Bug 377181 - 'Jump to here' system preference is not followed by (new) non-native scrollbars. r-cbarrett, sr=roc.

layout/xul/base/src/nsSliderFrame.cpp

@@ -65,6 +65,7 @@
 #include "nsIScrollbarFrame.h"
 #include "nsISupportsArray.h"
 #include "nsIScrollableView.h"
+#include "nsILookAndFeel.h"
 #include "nsRepeatService.h"
 #include "nsBoxLayoutState.h"
 #include "nsSprocketLayout.h"
@@ -831,6 +832,21 @@ nsSliderFrame::MouseDown(nsIDOMEvent* aMouseEvent)
     scrollToClick = PR_TRUE;
   }
 
+  // Check if we should scroll-to-click regardless of the pressed button and
+  // modifiers
+  if (!scrollToClick) {
+    nsresult rv;
+    nsCOMPtr<nsILookAndFeel> lookNFeel =
+      do_GetService("@mozilla.org/widget/lookandfeel;1", &rv);
+    if (NS_SUCCEEDED(rv)) {
+      PRInt32 scrollToClickMetric;
+      rv = lookNFeel->GetMetric(nsILookAndFeel::eMetric_ScrollToClick,
+                                scrollToClickMetric);
+      if (NS_SUCCEEDED(rv) && scrollToClickMetric == 1)
+        scrollToClick = PR_TRUE;
+    }
+  }
+
   PRInt32 clientPosPx;
   nsIntRect screenRect = GetScreenRect();
   nscoord pos;

modules/libpref/src/init/all.js

@@ -130,6 +130,11 @@ pref("accessibility.warn_on_browsewithcaret", true);
 // unless accessibility.tabfocus is set by the user.
 pref("accessibility.tabfocus", 7);
 pref("accessibility.tabfocus_applies_to_xul", false);
+
+// On OS X, we follow the "Click in the scrollbar to:" system preference
+// unless this preference was set manually
+pref("ui.scrollToClick", 0);
+
 #else
 // Only on mac tabfocus is expected to handle UI widgets as well as web content
 pref("accessibility.tabfocus_applies_to_xul", true);

widget/public/nsILookAndFeel.h

@@ -225,7 +225,15 @@ public:
      *     +-----------+
      *       2       0
      */
-    eMetric_AlertNotificationOrigin
+    eMetric_AlertNotificationOrigin,
+
+    /**
+     * If true, clicking on a scrollbar (not as in dragging the thumb) defaults
+     * to scrolling the view corresponding to the clicked point. Otherwise, we
+     * only do so if the scrollbar is clicked using the middle mouse button or
+     * if shift is pressed when the scrollbar is clicked.
+     */
+    eMetric_ScrollToClick
   } nsMetricID;
 
   enum {

widget/src/cocoa/nsLookAndFeel.mm

@@ -585,6 +585,20 @@ NS_IMETHODIMP nsLookAndFeel::GetMetric(const nsMetricID aID, PRInt32 & aMetric)
       }
     }
       break;
+    case eMetric_ScrollToClick:
+    {
+      CFPropertyListRef scrollToClickProperty =
+        ::CFPreferencesCopyValue(CFSTR("AppleScrollerPagingBehavior"),
+                                 kCFPreferencesAnyApplication,
+                                 kCFPreferencesCurrentUser,
+                                 kCFPreferencesAnyHost);
+      aMetric = 0;
+      if (scrollToClickProperty) {
+        aMetric = (PRInt32)::CFBooleanGetValue((CFBooleanRef)scrollToClickProperty);
+        ::CFRelease(scrollToClickProperty);
+      }
+    }
+      break;
     default:
       aMetric = 0;
       res = NS_ERROR_FAILURE;

widget/src/xpwidgets/nsXPLookAndFeel.cpp

@@ -108,6 +108,8 @@ nsLookAndFeelIntPref nsXPLookAndFeel::sIntPrefs[] =
     eMetric_TabFocusModel, PR_FALSE, nsLookAndFeelTypeInt, 0 },
   { "ui.alertNotificationOrigin",
     eMetric_AlertNotificationOrigin, PR_FALSE, nsLookAndFeelTypeInt, 0 },
+  { "ui.scrollToClick",
+    eMetric_ScrollToClick, PR_FALSE, nsLookAndFeelTypeInt, 0 },
 };
 
 nsLookAndFeelFloatPref nsXPLookAndFeel::sFloatPrefs[] =