Bug 324857 - MathML all screwed up in Cairo builds: implement nsIRenderingContext::GetBoundingMetrics() p=steve.swanson@mackichan.com and karlt, r=pavlov a=blocking1.9+

gfx/src/thebes/nsIThebesFontMetrics.h

@@ -99,12 +99,13 @@ public:
     // caller will have to update them to twips before passing it
     // back.
     virtual nsresult GetBoundingMetrics(const char *aString, PRUint32 aLength,
+                                        nsThebesRenderingContext *aContext,
                                         nsBoundingMetrics &aBoundingMetrics) = 0;
     // aCachedOffset will be updated with a new offset.
     virtual nsresult GetBoundingMetrics(const PRUnichar *aString,
                                         PRUint32 aLength,
-                                        nsBoundingMetrics &aBoundingMetrics,
-                                        PRInt32 *aFontID) = 0;
+                                        nsThebesRenderingContext *aContext,
+                                        nsBoundingMetrics &aBoundingMetrics) = 0;
 #endif /* MOZ_MATHML */
 
     // Set the direction of the text rendering

gfx/src/thebes/nsThebesFontMetrics.cpp

@@ -393,7 +393,6 @@ nsThebesFontMetrics::DrawString(const char *aString, PRUint32 aLength,
     return NS_OK;
 }
 
-// aCachedOffset will be updated with a new offset.
 nsresult
 nsThebesFontMetrics::DrawString(const PRUnichar* aString, PRUint32 aLength,
                                 nscoord aX, nscoord aY,
@@ -419,25 +418,57 @@ nsThebesFontMetrics::DrawString(const PRUnichar* aString, PRUint32 aLength,
 }
 
 #ifdef MOZ_MATHML
-// These two functions get the bounding metrics for this handle,
-// updating the aBoundingMetrics in Points.  This means that the
-// caller will have to update them to twips before passing it
-// back.
-nsresult
-nsThebesFontMetrics::GetBoundingMetrics(const char *aString, PRUint32 aLength,
-                                        nsBoundingMetrics &aBoundingMetrics)
+
+static void
+GetTextRunBoundingMetrics(gfxTextRun *aTextRun, PRUint32 aStart, PRUint32 aLength,
+                          nsThebesRenderingContext *aContext,
+                          nsBoundingMetrics &aBoundingMetrics)
 {
-    return NS_ERROR_NOT_IMPLEMENTED;
+    StubPropertyProvider provider;
+    gfxTextRun::Metrics theMetrics =
+        aTextRun->MeasureText(aStart, aLength, PR_TRUE, aContext->Thebes(), &provider);
+
+    aBoundingMetrics.leftBearing = NSToCoordFloor(theMetrics.mBoundingBox.X());
+    aBoundingMetrics.rightBearing = NSToCoordCeil(theMetrics.mBoundingBox.XMost());
+    aBoundingMetrics.width = NSToCoordRound(theMetrics.mAdvanceWidth);
+    aBoundingMetrics.ascent = NSToCoordCeil(- theMetrics.mBoundingBox.Y());
+    aBoundingMetrics.descent = NSToCoordCeil(theMetrics.mBoundingBox.YMost());
 }
 
