Cocoa: Add support for native application event filter

Support for adding application wide filters were never
implemented for the cocoa port because of NSApplication
singleton issues. This patch removes that problem by
using introspection if needed. And the patch also makes
qt_cocoaPostMessage more reliable.

10 files changed, 147 insertions, 125 deletions

diff --git a/src/gui/dialogs/qnspanelproxy_mac.mm b/src/gui/dialogs/qnspanelproxy_mac.mm
index 3229a4d..f01c035 100644
--- a/src/gui/dialogs/qnspanelproxy_mac.mm
+++ b/src/gui/dialogs/qnspanelproxy_mac.mm
@@ -42,6 +42,7 @@
 #include <qdialogbuttonbox.h>
 #if defined(Q_WS_MAC)
 #include <private/qt_mac_p.h>
+#include <private/qcocoaintrospection_p.h>
 #import <AppKit/AppKit.h>
 #import <Foundation/Foundation.h>
 #import <objc/objc-class.h>
@@ -137,46 +138,6 @@ QT_USE_NAMESPACE
 
 QT_BEGIN_NAMESPACE
 
-void macStartIntercept(SEL originalSel, SEL fakeSel, Class baseClass, Class proxyClass)
-{
-#ifndef QT_MAC_USE_COCOA
-    if (QSysInfo::MacintoshVersion >= QSysInfo::MV_10_5)
-#endif
-    {
-#if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5
-        // The following code replaces the _implementation_ for the selector we want to hack
-        // (originalSel) with the implementation found in proxyClass. Then it creates
-        // a new 'backup' method inside baseClass containing the old, original,
-        // implementation (fakeSel). You can let the proxy implementation of originalSel
-        // call fakeSel if needed (similar approach to calling a super class implementation).
-        // fakeSel must also be implemented in proxyClass, as the signature is used
-        // as template for the method one we add into baseClass.
-        // NB: You will typically never create any instances of proxyClass; we use it
-        // only for stealing its contents and put it into baseClass. 
-        Method originalMethod = class_getInstanceMethod(baseClass, originalSel);
-        Method newMethod = class_getInstanceMethod(proxyClass, originalSel);
-        Method fakeMethod = class_getInstanceMethod(proxyClass, fakeSel);
-
-        IMP originalImp = method_setImplementation(originalMethod, method_getImplementation(newMethod));
-        class_addMethod(baseClass, fakeSel, originalImp, method_getTypeEncoding(fakeMethod));
-#endif
-    }
-}
-
-void macStopIntercept(SEL originalSel, SEL fakeSel, Class baseClass, Class /* proxyClass */)
-{
-#ifndef QT_MAC_USE_COCOA
-    if (QSysInfo::MacintoshVersion >= QSysInfo::MV_10_5)
-#endif
-    {
-#if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5
-        Method originalMethod = class_getInstanceMethod(baseClass, originalSel);
-        Method fakeMethodInBaseClass = class_getInstanceMethod(baseClass, fakeSel);
-        method_setImplementation(originalMethod, method_getImplementation(fakeMethodInBaseClass));
-#endif
-    }
-}
-
 /*
     Intercept the NSColorPanel constructor if the shared
     color panel doesn't exist yet. What's going on here is
@@ -188,12 +149,18 @@ void macStopIntercept(SEL originalSel, SEL fakeSel, Class baseClass, Class /* pr
 */
 void macStartInterceptNSPanelCtor()
 {
-    macStartIntercept(@selector(initWithContentRect:styleMask:backing:defer:),
-                      @selector(qt_fakeInitWithContentRect:styleMask:backing:defer:),
-                      [NSPanel class], [QNSPanelProxy class]);
-    macStartIntercept(@selector(initWithContentRect:styleMask:backing:defer:screen:),
-                      @selector(qt_fakeInitWithContentRect:styleMask:backing:defer:screen:),
-                      [NSPanel class], [QNSPanelProxy class]);
+    qt_cocoa_change_implementation(
+            [NSPanel class],
+            @selector(initWithContentRect:styleMask:backing:defer:),
+            [QNSPanelProxy class],
+            @selector(initWithContentRect:styleMask:backing:defer:),
+            @selector(qt_fakeInitWithContentRect:styleMask:backing:defer:));
+    qt_cocoa_change_implementation(
+            [NSPanel class],
+            @selector(initWithContentRect:styleMask:backing:defer:screen:),
+            [QNSPanelProxy class],
+            @selector(initWithContentRect:styleMask:backing:defer:screen:),
+            @selector(qt_fakeInitWithContentRect:styleMask:backing:defer:screen:));
 }
 
