat CurrentDashOffset() const;
 
     /**
      * Sets the line width that's used for line drawing.