Implement back/forward toolbar menus on Mac....

chrome/browser/cocoa/clickhold_button_cell.mm

+// Copyright (c) 2009 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/cocoa/clickhold_button_cell.h"
+
+#include "base/logging.h"
+
+// Minimum and maximum click-hold timeout.
+static const NSTimeInterval kMinTimeout = 0.01;
+static const NSTimeInterval kMaxTimeout = 3600.0;
+
+@implementation ClickHoldButtonCell
+
+// Overrides:
+
++ (BOOL)prefersTrackingUntilMouseUp {
+  return NO;
+}
+
+- (BOOL)startTrackingAt:(NSPoint)startPoint
+                 inView:(NSView*)controlView {
+  return enableClickHold_ ?
+      YES :
+      [super startTrackingAt:startPoint
+                      inView:controlView];
+}
+
+- (BOOL)continueTracking:(NSPoint)lastPoint
+                      at:(NSPoint)currentPoint
+                  inView:(NSView*)controlView {
+  return enableClickHold_ ?
+      YES :
+      [super continueTracking:lastPoint
+                           at:currentPoint
+                       inView:controlView];
+}
+
+- (BOOL)trackMouse:(NSEvent*)originalEvent
+            inRect:(NSRect)cellFrame
+            ofView:(NSView*)controlView
+      untilMouseUp:(BOOL)untilMouseUp {
+  if (!enableClickHold_) {
+    return [super trackMouse:originalEvent
+                      inRect:cellFrame
+                      ofView:controlView
+                untilMouseUp:untilMouseUp];
+  }
+
+  // If doing click-hold, track the mouse ourselves.
+  NSPoint currPoint = [controlView convertPoint:[originalEvent locationInWindow]
+                                       fromView:nil];
+  NSPoint lastPoint = currPoint;
+  NSTimeInterval timeout =
+      MAX(MIN(clickHoldTimeout_, kMaxTimeout), kMinTimeout);
+  NSDate* clickHoldBailTime = [NSDate dateWithTimeIntervalSinceNow:timeout];
+
+  if (![self startTrackingAt:currPoint inView:controlView])
+    return NO;
+
+  enum {
+    kContinueTrack, kStopClickHold, kStopMouseUp, kStopLeftRect, kStopNoContinue
+  } state = kContinueTrack;
+  do {
+    NSEvent* event = [NSApp nextEventMatchingMask:(NSLeftMouseDraggedMask |
+                                                   NSLeftMouseUpMask)
+                                        untilDate:clickHoldBailTime
+                                           inMode:NSEventTrackingRunLoopMode
+                                          dequeue:YES];
+    currPoint = [controlView convertPoint:[event locationInWindow]
+                                 fromView:nil];
+
+    // Time-out or drag.
+    if (!event || (activateOnDrag_ && ([event type] == NSLeftMouseDragged))) {
+      state = kStopClickHold;
+
+    // Mouse up.
+    } else if ([event type] == NSLeftMouseUp) {
+      state = kStopMouseUp;
+
+    // Stop tracking if mouse left frame rectangle (if requested to do so).
+    } else if (trackOnlyInRect_ && ![controlView mouse:currPoint
+                                                inRect:cellFrame]) {
+      state = kStopLeftRect;
+
+    // Stop tracking if instructed to.
+    } else if (![self continueTracking:lastPoint
+                                    at:currPoint
+                                inView:controlView]) {
+      state = kStopNoContinue;
+    }
+
+    lastPoint = currPoint;
+  } while (state == kContinueTrack);
+
+  [self stopTracking:lastPoint
+                  at:lastPoint
+              inView:controlView
+           mouseIsUp:NO];
+
+  switch (state) {
+    case kStopClickHold:
+      if (clickHoldAction_) {
+        [static_cast<NSControl*>(controlView) sendAction:clickHoldAction_
+                                                      to:clickHoldTarget_];
+      }
+      return YES;
+
+    case kStopMouseUp:
+      if ([self action]) {
+        [static_cast<NSControl*>(controlView) sendAction:[self action]
+                                                      to:[self target]];
+      }
+      return YES;
+
+    case kStopLeftRect:
+    case kStopNoContinue:
+      return NO;
+
+    default:
+      NOTREACHED() << "Unknown terminating state!";
+  }
+
+  return NO;
+}
+
+// Accessors and mutators:
+
+@synthesize enableClickHold = enableClickHold_;
+@synthesize clickHoldTimeout = clickHoldTimeout_;
+@synthesize trackOnlyInRect = trackOnlyInRect_;
+@synthesize activateOnDrag = activateOnDrag_;
+@synthesize clickHoldTarget = clickHoldTarget_;
+@synthesize clickHoldAction = clickHoldAction_;
+
+@end  // @implementation ClickHoldButtonCell