 /*
@@ -201,12 +168,14 @@ void macStartInterceptNSPanelCtor()
 */
 void macStopInterceptNSPanelCtor()
 {
-    macStopIntercept(@selector(initWithContentRect:styleMask:backing:defer:screen:),
-                     @selector(qt_fakeInitWithContentRect:styleMask:backing:defer:screen:),
-                     [NSPanel class], [QNSPanelProxy class]);
-    macStopIntercept(@selector(initWithContentRect:styleMask:backing:defer:),
-                     @selector(qt_fakeInitWithContentRect:styleMask:backing:defer:),
-                     [NSPanel class], [QNSPanelProxy class]);
+    qt_cocoa_change_back_implementation(
+            [NSPanel class],
+            @selector(initWithContentRect:styleMask:backing:defer:screen:),
+            @selector(qt_fakeInitWithContentRect:styleMask:backing:defer:screen:));
+    qt_cocoa_change_back_implementation(
+            [NSPanel class],
+            @selector(initWithContentRect:styleMask:backing:defer:),
+            @selector(qt_fakeInitWithContentRect:styleMask:backing:defer:));
 }
 
 /*
@@ -216,8 +185,12 @@ void macStopInterceptNSPanelCtor()
 void macStartInterceptWindowTitle(QWidget *window)
 {
     currentWindow = window;
-    macStartIntercept(@selector(setTitle:), @selector(qt_fakeSetTitle:),
-                      [NSWindow class], [QNSWindowProxy class]);
+    qt_cocoa_change_implementation(
+            [NSWindow class],
+            @selector(setTitle:),
+            [QNSWindowProxy class],
+            @selector(setTitle:),
+            @selector(qt_fakeSetTitle:));
 }
 
 /*
@@ -226,8 +199,10 @@ void macStartInterceptWindowTitle(QWidget *window)
 void macStopInterceptWindowTitle()
 {
     currentWindow = 0;
-    macStopIntercept(@selector(setTitle:), @selector(qt_fakeSetTitle:),
-                     [NSWindow class], [QNSWindowProxy class]);
+    qt_cocoa_change_back_implementation(
+            [NSWindow class],
+            @selector(setTitle:),
+            @selector(qt_fakeSetTitle:));
 }
 
 /*
diff --git a/src/gui/kernel/kernel.pri b/src/gui/kernel/kernel.pri
index 6fd45ad..b6cc2ac 100644
--- a/src/gui/kernel/kernel.pri
+++ b/src/gui/kernel/kernel.pri
@@ -213,7 +213,8 @@ embedded {
                 qcocoaapplicationdelegate_mac_p.h \
                 qmacgesturerecognizer_mac_p.h \
                 qmultitouch_mac_p.h \
-                qcocoasharedwindowmethods_mac_p.h
+                qcocoasharedwindowmethods_mac_p.h \
+                qcocoaintrospection_p.h
 
         OBJECTIVE_SOURCES += \
                 kernel/qcursor_mac.mm \
@@ -233,7 +234,8 @@ embedded {
                 kernel/qeventdispatcher_mac.mm \
                 kernel/qcocoawindowcustomthemeframe_mac.mm \
                 kernel/qmacgesturerecognizer_mac.mm \
-                kernel/qmultitouch_mac.mm
+                kernel/qmultitouch_mac.mm \
+                kernel/qcocoaintrospection_mac.mm
 
