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// **************************************************************************
// * This file is part of the FreeFileSync project. It is distributed under *
// * GNU General Public License: http://www.gnu.org/licenses/gpl.html *
// * Copyright (C) Zenju (zenju AT gmx DOT de) - All Rights Reserved *
// **************************************************************************
#include "osx_file_icon.h"
#include <zen/osx_throw_exception.h>
#include <zen/scope_guard.h>
#include <zen/basic_math.h>
namespace
{
osx::ImageData extractBytes(NSImage* nsImg, int requestedSize) //throw SysError; NSException?
{
/*
wxBitmap(NSImage*) is not good enough: it calls "[NSBitmapImageRep imageRepWithData:[img TIFFRepresentation]]"
=> inefficient: TIFFRepresentation converts all contained images of an NSImage
=> lacking: imageRepWithData extracts the first contained image only!
=> wxBitmap(NSImage*) is wxCocoa only, deprecated!
=> wxWidgets generally is not thread-safe so care must be taken to use wxBitmap from main thread only! (e.g. race-condition on non-atomic ref-count!!!)
-> we need only a single bitmap at a specific size => extract raw bytes for use with wxImage in a thread-safe way!
*/
//we choose the Core Graphics solution; for the equivalent App-Kit way see: http://www.cocoabuilder.com/archive/cocoa/193131-is-lockfocus-main-thread-specific.html#193191
ZEN_OSX_ASSERT(requestedSize > 0);
NSRect rectProposed = NSMakeRect(0, 0, requestedSize, requestedSize); //this is merely a hint!
CGImageRef imgRef = [nsImg CGImageForProposedRect:&rectProposed context:nil hints:nil];
ZEN_OSX_ASSERT(imgRef != NULL); //can this fail? not documented; ownership?? not documented!
const size_t width = ::CGImageGetWidth (imgRef);
const size_t height = ::CGImageGetHeight(imgRef);
ZEN_OSX_ASSERT(width > 0 && height > 0 && requestedSize > 0);
int trgWidth = width;
int trgHeight = height;
const int maxExtent = std::max(width, height); //don't stretch small images, but shrink large ones instead!
if (requestedSize < maxExtent)
{
trgWidth = width * requestedSize / maxExtent;
trgHeight = height * requestedSize / maxExtent;
}
CGColorSpaceRef colorSpace = ::CGColorSpaceCreateDeviceRGB();
ZEN_OSX_ASSERT(colorSpace != NULL); //may fail
ZEN_ON_SCOPE_EXIT(::CGColorSpaceRelease(colorSpace));
std::vector<unsigned char> buf(trgWidth* trgHeight * 4); //32-bit ARGB, little endian byte order -> already initialized with 0 = fully transparent
//supported color spaces: https://developer.apple.com/library/mac/#documentation/GraphicsImaging/Conceptual/drawingwithquartz2d/dq_context/dq_context.html#//apple_ref/doc/uid/TP30001066-CH203-BCIBHHBB
CGContextRef ctxRef = ::CGBitmapContextCreate(&buf[0], //void *data,
trgWidth, //size_t width,
trgHeight, //size_t height,
8, //size_t bitsPerComponent,
4 * trgWidth, //size_t bytesPerRow,
colorSpace, //CGColorSpaceRef colorspace,
kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little); //CGBitmapInfo bitmapInfo
ZEN_OSX_ASSERT(ctxRef != NULL);
ZEN_ON_SCOPE_EXIT(::CGContextRelease(ctxRef));
::CGContextDrawImage(ctxRef, CGRectMake(0, 0, trgWidth, trgHeight), imgRef); //can this fail? not documented
//CGContextFlush(ctxRef); //"If you pass [...] a bitmap context, this function does nothing."
osx::ImageData imgOut(trgWidth, trgHeight);
auto it = buf.begin();
auto itOutRgb = imgOut.rgb.begin();
auto itOutAlpha = imgOut.alpha.begin();
for (int i = 0; i < trgWidth * trgHeight; ++i)
{
const unsigned char b = *it++;
const unsigned char g = *it++;
const unsigned char r = *it++;
const unsigned char a = *it++;
//unsigned arithmetics caveat!
auto demultiplex = [&](unsigned char c) { return static_cast<unsigned char>(numeric::confineCpy(a == 0 ? 0 : (c * 255 + a - 1) / a, 0, 255)); }; //=ceil(c * 255 / a)
*itOutRgb++ = demultiplex(r);
*itOutRgb++ = demultiplex(g);
*itOutRgb++ = demultiplex(b);
*itOutAlpha++ = a;
}
return imgOut;
}
}
osx::ImageData osx::getThumbnail(const char* filename, int requestedSize) //throw SysError
{
@try
{
@autoreleasepool
{
NSString* nsFile = [NSString stringWithCString:filename encoding:NSUTF8StringEncoding];
ZEN_OSX_ASSERT(nsFile != nil); //throw SysError; can this fail? not documented
//stringWithCString returns string which is already set to autorelease!
NSImage* nsImg = [[[NSImage alloc] initWithContentsOfFile:nsFile] autorelease];
ZEN_OSX_ASSERT(nsImg != nil); //may fail
return extractBytes(nsImg, requestedSize); //throw SysError
}
}
@catch(NSException* e)
{
throwSysError(e); //throw SysError
}
}
osx::ImageData osx::getFileIcon(const char* filename, int requestedSize) //throw SysError
{
@try
{
@autoreleasepool
{
NSString* nsFile = [NSString stringWithCString:filename encoding:NSUTF8StringEncoding];
ZEN_OSX_ASSERT(nsFile != nil); //throw SysError; can this fail? not documented
//stringWithCString returns string which is already set to autorelease!
NSImage* nsImg = [[NSWorkspace sharedWorkspace] iconForFile:nsFile];
ZEN_OSX_ASSERT(nsImg != nil); //can this fail? not documented
return extractBytes(nsImg, requestedSize); //throw SysError
}
}
@catch (NSException* e)
{
throwSysError(e); //throw SysError
}
}
osx::ImageData osx::getDefaultFileIcon(int requestedSize) //throw SysError
{
@try
{
@autoreleasepool
{
NSImage* nsImg = [[NSWorkspace sharedWorkspace] iconForFileType:NSFileTypeForHFSTypeCode(kGenericDocumentIcon)];
//NSImage* nsImg = [[NSWorkspace sharedWorkspace] iconForFileType:@"dat"];
ZEN_OSX_ASSERT(nsImg != nil); //can this fail? not documented
return extractBytes(nsImg, requestedSize); //throw SysError
}
}
@catch (NSException* e)
{
throwSysError(e); //throw SysError
}
}
osx::ImageData osx::getDefaultFolderIcon(int requestedSize) //throw SysError
{
@try
{
@autoreleasepool
{
NSImage* nsImg = [NSImage imageNamed:NSImageNameFolder];
//NSImage* nsImg = [[NSWorkspace sharedWorkspace] iconForFileType:NSFileTypeForHFSTypeCode(kGenericFolderIcon)];
ZEN_OSX_ASSERT(nsImg != nil); //may fail
return extractBytes(nsImg, requestedSize); //throw SysError
}
}
@catch (NSException* e)
{
throwSysError(e); //throw SysError
}
}
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