// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40285824): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif
#import "ui/base/cocoa/tool_tip_base_view.h"
#include "base/check.h"
#include "base/memory/raw_ptr.h"
#include "base/notreached.h"
// Below is the nasty tooltip stuff -- copied from WebKit's WebHTMLView.mm
// with minor modifications for code style and commenting.
//
// The 'public' interface is -setToolTipAtMousePoint:. This differs from
// -setToolTip: in that the updated tooltip takes effect immediately,
// without the user's having to move the mouse out of and back into the view.
//
// Unfortunately, doing this requires sending fake mouseEnter/Exit events to
// the view, which in turn requires overriding some internal tracking-rect
// methods (to keep track of its owner & userdata, which need to be filled out
// in the fake events.) --snej 7/6/09
/*
* Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
* (C) 2006, 2007 Graham Dennis (graham.dennis@gmail.com)
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
@implementation ToolTipBaseView {
// These are part of the magic tooltip code from WebKit's WebHTMLView:
id __weak _trackingRectOwner;
raw_ptr<void, DanglingUntriaged> _trackingRectUserData;
NSTrackingRectTag _lastToolTipTag;
NSString* __strong _toolTip;
}
// Any non-zero value will do, but using something recognizable might help us
// debug some day.
const NSTrackingRectTag kTrackingRectTag = 0xBADFACE;
// Override of a public NSView method, replacing the inherited functionality.
// See above for rationale.
- (NSTrackingRectTag)addTrackingRect:(NSRect)rect
owner:(id)owner
userData:(void *)data
assumeInside:(BOOL)assumeInside {
DCHECK(_trackingRectOwner == nil);
_trackingRectOwner = owner;
_trackingRectUserData = data;
return kTrackingRectTag;
}
// Override of (apparently) a private NSView method(!) See above for rationale.
- (NSTrackingRectTag)_addTrackingRect:(NSRect)rect
owner:(id)owner
userData:(void *)data
assumeInside:(BOOL)assumeInside
useTrackingNum:(int)tag {
DCHECK(tag == 0 || tag == kTrackingRectTag);
DCHECK(_trackingRectOwner == nil);
_trackingRectOwner = owner;
_trackingRectUserData = data;
return kTrackingRectTag;
}
// Override of (apparently) a private NSView method(!) See above for rationale.
- (void)_addTrackingRects:(NSRect *)rects
owner:(id)owner
userDataList:(void **)userDataList
assumeInsideList:(BOOL *)assumeInsideList
trackingNums:(NSTrackingRectTag *)trackingNums
count:(int)count {
DCHECK(count == 1);
DCHECK(trackingNums[0] == 0 || trackingNums[0] == kTrackingRectTag);
DCHECK(_trackingRectOwner == nil);
_trackingRectOwner = owner;
_trackingRectUserData = userDataList[0];
trackingNums[0] = kTrackingRectTag;
}
// Override of a public NSView method, replacing the inherited functionality.
// See above for rationale.
- (void)removeTrackingRect:(NSTrackingRectTag)tag {
if (tag == 0)
return;
if (tag == kTrackingRectTag) {
_trackingRectOwner = nil;
return;
}
if (tag == _lastToolTipTag) {
[super removeTrackingRect:tag];
_lastToolTipTag = 0;
return;
}
// If any other tracking rect is being removed, we don't know how it was
// created and it's possible there's a leak involved (see Radar 3500217).
NOTREACHED();
}
// Override of (apparently) a private NSView method(!)
- (void)_removeTrackingRects:(NSTrackingRectTag *)tags count:(int)count {
for (int i = 0; i < count; ++i) {
NSTrackingRectTag tag = tags[i];
if (tag == 0)
continue;
DCHECK(tag == kTrackingRectTag);
_trackingRectOwner = nil;
}
}
// Sends a fake NSEventTypeMouseExited event to the view for its current
// tracking rect.
- (void)_sendToolTipMouseExited {
// Nothing matters except window, trackingNumber, and userData.
NSEvent* fakeEvent =
[NSEvent enterExitEventWithType:NSEventTypeMouseExited
location:NSZeroPoint
modifierFlags:0
timestamp:NSApp.currentEvent.timestamp
windowNumber:self.window.windowNumber
context:nullptr
eventNumber:0
trackingNumber:kTrackingRectTag
userData:_trackingRectUserData];
[self._toolTipOwnerForSendingMouseEvents mouseExited:fakeEvent];
}
// Sends a fake NSEventTypeMouseEntered event to the view for its current
// tracking rect.
- (void)_sendToolTipMouseEntered {
NSInteger windowNumber = self.window.windowNumber;
// Only send a fake mouse enter if the mouse is actually over the window,
// versus over a window which overlaps it (see http://crbug.com/883269).
if ([NSWindow windowNumberAtPoint:NSEvent.mouseLocation
belowWindowWithWindowNumber:0] != windowNumber) {
return;
}
// Nothing matters except window, trackingNumber, and userData.
NSEvent* fakeEvent =
[NSEvent enterExitEventWithType:NSEventTypeMouseEntered
location:NSZeroPoint
modifierFlags:0
timestamp:NSApp.currentEvent.timestamp
windowNumber:windowNumber
context:nullptr
eventNumber:0
trackingNumber:kTrackingRectTag
userData:_trackingRectUserData];
[self._toolTipOwnerForSendingMouseEvents mouseEntered:fakeEvent];
}
// Identifies the owner responsible for handling mouse events related to
// tooltips. This method ensures correct tooltip behavior by checking the
// primary tracking rect owner and, if not found, searching through
// `NSTrackingArea` objects to find the tooltip manager.
- (id)_toolTipOwnerForSendingMouseEvents {
if (id owner = _trackingRectOwner) {
return owner;
}
static Class managerClass = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
managerClass = NSClassFromString(@"NSToolTipManager");
});
for (CrTrackingArea* trackingArea in self.trackingAreas) {
id owner = trackingArea.owner;
if ([owner isKindOfClass:managerClass]) {
return owner;
}
}
return nil;
}
// Sets the view's current tooltip, to be displayed at the current mouse
// location. (This does not make the tooltip appear -- as usual, it only
// appears after a delay.) Pass null to remove the tooltip.
- (void)setToolTipAtMousePoint:(NSString *)string {
NSString* toolTip = string.length == 0 ? nil : string;
if ((toolTip && _toolTip && [toolTip isEqualToString:_toolTip]) ||
(!toolTip && !_toolTip)) {
return;
}
if (_toolTip) {
[self _sendToolTipMouseExited];
}
_toolTip = [toolTip copy];
// The logic below was
//
// if (tooltip) {
// [self removeAllTooltips];
// ...
// }
//
// By moving the call to -removeAllTooltips outside of the conditional,
// we can ensure any visible tooltip will be removed from the screen.
// See crbug.com/1409942.
//
// The strategy of removing all tooltips rather than the single one that
// was added comes from WebKit, like the rest of the code here. It
// apparently works around some AppKit bug.
[self removeAllToolTips];
if (toolTip) {
NSRect wideOpenRect = NSMakeRect(-100000, -100000, 200000, 200000);
_lastToolTipTag = [self addToolTipRect:wideOpenRect
owner:self
userData:nullptr];
[self _sendToolTipMouseEntered];
}
}
// NSView calls this to get the text when displaying the tooltip.
- (NSString *)view:(NSView *)view
stringForToolTip:(NSToolTipTag)tag
point:(NSPoint)point
userData:(void *)data {
return [_toolTip copy];
}
@end
