[Mac] Factor out keyboard shortcut handling from ChromeEventProcessingWindow.

ui/base/cocoa/command_dispatcher.mm

Index: ui/base/cocoa/command_dispatcher.mm
diff --git a/chrome/browser/ui/cocoa/chrome_event_processing_window.mm b/ui/base/cocoa/command_dispatcher.mm
similarity index 34%
copy from chrome/browser/ui/cocoa/chrome_event_processing_window.mm
copy to ui/base/cocoa/command_dispatcher.mm
index 4dd2c644a574850fc78ae54c78c0da9b3a7c252b..64ac8fd1bb229d5c448b7f73195ead700d89e2cd 100644
--- a/chrome/browser/ui/cocoa/chrome_event_processing_window.mm
+++ b/ui/base/cocoa/command_dispatcher.mm
@@ -1,67 +1,13 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#import "chrome/browser/ui/cocoa/chrome_event_processing_window.h"
+#import "ui/base/cocoa/command_dispatcher.h"
 
 #include "base/logging.h"
-#include "chrome/browser/global_keyboard_shortcuts_mac.h"
-#include "chrome/browser/ui/browser_commands.h"
-#include "chrome/browser/ui/browser_finder.h"
-#import "chrome/browser/ui/cocoa/browser_window_controller_private.h"
-#import "chrome/browser/ui/cocoa/tabs/tab_strip_controller.h"
-#import "content/public/browser/render_widget_host_view_mac_base.h"
 
 namespace {
 
-// Type of functions listed in global_keyboard_shortcuts_mac.h.
-typedef int (*KeyToCommandMapper)(bool, bool, bool, bool, int, unichar);
-
-// If the event is for a Browser window, and the key combination has an
-// associated command, execute the command.
-bool HandleExtraKeyboardShortcut(
-    NSEvent* event,
-    NSWindow* window,
-    KeyToCommandMapper command_for_keyboard_shortcut) {
-  // Extract info from |event|.
-  NSUInteger modifers = [event modifierFlags];
-  const bool command = modifers & NSCommandKeyMask;
-  const bool shift = modifers & NSShiftKeyMask;
-  const bool control = modifers & NSControlKeyMask;
-  const bool option = modifers & NSAlternateKeyMask;
-  const int key_code = [event keyCode];
-  const unichar key_char = KeyCharacterForEvent(event);
-
-  int cmd = command_for_keyboard_shortcut(command, shift, control, option,
-                                          key_code, key_char);
-
-  if (cmd == -1)
-    return false;
-
-  // Only handle event if this is a browser window.
-  Browser* browser = chrome::FindBrowserWithWindow(window);
-  if (!browser)
-    return false;
-
-  chrome::ExecuteCommand(browser, cmd);
-  return true;
-}
-
-bool HandleExtraWindowKeyboardShortcut(NSEvent* event, NSWindow* window) {
-  return HandleExtraKeyboardShortcut(event, window,
-                                     CommandForWindowKeyboardShortcut);
-}
-
-bool HandleDelayedWindowKeyboardShortcut(NSEvent* event, NSWindow* window) {
-  return HandleExtraKeyboardShortcut(event, window,
-                                     CommandForDelayedWindowKeyboardShortcut);
-}
-
-bool HandleExtraBrowserKeyboardShortcut(NSEvent* event, NSWindow* window) {
-  return HandleExtraKeyboardShortcut(event, window,
-                                     CommandForBrowserKeyboardShortcut);
-}
-
 // Duplicate the given key event, but changing the associated window.
 NSEvent* KeyEventForWindow(NSWindow* window, NSEvent* event) {
   NSEventType event_type = [event type];
@@ -99,72 +45,64 @@ NSEvent* KeyEventForWindow(NSWindow* window, NSEvent* event) {
 
 }  // namespace
 
-@implementation ChromeEventProcessingWindow
+@implementation CommandDispatcher {
+ @private
+  BOOL redispatchingEvent_;
+  BOOL eventHandled_;
+  NSWindow<CommandDispatchingWindow>* owner_;  // Weak, owns us.
+}
+
+@synthesize delegate = delegate_;
 
-- (BOOL)handleExtraKeyboardShortcut:(NSEvent*)event {
-  return HandleExtraBrowserKeyboardShortcut(event, self) ||
-         HandleExtraWindowKeyboardShortcut(event, self) ||
-         HandleDelayedWindowKeyboardShortcut(event, self);
+- (instancetype)initWithOwner:(NSWindow<CommandDispatchingWindow>*)owner {
+  if ((self = [super init])) {
+    owner_ = owner;
+  }
+  return self;
 }
 