         HEADERS += \
                 kernel/qt_cocoa_helpers_mac_p.h \
diff --git a/src/gui/kernel/qapplication.h b/src/gui/kernel/qapplication.h
index c21b982..ebb329b 100644
--- a/src/gui/kernel/qapplication.h
+++ b/src/gui/kernel/qapplication.h
@@ -233,6 +233,7 @@ public:
 
 #if defined(Q_WS_MAC)
     virtual bool macEventFilter(EventHandlerCallRef, EventRef);
+    virtual bool macEventFilter(void *);
 #endif
 #if defined(Q_WS_X11)
     virtual bool x11EventFilter(XEvent *);
diff --git a/src/gui/kernel/qapplication_mac.mm b/src/gui/kernel/qapplication_mac.mm
index 321492d..4cd14df 100644
--- a/src/gui/kernel/qapplication_mac.mm
+++ b/src/gui/kernel/qapplication_mac.mm
@@ -1246,6 +1246,8 @@ void qt_init(QApplicationPrivate *priv, int)
     // Cocoa application delegate
 #ifdef QT_MAC_USE_COCOA
     NSApplication *cocoaApp = [QNSApplication sharedApplication];
+    qt_redirectNSApplicationSendEvent();
+
     QMacCocoaAutoReleasePool pool;
     NSObject *oldDelegate = [cocoaApp delegate];
     QT_MANGLE_NAMESPACE(QCocoaApplicationDelegate) *newDelegate = [QT_MANGLE_NAMESPACE(QCocoaApplicationDelegate) sharedDelegate];
@@ -2611,7 +2613,7 @@ OSStatus QApplicationPrivate::globalAppleEventProcessor(const AppleEvent *ae, Ap
 /*!
     \fn bool QApplication::macEventFilter(EventHandlerCallRef caller, EventRef event)
 
-    \warning This virtual function is only implemented under Mac OS X when against Carbon.
+    \warning This virtual function is only used under Mac OS X when Qt is based on Carbon.
 
     If you create an application that inherits QApplication and reimplement
     this function, you get direct access to all Carbon Events that Qt registers
@@ -2622,14 +2624,7 @@ OSStatus QApplicationPrivate::globalAppleEventProcessor(const AppleEvent *ae, Ap
     Return false for normal event dispatching. The default
     implementation returns false.
 
-    Cocoa uses a different event system which means this function is NOT CALLED
-    when building Qt against Cocoa. If you want similar functionality subclass
-    NSApplication and reimplement the sendEvent: message to handle all the
-    NSEvents. You also will need to to instantiate your custom NSApplication
-    before creating a QApplication. See \l
-    {http://developer.apple.com/documentation/Cocoa/Reference/ApplicationKit/Classes/NSApplication_Class/Reference/Reference.html}{Apple's
-    NSApplication Reference} for more information.
-
+    \sa macEventFilter(void *nsevent)
 */
 bool QApplication::macEventFilter(EventHandlerCallRef, EventRef)
 {
@@ -2637,6 +2632,29 @@ bool QApplication::macEventFilter(EventHandlerCallRef, EventRef)
 }
 
 /*!
+    \fn bool QApplication::macEventFilter(void *nsevent)
+
+    \warning This virtual function is only used under Mac OS X when Qt is based on Cocoa.
+
+    If you create an application that inherits QApplication and reimplement
+    this function, you get direct access to all NSEvents that Qt receives
+    from Cocoa.
+    \a nsevent is of type NSEvent *:
+
+    NSEvent *e = static_cast<NSEvent *>(nsevent);
+
+    Return true if you want to stop the event from being processed.
+    Return false for normal event dispatching. The default
+    implementation returns false.
+
+    \sa macEventFilter(EventHandlerCallRef caller, EventRef event)
+*/
+bool QApplication::macEventFilter(void * /*NSEvent*/)
+{
+    return false;
+}
+
+/*!
     \internal
 */
 void QApplicationPrivate::openPopup(QWidget *popup)
@@ -3110,11 +3128,7 @@ void onApplicationChangedActivation( bool activated )
         }
 
