Bug 495002 - nsPresContext ought to have CSSPixelsToDevPixels and DevPixelsToCSSPixels methods

r=bz, sr=roc

dom/base/nsGlobalWindow.cpp

@@ -3115,9 +3115,8 @@ nsGlobalWindow::DevToCSSIntPixels(PRInt32 px)
   mDocShell->GetPresContext(getter_AddRefs(presContext));
   if (!presContext)
     return px;
-  
+
-  return nsPresContext::AppUnitsToIntCSSPixels(
+  return presContext->DevPixelsToIntCSSPixels(px);
-    presContext->DevPixelsToAppUnits(px));
 }
 
 PRInt32
@@ -3130,9 +3129,8 @@ nsGlobalWindow::CSSToDevIntPixels(PRInt32 px)
   mDocShell->GetPresContext(getter_AddRefs(presContext));
   if (!presContext)
     return px;
-  
+
-  return presContext->AppUnitsToDevPixels(
+  return presContext->CSSPixelsToDevPixels(px);
-    nsPresContext::CSSPixelsToAppUnits(px));
 }
 
 nsIntSize
@@ -3147,10 +3145,8 @@ nsGlobalWindow::DevToCSSIntPixels(nsIntSize px)
     return px;
   
   return nsIntSize(
-    nsPresContext::AppUnitsToIntCSSPixels(
+      presContext->DevPixelsToIntCSSPixels(px.width),
-      presContext->DevPixelsToAppUnits(px.width)),
+      presContext->DevPixelsToIntCSSPixels(px.height));
-    nsPresContext::AppUnitsToIntCSSPixels(
-      presContext->DevPixelsToAppUnits(px.height)));
 }
 
 nsIntSize
@@ -3165,10 +3161,8 @@ nsGlobalWindow::CSSToDevIntPixels(nsIntSize px)
     return px;
   
   return nsIntSize(
-    presContext->AppUnitsToDevPixels(
+    presContext->CSSPixelsToDevPixels(px.width),
-      nsPresContext::CSSPixelsToAppUnits(px.width)),
+    presContext->CSSPixelsToDevPixels(px.height));
-    presContext->AppUnitsToDevPixels(
-      nsPresContext::CSSPixelsToAppUnits(px.height)));
 }
 
 

layout/analysis/pixel-conversion.js

@@ -0,0 +1,6 @@
+include("simple-match.js");
+
+var patterns = {CSSPixelsToDevPixels: ['AppUnitsToDevPixels', 'CSSPixelsToAppUnits'],
+                DevPixelsToIntCSSPixels: ['AppUnitsToIntCSSPixels', 'DevPixelsToAppUnits'],
+                DevPixelsToFloatCSSPixels: ['AppUnitsToFloatCSSPixels', 'DevPixelsToAppUnits'],
+               };

layout/analysis/simple-match.js

@@ -0,0 +1,39 @@
+// This executes a very simple search for all functions that call a
+// given set of functions. It's intended to be the simplest possible
+// way of refactoring a common pattern of function calls. Of course,
+// it's still up to a human to decide if the replacement is truely
+// suitable, but this gets the low-hanging fruit.
+
+// Expects the variable 'patterns' to hold an object with replacement
+// function names as keys and function lists as values. Any function
+// in the tested source that calls all of the functions named in the
+// list will be listed in the output as being likely candidates to
+// instead call the replacement function.
+
+include("unstable/lazy_types.js");
+
+var matches = {};
+
+function identity(x) x;
+
+function process_cp_pre_genericize(fndecl)
+{
+    var c = [];
+    function calls(t, stack)
+    {
+        try {
+            t.tree_check(CALL_EXPR);
+            var fn = callable_arg_function_decl(CALL_EXPR_FN(t));
+            if (fn)
+                c.push(decl_name_string(fn));
+        }
+        catch (e if e.TreeCheckError) { }
+    }
+
+    walk_tree(DECL_SAVED_TREE(fndecl), calls);
+
+    for (let [fnreplace, pattern] in patterns)
+        if (pattern.map(function(e){ return c.some(function(f) { return e == f; }); }).every(identity))
+            if (fnreplace != (n = decl_name_string(fndecl)))
+                print(fnreplace +" could probably be used in "+ n);
+}

layout/base/nsPresContext.h

@@ -568,6 +568,21 @@ public:
   { return NSAppUnitsToIntPixels(aAppUnits,
              float(mDeviceContext->AppUnitsPerDevPixel())); }
 
+  PRInt32 CSSPixelsToDevPixels(PRInt32 aPixels)
+  { return AppUnitsToDevPixels(CSSPixelsToAppUnits(aPixels)); }
+
+  float CSSPixelsToDevPixels(float aPixels)
+  {
+    return NSAppUnitsToFloatPixels(CSSPixelsToAppUnits(aPixels),
+                                   float(mDeviceContext->AppUnitsPerDevPixel()));
+  }
+
+  PRInt32 DevPixelsToIntCSSPixels(PRInt32 aPixels)
+  { return AppUnitsToIntCSSPixels(DevPixelsToAppUnits(aPixels)); }
+
+  float DevPixelsToFloatCSSPixels(PRInt32 aPixels)
+  { return AppUnitsToFloatCSSPixels(DevPixelsToAppUnits(aPixels)); }
+
   // If there is a remainder, it is rounded to nearest app units.
   nscoord GfxUnitsToAppUnits(gfxFloat aGfxUnits) const
   { return mDeviceContext->GfxUnitsToAppUnits(aGfxUnits); }

layout/xul/base/src/nsXULPopupManager.cpp

@@ -361,8 +361,8 @@ nsXULPopupManager::SetTriggerEvent(nsIDOMEvent* aEvent, nsIContent* aPopup)
               mouseEvent->GetClientY(&mCachedMousePoint.y);
 
               // convert to device pixels
-              mCachedMousePoint.x = presContext->AppUnitsToDevPixels(nsPresContext::CSSPixelsToAppUnits(mCachedMousePoint.x));
+              mCachedMousePoint.x = presContext->CSSPixelsToDevPixels(mCachedMousePoint.x);
-              mCachedMousePoint.y = presContext->AppUnitsToDevPixels(nsPresContext::CSSPixelsToAppUnits(mCachedMousePoint.y));
+              mCachedMousePoint.y = presContext->CSSPixelsToDevPixels(mCachedMousePoint.y);
             }
             else if (rootFrame) {
               nsPoint pnt =