 - (BOOL)performKeyEquivalent:(NSEvent*)event {
-  // Some extension commands have higher priority than web content, and some
-  // have lower priority. Regardless of whether the event is being
-  // redispatched, let the extension system try to handle the event.
-  NSWindow* window = event.window;
-  if (window) {
-    BrowserWindowController* controller = [window windowController];
-    if ([controller respondsToSelector:@selector(handledByExtensionCommand:
-                                                                  priority:)]) {
-      ui::AcceleratorManager::HandlerPriority priority =
-          redispatchingEvent_ ? ui::AcceleratorManager::kNormalPriority
-                              : ui::AcceleratorManager::kHighPriority;
-      if ([controller handledByExtensionCommand:event priority:priority])
-        return YES;
-    }
+  if ([delegate_ eventHandledByExtensionCommand:event
+                                   isRedispatch:redispatchingEvent_]) {
+    return YES;
   }
 
   if (redispatchingEvent_)
     return NO;
 
-  // Give the web site a chance to handle the event. If it doesn't want to
-  // handle it, it will call us back with one of the |handle*| methods above.
-  NSResponder* r = [self firstResponder];
-  if ([r conformsToProtocol:@protocol(RenderWidgetHostViewMacBase)])
+  // Give a CommandDispatcherTarget (e.g. a web site) a chance to handle the
+  // event. If it doesn't want to handle it, it will call us back with
+  // -redispatchKeyEvent:.
+  NSResponder* r = [owner_ firstResponder];
+  if ([r conformsToProtocol:@protocol(CommandDispatcherTarget)])
     return [r performKeyEquivalent:event];
 
-  // Handle per-window shortcuts like cmd-1, but do not handle browser-level
-  // shortcuts like cmd-left (else, cmd-left would do history navigation even
-  // if e.g. the Omnibox has focus).
-  if (HandleExtraWindowKeyboardShortcut(event, self))
+  if ([delegate_ prePerformKeyEquivalent:event window:owner_])
     return YES;
 
-  if ([super performKeyEquivalent:event])
+  if ([owner_ defaultPerformKeyEquivalent:event])
     return YES;
 
-  // Handle per-window shortcuts like Esc after giving everybody else a chance
-  // to handle them
-  return HandleDelayedWindowKeyboardShortcut(event, self);
+  return [delegate_ postPerformKeyEquivalent:event window:owner_];
 }
 
 - (BOOL)redispatchKeyEvent:(NSEvent*)event {
   DCHECK(event);
   NSEventType eventType = [event type];
-  if (eventType != NSKeyDown &&
-      eventType != NSKeyUp &&
+  if (eventType != NSKeyDown && eventType != NSKeyUp &&
       eventType != NSFlagsChanged) {
     NOTREACHED();
     return YES;  // Pretend it's been handled in an effort to limit damage.
   }
 
-  // Ordinarily, the event's window should be this window. However, when
-  // switching between normal and fullscreen mode, we switch out the window, and
-  // the event's window might be the previous window (or even an earlier one if
-  // the renderer is running slowly and several mode switches occur). In this
-  // rare case, we synthesize a new key event so that its associate window
-  // (number) is our own.
-  if ([event window] != self)
-    event = KeyEventForWindow(self, event);
+  // Ordinarily, the event's window should be |owner_|. However, when switching
+  // between normal and fullscreen mode, we switch out the window, and the
+  // event's window might be the previous window (or even an earlier one if the
+  // renderer is running slowly and several mode switches occur). In this rare
+  // case, we synthesize a new key event so that its associate window (number)
+  // is our |owner_|'s.
+  if ([event window] != owner_)
+    event = KeyEventForWindow(owner_, event);
 
   // Redispatch the event.
   eventHandled_ = YES;
@@ -178,11 +116,15 @@ NSEvent* KeyEventForWindow(NSWindow* window, NSEvent* event) {
   return eventHandled_;
 }
 
-- (void)sendEvent:(NSEvent*)event {
-  if (!redispatchingEvent_)
-    [super sendEvent:event];
-  else
+- (BOOL)preSendEvent:(NSEvent*)event {
+  if (redispatchingEvent_) {
+    // If we get here, then the event was not handled by NSApplication.
     eventHandled_ = NO;
+    // Return YES to stop native -sendEvent handling.
+    return YES;
+  }
+
+  return NO;
 }
 
-@end  // ChromeEventProcessingWindow
+@end