         if (!app->activeWindow()) {
-#if QT_MAC_USE_COCOA
-            OSWindowRef wp    = [NSApp keyWindow];
-#else
-            OSWindowRef wp = ActiveNonFloatingWindow();
-#endif
+            OSWindowRef wp = [NSApp keyWindow];
             if (QWidget *tmp_w = qt_mac_find_window(wp))
                 app->setActiveWindow(tmp_w);
         }
diff --git a/src/gui/kernel/qcocoaapplication_mac.mm b/src/gui/kernel/qcocoaapplication_mac.mm
index 4962863..5cd32a1 100644
--- a/src/gui/kernel/qcocoaapplication_mac.mm
+++ b/src/gui/kernel/qcocoaapplication_mac.mm
@@ -78,6 +78,7 @@
 #include <private/qcocoaapplication_mac_p.h>
 #include <private/qcocoaapplicationdelegate_mac_p.h>
 #include <private/qt_cocoa_helpers_mac_p.h>
+#include <private/qcocoaintrospection_p.h>
 
 QT_USE_NAMESPACE
 
@@ -116,12 +117,26 @@ QT_USE_NAMESPACE
     quint64 lower = [event data1];
     quint64 upper = [event data2];
     QCocoaPostMessageArgs *args = reinterpret_cast<QCocoaPostMessageArgs *>(lower | (upper << 32));
-    [args->target performSelector:args->selector];
+    switch (args->argCount) {
+    case 0:
+        [args->target performSelector:args->selector];
+        break;
+    case 1:
+        [args->target performSelector:args->selector withObject:args->arg1];
+        break;
+    case 3:
+        [args->target performSelector:args->selector withObject:args->arg1 withObject:args->arg2];
+        break;
+    }
+
     delete args;
 }
 
-- (BOOL)qt_sendEvent:(NSEvent *)event
+- (BOOL)qt_filterEvent:(NSEvent *)event
 {
+    if (qApp->macEventFilter(event))
+        return true;
+
     if ([event type] == NSApplicationDefined) {
         switch ([event subtype]) {
             case QtCocoaEventSubTypePostMessage:
@@ -138,20 +153,55 @@ QT_USE_NAMESPACE
 
 @implementation QNSApplication
 
-// WARNING: If Qt did not create NSApplication (this can e.g.
-// happend if Qt is used as a plugin from a 3rd-party cocoa
-// application), QNSApplication::sendEvent will never be called.
-// SO DO NOT RELY ON THIS FUNCTION BEING AVAILABLE. 
-// Plugin developers that _do_ control the NSApplication sub-class
-// implementation of the 3rd-party application can call qt_sendEvent
-// from the sub-class event handler (like we do here) to work around
-// any issues.
+- (void)qt_sendEvent_original:(NSEvent *)event
+{
+    Q_UNUSED(event);
+    // This method will only be used as a signature
+    // template for the method we add into NSApplication
+    // containing the original [NSApplication sendEvent:] implementation
+}
+
+- (void)qt_sendEvent_replacement:(NSEvent *)event
+{
+    // This method (or its implementation to be precise) will
+    // be called instead of sendEvent if redirection occurs.
+    // 'self' will then be an instance of NSApplication
+    // (and not QNSApplication)
+    if (![NSApp qt_filterEvent:event])
+        [self qt_sendEvent_original:event];
+}
+
 - (void)sendEvent:(NSEvent *)event
 {
-    if (![self qt_sendEvent:event])
+    // This method will be called if
+    // no redirection occurs
+    if (![NSApp qt_filterEvent:event])
         [super sendEvent:event];
 }
 
