From 6d86e37dc1323f70ec58e98954fabff883c6b4c9 Mon Sep 17 00:00:00 2001
From: "smichaud@pobox.com" <none@none>
Date: Tue, 18 Dec 2007 16:35:14 -0800
Subject: [PATCH] Fix multiple focus bugs. b=403232 r=joshmoz sr=roc

---
 widget/src/cocoa/nsChildView.h  |  6 +++
 widget/src/cocoa/nsChildView.mm | 87 +++++++++++++++++++++++++++++++--
 2 files changed, 89 insertions(+), 4 deletions(-)

diff --git a/widget/src/cocoa/nsChildView.h b/widget/src/cocoa/nsChildView.h
index 12f9ab4c2ad..aa52f856f9d 100644
--- a/widget/src/cocoa/nsChildView.h
+++ b/widget/src/cocoa/nsChildView.h
@@ -91,6 +91,9 @@ union nsPluginPort;
   // Whether we're a plugin view.
   BOOL mIsPluginView;
 
+  // Whether we're in nsChildView::SetFocus()
+  int mInSetFocusLevel;
+
   NSEvent* mCurKeyEvent;   // only valid during a keyDown
   PRBool mKeyDownHandled;
   
@@ -127,6 +130,9 @@ union nsPluginPort;
 
 // Stop NSView hierarchy being changed during [ChildView drawRect:]
 - (void)delayedTearDown;
+
+-(void)setInSetFocus:(BOOL)aInSetFocus;
+-(BOOL)inSetFocus;
 @end
 
 
diff --git a/widget/src/cocoa/nsChildView.mm b/widget/src/cocoa/nsChildView.mm
index 119f20e24a5..2ccae73114b 100644
--- a/widget/src/cocoa/nsChildView.mm
+++ b/widget/src/cocoa/nsChildView.mm
@@ -718,11 +718,64 @@ NS_IMETHODIMP nsChildView::IsEnabled(PRBool *aState)
 }
 
 
+class nsAutoSetInSetFocus {
+  public:
+    nsAutoSetInSetFocus(NSView *aView)
+    {
+      if ([aView isKindOfClass:[ChildView class]]) {
+        mChildView = (ChildView *) [aView retain];
+        [mChildView setInSetFocus:PR_TRUE];
+      } else {
+        mChildView = nil;
+      }
+    }
+    ~nsAutoSetInSetFocus()
+    {
+      if (mChildView) {
+        [mChildView setInSetFocus:PR_FALSE];
+        [mChildView release];
+      }
+    }
+
+  private:
+    ChildView *mChildView;  // [STRONG]
+};
+
+
 NS_IMETHODIMP nsChildView::SetFocus(PRBool aRaise)
 {
   NSWindow* window = [mView window];
-  if (window)
-    [window makeFirstResponder:mView];
+  if (window) {
+    // For reasons that aren't yet clear, focus changes within a window (as
+    // opposed to those between windows or between apps) should only trigger
+    // NS_LOSTFOCUS and NS_GOTFOCUS messages (to Gecko) in the context of a
+    // call to nsChildView::SetFocus() (or nsCocoaWindow::SetFocus(), which
+    // in any case re-routes to nsChildView::SetFocus()).  If we send these
+    // messages on every intra-window focus change (on every call to
+    // [ChildView becomeFirstResponder:] or [ChildView resignFirstResponder:]),
+    // the result will be strange focus bugs (like bmo bugs 399471, 403232,
+    // 404433 and 408266).
+    nsAutoSetInSetFocus setInSetFocus(mView);
+    NSResponder* firstResponder = [window firstResponder];
+    if ([mView isEqual:firstResponder]) {
+      // Sometimes SetFocus() is called on an nsChildView object that's
+      // already focused.  If we simply call [NSWindow makeFirstResponder:],
+      // neither [ChildView becomeFirstResponder:] nor [ChildView
+      // resignFirstResponder:] will get called, and no NS_LOSTFOCUS or
+      // NS_GOTFOCUS messages will be sent.  But in this case we sometimes
+      // get text-input cursors blinking in more than one text field.  So we
+      // need to guarantee that the code in nsEventStateManager::
+      // PreHandleEvent() which handles NS_LOSTFOCUS messages (and calls
+      // SetContentCaretVisible(... PR_FALSE)) gets invoked on every call to
+      // nsChildView::SetFocus().
+      if ([mView isKindOfClass:[ChildView class]]) {
+        [(ChildView *)mView sendFocusEvent:NS_LOSTFOCUS];
+        [(ChildView *)mView sendFocusEvent:NS_GOTFOCUS];
+      }
+    } else {
+      [window makeFirstResponder:mView];
+    }
+  }
   return NS_OK;
 }
 
@@ -1763,6 +1816,7 @@ NSEvent* gLastDragEvent = nil;
     mWindow = nil;
     mGeckoChild = inChild;
     mIsPluginView = NO;
+    mInSetFocusLevel = 0;
     mCurKeyEvent = nil;
     mKeyDownHandled = PR_FALSE;
     
@@ -2074,6 +2128,24 @@ NSEvent* gLastDragEvent = nil;
 }
 
 
+-(void)setInSetFocus:(BOOL)aInSetFocus
+{
+  if (aInSetFocus) {
+    ++mInSetFocusLevel;
+  } else if (mInSetFocusLevel > 0) {
+    --mInSetFocusLevel;
+  } else {
+    NS_WARNING("ChildView setInFocus: inSetFocus already false");
+  }
+}
+
+
+-(BOOL)inSetFocus
+{
+  return mInSetFocusLevel > 0;
+}
+
+
 - (void)sendFocusEvent:(PRUint32)eventType
 {
   if (!mGeckoChild)
@@ -4086,7 +4158,11 @@ static BOOL keyUpAlreadySentKeyDown = NO;
   if (!mGeckoChild)
     return NO;
 
-  [self sendFocusEvent:NS_GOTFOCUS];
+  // Focus events should only be sent to Gecko here in the context of a call
+  // to nsChildView::SetFocus().  For more info see nsChildView::SetFocus()
+  // above.
+  if ([self inSetFocus])
+    [self sendFocusEvent:NS_GOTFOCUS];
 
   return [super becomeFirstResponder];
 }
@@ -4099,7 +4175,10 @@ static BOOL keyUpAlreadySentKeyDown = NO;
 {
   nsTSMManager::CommitIME();
 
-  if (mGeckoChild)
+  // Focus events should only be sent to Gecko here in the context of a call
+  // to nsChildView::SetFocus().  For more info see nsChildView::SetFocus()
+  // above.
+  if (mGeckoChild && [self inSetFocus])
     [self sendFocusEvent:NS_LOSTFOCUS];
 
   return [super resignFirstResponder];