/**
 * QuartzProgressBar.c - Quartz Progress Bar
 * $Apple$
 **
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
 * Reserved.  This file contains Original Code and/or Modifications of
 * Original Code as defined in and that are subject to the Apple Public
 * Source License Version 1.1 (the "License").  You may not use this file
 * except in compliance with the License.  Please obtain a copy of the
 * License at http://www.apple.com/publicsource and read it before using
 * this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 **
 * Draws the progress bar using CoreGraphics (Quartz).
 *
 * WARNING: This code uses private Core Graphics API.  Private API is
 * subject to change at any time without notice, and it's use by
 * parties unknown to the Core Graphics authors is in no way supported.
 * If you borrow code from here for other use and it later breaks, you
 * have no basis for complaint.
 **/

#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>
#include <CoreGraphics/CoreGraphicsPrivate.h>
#include <CoreGraphics/CGGraphics.h>

/*
 * This is an opaque (void *) pointer in QuartzProgressBar.h.
 * The following definition is private to this file.
 */
typedef struct ProgressBar
{
    CGContextRef context;
    CGRect	 frame;
    float	 percent;
    int		 offset;
    int		 active;
    pthread_t	 thread;
} *ProgressBarRef;
#define _QuartzProgressBar_C_
#include "QuartzProgressBar.h"

#include "QuartzProgressBarData.c"

static void _ProgressBarDrawBackground (ProgressBarRef aProgressBar)
{
    CGColorSpaceRef aColorspace = CGColorSpaceCreateDeviceRGB();
    const unsigned char *aBitmapData[5] = {0, 0, 0, 0, 0};
    float x, y, w, xcur;

    x = aProgressBar->frame.origin.x;
    y = aProgressBar->frame.origin.y;
    w = aProgressBar->frame.size.width;

    /**
     * Lay down the progress bar frame and background.
     **/
    aBitmapData[0] = gEndcapData;

    /* Using only 1/4th the image on each end cap may seem like a waste, */
    /* but is necessary so that shadows do not overlap.                  */

    /* Left endcap */
    CGSaveGState    (aProgressBar->context);
    CGClipRect      (aProgressBar->context, CGRectCreate(x, y, gEndCapWidth / 2.0, gEndCapHeight));
    CGDrawBitmap    (aProgressBar->context, CGRectCreate(x, y, gEndCapWidth, gEndCapHeight),
                                            gEndCapWidth, gEndCapHeight, 8, 4, 32,
                                            gEndCapWidth * 4, 0, 1, aColorspace, aBitmapData);
    CGRestoreGState (aProgressBar->context);

    /* Right endcap */
    CGSaveGState    (aProgressBar->context);
    CGClipRect      (aProgressBar->context, CGRectCreate(x + w - gEndCapWidth / 2.0, y, gEndCapWidth / 2.0, gEndCapHeight));
    CGDrawBitmap    (aProgressBar->context, CGRectCreate(x + w - gEndCapWidth, y, gEndCapWidth, gEndCapHeight),
                                            gEndCapWidth, gEndCapHeight, 8, 4, 32,
                                            gEndCapWidth * 4, 0, 1, aColorspace, aBitmapData);
    CGRestoreGState (aProgressBar->context);

    /* Bar */
    aBitmapData[0] = gBackfillData;
    CGSaveGState    (aProgressBar->context);
    CGClipRect      (aProgressBar->context, CGRectCreate(x + gEndCapWidth / 2.0 , y, w - gEndCapWidth, gEndCapHeight));
    for (xcur = x; xcur < x + w; xcur += gBackFillWidth)
      {
        CGDrawBitmap(aProgressBar->context, CGRectCreate(xcur, y, gBackFillWidth, gBackFillHeight),
                                            gBackFillWidth, gBackFillHeight, 8, 4, 32,
                                            gBackFillWidth * 4, 0, 1, aColorspace, aBitmapData);
      }
    CGRestoreGState (aProgressBar->context);

    /* Clean up */
    CGSFlushContext (aProgressBar->context);
    CGColorSpaceRelease (aColorspace);
}

static void _ProgressBarDraw (ProgressBarRef aProgressBar)
{
    CGColorSpaceRef aColorspace = CGColorSpaceCreateDeviceRGB();
    const unsigned char *aBitmapData[5] = {0, 0, 0, 0, 0};
    float x, y, w, xcur;

    x = aProgressBar->frame.origin.x;
    y = aProgressBar->frame.origin.y;
    w = aProgressBar->frame.size.width;

    /**
     * Lay down the progress bar.
     **/
    aBitmapData[0] = gFillData;
    CGSaveGState (aProgressBar->context);
    CGClipRect   (aProgressBar->context,
                  CGRectCreate(x + gEndCapWidth / 4.0, y + (gEndCapHeight - gFillHeight),
                               (w - gEndCapWidth / 2.0) * aProgressBar->percent, gFillHeight));
    for (xcur = x + gEndCapWidth / 4.0 - aProgressBar->offset;
         xcur < x + w - gEndCapWidth / 4.0;
         xcur += gFillWidth)
      {
        CGDrawBitmap(aProgressBar->context,
                     CGRectCreate(xcur, y + (gEndCapHeight - gFillHeight), gFillWidth, gFillHeight),
                     gFillWidth, gFillHeight, 8, 4, 32, gFillWidth * 4, 0, 1, aColorspace, aBitmapData);
      }
    CGRestoreGState (aProgressBar->context);

    /* Clean up */
    CGSFlushContext (aProgressBar->context);
    CGColorSpaceRelease (aColorspace);
}

/* FIXME: This should be in a public header */
extern int nanosleep(const struct timespec *rqtp, struct timespec *rmtp);

static void *_ProgressBarBackgroundThread (void *arg)
{
    ProgressBarRef aProgressBar = (ProgressBarRef)arg;
    static const struct timespec aThirty = { 0, 1000000000 / 30};

    _ProgressBarDrawBackground (aProgressBar);

    while (aProgressBar->active)
      {
        aProgressBar->offset++;

        if (aProgressBar->offset > 15) aProgressBar->offset = 0;

        _ProgressBarDraw (aProgressBar);

        nanosleep(&aThirty, NULL);
      }

    return NULL;
}

ProgressBarRef ProgressBarCreate (CGContextRef aContext, float x, float y, float w)
{
    ProgressBarRef aProgressBar = (ProgressBarRef)malloc(sizeof(struct ProgressBar));

    aProgressBar->context           = aContext;
    aProgressBar->frame.origin.x    = x;
    aProgressBar->frame.origin.y    = y;
    aProgressBar->frame.size.width  = w;
    aProgressBar->frame.size.height = gEndCapHeight;
    aProgressBar->percent           = 0.0;
    aProgressBar->offset            = 0;
    aProgressBar->active	    = 1;

    pthread_create (&aProgressBar->thread, NULL, _ProgressBarBackgroundThread, aProgressBar);

    return aProgressBar;
}

void ProgressBarFree (ProgressBarRef aProgressBar)
{
    aProgressBar->active = 0;
    pthread_join(aProgressBar->thread, NULL);

    free(aProgressBar);
}

void ProgressBarDisplay (ProgressBarRef aProgressBar)
{
    /**
     * Assumes that the opaque ancestor (what is underneath the bar)
     * has been redrawn, and the bar is to be drawn atop that.
     **/
    _ProgressBarDrawBackground (aProgressBar);
    _ProgressBarDraw           (aProgressBar);
}

void ProgressBarSetPercent (ProgressBarRef aProgressBar, float aPercent)
{
    aProgressBar->percent = aPercent;
}