 @end
 
+QT_BEGIN_NAMESPACE
+
+void qt_redirectNSApplicationSendEvent()
+{
+    if ([NSApp isMemberOfClass:[QNSApplication class]]) {
+        // No need to change implementation since Qt
+        // already controls a subclass of NSApplication
+        return;
+    }
+
+    // Change the implementation of [NSApplication sendEvent] to the
+    // implementation of qt_sendEvent_replacement found in QNSApplication.
+    // And keep the old implementation that gets overwritten inside a new
+    // method 'qt_sendEvent_original' that we add to NSApplication
+    qt_cocoa_change_implementation(
+            [NSApplication class],
+            @selector(sendEvent:),
+            [QNSApplication class],
+            @selector(qt_sendEvent_replacement:),
+            @selector(qt_sendEvent_original:));
+ }
+
+QT_END_NAMESPACE
 #endif
diff --git a/src/gui/kernel/qcocoaapplication_mac_p.h b/src/gui/kernel/qcocoaapplication_mac_p.h
index 5569feb..c89ff36 100644
--- a/src/gui/kernel/qcocoaapplication_mac_p.h
+++ b/src/gui/kernel/qcocoaapplication_mac_p.h
@@ -101,11 +101,17 @@ QT_FORWARD_DECLARE_CLASS(QApplicationPrivate)
 - (int)QT_MANGLE_NAMESPACE(qt_validModesForFontPanel):(NSFontPanel *)fontPanel;
 
 - (void)qt_sendPostedMessage:(NSEvent *)event;
-- (BOOL)qt_sendEvent:(NSEvent *)event;
+- (BOOL)qt_filterEvent:(NSEvent *)event;
 @end
 
 @interface QNSApplication : NSApplication {
 }
 @end
 
+QT_BEGIN_NAMESPACE
+
+void qt_redirectNSApplicationSendEvent();
+
+QT_END_NAMESPACE
+
 #endif
diff --git a/src/gui/kernel/qcocoasharedwindowmethods_mac_p.h b/src/gui/kernel/qcocoasharedwindowmethods_mac_p.h
index 8652816..717cfa5 100644
--- a/src/gui/kernel/qcocoasharedwindowmethods_mac_p.h
+++ b/src/gui/kernel/qcocoasharedwindowmethods_mac_p.h
@@ -149,17 +149,6 @@ QT_END_NAMESPACE
 
 - (void)sendEvent:(NSEvent *)event
 {
-    if ([event type] == NSApplicationDefined) {
-        switch ([event subtype]) {
-            case QtCocoaEventSubTypePostMessage:
-                [NSApp qt_sendPostedMessage:event];
-                return;
-            default:
-                break;
-        }
-        return;
-    }
-
     QWidget *widget = [[QT_MANGLE_NAMESPACE(QCocoaWindowDelegate) sharedDelegate] qt_qwidgetForWindow:self];
     // Cocoa can hold onto the window after we've disavowed its knowledge. So,
     // if we get sent an event afterwards just have it go through the super's
diff --git a/src/gui/kernel/qt_cocoa_helpers_mac.mm b/src/gui/kernel/qt_cocoa_helpers_mac.mm
index 8cef03c..cbfbf86 100644
--- a/src/gui/kernel/qt_cocoa_helpers_mac.mm
+++ b/src/gui/kernel/qt_cocoa_helpers_mac.mm
@@ -1423,39 +1423,17 @@ void qt_cocoaChangeOverrideCursor(const QCursor &cursor)
     [static_cast<NSCursor *>(qt_mac_nsCursorForQCursor(cursor)) set];
 }
 
