Bug 1093686 - Add some debug logging code for PositionedEventTargeting.cpp. r=roc

gfx/layers/LayersLogging.cpp

@@ -67,6 +67,26 @@ AppendToString(std::stringstream& aStream, const gfxRGBA& c,
   aStream << sfx;
 }
 
+void
+AppendToString(std::stringstream& aStream, const nsPoint& p,
+               const char* pfx, const char* sfx)
+{
+  aStream << pfx;
+  aStream << nsPrintfCString("(x=%d, y=%d)", p.x, p.y).get();
+  aStream << sfx;
+}
+
+void
+AppendToString(std::stringstream& aStream, const nsRect& r,
+               const char* pfx, const char* sfx)
+{
+  aStream << pfx;
+  aStream << nsPrintfCString(
+    "(x=%d, y=%d, w=%d, h=%d)",
+    r.x, r.y, r.width, r.height).get();
+  aStream << sfx;
+}
+
 void
 AppendToString(std::stringstream& aStream, const nsIntPoint& p,
                const char* pfx, const char* sfx)

gfx/layers/LayersLogging.h

@@ -45,6 +45,14 @@ void
 AppendToString(std::stringstream& aStream, const gfxRGBA& c,
                const char* pfx="", const char* sfx="");
 
+void
+AppendToString(std::stringstream& aStream, const nsPoint& p,
+               const char* pfx="", const char* sfx="");
+
+void
+AppendToString(std::stringstream& aStream, const nsRect& r,
+               const char* pfx="", const char* sfx="");
+
 void
 AppendToString(std::stringstream& aStream, const nsIntPoint& p,
                const char* pfx="", const char* sfx="");

layout/base/PositionedEventTargeting.cpp

@@ -16,6 +16,12 @@
 #include "nsDeviceContext.h"
 #include "nsIFrame.h"
 #include <algorithm>
+#include "LayersLogging.h"
+
+// If debugging this code you may wish to enable this logging, and also
+// uncomment the DumpFrameTree call near the bottom of the file.
+#define PET_LOG(...)
+// #define PET_LOG(...) printf_stderr("PET: " __VA_ARGS__);
 
 namespace mozilla {
 
@@ -318,6 +324,7 @@ GetClosest(nsIFrame* aRoot, const nsPoint& aPointRelativeToRootFrame,
   nsRegion exposedRegion(aTargetRect);
   for (uint32_t i = 0; i < aCandidates.Length(); ++i) {
     nsIFrame* f = aCandidates[i];
+    PET_LOG("Checking candidate %p\n", f);
 
     bool preservesAxisAlignedRectangles = false;
     nsRect borderBox = nsLayoutUtils::TransformFrameRectToAncestor(f,
@@ -326,6 +333,7 @@ GetClosest(nsIFrame* aRoot, const nsPoint& aPointRelativeToRootFrame,
     region.And(exposedRegion, borderBox);
 
     if (region.IsEmpty()) {
+      PET_LOG("  candidate %p had empty hit region\n", f);
       continue;
     }
 
@@ -336,14 +344,17 @@ GetClosest(nsIFrame* aRoot, const nsPoint& aPointRelativeToRootFrame,
     }
 
     if (!IsElementClickable(f, nsGkAtoms::body)) {
+      PET_LOG("  candidate %p was not clickable\n", f);
       continue;
     }
     // If our current closest frame is a descendant of 'f', skip 'f' (prefer
     // the nested frame).
     if (bestTarget && nsLayoutUtils::IsProperAncestorFrameCrossDoc(f, bestTarget, aRoot)) {
+      PET_LOG("  candidate %p was ancestor for bestTarget %p\n", f, bestTarget);
       continue;
     }
     if (!nsLayoutUtils::IsAncestorFrameCrossDoc(aRestrictToDescendants, f, aRoot)) {
+      PET_LOG("  candidate %p was not descendant of restrictroot %p\n", f, aRestrictToDescendants);
       continue;
     }
 
@@ -356,6 +367,7 @@ GetClosest(nsIFrame* aRoot, const nsPoint& aPointRelativeToRootFrame,
       distance *= aPrefs->mVisitedWeight / 100.0f;
     }
     if (distance < bestDistance) {
+      PET_LOG("  candidate %p is the new best\n", f);
       bestDistance = distance;
       bestTarget = f;
     }
@@ -373,9 +385,14 @@ FindFrameTargetedByInputEvent(WidgetGUIEvent* aEvent,
      nsLayoutUtils::IGNORE_ROOT_SCROLL_FRAME : 0;
   nsIFrame* target =
     nsLayoutUtils::GetFrameForPoint(aRootFrame, aPointRelativeToRootFrame, flags);
+  PET_LOG("Found initial target %p for event class %s point %s relative to root frame %p\n",
+    target, (aEvent->mClass == eMouseEventClass ? "mouse" :
+             (aEvent->mClass == eTouchEventClass ? "touch" : "other")),
+    mozilla::layers::Stringify(aPointRelativeToRootFrame).c_str(), aRootFrame);
 
   const EventRadiusPrefs* prefs = GetPrefsFor(aEvent->mClass);
   if (!prefs || !prefs->mEnabled || (target && IsElementClickable(target, nsGkAtoms::body))) {
+    PET_LOG("Retargeting disabled or target %p is clickable\n", target);
     return target;
   }
 
@@ -385,6 +402,7 @@ FindFrameTargetedByInputEvent(WidgetGUIEvent* aEvent,
       prefs->mTouchOnly &&
       aEvent->AsMouseEvent()->inputSource !=
         nsIDOMMouseEvent::MOZ_SOURCE_TOUCH) {
+    PET_LOG("Mouse input event is not from a touch source\n");
     return target;
   }
 
@@ -398,6 +416,8 @@ FindFrameTargetedByInputEvent(WidgetGUIEvent* aEvent,
 
   nsRect targetRect = GetTargetRect(aRootFrame, aPointRelativeToRootFrame,
                                     restrictToDescendants, prefs, aFlags);
+  PET_LOG("Expanded point to target rect %s\n",
+    mozilla::layers::Stringify(targetRect).c_str());
   nsAutoTArray<nsIFrame*,8> candidates;
   nsresult rv = nsLayoutUtils::GetFramesForArea(aRootFrame, targetRect, candidates, flags);
   if (NS_FAILED(rv)) {
@@ -410,6 +430,12 @@ FindFrameTargetedByInputEvent(WidgetGUIEvent* aEvent,
   if (closestClickable) {
     target = closestClickable;
   }
+  PET_LOG("Final target is %p\n", target);
+
+  // Uncomment this to dump the frame tree to help with debugging.
+  // Note that dumping the frame tree at the top of the function may flood
+  // logcat on Android devices and cause the PET_LOGs to get dropped.
+  // aRootFrame->DumpFrameTree();
 
   if (!target || !prefs->mRepositionEventCoords) {
     // No repositioning required for this event