/*

    File:  CollapsibleBox.m

    Abstract:  An NSBox subclass that can toggle its frame size using animation

    Version:  1.0

    Copyright:  © Copyright 2005 Apple Computer, Inc. All rights reserved.

    Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple Computer, Inc.

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    The Apple Software is provided by Apple on an "AS IS" basis.  APPLE MAKES NO

    WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED

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*/

#import "CollapsibleBox.h"

#define ANIMATION_DURATION           0.25

#define DEFAULT_COLLAPSED_HEIGHT    38.0

@implementation CollapsibleBox

// Initializes the attributes that CollapsibleBox adds to NSBox.  This method is called by -initWithFrame:, and is also used by our Interface Builder palette.

- (void)initAddedProperties {

    expanded = YES;

    otherFrameSize = NSMakeSize([self frame].size.width, DEFAULT_COLLAPSED_HEIGHT);

}

- (id)initWithFrame:(NSRect)frame {

    self = [super initWithFrame:frame];

    if (self) {

        [self setTitlePosition:NSNoTitle];

        [self initAddedProperties];

    }

    return self;

}

#pragma mark -

#pragma mark *** Key-Value Binding Support ***

+ (void)initialize {

    if (self == [CollapsibleBox class]) {

        // Declare the attributes of this class that should be shown in the Bindings inspector in Interface Builder.

        [self exposeBinding:@"expanded"];

    }

}

#pragma mark -

#pragma mark *** NSView Method Overrides ***

- (BOOL)isFlipped {

    return YES;

}

#pragma mark -

#pragma mark *** State Accessors ***

- (BOOL)isExpanded {

    return expanded;

}

- (void)setExpanded:(BOOL)flag {

    [self setExpanded:flag animate:YES];

}

- (void)setExpanded:(BOOL)flag animate:(BOOL)animate {

    if (expanded != flag) {

        // Save new state.

        expanded = flag;

        // Get frame size for new state, and remember the frame size for the state we're leaving.

        NSSize newFrameSize = otherFrameSize;

        otherFrameSize = [self frame].size;

        // Resize self, possibly using animation.

        [self setFrameSize:newFrameSize animate:animate];

    }

}

#pragma mark -

#pragma mark *** Resizing / Animation Support ***

- (NSRect)frameForNewSizePinnedToTopLeft:(NSSize)newFrameSize {

    NSRect frame = [self frame];

    if (![[self superview] isFlipped]) {

        float yOffset = newFrameSize.height - frame.size.height;

        frame.origin.y -= yOffset;

    }

    frame.size = newFrameSize;

    return frame;

}

- (void)setFrameSizeWithPinningToTopLeft:(NSSize)newFrameSize {

    NSRect oldFrame = [self frame];

    NSRect newFrame = [self frameForNewSizePinnedToTopLeft:newFrameSize];

    [self setFrame:newFrame];

    // Offset all children of box's contentView to match.

    float yOffset = newFrame.size.height - oldFrame.size.height;

    NSArray *subviews = [[self contentView] subviews];

    unsigned count = [subviews count];

    unsigned index;

    for (index = 0; index < count; index++) {

        NSView *subview = [subviews objectAtIndex:index];

        NSPoint origin = [subview frame].origin;

        origin.y += yOffset;

        [subview setFrameOrigin:origin];

    }

}

- (void)setFrameSize:(NSSize)newFrameSize animate:(BOOL)animate {

    NSView *superview = [self superview];

    if (animate) {

        // Compute the new frame.

        NSRect newFrame = [self frameForNewSizePinnedToTopLeft:newFrameSize];

        // Give animationDelegate, if any, first shot at animating the resize (in case the app needs to coordinate with other animations).

        if (animationDelegate != nil && [animationDelegate respondsToSelector:@selector(collapsibleBox:shouldAnimateToFrame:expanding:)]) {

            if (![animationDelegate collapsibleBox:self shouldAnimateToFrame:newFrame expanding:expanded]) {

                return;

            }

        }

        // Else, do the animation ourselves.

        NSMutableArray *animationArray = [NSMutableArray arrayWithObject:[NSDictionary dictionaryWithObjectsAndKeys:self, NSViewAnimationTargetKey, [NSValue valueWithRect:newFrame], NSViewAnimationEndFrameKey, nil]];

        NSAnimation *animation = [[NSViewAnimation alloc] initWithViewAnimations:animationArray];

        [animation setAnimationBlockingMode:NSAnimationBlocking];

        [animation setDuration:ANIMATION_DURATION];

        [animation startAnimation];

        [animation release];

    } else {

        [superview setNeedsDisplayInRect:[self frame]];

        [self setFrameSizeWithPinningToTopLeft:newFrameSize];

        [self setNeedsDisplay:YES];

    }

}

#pragma mark -

#pragma mark *** Archiving ***

// A view must know how to archive and unarchive itself in order to be placed in a custom Interface Builder palette.

- (void)encodeWithCoder:(NSCoder *)aCoder {

    [super encodeWithCoder:aCoder];

    if ([aCoder allowsKeyedCoding]) {

        [aCoder encodeBool:expanded forKey:@"expanded"];

        [aCoder encodeSize:otherFrameSize forKey:@"otherFrameSize"];

        [aCoder encodeConditionalObject:animationDelegate forKey:@"animationDelegate"];

    }

}

- (id)initWithCoder:(NSCoder *)aDecoder {

    self = [super initWithCoder:aDecoder];

    if (self) {

        if ([aDecoder allowsKeyedCoding]) {

            // Read archived attributes.

            expanded = [aDecoder decodeBoolForKey:@"expanded"];

            otherFrameSize = [aDecoder decodeSizeForKey:@"otherFrameSize"];

            animationDelegate = [aDecoder decodeObjectForKey:@"animationDelegate"];

        }

    }

    return self;

}

@end