-//  WARNING: If Qt did not create NSApplication (e.g. in case it is
-//  used as a plugin), and at the same time, there is no window on
-//  screen (or the window that the event is sendt to becomes hidden etc
-//  before the event gets delivered), the message will not be performed.
-bool qt_cocoaPostMessage(id target, SEL selector)
+void qt_cocoaPostMessage(id target, SEL selector, int argCount, id arg1, id arg2)
 {
-    if (!target)
-        return false;
-
-    NSInteger windowNumber = 0;
-    if (![NSApp isMemberOfClass:[QNSApplication class]]) {
-        // INVARIANT: Cocoa is not using our NSApplication subclass. That means
-        // we don't control the main event handler either. So target the event
-        // for one of the windows on screen:
-        NSWindow *nswin = [NSApp mainWindow];
-        if (!nswin) {
-            nswin = [NSApp keyWindow];
-            if (!nswin)
-                return false;
-        }
-        windowNumber = [nswin windowNumber];
-    }
-
-    // WARNING: data1 and data2 is truncated to from 64-bit to 32-bit on OS 10.5! 
+    // WARNING: data1 and data2 is truncated to from 64-bit to 32-bit on OS 10.5!
     // That is why we need to split the address in two parts:
-    QCocoaPostMessageArgs *args = new QCocoaPostMessageArgs(target, selector);
+    QCocoaPostMessageArgs *args = new QCocoaPostMessageArgs(target, selector, argCount, arg1, arg2);
     quint32 lower = quintptr(args);
     quint32 upper = quintptr(args) >> 32;
     NSEvent *e = [NSEvent otherEventWithType:NSApplicationDefined
-        location:NSZeroPoint modifierFlags:0 timestamp:0 windowNumber:windowNumber
+        location:NSZeroPoint modifierFlags:0 timestamp:0 windowNumber:0
         context:nil subtype:QtCocoaEventSubTypePostMessage data1:lower data2:upper];
     [NSApp postEvent:e atStart:NO];
-    return true;
 }
 #endif
 
diff --git a/src/gui/kernel/qt_cocoa_helpers_mac_p.h b/src/gui/kernel/qt_cocoa_helpers_mac_p.h
index 5db121a..6b005ca 100644
--- a/src/gui/kernel/qt_cocoa_helpers_mac_p.h
+++ b/src/gui/kernel/qt_cocoa_helpers_mac_p.h
@@ -198,17 +198,25 @@ class QCocoaPostMessageArgs {
 public:
     id target;
     SEL selector;
-    QCocoaPostMessageArgs(id target, SEL selector) : target(target), selector(selector)
+    int argCount;
+    id arg1;
+    id arg2;
+    QCocoaPostMessageArgs(id target, SEL selector, int argCount=0, id arg1=0, id arg2=0)
+        : target(target), selector(selector), argCount(argCount), arg1(arg1), arg2(arg2)
     {
         [target retain];
+        [arg1 retain];
+        [arg2 retain];
     }
 
     ~QCocoaPostMessageArgs()
     {
+        [arg2 release];
+        [arg1 release];
         [target release];
     }
 };
-bool qt_cocoaPostMessage(id target, SEL selector);
+void qt_cocoaPostMessage(id target, SEL selector, int argCount=0, id arg1=0, id arg2=0);
 #endif
 
 #endif
diff --git a/src/gui/widgets/qmenu_mac.mm b/src/gui/widgets/qmenu_mac.mm
index aaa113b..8016da9 100644
--- a/src/gui/widgets/qmenu_mac.mm
+++ b/src/gui/widgets/qmenu_mac.mm
@@ -2052,8 +2052,7 @@ bool QMenuBar::macUpdateMenuBar()
 {
 #ifdef QT_MAC_USE_COCOA
     QMacCocoaAutoReleasePool pool;
-    if (!qt_cocoaPostMessage(getMenuLoader(), @selector(qtUpdateMenubar)))
-        return QMenuBarPrivate::macUpdateMenuBarImmediatly();
+    qt_cocoaPostMessage(getMenuLoader(), @selector(qtUpdateMenubar));
     return true;
 #else
     return QMenuBarPrivate::macUpdateMenuBarImmediatly();