Quartz Composer / WebViewの画像を取得するパッチ

追記(2011/07/31): 修正版を書きました．

---

やってみた

WebKit.frameworkを追加

WebViewPlugIn.h

#import <Quartz/Quartz.h>
#import <Webkit/WebKit.h>

@interface WebViewPlugIn : QCPlugIn {
@private
    WebView *aWebView;
    NSString *oldURL;
    NSBitmapImageRep    *aBitmapImageRep;
}

@property(assign) NSString *inputURL; 
@property(assign) id outputImage; 
@end

WebViewPlugIn.m

#import <OpenGL/CGLMacro.h>
#import "WebViewPlugIn.h"

#define    kQCPlugIn_Name                @"WebView"
#define    kQCPlugIn_Description        @"WebView description"

@implementation WebViewPlugIn
@dynamic inputURL;
@dynamic outputImage;
+ (NSDictionary *)attributes
{
    return [NSDictionary dictionaryWithObjectsAndKeys:
            kQCPlugIn_Name, QCPlugInAttributeNameKey,
            kQCPlugIn_Description, QCPlugInAttributeDescriptionKey,
            nil];
}

+ (NSDictionary *)attributesForPropertyPortWithKey:(NSString *)key
{
    return nil;
}

+ (QCPlugInExecutionMode)executionMode
{
    return kQCPlugInExecutionModeProvider;
}

+ (QCPlugInTimeMode)timeMode
{
    return kQCPlugInTimeModeIdle;
}

- (id)init
{
    self = [super init];
    if (self) {
        NSRect r= NSMakeRect(0,0, 16, 16);
        aWebView= [[WebView alloc] initWithFrame:r
                                       frameName:nil
                                       groupName:nil];
        NSWindow *w= [[NSWindow alloc] init];
        [w setContentView:aWebView];
        [w setFrame:r display:YES];
        [aWebView setFrameLoadDelegate:self];  
    }    
    return self;
}
- (void)finalize
{
    [super finalize];
}
- (void)dealloc
{
    [aWebView release];
    [oldURL release];
    [super dealloc];
}
@end
@implementation WebViewPlugIn (Execution)
- (BOOL)startExecution:(id <QCPlugInContext>)context
{
    return YES;
}
- (void)enableExecution:(id <QCPlugInContext>)context
{
}
static void _BufferReleaseCallback(const void* address, void* info)
{
    free(CGBitmapContextGetData((CGContextRef)info));
    CGContextRelease(info);
}
- (BOOL)execute:(id <QCPlugInContext>)context atTime:(NSTimeInterval)time withArguments:(NSDictionary *)arguments
{
    if (![oldURL isEqualToString:self.inputURL]) {
        [aWebView setMainFrameURL:self.inputURL];
        [oldURL release];
        oldURL= [self.inputURL retain];
    }
    if (aBitmapImageRep!=nil) {
        NSSize size= [aBitmapImageRep size];
        id provider= [[context outputImageProviderFromBufferWithPixelFormat:QCPlugInPixelFormatBGRA8             
                                                                 pixelsWide:size.width
                                                                 pixelsHigh:size.height
                                                                baseAddress:[aBitmapImageRep bitmapData]
                                                                bytesPerRow:[aBitmapImageRep bytesPerRow]
                                                            releaseCallback:_BufferReleaseCallback
                                                             releaseContext:NULL
                                                                 colorSpace:[context colorSpace]
                                                           shouldColorMatch:YES]
                      retain];
        if(provider == nil) 
            return NO; 
        self.outputImage = provider; 
    }
    else {
        self.outputImage= nil;
    }
    return YES;
}
- (void)disableExecution:(id <QCPlugInContext>)context
{
}
- (void)stopExecution:(id <QCPlugInContext>)context
{
}
@end
@implementation WebViewPlugIn (WebView)
- (void)webView:(WebView *)sender didFinishLoadForFrame:(WebFrame *)frame 
{      
    NSView *view = [[[aWebView mainFrame] frameView] documentView];
    NSSize size= [view bounds].size;
    size.width+= (4-((NSUInteger)size.width)%4);
    [[view window] setContentSize:size];  
    [aBitmapImageRep release];
    [view lockFocus];
    aBitmapImageRep = [[NSBitmapImageRep alloc] initWithFocusedViewRect:[view bounds]];  
    [view unlockFocus];  
}  
@end

bytesPerRowの値は16で割り切れないと駄目なんだって．
1pixelで4byte(QCPlugInPixelFormatBGRA8)だから'4-(width%4)'を加えてみた．
これだと4で割り切れたとしても無駄に4pixel増えちゃうけど．

結果

Editor

View( ここを表示したもの ）