webkit/src/WebKit/mac/WebInspector/WebNodeHighlight.mm

/*
 * Copyright (C) 2007, 2008 Apple Inc.  All rights reserved.
 *
 * 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.
 */

#import "WebNodeHighlight.h"
#import "WebNodeHighlightView.h"
#import "WebNSViewExtras.h"

#import <WebCore/InspectorController.h>
#import <wtf/Assertions.h>

using namespace WebCore;

@interface WebNodeHighlight (FileInternal)
- (NSRect)_computeHighlightWindowFrame;
- (void)_repositionHighlightWindow;
@end

@implementation WebNodeHighlight

- (id)initWithTargetView:(NSView *)targetView inspectorController:(InspectorController*)inspectorController
{
    self = [super init];
    if (!self)
        return nil;

    _targetView = [targetView retain];
    _inspectorController = inspectorController;

    int styleMask = NSBorderlessWindowMask;
    NSRect contentRect = [NSWindow contentRectForFrameRect:[self _computeHighlightWindowFrame] styleMask:styleMask];
    _highlightWindow = [[NSWindow alloc] initWithContentRect:contentRect styleMask:styleMask backing:NSBackingStoreBuffered defer:NO];
    [_highlightWindow setBackgroundColor:[NSColor clearColor]];
    [_highlightWindow setOpaque:NO];
    [_highlightWindow setIgnoresMouseEvents:YES];
    [_highlightWindow setReleasedWhenClosed:NO];

    _highlightView = [[WebNodeHighlightView alloc] initWithWebNodeHighlight:self];
    [_highlightWindow setContentView:_highlightView];
    [_highlightView release];

    return self;
}

- (void)dealloc
{
    ASSERT(!_highlightWindow);
    ASSERT(!_targetView);
    ASSERT(!_highlightView);

    [super dealloc];
}

- (void)attach
{
    ASSERT(_targetView);
    ASSERT([_targetView window]);
    ASSERT(_highlightWindow);

    if (!_highlightWindow || !_targetView || ![_targetView window])
        return;

    [[_targetView window] addChildWindow:_highlightWindow ordered:NSWindowAbove];

    // Observe both frame-changed and bounds-changed notifications because either one could leave
    // the highlight incorrectly positioned with respect to the target view. We need to do this for
    // the entire superview hierarchy to handle scrolling, bars coming and going, etc. 
    // (without making concrete assumptions about the view hierarchy).
    NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];
    for (NSView *v = _targetView; v; v = [v superview]) {
        [notificationCenter addObserver:self selector:@selector(_repositionHighlightWindow) name:NSViewFrameDidChangeNotification object:v];
        [notificationCenter addObserver:self selector:@selector(_repositionHighlightWindow) name:NSViewBoundsDidChangeNotification object:v];
    }

    if (_delegate && [_delegate respondsToSelector:@selector(didAttachWebNodeHighlight:)])
        [_delegate didAttachWebNodeHighlight:self];
}

- (id)delegate
{
    return _delegate;
}

- (void)detach
{
    if (!_highlightWindow) {
        ASSERT(!_targetView);
        return;
    }

    if (_delegate && [_delegate respondsToSelector:@selector(willDetachWebNodeHighlight:)])
        [_delegate willDetachWebNodeHighlight:self];

    NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];
    [notificationCenter removeObserver:self name:NSViewFrameDidChangeNotification object:nil];
    [notificationCenter removeObserver:self name:NSViewBoundsDidChangeNotification object:nil];

    [[_highlightWindow parentWindow] removeChildWindow:_highlightWindow];

    [_highlightWindow release];
    _highlightWindow = nil;

    [_targetView release];
    _targetView = nil;

    // We didn't retain _highlightView, but we do need to tell it to forget about us, so it doesn't
    // try to send our delegate messages after we've been dealloc'ed, e.g.
    [_highlightView detachFromWebNodeHighlight];
    _highlightView = nil;
}

- (WebNodeHighlightView *)highlightView
{
    return _highlightView;
}

- (void)setDelegate:(id)delegate
{
    // The delegate is not retained, as usual in Cocoa.
    _delegate = delegate;
}

- (void)setNeedsUpdateInTargetViewRect:(NSRect)rect
{
    ASSERT(_targetView);

    [[_targetView window] disableScreenUpdatesUntilFlush];

    // Mark the whole highlight view as needing display since we don't know what areas
    // need updated, since the highlight can be larger than the element to show margins.
    [_highlightView setNeedsDisplay:YES];

    // Redraw highlight view immediately so it updates in sync with the target view.
    // This is especially visible when resizing the window, scrolling or with DHTML.
    [_highlightView displayIfNeeded];
}

- (NSView *)targetView
{
    return _targetView;
}

- (InspectorController*)inspectorController
{
    return _inspectorController;
}

@end

@implementation WebNodeHighlight (FileInternal)

- (NSRect)_computeHighlightWindowFrame
{
    ASSERT(_targetView);
    ASSERT([_targetView window]);

    NSRect highlightWindowFrame = [_targetView convertRect:[_targetView visibleRect] toView:nil];
    highlightWindowFrame.origin = [[_targetView window] convertBaseToScreen:highlightWindowFrame.origin];

    return highlightWindowFrame;
}

- (void)_repositionHighlightWindow
{
    // This assertion fires in cases where a new tab is created while the highlight
    // is showing (<http://bugs.webkit.org/show_bug.cgi?id=14254>)
    ASSERT([_targetView window]);
    
    // Until that bug is fixed, bail out to avoid worse problems where the highlight
    // moves to a nonsense location.
    if (![_targetView window])
        return;

    // Disable screen updates so the highlight moves in sync with the view.
    [[_targetView window] disableScreenUpdatesUntilFlush];

    [_highlightWindow setFrame:[self _computeHighlightWindowFrame] display:YES];
}

@end