/*

File: ShadingView.m

Abstract: Implements a view that uses a CGFunctionRef, CGShadingRef

    and the given parameters to render a gradient within it's bounds.

Version: 1.0

Disclaimer: IMPORTANT:  This Apple software is supplied to you by 

Apple Inc. ("Apple") in consideration of your agreement to the

following terms, and your use, installation, modification or

redistribution of this Apple software constitutes acceptance of these

terms.  If you do not agree with these terms, please do not use,

install, modify or redistribute this Apple software.

In consideration of your agreement to abide by the following terms, and

subject to these terms, Apple grants you a personal, non-exclusive

license, under Apple's copyrights in this original Apple software (the

"Apple Software"), to use, reproduce, modify and redistribute the Apple

Software, with or without modifications, in source and/or binary forms;

provided that if you redistribute the Apple Software in its entirety and

without modifications, you must retain this notice and the following

text and disclaimers in all such redistributions of the Apple Software. 

Neither the name, trademarks, service marks or logos of Apple Inc. 

may be used to endorse or promote products derived from the Apple

Software without specific prior written permission from Apple.  Except

as expressly stated in this notice, no other rights or licenses, express

or implied, are granted by Apple herein, including but not limited to

any patent rights that may be infringed by your derivative works or by

other works in which the Apple Software may be incorporated.

The Apple Software is provided by Apple on an "AS IS" basis.  APPLE

MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION

THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS

FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND

OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.

IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL

OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION,

MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED

AND WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE),

STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE

POSSIBILITY OF SUCH DAMAGE.

Copyright (C) 2007 Apple Inc. All Rights Reserved.

*/

#import "QuartzDrawing.h"

#import "ShadingView.h"

@implementation ShadingView

- (id)initWithFrame:(NSRect)frameRect

{

    self = [super initWithFrame:frameRect];

    if(self != nil)

    {

        // Default to a square clipping area,

        // linear gradient, show the clip & end points,

        // and don't extend past start or end point.

        shape = 0;

        type = 0;

        shadingFunction = NULL;

        shading = NULL;

        showClip = showEndpoints = true;

        extendStart = extendEnd = false;

    }

    return self;

}

-(void)dealloc

{

    CGShadingRelease(shading);

    CGFunctionRelease(shadingFunction);

    [super dealloc];

}

-(void)drawRect:(NSRect)rect

{

    // Obtain the current context

    CGContextRef context = (CGContextRef)[[NSGraphicsContext currentContext] graphicsPort];

    // Move 0,0 to the center of the view

    CGContextTranslateCTM(context, rect.size.width / 2.0, rect.size.height / 2.0);

    CGContextSaveGState(context);

    // Scale the coordinate system to -1,1 on both axies.

    CGContextScaleCTM(context, rect.size.width / 2.0, rect.size.height / 2.0);

    // Clip to the correct shape.

    switch(shape)

    {

        case 0: // Square

            CGContextAddPath(context, GetSquarePath());

            CGContextClip(context);

            break;

        case 1: // Circle

            CGContextAddPath(context, GetCirclePath());

            CGContextClip(context);

            break;

        case 2: // Filled Star

            CGContextAddPath(context, GetStarPath());

            CGContextClip(context);

            break;

        case 3: // Hollow Star

            CGContextAddPath(context, GetStarPath());

            CGContextEOClip(context);

            break;

    }

    // If the shading function has been set, but the shading hasn't been created yet

    // create the correct shading function for this view.

    if((shading == NULL) && (shadingFunction != NULL))

    {

        switch(type)

        {

            case 0: // Linear (perpendicular to the line from startPoint to endPoint)

                shading = CGShadingCreateAxial(GetGenericRGBColorspace(), startPoint, endPoint, shadingFunction, extendStart, extendEnd);

                break;

        case 1: // Radial (concentric circles, interpolating radius from startRadius to endRadius,

                //and center from startPoint to endPoint)

                shading = CGShadingCreateRadial(GetGenericRGBColorspace(), startPoint, startRadius, endPoint, endRadius, shadingFunction, extendStart, extendEnd);

                break;

        }

    }

    // If we need to show the clipping region, then add a black fill with 25% opacity.

    if(showClip)

    {

        CGContextSetGrayFillColor(context, 0.0, 0.25);

        CGContextFillRect(context, CGRectMake(-1.0, -1.0, 2.0, 2.0));

    }

    // Draw the shading

    if(shading != NULL)

    {

        CGContextDrawShading(context, shading);

    }

    CGContextRestoreGState(context);

    // If we need to show the endpoints, then draw them.

    if(showEndpoints)

    {

        DrawEmbellishments(context, NSSizeToCGSize(rect.size), startPoint, startRadius, endPoint, endRadius, type == 1);

    }

}

-(void)setShapeSquare

{

    shape = 0;

    [self setNeedsDisplay:YES];

}

-(void)setShapeCircle

{

    shape = 1;

    [self setNeedsDisplay:YES];

}

-(void)setShapeFilledStar

{

    shape = 2;

    [self setNeedsDisplay:YES];

}

-(void)setShapeHollowStar

{

    shape = 3;

    [self setNeedsDisplay:YES];

}

// Called when the shading needs to be reset (so that it will be recreated later)

// This is called when any of the shading parameters are changed.

-(void)clearShading

{

    CGShadingRelease(shading);

    shading = NULL;

}

-(void)setTypeAxial

{

    if(type != 0)

    {

        type = 0;

        [self clearShading];

        [self setNeedsDisplay:YES];

    }

}

-(void)setTypeRadial

{

    if(type != 1)

    {

        type = 1;

        [self clearShading];

        [self setNeedsDisplay:YES];

    }

}

-(void)setExtendStart:(BOOL)extend

{

    if(extend != extendStart)

    {

        extendStart = extend;

        [self clearShading];

        [self setNeedsDisplay:YES];

    }

}

-(void)setExtendEnd:(BOOL)extend

{

    if(extend != extendEnd)

    {

        extendEnd = extend;

        [self clearShading];

        [self setNeedsDisplay:YES];

    }

}

-(void)setStartPoint:(CGPoint)p

{

    startPoint = p;

    [self clearShading];

    [self setNeedsDisplay:YES];

}

-(void)setEndPoint:(CGPoint)p

{

    endPoint = p;

    [self clearShading];

    [self setNeedsDisplay:YES];

}

-(void)setStartRadius:(CGFloat)r

{

    startRadius = r;

    [self clearShading];

    [self setNeedsDisplay:YES];

}

-(void)setEndRadius:(CGFloat)r

{

    endRadius = r;

    [self clearShading];

    [self setNeedsDisplay:YES];

}

-(void)setShowClip:(BOOL)yn

{

    showClip = yn;

    [self setNeedsDisplay:YES];

}

-(void)setShowEndpoints:(BOOL)yn

{

    showEndpoints = yn;

    [self setNeedsDisplay:YES];

}

-(void)setShadingFunction:(CGFunctionRef)f

{

    if(f != shadingFunction)

    {

        CGFunctionRelease(shadingFunction);

        CGFunctionRetain(f);

        shadingFunction = f;

    }

    [self clearShading];

    [self setNeedsDisplay:YES];

}

@end