-// aCachedOffset will be updated with a new offset.
 nsresult
-nsThebesFontMetrics::GetBoundingMetrics(const PRUnichar *aString,
-                                        PRUint32 aLength,
-                                        nsBoundingMetrics &aBoundingMetrics,
-                                        PRInt32 *aFontID)
+nsThebesFontMetrics::GetBoundingMetrics(const char *aString, PRUint32 aLength,
+                                        nsThebesRenderingContext *aContext,
+                                        nsBoundingMetrics &aBoundingMetrics)
 {
-    return NS_ERROR_NOT_IMPLEMENTED;
+    if (aLength == 0) {
+        aBoundingMetrics.Clear();
+        return NS_OK;
+    }
+
+    AutoTextRun textRun(this, aContext, aString, aLength);
+    if (!textRun.get())
+        return NS_ERROR_FAILURE;
+
+    GetTextRunBoundingMetrics(textRun.get(), 0, aLength, aContext, aBoundingMetrics);
+    return NS_OK;
+}
+
+nsresult
+nsThebesFontMetrics::GetBoundingMetrics(const PRUnichar *aString, PRUint32 aLength,
+                                        nsThebesRenderingContext *aContext,
+                                        nsBoundingMetrics &aBoundingMetrics)
+{
+    if (aLength == 0) {
+        aBoundingMetrics.Clear();
+        return NS_OK;
+    }
+
+    AutoTextRun textRun(this, aContext, aString, aLength);
+    if (!textRun.get())
+        return NS_ERROR_FAILURE;
+
+    GetTextRunBoundingMetrics(textRun.get(), 0, aLength, aContext, aBoundingMetrics);
+    return NS_OK;
 }
 
 #endif /* MOZ_MATHML */

gfx/src/thebes/nsThebesFontMetrics.h

@@ -85,7 +85,6 @@ public:
 
     virtual nsresult GetWidth(const char* aString, PRUint32 aLength, nscoord& aWidth,
                               nsThebesRenderingContext *aContext);
-    // aCachedOffset will be updated with a new offset.
     virtual nsresult GetWidth(const PRUnichar* aString, PRUint32 aLength,
                               nscoord& aWidth, PRInt32 *aFontID,
                               nsThebesRenderingContext *aContext);
@@ -119,7 +118,6 @@ public:
                                 nscoord aX, nscoord aY,
                                 const nscoord* aSpacing,
                                 nsThebesRenderingContext *aContext);
-    // aCachedOffset will be updated with a new offset.
     virtual nsresult DrawString(const PRUnichar* aString, PRUint32 aLength,
                                 nscoord aX, nscoord aY,
                                 PRInt32 aFontID,
@@ -128,16 +126,14 @@ public:
 
 #ifdef MOZ_MATHML
     // These two functions get the bounding metrics for this handle,
-    // updating the aBoundingMetrics in Points.  This means that the
-    // caller will have to update them to twips before passing it
-    // back.
+    // updating the aBoundingMetrics in app units.
     virtual nsresult GetBoundingMetrics(const char *aString, PRUint32 aLength,
+                                        nsThebesRenderingContext *aContext,
                                         nsBoundingMetrics &aBoundingMetrics);
-    // aCachedOffset will be updated with a new offset.
     virtual nsresult GetBoundingMetrics(const PRUnichar *aString,
                                         PRUint32 aLength,
-                                        nsBoundingMetrics &aBoundingMetrics,
-                                        PRInt32 *aFontID);
+                                        nsThebesRenderingContext *aContext,
+                                        nsBoundingMetrics &aBoundingMetrics);
 #endif /* MOZ_MATHML */
 
     // Set the direction of the text rendering

gfx/src/thebes/nsThebesRenderingContext.cpp

@@ -973,7 +973,7 @@ nsThebesRenderingContext::GetBoundingMetricsInternal(const char*        aString,
                                                      PRUint32           aLength,
                                                      nsBoundingMetrics& aBoundingMetrics)
 {
-  return NS_ERROR_NOT_IMPLEMENTED;
+    return mFontMetrics->GetBoundingMetrics(aString, aLength, this, aBoundingMetrics);
 }
 
 NS_IMETHODIMP
@@ -982,7 +982,7 @@ nsThebesRenderingContext::GetBoundingMetricsInternal(const PRUnichar*   aString,
                                                      nsBoundingMetrics& aBoundingMetrics,
                                                      PRInt32*           aFontID)
 {
-    return NS_ERROR_NOT_IMPLEMENTED;
+    return mFontMetrics->GetBoundingMetrics(aString, aLength, this, aBoundingMetrics);
 }
 #endif // MOZ_MATHML