menu_tracked_button.mm revision 72a454cd3513ac24fbdd0e0cb9ad70b86a99b801 
1// Copyright (c) 2010 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#import "chrome/browser/ui/cocoa/wrench_menu/menu_tracked_button.h"
6
7#include <cmath>
8
9@interface MenuTrackedButton (Private)
10- (void)doHighlight:(BOOL)highlight;
11- (void)checkMouseInRect;
12- (NSRect)insetBounds;
13- (BOOL)shouldHighlightOnHover;
14@end
15
16@implementation MenuTrackedButton
17
18@synthesize tracking = tracking_;
19
20- (void)updateTrackingAreas {
21  [super updateTrackingAreas];
22  [self removeTrackingRect:trackingTag_];
23  trackingTag_ = [self addTrackingRect:NSInsetRect([self bounds], 1, 1)
24                                 owner:self
25                              userData:NULL
26                          assumeInside:NO];
27}
28
29- (void)viewDidMoveToWindow {
30  [self updateTrackingAreas];
31  [self doHighlight:NO];
32}
33
34- (void)mouseEntered:(NSEvent*)theEvent {
35  if (!tracking_) {
36    didEnter_ = YES;
37  }
38  [self doHighlight:YES];
39  [super mouseEntered:theEvent];
40}
41
42- (void)mouseExited:(NSEvent*)theEvent {
43  didEnter_ = NO;
44  tracking_ = NO;
45  [self doHighlight:NO];
46  [super mouseExited:theEvent];
47}
48
49- (void)mouseDragged:(NSEvent*)theEvent {
50  tracking_ = !didEnter_;
51
52  NSPoint point = [self convertPoint:[theEvent locationInWindow] fromView:nil];
53  BOOL highlight = NSPointInRect(point, [self insetBounds]);
54  [self doHighlight:highlight];
55
56  // If tracking in non-sticky mode, poll the mouse cursor to see if it is still
57  // over the button and thus needs to be highlighted.  The delay is the
58  // smallest that still produces the effect while minimizing jank. Smaller
59  // values make the selector fire too close to immediately/now for the mouse to
60  // have moved off the receiver, and larger values produce lag.
61  if (tracking_ && [self shouldHighlightOnHover]) {
62    [self performSelector:@selector(checkMouseInRect)
63               withObject:nil
64               afterDelay:0.05
65                  inModes:[NSArray arrayWithObject:NSEventTrackingRunLoopMode]];
66  }
67  [super mouseDragged:theEvent];
68}
69
70- (void)mouseUp:(NSEvent*)theEvent {
71  [self doHighlight:NO];
72  if (!tracking_) {
73    return [super mouseUp:theEvent];
74  }
75  [self performClick:self];
76  tracking_ = NO;
77}
78
79- (void)doHighlight:(BOOL)highlight {
80  if (![self shouldHighlightOnHover]) {
81    return;
82  }
83  [[self cell] setHighlighted:highlight];
84  [self setNeedsDisplay];
85}
86
87// Checks if the user's current mouse location is over this button.  If it is,
88// the user is merely hovering here.  If it is not, then disable the highlight.
89// If the menu is opened in non-sticky mode, the button does not receive enter/
90// exit mouse events and thus polling is necessary.
91- (void)checkMouseInRect {
92  NSPoint point = [NSEvent mouseLocation];
93  point = [[self window] convertScreenToBase:point];
94  point = [self convertPoint:point fromView:nil];
95  if (!NSPointInRect(point, [self insetBounds])) {
96    [self doHighlight:NO];
97  }
98}
99
100// Returns the bounds of the receiver slightly inset to avoid highlighting both
101// buttons in a pair that overlap.
102- (NSRect)insetBounds {
103  return NSInsetRect([self bounds], 2, 1);
104}
105
106- (BOOL)shouldHighlightOnHover {
107  // Apple does not define NSAppKitVersionNumber10_5 when using the 10.5 SDK.
108  // The Internets have come up with this solution.
109  #ifndef NSAppKitVersionNumber10_5
110  #define NSAppKitVersionNumber10_5 949
111  #endif
112
113  // There's a cell drawing bug in 10.5 that was fixed on 10.6.  Hover states
114  // look terrible due to this, so disable highlighting on 10.5.
115  return std::floor(NSAppKitVersionNumber) > NSAppKitVersionNumber10_5;
116}
117
118@end
119